ABSTRACT Background: We evaluated the association between polymorphisms in the tumor necrosis factor alpha (TNF-α) (-G308A) gene and upper gastrointestinal bleeding (UGIB) in schistosomiasis. Methods: This was a transverse study involving 294 Brazilian patients infected with Schistosoma mansoni. Results: The homozygous A/A genotype in TNF-α (-G308A) showed a risk association (prevalence ratio = 1.90, p = 0.008) with UGIB. There was no statistically significant difference in serum TNF-α levels between the clinical groups. Conclusions: The polymorphic TNF-α (-G308A) can be a risk factor for UGIB, in addition to being a potentially predictive factor for the severity of UGIB in schistosomiasis.

Abstract INTRODUCTION: We evaluated the association between genetic polymorphisms in exon 1 (A/O alleles) and promoter regions at positions -550 (H/L variant, rs11003125) and -221 (X/Y variant, rs7096206) MBL2 and periportal fibrosis regression. METHODS: This was a retrospective cohort study involving 114 Brazilians infected with Schistosoma mansoni, who were subjected to follow-up for three years after specific treatment for schistosomiasis to estimate the probability of periportal fibrosis regression. RESULTS: A risk association was observed between polymorphism at the exon 1 MBL2 and periportal fibrosis regression. CONCLUSIONS: This study suggests that the polymorphism of exon 1 MBL2 may potentially be used to predict periportal fibrosis regression in this population.

Abstract INTRODUCTION: We evaluated the associations between interleukin-10 (IL-10) gene polymorphisms -G1082A/-C819T/-C592A and periportal fibrosis regression after specific treatment for schistosomiasis. METHODS: This retrospective cohort study involved 125 Brazilian patients infected with Schistosomiasis mansoni, who were followed up for 2 years after specific treatment to estimate the probability of periportal fibrosis regression. RESULTS: There was no evidence of associations between IL-10 polymorphisms and periportal fibrosis regression after treatment. CONCLUSIONS: There was no evidence of associations between gene promoter polymorphisms of IL-10 and the regression of periportal fibrosis in this Brazilian population.

INTRODUCTION : We hypothesized higher mannose-binding lectin level and classic factors (i.e., age, sex, alcohol consumption, exposure, and specific treatment) are associated with the severity of periportal fibrosis in schistosomiasis. METHODS : This cross-sectional study involved 79 patients infected with Schistosoma mansoni with severe or mild/moderate periportal fibrosis. Serum concentrations of mannose-binding lectin were obtained by enzyme-linked immunosorbent assay (ELISA). RESULTS: Higher serum level of mannose-binding lectin was significantly associated with advanced periportal fibrosis. CONCLUSIONS: Mannose-binding lectin may contribute to liver pathology in schistosomiasis and may represent a risk factor for advanced periportal fibrosis in the Brazilian population studied.