Influência dos polimorfismos nos genes dos receptores TLR4 e TLR9 no desenvolvimento da fibrose hepática associada a infecção pelo Vírus da Hepatite C

Abstract

Hepatitis C is a public health problem that affects approximately 3% of the world's population. It is a very variable prognosis disease that can progress to cure or to the development of chronic hepatitis C, liver cirrhosis, hepatocellular carcinoma and death. Several polymorphisms in the Toll receptor genes are associated with clinical hepatic changes and disorders are related to inflammation. In this study we investigated the influence of polymorphisms on the TLR4 and TLR9 receptor genes and their association on the cytokine profile in patients with chronic liver disease. TLR4 and TLR9 SNPs were genotyped by PCR-RFLP in 151 patients with chronic liver disease caused by HCV from the Tropical Medicine Foundation Doctor Heitor Vieira Dourado and 206 blood donors from the Hospital Hematology and Hemotherapy Foundation of Amazonas. Of these, 45 subjects were randomly selected for the culture assay, 15 of which were from healthy donors and 30 from patients with chronic liver disease (15 ≤ F2 and 15 ≥ F2), treated with DAAs and sustained virological response ) confirmed by the absence of viral RNA by quantitative molecular tests. The cytokines IL-6, TNF, IL-10, IL-2, IFN-γ, IL-4 and IL17A were performed using the Flow Cytometry technique using the Ctom Kit (Cytometric Bead Array). Among the results obtained, we report the presence of genotype 4, from a patient from the state of Pará, described for the first time in the state of Amazonas. None of the TLR4 and TLR9 polymorphisms analyzed in this study were significantly associated with chronic liver disease. The TLR4 A299G A / A + A / G and TLR4 T399I C / C + C / T variants are more frequently found in the study population. We also observed that the combination of the TLR9 -1237T / T and TLR9 -1486C / T variants was higher in the studied groups compared to other genotype combinations. Next, we studied the influence of the genotypes in combination for TLR9 TLR9 -1237T / T variants and -1486C / T on serum cytokine profile and in LPS-stimulated culture supernatant. Thus, we observed that patients with the combined TLR9 -1237T / T and -1486C / T genotypes showed a significant increase in serum IL-6 (p = 0.005) and IL-4 (p = 0.0007) compared to healthy subjects A significant increase in IL-10 was observed in patients with HCV ≥ F2 (p = 0.028) compared to ≤ F2, whereas the cytokines IL-6, TNF, IL-2, IFN-γ, IL-4 and IL17A did not were significant when compared among patients with different stages of liver disease. No significant difference was observed in IL-6, TNF, IL-10, IL-2, IFN-γ and IL-4 in LPS-stimulated PBMC culture. Only IL-17A presented a significant increase in patients ≥ F2 (p = 0.043) compared to ≤ F2. At the end, we could observe a change in the cytokine profile for TH17 under the LPS stimulus, especially among patients with advanced chronic liver disease, even if they had sustained virological response. We conclude that the polymorphisms associated with the risk of developing cancer may help to better select patients for the treatment of HCV.