10-01-2007, 03:03 PM
A 3-year-old boy is brought to the physician because of a 7-day history of fever and a painful swollen lymph node in his groin. This is his sixth episode of lymph node swelling; the previous episodes resolved after drainage and prolonged antibiotic therapy. He also had pneumonia at the age of 12 months that required chest tube placement for drainage. A maternal uncle died during childhood of recurrent infections. The patient is at the 5th percentile for height and weight. His temperature is 38.5 C (101.3 F). Examination shows a warm, tender, erythematous lymph node in the right inguinal area. There are several healed incisions over the inguinal area and neck from old drainage sites. Laboratory studies show:
Hematocrit 35%
Leukocyte count 17,000/mm3
Segmented neutrophils 65%
Bands 10%
Lymphocytes 25%
Platelet count 350,000/mm3
A Gram's stain of the lymph node aspirate shows numerous segmented neutrophils filled with bacteria; cultures grow Staphylococcus aureus. Which of the following is the most likely mechanism for these findings?
A
) Adenosine deaminase deficiency
B
) Consumption of complement
C
) Defective opsonization
D
) Destruction of CD4+ T lymphocytes
E
) Developmental arrest of maturation of B lymphocytes
F
) Dysmorphogenesis of the third and fourth pharyngeal pouches
G
) Impaired chemotaxis
H
Hematocrit 35%
Leukocyte count 17,000/mm3
Segmented neutrophils 65%
Bands 10%
Lymphocytes 25%
Platelet count 350,000/mm3
A Gram's stain of the lymph node aspirate shows numerous segmented neutrophils filled with bacteria; cultures grow Staphylococcus aureus. Which of the following is the most likely mechanism for these findings?
A
) Adenosine deaminase deficiency
B
) Consumption of complement
C
) Defective opsonization
D
) Destruction of CD4+ T lymphocytes
E
) Developmental arrest of maturation of B lymphocytes
F
) Dysmorphogenesis of the third and fourth pharyngeal pouches
G
) Impaired chemotaxis
H