Immunology Question Set 1

Fluorescein is an artificial dark orange colored organic molecule used in the diagnosis of corneal ulcers and herpetic corneal infections. It is observed that in experimental animals the fluorescein binds to receptors on certain B cells, but does not stimulate them to produce fluorescein specific antibodies unless it is first attached to a larger molecule such as albumin. These findings indicate that fluorescein is?

A 3-month-old infant boy presents to his pediatrician with persistent diarrhea, oral candidiasis, signs, and symptoms of respiratory syncytial virus (RSV) pneumonia. He is very lean with weight in the 10th percentile. He is being evaluated for an immunodeficiency disease. Laboratory results for HIV are negative by PCR. The most likely cause of these findings is:

A previously healthy 7-month-old boy presents with fever, chills, cough, runny nose, and watery eyes. His elder brother is having similar symptoms. He is diagnosed with influenza virus infection. Assuming that this is the child's first exposure to influenza virus, which of the following immune mechanisms will most likely function to combat this kind of infections?

A 1-year-old immigrant girl has not received any recommended vaccines since birth. She attends day care and remains healthy despite her daily association with several other children for the past 3 months at a home day-care facility. Which of the following phenomenon explains why she has not contracted any vaccine-preventable diseases such as measles, diphtheria, or pertussis?

A 4-month-old neonate girl is brought to the pediatrician because of feeding problems and recurrent infections. On evaluation, she has a cleft palate, malformed jaw, structural cardiac abnormalities, and diminished cell-mediated responses. Laboratory investigations reveal hypocalcemia. These findings support a diagnosis of:

A 31-year-old female comes to the clinic with a characteristic butterfly rash on her face and history of photosensitivity presents with decreased renal function, hypertension, edema, and anemia. Laboratory findings reveal decreased serum C3 levels. Her urine sediment contains proteins, WBCs, and red blood cell casts. Her renal biopsy is consistent with acute inflammation and immune deposits. Which type of hypersensitivity is suggested by her findings?

A 2-year-old boy presents to you with multiple skin abscesses caused by Staphylococcus aureus. He has a past history of recurrent infections by the same organism. The nitroblue tetrazolium test demonstrates his inability to kill microbes. Which of the following key pathophysiologic events relate to the condition that is most likely responsible for the findings in this patient?

A 55-year-old female presents with pain in both hands and wrists for several years. It is associated with the morning stiffness that lasts for almost an hour. Physical examination reveals tenderness and swelling in both hands and wrists. Laboratory investigations reveal the presence of anti-cyclic citrullinated peptide. Which one of the following immune-mediated injuries is responsible for this patient’s condition?