SummaryIn the present work we demonstrate that hamsters infected withL. donovanieliminate large quantities of immunoglobulins in the urine. This alteration is clearly a consequence of a conspicuous immune complex glomerulonephritis readily detectable 7 days after the beginning of infection.L. donovaniantigens and hamsters immunoglobulins (Igs) were revealed as granular deposits in the mesangial areas and contiguous loops of the glomeruli.Histopathological alterations such as focal mesangial proliferation with progression to diffuse proliferation were observed in the first 3 weeks of infection. From day 35 onwards, all diseased animals presented large deposits of amyloid material of predominantly glomerular localization.In consonance with these alterations, Igs were detected in the urine by day 21 of infection and their concentration increased substantially with the progression of disease. In contrast, serum Igs increased until day 21, when their concentration dropped steadily.