09-22-2007, 09:42 AM
An 11-month-old infant has had upper and lower respiratory tract infections almost continuously since the time of birth, with organisms including Pneumocystis carinii (jiroveci) and Pseudomonas aeruginosa identified. The baby also has oropharyngeal candidiasis. The baby succumbs to a cytomegalovirus pneumonitis. At autopsy, the thymus is markedly hypoplastic, and lymph nodes throughout the body are small, with absent germinal centers on microscopic examination. Which of the following mechanisms is most likely to explain these findings?
A Adenosine deaminase deficiency
B Failure of B cells to become plasma cells
C Human immunodeficiency virus infection
D Autoantibodies to both T and B lymphocytes
E Failure of development of 3rd and 4th pharyngeal pouches
A Adenosine deaminase deficiency
B Failure of B cells to become plasma cells
C Human immunodeficiency virus infection
D Autoantibodies to both T and B lymphocytes
E Failure of development of 3rd and 4th pharyngeal pouches