Avaliação das citocinas IL-10 e IL-13 como mediadores na progressão da fibrose de Symmers em portadores de esquistossomose mansônica na forma hepatoesplênica

Low IL-6, IL-10, and TNF-α and High IL-13 Cytokine Levels Are Associated with Severe Hepatic Fibrosis in Schistosoma mansoni Chronically Exposed Individuals

Several studies have attributed the etiopathogenesis of chronic Schistosoma mansoni related hepatic fibrosis to unregulated immune responses against trapped parasite ova in the host. However, there is limited data on immune profiles associated with varying degrees of the disease in a population under chronic exposure to the parasite. We therefore investigated the role of selected T-helper (Th)1, Th2, and Th17 cytokines in relation to hepatic fibrosis severity among individuals resident in a hyper-Schistosoma mansoni endemic region of Western Zambia. Two hundred and forty-four S. mansoni infected individuals with and without fibrosis were analysed for cytokine profiles. Based on hepatic fibrosis stage as determined by ultrasound, participants were categorized into Group 0, Group I, Group II, and Group III. Cytokines were measured in S. mansoni egg stimulated whole blood culture supernatants using the BD Cytometric Bead Array kits. Compared to the nonfibrotic group, participants in the severe hepatic fibrotic group produced less interleukin- (IL-) 6, IL-10, and tumour necrosis factor-alpha (TNF-α). On the other hand, IL-13 was significantly elevated in this group compared to the nonfibrotic group (p < 0.001). Our results suggest that low IL-6, IL-10, and TNF-α and high IL-13 levels may influence S. mansoni disease progression.

Evidence of microglial activation following exposure to serum from first-onset drug-naïve schizophrenia patients

Abnormal activation of brain microglial cells is widely implicated in the pathogenesis of schizophrenia. Previously the pathophysiology of microglial activation was considered to be intrinsic to the central nervous system. We hypothesised that due to their perivascular localization, microglia can also be activated by factors present in circulating blood. Through application of high-content functional screening, we show that peripheral blood serum from first-onset drug-naïve schizophrenia patients is sufficient to provoke microglial cell signalling network responses in vitro which are indicative of proinflammatory activation. We further explore the composition of the serum for the presence of analytes, with the potential to activate microglia, and the utility of the resultant microglial cellular phenotype for novel drug discovery.

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.

Receptor Antagonist of IL-13 Exerts a Potential Negative Regulation During Early Infection of Human Schistosomiasis

The pathology of schistosomiasis is associated with the formation of granulomas, and this process is associated with liver fibrosis. Studies indicate that Th1 cytokines reduce fibrosis in schistosomiasis, while Th2 cytokines play a part in the progression of fibrosis, and IL-13 has a critical role in this process. The IL-13Rα2 receptor, known as a 'receptor antagonist' binds with high affinity to IL-13, and studies have identified that this plays a part in reducing fibrosis and the size of granulomas. The objective of this study was to evaluate the function of IL-13Rα2 and cellular immune response in hepatic fibrosis. A negative correlation between IL-13Rα2 and IL-13 was found, suggesting an increase in cytokine in early fibrosis. Initially, a negative correlation between IFN-γ and IL-13 was found in patients without fibrosis, and subsequently, this correlation was found to be positive in patients with severe fibrosis, thereby highlighting a new mechanism for regulating the progress of periportal fibrosis. There was a positive correlation between the profiles of Th1 and Th2 cytokines, suggesting the presence of both responses, thus regulating the disease. The results contribute to a better understanding of the immune mechanisms that control the process of hepatic fibrogenesis in schistosomiasis in humans.

The chronic enteropathogenic disease schistosomiasis

Schistosomiasis is a chronic enteropathogenic disease caused by blood flukes of the genus Schistosoma. The disease afflicts approximately 240 million individuals globally, causing approximately 70 million disability-adjusted life years lost. Chronic infections with morbidity and mortality occur as a result of granuloma formation in the intestine, liver, or in the case of Schistosoma haematobium, the bladder. Various methods are utilized to diagnose and evaluate liver fibrosis due to schistosomiasis. Liver biopsy is still considered the gold standard, but it is invasive. Diagnostic imaging has proven to be an invaluable method in assessing hepatic morbidity in the hospital setting, but has practical limitations in the field. The potential of non-invasive biological markers, serum antibodies, cytokines, and circulating host microRNAs to diagnose hepatic fibrosis is presently undergoing evaluation. This review provides an update on the recent advances made with respect to gastrointestinal disease associated with chronic schistosomiasis.

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.