The role of the spleen in the process of liver fibrosis in schistosomiasis still needs clarification. The aim of this Study was to assess the effect of splenectomy on serum levels of two markers of fibrosis, type IV collagen and TIMP-1, in patients with schistosomiasis mansoni. Twenty-four patients with hepatosplenic schistosomiasis mansoni participated in the study. Type IV collagen and TIMP-1 serum levels were measured preoperatively, and after 2 (POD-1) and 60 days (POD-2) of spleen removal. Before splenectomy, both type IV collagen and TIMP-1 serum levels were elevated in the majority of patients. After splenectomy, the levels of type IV collagen showed a significant decrease in relation to the preoperative values both in POD-1 (median pre-splenectomy: 143.7 ng/ml versus 77.01 ng/ml p = 0.04) and POD-2 (103.3 ng/ml; p = 0.015). Serum levels of TIMP-1 also showed a significant decrease in relation to the preoperative values both in POD-1 (pre-splenectomy: 585.9 ng/ml versus 196.4 ng/ml; p = 0.008) and POD-2 (97.4 ng/ml; p < 0.001). There was no difference between POD-land POD-2 values for each serum marker. In conclusion, splenectomy in schistosomotic patients was associated with it decrease in serum markers of fibrosis levels, which persisted for at least 60 days. These results suggest that the spleen may play a role in the extra cellular matrix production, and therefore may contribute to liver fibrosis in schistosomiasis mansoni. (c) 2006 Elsevier B.V. All rights reserved.973301308