Definition of Neutropenia
Neutropenia is a condition in which the count of neutrophils is reduced. The role of white blood cells is to fight against the infections caused by the microorganisms. The human blood consists of many types of white blood cells, lymphocytes, monocytes, Basophils, Eosinophils, and Neutrophils.
Neutrophils are present in most abundance, making about 40 – 75% of the white blood cells. They are the first cells to move in response to the inflammatory chemicals released from the damaged or invaded cells.
Neutropenia can occur as a result of the following conditions:
- A child not making enough Neutrophils
- Excessive Neutrophils are getting destroyed in the circulation
- Neutrophils are defective; they get accumulated in improper places instead of migrating through proper channels
Neutropenia is defined differently in infants (up until one year of age) and older children. In infants, less than 1000/ul count is defined as Neutropenia. In children older than one year of age, the definition is the same as that of adults, that is less than 1,500/ul.
Classification of Neutropenia
- In mild Neutropenia, the ANC (absolute neutrophil count) is 1000—1500/ul.
- In moderate cases, the ANC ranges from 500—1000/ul
- In severe Neutropenia, it is < 500/ul
ANC = White Blood Cells/microlitre x percent (Polymorphonuclear cells + bands)/100
Types of Neutropenia
There are three types of Neutropenias – the hereditary type, acquired and the mixed forms. The important types in each category are discussed as below.
It is the inherited and severe type of Neutropenia. Inheritance is autosomal dominant. It is more common in infants and young children. The symptoms include mouth sores, frequent fever, pneumonia, ear infections, and rectal sores. If treatment is not immediately started, a child may start to lose teeth due to severe gum infections.
Kostmann’s Syndrome is a chronic sub-type of hereditary Neutropenia. It is transmitted in an autosomal recessive pattern and is an aggressive condition.
It is present in many members of the family. It occurs every 3 weeks (the range can be from 12–35 days) and continues for 3–6 days in a single cycle. The symptoms include infections, fever, and ulcers. Most children improve after puberty.
Acquired types are more common than hereditary types.
Drug-induced: A drug can act as a hapten and induce antibody formation. The drugs that can cause Neutropenia are Quinidine, Aminopyrine, Penicillin, Cephalosporin, Phenothiazines, Sulfonamides, and Hydralazine.
Autoimmune: The Neutropenia can be primary or secondary autoimmune Neutropenia. In the primary form, there is no other abnormality except the antibodies (Antineutrophil antibodies) that attach to neutrophils causing their peripheral destruction; infections that occur as a result of Neutropenia are mild and limited.
The secondary Neutropenia occurs due to some other primary pathology, like any other autoimmune disease, infections, and malignancy. In infants, the secondary Neutropenia is very rare. Above one year of age, the incidence of secondary Neutropenia increases; therefore, rigorous research to find the underlying autoimmune diseases is done.
The following are the infections that can result in the acquired form of Neutropenia:
- Viral infections (Measles, influenza, EBV, CMV, Viral hepatitis, HIV)
- Bacterial sepsis
- Rickettsial infection
- Dengue Fever
Mixed type of Neutropenia
Chronic Benign Neutropenia
It is a rare form that can lead to life-threatening infections. It is more common in children less than four years of age. The infections tend to decrease with age.
Causes of Neutropenia
- Aplastic anemia
- Tumor infiltration
- Ionizing radiation
- Bacterial infections
- Viral infections
Signs and Symptoms of Neutropenia
The signs and symptoms are those of the infections that have occurred due to Neutropenia:
- Otitis media
- Bladder infection
- Sore throat
- Gum infections
Diagnosis of Neutropenia
The diagnosis is based on history, physical examination, and laboratory investigations. Imaging studies are also performed in certain cases.
The child often has complaints of pneumonia, ear infection, tonsillitis, gastroenteritis, skin infection, and pharyngitis. Family history is important, especially in cases of inherited Neutropenia.
It shows the signs of infections, fever, ulcers, gingivitis, abscesses, pneumonia, skin infections, sepsis, cervical lymphadenopathy, and growth retardation. Many times, there is a fever without any focal signs of the disease.
- Complete blood count
- Differential Leukocyte Count (DLC)
- Peripheral blood smears
- Liver function tests
- Antineutrophil antibody tests
- Rheumatoid factor (RF)
- Quantification of serum immunoglobulin
- Peripheral blood flow cytometry
- Others may include testing for infections (mentioned in types) like Typhoid, TB, Hepatitis, and AIDS
Urine culture, blood cultures, wound cultures, sputum cultures, and Gram-staining, skin biopsy and stool cultures for Clostridium Difficile. The list can vary depending upon the type of infection.
- Radiographs of long bones for cases of congenital neutropenias
- Chest X-rays and CT scans for signs of pneumonia
- Abdominal radiographs for the liver and spleen
Management of Neutropenia
There is a general approach and specific treatment for Neutrogena.
- Remove offending drugs
- Oral hygiene
- Stool softeners
- Correction of folic acid deficiency
- Dietary measures to include properly cooked meat, clean water and the avoidance of acidic food
- Colony-stimulating factors
- Granulocyte transfusion