Association of Tumor Necrosis Factor-α (-G308A) Polymorphism with risk of Upper Gastrointestinal Bleeding from Schistosomiasis in Pernambuco

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.

Influence of a TNF-α Polymorphism on the Severity of Schistosomiasis Periportal Fibrosis in the Northeast of Brazil

AIMS

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-α) is an essential component in the host immune response to infection, and it has been reported to be an important mediator in severe periportal fibrosis (PPF). We hypothesized that the (-G308A) polymorphism of the TNF-α gene is associated with the severity of PPF and that these polymorphisms influence TNF-α expression.

METHODS

In this cross-sectional study, we genotyped these polymorphisms within the TNF-α gene in 256 Brazilian subjects infected with Schistosoma mansoni, with different patterns of PPF.

RESULTS

The genotype (-308) AA was associated with a significant increase in the risk to advanced PPF (OR = 4.60; p = 0.009). In addition, median levels of TNF-α were higher in patients with moderate to advanced PPF, compared with mild fibrosis (20 and 17.3 pg/mL, respectively; p = 0.040). There was no association between average serum levels of TNF-α and (-G308A) TNF-α polymorphism.

CONCLUSIONS

Our results suggest the (-308) AA genotype may be a risk factor for severity in advanced PPF, in this Brazilian population, and could potentially be used to predict the severity of advanced PPF in schistosomiasis.

Association Between Polymorphisms of the Mannose-Binding Lectin and Severity of Periportal Fibrosis in Schistosomiasis, in the Northeast of Brazil

AIMS

Mannose-binding lectin (MBL) is a protein synthesized by the liver and its immune response is associated with the development of liver fibrosis. We hypothesized that the polymorphisms in the Exon 1 region (52, 54, 57) and promoter regions (-550 H/L, -221 X/Y) of the MBL2 gene were associated with the severity of periportal fibrosis (PPF), and that these polymorphisms affect the MBL serum levels.

MATERIALS AND METHODS

In this cross-sectional study we genotyped these polymorphisms within the MBL2 gene in 229 Brazilian subjects infected with Schistosoma mansoni, with different patterns of PPF.

RESULTS

There was no association between the polymorphisms and haplotypes of the MBL2 gene and the advanced PPF pattern. The MBL levels were higher in individuals with advanced fibrosis. There was risk association among high-expression haplotypes of MBL, and a protection association between the A/O Exon 1 genotype and elevated MBL serum levels.

CONCLUSIONS

Our results suggest that polymorphism of Exon 1 and MBL haplotypes could potentially be used to predict the severity of advanced PPF in the Brazilian population.

There is no evident correlation between interleukin-10 gene polymorphisms and periportal fibrosis regression after specific treatment

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.

Evaluation of the cytokine mannose-binding lectin as a mediator of periportal fibrosis progression in patients with schistosomiasis

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.

Association of SNP (-G1082A) IL-10 with increase in severity of periportal fibrosis in schistosomiasis, in the northeast of Brazil

Interleukin 10 (IL-10) is an important anti-inflammatory cytokine that modulates severe periportal fibrosis (PPF). We hypothesized that genetic polymorphisms (-G1082A/-C819T/-C592A) of the IL-10 gene and classic factors (age, sex, alcohol, exposure, and specific treatment) are associated with the severity of PPF and that these polymorphisms influence IL-10 expression. In this cross-sectional study, we genotyped these polymorphisms within the IL-10 gene in 203 Brazilian subjects infected with Schistosoma mansoni, with different patterns of PPF. There was an association of protection between the ages of 41 and 60 years and advanced standard PPF. The -1082AA genotype was significantly associated with severity in PPF when compared with the -1082GG genotype. Similarly, when analyzed together, both the -1082GA+AA genotypes were significantly associated. The ACC and GTA haplotypes indicated a protective effect against PPF, while the ATA haplotype was significantly associated with PPF severity when compared with the GCC haplotype. There was no significant difference between average levels of IL-10 between clinical groups, and there was no association between average serum levels of IL-10 and (-G1082A) IL-10 polymorphism. Our results suggest that (-G1082A) IL-10 polymorphism and putative haplotypes are associated with PPF severity in the Brazilian population.