Pneumocystis carinii pneumonia and primary immune deficiency diseases of infancy and childhood

Abstract

Twenty-nine of 194 cases of <i>Pneumocystis carinii</i> pneumonia in the United States reported to the Parasitic Disease Drug Service over a 3 year period were in children less than one year of age; this attack rate is five times higher than that for any other age group in the general population. Twenty-four of the 29 children had primary immune deficiency disorders. By contrast, acute lymphatic leukemia was the most common disease associated with <i>P. carinii</i> pneumonia in children 1 to 4 years of age (18 to 22 cases). Only one child over one year of age had an immunologic deficiency disease. Severe combined immunodeficiency was the most commonly encountered type of immune deficiency disease (15 of 25 cases). Six (24 per cent) of the patients with immunodeficiencies had at least one sibling with an immunologic deficiency disease who developed proved <i>P. carinii</i> pneumonia in infancy. Although defects in both humoral and cellular immunity appear to be present in these patients, the mode of transmission of <i>P. carinii</i> and its association with immune deficiency states are poorly understood.