Most urinary symptoms, however, are caused by ulcerative and fibrosing bladder lesions and carcinoma. A common complication, transient VUR, may occur during active disease and with moderate to severe secondary bacterial infection. As with other chronic UTIs, urolithiasis occurs, particularly with Proteus infections. Clinical findings with S. mansoni infections include moderate to nephrotic-range proteinuria, hematuria, and RBC casts. Glomerular disease associated with schistosomiasis is usually described as proliferative with little expansion of the mesangium but with occasional focal thickening of the glomerular basement lamina.
Immunofluorescence shows mesangial deposits containing immune complexes.
The most common histopathologic lesions are membranoproliferative and focal segmental sclerosis. Disease severity and progression are related to the presence of hepatic fibrosis, perhaps due to an increased schistosomal antigen load presented to the systemic circulation. In some areas endemic for schistosomiasis, the reported incidence of cases of renal amyloidosis is about 3 times that of matching controls. The usual clinical presentation is nephrotic, and renal biopsy demonstrates the overlapping histopathologic lesions of amyloidosis and schistosomal glomerular disease. An occult form of glomerulopathy occurs with S. haematobium.