SECRETORY IGA ANTIBODIES TO CRYPTOSPORIDIUM-PARVUM IN AIDS PATIENTS WITH CHRONIC CRYPTOSPORIDIOSIS

Immune mechanisms that may control Cryptosporidium parvum infection re main unknown. The role of T cell-mediated immunity is suggested by the chronic disease observed in AIDS patients and in athymic or CD4(+) T cell-depleted mice. The role of specific antibodies is also unclear. T his study sought to determine serum and secretory antibodies to C. par vum in patients infected with human immunodeficiency virus type 1 (HIV -1) with or without chronic cryptosporidiosis. C. parvum-specific anti bodies and specific secretory antibodies were determined by ELISA in s aliva and sera from 50 HIV-1-infected patients, 27 healthy adults, and 21 healthy children. Despite lower CD4(+) lymphocyte counts, patients with chronic cryptosporidiosis had increased levels of C. parvum-spec ific antibodies in saliva and serum and higher specific secretory anti body levels in saliva than did controls. Persistance of protracted dia rrhea despite high levels of both serum and secretory antibodies sugge sts that specific secretory antibodies are not sufficient to control t his protozoan parasite infection of intestinal mucosa.