Severe, protracted intestinal cryptosporidiosis associated with interferon gamma deficiency: pediatric case report.

We describe a human immunodeficiency virus-negative infant with chronic intractable diarrhea due to Cryptosporidium parvum; he had a history of significant weight loss since the second week of life. A preliminary study of his immune function was negative for primary immunodeficiency. To further study his immune function, proliferation of peripheral blood mononuclear cells (PBMCs) was elicited by crude antigenic extract from C. parvum oocysts (CCE). Supernatants of CCE-stimulated PBMCs contained interleukin 10 but not interferon gamma (IFN-gamma), while PBMCs from a control (a 2-year-old immunocompetent infant who had recovered from cryptosporidiosis) showed a strong response to IFN-gamma when stimulated with CCE. These results stress the role of IFN-gamma in recovery from cryptosporidiosis.