Primary Lymphopenic Immunologic Deficiency: Disseminated Mycobacterium kansasii Infection

A 7½-month-old boy with primary lymphopenic immunologic deficiency, disseminated Mycobacterium kansasii infection, and Pneumocystis carinii pneumonia had a profound defect in lymphocytemediated immunity associated with a selective immunoglobulin deficiency. There was evidence of IgM and IgG antibody activity. Leukocyte phagocytic function was normal, but opsonin and total hemolytic complement activity was found to be markedly low. Disseminated atypical mycobacterial infection has been previously described in 27 cases. Altered host resistance has been postulated in the pathogenesis, but the present case is the first reported with documented immunologic deficiency. The immunopathology of this patient's mycobacterial infection is similar to that described in infants with fatal disseminated BCG infection.