Assessment of treatment options for patients with hepatitis C virus recombinant form 2k/1b.

AIM: Hepatitis C virus (HCV) intergenotype recombinant form (RF) 2k/1b has been actively circulating in HCV-infected patients, and the prevalence of this RF virus in the Republic of Georgia is one of the highest reported worldwide. The aim of this study was to define the optimal treatment regimen for patients with RF_2k/1b. METHODS: We analyzed the data of 2735 patients who started treatment at the Medical Center Mrcheveli within Georgia's hepatitis C elimination program from May 2015 through December 2019. The patients were treated with sofosbuvir (SOF)-based regimens. For identification of RF_2k/1b variants, refinement of standard (INNO-LiPA) genotyping results for all patient samples assigned the unspecific HCV genotypes (GT) 2a/2c was carried out by sequencing of core and non-structural protein 5B genes. RESULTS: Overall, 444 patients, representing 66% of GT2 and 16% of the total samples, were RF_2k/1b. Treatment of patients with RF_2k/1b with SOF/ledipasvir and SOF/velpatasvir was highly effective and viral cure rates did not differ among genotypes treated with the same regimen: RF_2k/1b, 99% (343/346); GT1, 99% (876/885); GT2, 96% (156/162); and GT3, 99% (545/552). A separate comparison analysis of sustained virologic response rate, treated with SOF plus ribavirin, showed significantly higher sustained virologic response (96%) in patients with confirmed GT2 (by sequencing) compared to unspecified GT2 (by INNO-LiPA) (79%) (P < 0.05). CONCLUSION: Sofosbuvir-based regimens are highly effective for treatment of RF 2k/1b patients, and with availability of new pan-genotypic direct-acting antivirals, genotyping to identify RF 2k/1b patients might not be necessary.

Identification of hepatitis C virus 2k/1b intergenotypic recombinants in Georgia.

BACKGROUND AND AIMS: This study aimed to evaluate the prevalence of the hepatitis C virus intergenotype recombinant strain RF1_2k/1b in Georgia, confirm viral recombination by full genome sequencing, and determine a genetic relationship with previously described recombinant hepatitis C viruses. METHODS: We retrospectively analysed data from 1421 Georgian patients with chronic hepatitis C. Genotyping was performed with the INNO-LiPA VERSANT HCV Genotype 2.0 Assay. RESULTS: Virus isolates were assigned to nonspecific hepatitis C genotypes 2a/2c (n = 387) as performed by sequencing of core and NS5B genes. Subsequently, sequencing results classified the core region as genotype 2k and the NS5B region as genotype 1b for 72% (n = 280) of genotype 2 patients, corresponding to 19.7% of hepatitis C patients in Georgia. Eight samples were randomly selected for full genome sequencing which was successful in 7 of 8 samples. Analysis of the generated consensus sequences confirmed that all 7 viruses were 2k/1b recombinants, with the recombination breakpoint located within 73-77 amino acids before the NS2-NS3 junction, similar to the previously described RF1_2k/1b virus. Phylogenetic analysis revealed clustering of the Georgian 2k/1b viruses and RF1_2k/1b, suggesting that they are genetically related. CONCLUSIONS: The 19.7% prevalence of RF1_2k/1b in Georgia patients is far higher than has generally been reported to date worldwide. Identification of recombinants in low income countries with a high prevalence of HCV infection might be reasonable for choosing the most cost-effective treatment regimens.

Emergence of Hepatitis C Virus Genotype Recombinant Forms 2k/1b in Georgia.

BACKGROUND: Hepatitis C virus (HCV) evolution is thought to proceed by mutations within the six major genotypes. Studies of HCV recombinant genotypes in different parts of the world have recently been initiated. Only a few cases of recombination have been identified worldwide, predominantly in Eastern Europe and Asia. In 2011 we detected the recombinant form (RF) of a HCV genotype RF_2k/1b in Georgia. Therefore, we reviewed HCV genotyping data of 491 patients with chronic hepatitis C virus infections of our center in Tbilisi over a period of two years. METHODS: Initially all genotyping analyses were performed with the VERSANT HCV genotype assay (Siemens, LiPA). In a second analysis, parts of the core and the NS5B region were sequenced for all HCV genotypes 2a/2c. RESULTS: Approximately 2/3 of genotype 2 cases were identified as the recombinant form HCV-RF 2k/1b. Overall, this type represented 19% of all HCV patients who underwent genotyping. CONCLUSIONS: We can conclude that almost 20% of HCV infected Georgian patients are infected with HCVRF_2k/ 1b.