Schistosoma-induced amyloidosis in hamsters is gender-dependent.

Background: A high serum level of female protein (FP), found to be a constituent of Syrian hamster amyloid was associated with enhanced amyloidosis. In this work, we studied the sex-limited factors in the induction of amyloidosis in Syrian hamsters infected with either Schistosoma mansoni or S. hematobium cercariae.
Methods: Hamsters were infected with different species of schistosome cercariae and sacrificed after different time periods of infection. Kidney and liver specimens were processed in paraffin, stained with Congo-red and examined by ordinary light and polarized light microscopy.
Results: Statistical analysis showed a significant difference in intensity of kidney and liver amyloid deposits (P<0.002 & <0.007 respectively) between females and male hamsters with extensive deposits in the former. Amyloid deposits were correlated significantly to the duration of infection (P<0.001) than the load of worm recovered.
Conclusion: From this study, we conclude that, in hamster model, Schistosoma-induced amyloidosis is enhanced in females than male hamsters. This may be due to the high serum level of FP that is normally detected in females. As an experimental model for schistosomal nephropathy, we recommend to use male hamsters instead of females to minimize the effect of amyloid deposits, which may mask other pathological changes associated with schistosomal infection.