Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Veterans Administration Hospital, Department of Medicine, Departments of Pathology and Medicine, Albert Einstein School of Medicine, Bethesda, Maryland 20205
Peripheral lymphocytes from 16 patients with chronic uncomplicated strongyloidiasis and 15 non-infected controls were stimulated in vitro with Strongyloides stercoralis larval antigens, other non-parasite antigens and the T cell mitogen phytohemagglutinin (PHA). In the presence of autologous plasma the patients' responses to Strongyloides antigens were similar to those of controls. When lymphocytes from nine patients were cultured in the presence of normal human serum, responses to parasite antigens were enhanced, while responses to other antigens and to PHA were unaffected. Lymphoproliferative responses to PHA were significantly lower in the patients' group than in the controls. These findings suggest that in chronic strongyloidiasis, in addition to a depression of T cell activity, factors are present in the patients' serum that inhibit parasite-specific cellular responses in vitro.
Present address: Department of Pathology, University of Cincinnati Medical Center, 231 Bethesda Avenue, Cincinnati, Ohio 45267. Send reprint requests to this address.
Present address: Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio 45267.