Impact of hepatitis C virus recombinant form RF1_2k/1b on treatment outcomes within the Georgian national hepatitis C elimination program

Hepatitis C virus-specific markers in pediatric patients with chronic hepatitis C

BACKGROUND

The study aimed to investigate hepatitis C virus (HCV) specific markers in chronically infected children. The main objective was to explore the patterns of marker variability.

METHODS

HCV RNA, core antigen, anti-HCV IgM, and antibodies to individual viral proteins were detected using commercially available assays or experimental ELISA. RNA genotyping and recombination were performed by sequencing.

RESULTS

HCV RNA and core antigen were detected in serum samples of all children (N.=100). Anti-HCV IgM, anti-NS4AB IgG, and anti-NS5A IgG were revealed less often than antibodies to core and NS3 proteins. To elucidate the cause of this finding, all subjects were divided into 4 groups differing in hepatitis duration. It was anti-NS4AB only whose detection depended on the infection duration. A trend was established that the longer the hepatitis duration, the more frequently anti-HCV IgM was observed. No significant impact of HCV RNA load and NS4A/NS4B amino acid substitutions on anti-NS4AB IgG detection was found. The increase HCV genotype 3 was observed among children infected after 2000. The earliest case of infection caused by HCV intergenotype recombinant RF1_2k/1b was identified in a child vertically infected in 1997.

CONCLUSIONS

HCV genotypes and subtypes were found to be variable virus specific markers in children infected in 1997-2015. Over the period, there has been a trend to change the dominant HCV subtype and appearance of recombinant RF1_2k/1b in children. Among humoral markers, anti-NS4AB revealing is depended on chronic hepatitis C duration, while for anti-HCV IgM, only a trend was established. The detection of anti-NS4AB can be helpful in assessing the duration of chronic hepatitis C.

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.

Treatment outcomes of patients with chronic hepatitis C receiving sofosbuvir-based combination therapy within national hepatitis C elimination program in the country of Georgia

Background

Georgia has one of the highest HCV prevalence in the world and launched the world’s first national HCV elimination programs in 2015. Georgia set the ambitious target of diagnosing 90% of people living with HCV, treating 95% of those diagnosed and curing 95% of treated patients by 2020. We report outcomes of Sofosbuvir (SOF) based treatment regimens in patients with chronic HCV infection in Georgia.

Methods

Patients with cirrhosis, advanced liver fibrosis and severe extrahepatic manifestations were enrolled in the treatment program. Initial treatment consisted of SOF plus ribavirin (RBV) with or without pegylated interferon (INF). Sustained virologic response (SVR) was defined as undetectable HCV RNA at least 12 weeks after the end of treatment. SVR were calculated using both per-protocol and modified intent-to-treat (mITT) analysis. Results for patients who completed treatment through 31 October 2018 were analyzed.

Results

Of the 7342 patients who initiated treatment with SOF-based regimens, 5079 patients were tested for SVR. Total SVR rate was 82.1% in per-protocol analysis and 74.5% in mITT analysis. The lowest response rate was observed among genotype 1 patients (69.5%), intermediate response rate was achieved in genotype 2 patients (81.4%), while the highest response rate was among genotype 3 patients (91.8%). Overall, SOF/RBV regimens achieved lower response rates than IFN/SOF/RBV regimen (72.1% vs 91.3%, P < 0.0001).

In multivariate analysis being infected with HCV genotype 2 (RR =1.10, CI [1.05–1.15]) and genotype 3 (RR = 1.14, CI [1.11–1.18]) were associated with higher SVR. Patients with cirrhosis (RR = 0.95, CI [0.93–0.98]), receiving treatment regimens of SOF/RBV 12 weeks, SOF/RBV 20 weeks, SOF/RBV 24 weeks and SOF/RBV 48 weeks (RR = 0.85, CI [0.81–0.91]; RR = 0.86, CI [0.82–0.92]; RR = 0.88, CI [0.85–0.91] and RR = 0.92, CI [0.87–0.98], respectively) were less likely to achieve SVR.

Conclusions

Georgia’s real world experience resulted in high overall response rates given that most patients had severe liver damage. Our results provide clear evidence that SOF plus IFN and RBV for 12 weeks can be considered a treatment option for eligible patients with all three HCV genotypes. With introduction of next generation DAAs, significantly improved response rates are expected, paving the way for Georgia to achieve HCV elimination goals.

Successful direct-acting antiviral treatment of three patients with genotype 2/1 recombinant hepatitis C virus

There have been a few reports on the treatment of patients infected with recombinant hepatitis C virus (HCV) genotype 2/1 strains with direct-acting antivirals (DAAs). We experienced three patients, with genotype 2/1 recombinant HCV, treated with DAAs successfully. The first, a 39-year-old man, was infected with recombinant HCV genotype 2a/1b, a rare variant. The sequence of the relapsed virus showed chimeric HCV 2a/1b with the recombinant breakpoint found at nucleotide +49 from the start of the NS3 region. Sofosbuvir plus ribavirin, a regimen recommended for HCV genotype 2, did not lead to a sustained viral response (SVR). Retreatment with grazoprevir plus elbasvir resulted in an SVR. The second case, a 70-year-old woman, was infected with recombinant HCV genotype 2b/1b. DAA therapy with sofosbuvir plus ledipasvir resulted in an SVR. The third case, a 48-year-old woman, was also infected with recombinant HCV genotype 2b/1b. DAA therapy with daclatasvir plus asunaprevir resulted in an SVR. The baseline sequences of the viruses from both the second and third cases showed chimeric HCV 2b/1b with the recombinant breakpoint found at nucleotide +10 from the NS3 start. We report three cases with 2/1 chimeras and discuss the prevalence and response to therapy.