B. J. is a 5-year-old boy who has suffered from repeated upper respiratory infections since he was 16 months old. At 4 years of age, he was diagnosed with allergic asthma. The following winter, at age 5, he was admitted to the hospital twice for acute asthma with a secondary bacterial pulmonary infection. At the second admission, a complete blood count, sputum culture, and immune status work-up were ordered. Laboratory Data

Assay Patient Results Reference Range
Hemoglobin 13.5 g/dL 11.5-14.5 g/dL
Hematocrit 40% 33-43%
Total WBC count 16.2 x 10^9/L 4-12 x 10^9/L
Lymphocyte Count 4.3 x 10^9/L 2.7-5.4
T lymphocytes 2.4 x 10^9/L 2.7-5.3
B lymphocytes 1.0 x 10^9/L 0.6-1.4

Required:
What is the etiology of this patientâs recurring infections?