Immunological studies of pancytopenia in visceral leishmaniasis.

We report three cases of combined anemia, neutropenia and thrombocytopenia in patients with visceral leishmaniasis (kala-azar). Using immunofluorescence techniques and the common antiglobulin (Coombs') test, we showed membrane-associated antiplatelet, antineutrophil and antierythrocytic IgG antibodies in all three cases. Treatment with sodium stibogluconate raised the patients' platelet, neutrophil and erythrocyte count. At that time no antibodies were detected on peripheral blood cells. Immunological studies performed on these patients did not show marked abnormalities except for reduced T-helper cells and elevated OKM1-positive cells, which normalized after recovery. As bone marrow suppression was not found, it is suggested that pancytopenia resulted from rapid destruction of antibody-coated blood cells. Whether these antibodies are specific is not clear.