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Hepatitis E Virus

The hepatitis E virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology (HEV) is a small nonenveloped virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology that contains linear, single-stranded, positive-sense RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure, making it similar to norovirus Norovirus Norovirus is a nonenveloped, single-stranded, positive-sense RNA virus belonging to the Caliciviridae family. Norovirus infections are transmitted via the fecal-oral route or by aerosols from vomiting. The virus is one of the most common causes of nonbacterial gastroenteritis epidemic worldwide. Symptoms include watery and nonbloody diarrhea, nausea, vomiting, and low-grade fever. Norovirus. Transmission of HEV is via the fecal–oral route and is clinically similar to that of hepatitis A Hepatitis A Hepatitis A is caused by the hepatitis A virus (HAV), a nonenveloped virus of the Picornaviridae family with single-stranded RNA. HAV causes an acute, highly contagious hepatitis with unspecific prodromal symptoms such as fever and malaise followed by jaundice and elevated liver transaminases. Hepatitis A Virus. However, unlike hepatitis A Hepatitis A Hepatitis A is caused by the hepatitis A virus (HAV), a nonenveloped virus of the Picornaviridae family with single-stranded RNA. HAV causes an acute, highly contagious hepatitis with unspecific prodromal symptoms such as fever and malaise followed by jaundice and elevated liver transaminases. Hepatitis A Virus, hepatitis E is quite severe, especially in pregnant women, and may cause fulminant hepatitis Fulminant hepatitis Echovirus along with hepatic encephalopathy Encephalopathy Hyper-IgM Syndrome over a period of approximately 8 weeks. Management is mainly preventive and includes avoiding contaminated drinking water, good sanitation, and adequate personal hygiene.

Last updated: 17 Sep, 2021

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Classification

Rna viruses flowchart classification

RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology identification Identification Defense Mechanisms:
Viruses can be classified in many ways. Most viruses, however, will have a genome formed by either DNA or RNA. RNA genome viruses can be further characterized by either a single- or double-stranded RNA. “Enveloped” viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology are covered by a thin coat of cell membrane Cell Membrane A cell membrane (also known as the plasma membrane or plasmalemma) is a biological membrane that separates the cell contents from the outside environment. A cell membrane is composed of a phospholipid bilayer and proteins that function to protect cellular DNA and mediate the exchange of ions and molecules. The Cell: Cell Membrane (usually taken from the host cell). If the coat is absent, the viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology are called “naked” viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology. Viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology with single-stranded genomes are “positive-sense” viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology if the genome Genome The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics is directly employed as messenger RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure ( mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure), which is translated into proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis. “Negative-sense,” single-stranded viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology employ RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure dependent RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure polymerase, a viral enzyme, to transcribe their genome Genome The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics into messenger RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure.

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General Characteristics

Structure

  • RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology: genus Hepevirus
  • 27–34 nm in diameter
  • Linear, single-stranded, positive-sense RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure (resembles norovirus Norovirus Norovirus is a nonenveloped, single-stranded, positive-sense RNA virus belonging to the Caliciviridae family. Norovirus infections are transmitted via the fecal-oral route or by aerosols from vomiting. The virus is one of the most common causes of nonbacterial gastroenteritis epidemic worldwide. Symptoms include watery and nonbloody diarrhea, nausea, vomiting, and low-grade fever. Norovirus)
  • Nonenveloped
  • Icosahedral capsule Capsule An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides. Bacteroides
  • 5 identified genotypes (only genotypes 1 and 2 affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment humans)

Basic features

  • Viable for years 
  • Elimination Elimination The initial damage and destruction of tumor cells by innate and adaptive immunity. Completion of the phase means no cancer growth. Cancer Immunotherapy: Boiling water, chlorine, and iodine Iodine A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126. 90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically. Thyroid Hormones can effectively destroy the virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
  • Primary reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli: animals Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, animalia was one of the kingdoms. Under the modern three domain model, animalia represents one of the many groups in the domain eukaryota. Cell Types: Eukaryotic versus Prokaryotic (zoonotic virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology)
  • Acute versus chronic:
    • Causes acute hepatitis Acute Hepatitis Autoimmune Hepatitis
    • Chronic cases of hepatitis E virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology (HEV) have been reported in immunosuppressed patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship but are very rare.

Epidemiology

  • Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency:
    • Antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions can be found in 21% of U.S. adults. 
    • Antibody rates ↑ with age, with those > 60 years old having the highest prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency.
  • Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency:
    • At least 20 million cases worldwide each year
    • Most affected:
      • East and South Asia ASIA Spinal Cord Injuries
      • Resource-poor areas with frequent water contamination
      • Areas with unsafe drinking water supplies
  • Mortality Mortality All deaths reported in a given population. Measures of Health Status rate: 4% overall, but 20% for pregnant patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship

Pathogenesis

Transmission

  • Fecal–oral route
  • Foodborne outbreaks Outbreaks Sudden increase in the incidence of a disease. The concept includes epidemics and pandemics. Influenza Viruses/Influenza are common (e.g., shellfish cultivated in contaminated water).
  • Highest transmission: greatest viral shedding Viral shedding The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Hepatitis A Virus during the anicteric prodrome Prodrome Symptoms that appear 24–48 hours prior to migraine onset. Migraine Headache (14–21 days)

Host risk factors

  • Institutionalization (e.g., nursing homes)
  • Occupation (e.g., daycare)
  • Foreign travel
  • Contaminated blood products
  • IV or other illicit drug users
  • Men who have sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria with men (MSM)
  • Homeless population
  • Liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy transplant recipients

Pathophysiology

Primary replication:

  • Ingestion of contaminated food/fecal–oral transmission → replicates in the oropharynx Oropharynx The middle portion of the pharynx that lies posterior to the mouth, inferior to the soft palate, and superior to the base of the tongue and epiglottis. It has a digestive function as food passes from the mouth into the oropharynx before entering esophagus. Pharynx: Anatomy/intestines → bloodstream = 1st viremia Viremia The presence of viruses in the blood. Erythema Infectiosum
  • Reaches the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy because of tissue tropism ( hepatotropic Hepatotropic Hepatitis A Virus)
  • Hepatocytes Hepatocytes The main structural component of the liver. They are specialized epithelial cells that are organized into interconnected plates called lobules. Liver: Anatomy take up the virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology by a receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors on the plasma membrane Plasma membrane A cell membrane (also known as the plasma membrane or plasmalemma) is a biological membrane that separates the cell contents from the outside environment. A cell membrane is composed of a phospholipid bilayer and proteins that function to protect cellular DNA and mediate the exchange of ions and molecules. The Cell: Cell Membrane.
  • Replication occurs in hepatocytes Hepatocytes The main structural component of the liver. They are specialized epithelial cells that are organized into interconnected plates called lobules. Liver: Anatomy and Kupffer cells Kupffer cells Specialized phagocytic cells of the mononuclear phagocyte system found on the luminal surface of the hepatic sinusoids. They filter bacteria and small foreign proteins out of the blood, and dispose of worn out red blood cells. Benign Liver Tumors (hepatic macrophages Macrophages The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood monocytes. Main types are peritoneal macrophages; alveolar macrophages; histiocytes; kupffer cells of the liver; and osteoclasts. They may further differentiate within chronic inflammatory lesions to epithelioid cells or may fuse to form foreign body giant cells or langhans giant cells. Innate Immunity: Phagocytes and Antigen Presentation):
    • After cell entry, viral RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure is uncoated and the host ribosomes Ribosomes Multicomponent ribonucleoprotein structures found in the cytoplasm of all cells, and in mitochondria, and plastids. They function in protein biosynthesis via genetic translation. The Cell: Organelles bind BIND Hyperbilirubinemia of the Newborn to form polysomes. 
    • Viral proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis are synthesized, and the viral genome Viral genome The complete genetic complement contained in a DNA or RNA molecule in a virus. Virology is copied by a viral RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure polymerase.
  • Virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology particles shed into the biliary tree Biliary tree The bile ducts and the gallbladder. Gallbladder and Biliary Tract: Anatomy → excreted in the feces

Clinical Presentation

  • Causes acute viral hepatitis Acute viral hepatitis Hepatitis A Virus
  • Incubation Incubation The amount time between exposure to an infectious agent and becoming symptomatic. Rabies Virus period: 2–6 weeks 
  • Infectious Infectious Febrile Infant period: 2 weeks before to 1 week after the onset of symptoms
  • HEV can be asymptomatic or very mild in children.
  • Prodromal symptoms:
  • Icteric-phase symptoms:
    • May last days to several weeks
    • Jaundice Jaundice Jaundice is the abnormal yellowing of the skin and/or sclera caused by the accumulation of bilirubin. Hyperbilirubinemia is caused by either an increase in bilirubin production or a decrease in the hepatic uptake, conjugation, or excretion of bilirubin. Jaundice
    • Dark urine Urine Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the urethra. Bowen Disease and Erythroplasia of Queyrat
    • Grayish stools 
    • Itching
  • Relapsing hepatitis occurs in 15% of cases (but only for a year at most).

Diagnosis and Management

Diagnosis

  • Abdominal ultrasonography: Rule out extrahepatic causes of biliary obstruction.
  • Serologic testing: 
    • Anti-HEV IgM IgM A class of immunoglobulin bearing mu chains (immunoglobulin mu-chains). Igm can fix complement. The name comes from its high molecular weight and originally being called a macroglobulin. Immunoglobulins: Types and Functions antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions:
      • Positive in current or recent infection
      • Starts rising 4 weeks after infection and remains detectable for 2 months after
    • Anti-HEV IgG IgG The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b. Hypersensitivity Pneumonitis antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions: previous infection
    • HEV RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure: tested in stool or serum 
  • During acute infection, the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy enzyme ALT ALT An enzyme that catalyzes the conversion of l-alanine and 2-oxoglutarate to pyruvate and l-glutamate. Liver Function Tests is elevated.

Management

  • Acute, uncomplicated cases: supportive care sufficient
  • Severe cases: Reduce immunosuppressive therapy, if possible.
  • Antiviral Antiviral Antivirals for Hepatitis B options:
    • Ribavirin Ribavirin A nucleoside antimetabolite antiviral agent that blocks nucleic acid synthesis and is used against both RNA and DNA viruses. Antivirals for Hepatitis C (contraindicated in pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care)
    • Sofosbuvir: in combination with ribavirin Ribavirin A nucleoside antimetabolite antiviral agent that blocks nucleic acid synthesis and is used against both RNA and DNA viruses. Antivirals for Hepatitis C
    • Pegylated interferon alfa Pegylated interferon alfa Hepatitis B Virus (PEG- IFN IFN Interferon (IFN) is a cytokine with antiviral properties (it interferes with viral infections) and various roles in immunoregulation. The different types are type I IFN (IFN-ɑ and IFN-β), type II IFN (IFN-ɣ), and type III IFN (IFN-ƛ). Interferons-α)

Prevention

  • Sanitation: 
    • Chlorine treatment of water and sewage and regular Regular Insulin handwashing
    • Avoidance of possibly contaminated food, such as uncooked shellfish
  • To date, there is no FDA-approved vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination.

Comparison of Hepatitis Viruses

Table: Comparison of hepatitis viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology A–E

Comparison table of hepatitis viruses

Anti-HBc anti-HBc Hepatitis B Virus antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions: antihepatitis B core antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions
Anti- HBs HbS An abnormal hemoglobin resulting from the substitution of valine for glutamic acid at position 6 of the beta chain of the globin moiety. The heterozygous state results in sickle cell trait, the homozygous in sickle cell anemia. Sickle Cell Disease antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions: antihepatitis B surface antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions
HBcAg: hepatitis B core antigen Hepatitis B core antigen The hepatitis B antigen within the core of the dane particle, the infectious hepatitis virion. Hepatitis B Virus
HBsAg: hepatitis B surface antigen Hepatitis B surface antigen Those hepatitis B antigens found on the surface of the dane particle and on the 20 nm spherical and tubular particles. Several subspecificities of the surface antigen are known. These were formerly called the Australia antigen. Hepatitis B Virus
HBV HBV Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Hepatitis B virus is transmitted by exposure to infectious blood or body fluids. Examples of types of exposure include sexual intercourse, IV drug use, and childbirth. Hepatitis B Virus: hepatitis B Hepatitis B Hepatitis B virus (HBV) is a partially double-stranded DNA virus, which belongs to the Orthohepadnavirus genus and the Hepadnaviridae family. Most individuals with acute HBV infection are asymptomatic or have mild, self-limiting symptoms. Chronic infection can be asymptomatic or create hepatic inflammation, leading to liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis B Virus virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
HCC HCC Hepatocellular carcinoma (HCC) typically arises in a chronically diseased or cirrhotic liver and is the most common primary liver cancer. Diagnosis may include ultrasound, CT, MRI, biopsy (if inconclusive imaging), and/or biomarkers. Hepatocellular Carcinoma (HCC) and Liver Metastases: hepatocellular carcinoma Hepatocellular carcinoma Hepatocellular carcinoma (HCC) typically arises in a chronically diseased or cirrhotic liver and is the most common primary liver cancer. Diagnosis may include ultrasound, CT, MRI, biopsy (if inconclusive imaging), and/or biomarkers. Hepatocellular Carcinoma (HCC) and Liver Metastases
HCV HCV Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). Hepatitis C virus is an RNA virus and a member of the genus Hepacivirus and the family Flaviviridae. The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C Virus: hepatitis C Hepatitis C Hepatitis C is an infection of the liver caused by the hepatitis C virus (HCV). The infection can be transmitted through infectious blood or body fluids and may be transmitted during childbirth or through IV drug use or sexual intercourse. Hepatitis C virus can cause both acute and chronic hepatitis, ranging from a mild to a serious, lifelong illness including liver cirrhosis and hepatocellular carcinoma (HCC). Hepatitis C Virus virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
HDV HDV Hepatitis D virus (HDV) is a small enveloped, single-stranded RNA virus. Hepatitis D virus is considered a satellite virus, as it requires the presence of hepatitis B virus (HBV) for assembly and secretion. Therefore, in order for an individual to contract hepatitis D, coinfection or superinfection with HBV is required. Hepatitis D Virus: hepatitis D virus Hepatitis D virus Hepatitis D virus (HDV) is a small enveloped, single-stranded RNA virus. Hepatitis D virus is considered a satellite virus, as it requires the presence of hepatitis B virus (HBV) for assembly and secretion. Therefore, in order for an individual to contract hepatitis D, coinfection or superinfection with HBV is required. Hepatitis D Virus

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Differential Diagnosis

  • Alcoholic Alcoholic Persons who have a history of physical or psychological dependence on ethanol. Mallory-Weiss Syndrome (Mallory-Weiss Tear) liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease (ALD): liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy pathology that occurs because of prolonged excessive alcohol consumption. The 1st stage is an asymptomatic fatty liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy, which is reversible. The 2nd stage is alcoholic Alcoholic Persons who have a history of physical or psychological dependence on ethanol. Mallory-Weiss Syndrome (Mallory-Weiss Tear) hepatitis, which most commonly presents with jaundice Jaundice Jaundice is the abnormal yellowing of the skin and/or sclera caused by the accumulation of bilirubin. Hyperbilirubinemia is caused by either an increase in bilirubin production or a decrease in the hepatic uptake, conjugation, or excretion of bilirubin. Jaundice, fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, and RUQ pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways. The 3rd stage is cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis of the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy. Diagnosis is established by history, liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy-function tests, and imaging studies. 
  • Drug-induced liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy injury (DILI): occurs when drugs ingested cause injury to the hepatocytes Hepatocytes The main structural component of the liver. They are specialized epithelial cells that are organized into interconnected plates called lobules. Liver: Anatomy directly in a predictable dose-dependent way or through idiosyncratic reactions. The presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor of DILI can be acute or chronic, with severe toxicity Toxicity Dosage Calculation manifesting as fulminant liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy failure. The diagnosis of DILI requires a thorough history and laboratory tests. Management consists of early diagnosis and discontinuing the drug, as well as supportive therapy.
  • Autoimmune hepatitis Autoimmune hepatitis Autoimmune hepatitis (AIH) is a rare form of chronic liver disease in which the immune system attacks the liver causing inflammation. It predominantly affects women. Clinical presentation ranges from asymptomatic cases to patients that present with symptoms of acute liver failure (jaundice, right upper quadrant pain). Autoimmune Hepatitis ( AIH AIH Autoimmune hepatitis (AIH) is a rare form of chronic liver disease in which the immune system attacks the liver causing inflammation. It predominantly affects women. Clinical presentation ranges from asymptomatic cases to patients that present with symptoms of acute liver failure (jaundice, right upper quadrant pain). Autoimmune Hepatitis): liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation that occurs when the body’s immune system Immune system The body’s defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components. Primary Lymphatic Organs attacks its own liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy cells. Clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor ranges from asymptomatic to symptoms of acute liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy failure. Diagnosis is established via testing the blood for characteristic autoantibodies Autoantibodies Antibodies that react with self-antigens (autoantigens) of the organism that produced them. Blotting Techniques (especially, anti–smooth muscle antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions) and liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Management includes corticosteroids Corticosteroids Chorioretinitis and azathioprine Azathioprine An immunosuppressive agent used in combination with cyclophosphamide and hydroxychloroquine in the treatment of rheumatoid arthritis. According to the fourth annual report on carcinogens, this substance has been listed as a known carcinogen. Immunosuppressants
  • Wilson disease: autosomal recessive Autosomal recessive Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal recessive diseases are only expressed when 2 copies of the recessive allele are inherited. Autosomal Recessive and Autosomal Dominant Inheritance disorder from a mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in the ATP7B gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics, which regulates copper Copper A heavy metal trace element with the atomic symbol cu, atomic number 29, and atomic weight 63. 55. Trace Elements transport within hepatocytes Hepatocytes The main structural component of the liver. They are specialized epithelial cells that are organized into interconnected plates called lobules. Liver: Anatomy. Neuropsychiatric manifestations of Wilson disease help differentiate it from other causes of hepatitis. In early stages, Wilson disease may be confused with hepatic encephalopathy Encephalopathy Hyper-IgM Syndrome. Kayser-Fleischer rings Kayser-Fleischer rings Copper deposits in Descemet’s membrane of the cornea, manifested as green-brown rings that encircle the iris. Wilson’s Disease, low ceruloplasmin Ceruloplasmin A multi-copper blood ferroxidase involved in iron and copper homeostasis and inflammation. Wilson’s Disease levels help separate Wilson disease from other causes of hepatitis.
  • Nonalcoholic fatty liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease (NAFLD): spectrum of liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy pathology that arises due to accumulation of triglycerides Triglycerides Fatty Acids and Lipids in hepatocytes Hepatocytes The main structural component of the liver. They are specialized epithelial cells that are organized into interconnected plates called lobules. Liver: Anatomy. Nonalcoholic fatty liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease ranges from fatty liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy or hepatic steatosis Steatosis Nonalcoholic Fatty Liver Disease but can lead to nonalcoholic steatohepatitis Steatohepatitis Drug-induced Liver Injury which has fatty deposits and inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation. Progressive liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy injury and fibrosis Fibrosis Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury. Bronchiolitis Obliterans irreversibly develop into cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis and possibly, primary liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy cancer. Management is with lifestyle modifications (diet and exercise).

References

  1. Remy, M. (2019). Hepatitis E. Emedicine. Retrieved January 28, 2021, from https://emedicine.medscape.com/article/178140-overview
  2. Sherman, K. (2020). Hepatitis E virus infection. UpToDate. Retrieved January 27, 2021, from https://www.uptodate.com/contents/hepatitis-e-virus-infection
  3. Mast EE, Krawczynski K. (1996). Hepatitis E: an overview. Annu Rev Med 47:257–266.
  4. Kamar N, Bendall R, Legrand-Abravanel F, et al. (2012). Hepatitis E. Lancet 379:2477–2488.

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