Hepatitis C: evolution of infection by hepatitis C virus (HCV) and IL28B genetic polimofismo in region
Infection with hepatitis C virus (HCV) can follow various patterns of evolution. In some individuals (25%) after acute infection, the virus spontaneously disappears from the body in about 6 months, while other individuals a chronic infection develops.
In patients who develop chronic infection antiviral treatment is required, today made a pegylated interferon-associated with ribavirin (PEG-IFN-a / RBV). This treatment is more effective the earlier it is administered. Therefore interested in knowing the factors that can predict the spontaneous elimination to establish the antiviral therapy early when it is expected that infection can evolve into chronicity.
The evolution to chronicity depends on factors of the host and the virus. Among dependent host factors, now known that genetic variations in the region of chromosome 19 near the gene encoding interleukin-28B (IL28B) encoding the interferon-?3 (INF-?3) are related to the response to treatment of chronic hepatitis C, and that some variants in that region are present in individuals in which no HCV RNA detected, whereas if they possess anti-HCV antibodies, as evidence that there has been removal of virus.
They described several single nucleotide polymorphisms (SNPs: single nucleotide polymorphisms) related to the natural history of infection virus HEPATITIS C and response to treatment. These polymorphisms are located in the vicinity of IL28B gene: rs8103142, rs11881222, rs12979860 rs8099917 and. These four polymorphisms are most have been associated with response to treatment. Of these polymorphism rs12979860, would lead to the CC, CT and TT genotypes. IL28B CC genotype (rs12979860) has been linked with a two - fold difference in the rate of virological response, with rapid virological response (RVR: Rapid Virologic Response) maintained and (SVR: Sustained Virologic Response), compared to CT- IL28B genotype and IL28B TT. Therefore, the genotype CC IL28B (rs12979860) is currently considered the most important predictor pretreatment to provide spontaneously clear and better therapeutic response. The discovery of the CT-IL28B TT-IL28B genotypes and recommend initiating therapy early to facilitate removal of the virus and prevent its progression to chronicity.
Tests in IVAMI: in IVAMI perform PCR amplification of the genomic region IL28B, performing, unless otherwise indicated, to the rs12979860 polymorphism, followed by sequencing to determine the genetic polymorphism of the patient and to sense the evolution foreseeable and whether or not to start antiviral therapy early.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).