Red cell, white cell and platelet autoantibodies in visceral leishmaniasis.

The blood of twelve patients with parasitologically proved visceral leishmaniasis was examined for the presence of antibodies against blood cells. The direct antiglobulin test (Coombs' test) was positive in ten. IgG and complement were found on the red cells (alone or combined), but no IgA or IgM. In the serum of two, warm antibodies were found in the bromelin test. Pseudo-agglutination was detected in 8. Investigations for white cell antibodies included the lymphocytotoxicity test (positive in 10), the leuco-agglutination test (positive in 1) and the indirect immunofluorescence test on lymphocytes (none positive) and granulocytes (2 positive). Platelet autoantibodies were demonstrated in the direct (10 positive) and indirect (7 positive) platelet suspension immunofluorescence test. How important these various antibodies are in influencing the lifespan and functions of the respective cells and thus in the pathogenesis of the pancytopenia of kala-azar, can not be concluded from this work but the absence of a direct correlation between haematological values and presence or absence of antibodies and/or their titres argues against a primary role of these antibodies.