CASE 7
Paul is 4 years of age and suffers from recurrent gram-negative bacterial infections, all of which have eventually cleared with long-term antibiotic therapy. Although he has been hospitalized three times for pneumonia (Chlamydia pneumoniae), there is no evidence for increased susceptibility to viral or fungal infections, and all of his childhood immunizations are up to date. An infectious disease specialist at a local tertiary care center was unable to establish an etiology for the problem. Further exploration of the family tree revealed that both male and female relatives had presented with a similar clinical history of recurrent infectious illnesses. Blood cell count and differential, performed on several occasions, indicated normal numbers of B cells, T cells, neutrophils, and monocytes. Serum immunoglobulin levels were also shown to be normal for all isotypes, as were antibody titers for various vaccine antigens. Other culture assays, performed to investigate cytokine production (from T cells) after stimulation with known T cell polyclonal activators, were normal. How would you proceed?
QUESTIONS FOR GROUP DISCUSSION
RECOMMENDED APPROACH
Implications/Analysis of Family History
An analysis of Paul’s family history revealed that both males and females had presented with similar symptoms, indicating that the recurrent infections are not likely caused by a defective gene encoded on the X chromosome. The familial nature of the problem, however, suggests a genetic basis for the recurrent infections.
