Molecular epidemiologic analysis of hepatitis C virus infection in injecting drug users with acute hepatitis C in Japan

High dropout rate from aftercare program of antihepatitis C therapy for patients with history of injection drug use

Background and Aim

We assessed direct‐acting antiviral (DAA) treatment for patients with hepatitis C virus (HCV) and a history of injection drug use (IDU) in Japan.

Method

This retrospective observational study was based on clinical records. Overall, 804 DAA‐naïve HCV‐infected patients were enrolled, treated with a 12‐week regimen of DAAs, and had available information about a history of IDU. Anti‐HCV efficacy was defined as a sustained viral response 12 weeks post‐treatment (SVR12) only in patients who were assessed after 12 weeks [modified intention‐to‐treat (ITT) analyses]. We compared the antiviral effect between patients with (past‐IDU) and without a history of IDU (non‐IDU). We also evaluated the characteristics of each group, including the overall dropout rate and economic background.

Results

Overall, 78 (9.7%) patients had a history of IDU. Compared to the non‐IDU group at baseline, the past‐IDU group consisted of predominantly male and younger patients infected with HCV genotype 2. Overall, 3% (3/78) and 16% (116/726) of the patients had cirrhosis in the past‐IDU and non‐IDU group, respectively. There was a significantly higher rate of welfare recipients in the past‐IDU group. SVR rate was 97% (59/61) in the past‐IDU group and 99% (689/699) in the non‐IDU group. The cumulative rate of dropout from an aftercare program was high in the past‐IDU group (P < 0.01).

Conclusions

DAAs had a remarkable anti‐HCV effect in patients with past‐IDU who continued in an aftercare program. It is necessary to understand the characteristics of past‐IDU patients to establish a support system for aftercare programs.

Intention-to-treat assessment of glecaprevir + pibrentasvir combination therapy for patients with chronic hepatitis C in the real world

AIMS

We assessed the problems and efficacy of glecaprevir + pibrentasvir (GLE/PIB) therapy for patients infected with hepatitis C virus (HCV) in the real world.

METHOD

A total of 423 patients infected with HCV who started treatment at eight different centers in Japan were enrolled in the study. Glecaprevir (300 mg) and pibrentasvir (120 mg) were given once daily for 8 weeks to 246 non-cirrhotic direct-acting antiviral (DAA)-naive patients with HCV genotype (GT)-1 or -2, and for 12 weeks to patients who: were DAA-naive cirrhotic (n = 55), had experienced DAA failure (n = 78), were cirrhotic and had DAA failure (n = 37), and were other GT-1/2 (n = 7). Anti-HCV efficacy was defined as a sustained virologic response 12 weeks post-treatment (SVR12). The evaluation was undertaken in an intention-to-treat (ITT) population and in patients who were assessed at SVR12 (modified ITT population).

RESULTS

In the ITT population, 220 (89%) patients on the 8-week regimen and 164 (93%) patients on the 12-week regimen achieved SVR12. The 30 dropout patients were predominantly men and with GT-2. All other DAA-naive GT-1 patients achieved SVR12. The 12-week regimen resulted in 100% SVR12 in 41 GT-2 patients. Nine patients did not achieve SVR12: two DAA naive with GT-2a, two GT-3b patients, two GT-1 patients with discontinuation, and three other GT-1 patients with a history of DAA failure. Four of seven patients who discontinued treatment due to severe adverse effects were more than 75 years old.

CONCLUSIONS

Glecaprevir + pibrentasvir had a remarkable anti-HCV effect in GT-1 and GT-2 patients, but not in GT-3b patients. Although this therapy was reasonably safe, it is necessary to carefully consider elderly and dropout patients.

Molecular epidemiology of acute HCV infection in HIV-positive patients from Hong Kong, Taipei, Tokyo

BACKGROUND

Acute hepatitis C virus (HCV) infections have been increasingly reported among human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) in the Asia-Pacific region. It remains unknown whether international network of HCV transmission has occurred in this region.

METHODS

HIV-positive patients with acute HCV infection, defined as HCV seroconversion within a year or documented acute hepatitis with seroconversion, diagnosed in Hong Kong, Taipei and Tokyo during 2010-2016 were included in this molecular epidemiology study. The NS5B region of the HCV genome (365 bp) was amplified using nested polymerase chain reaction and sequenced.

RESULTS

Of 234 HIV-positive patients with acute HCV infection, all were male with 94% being MSM. At the diagnosis of acute HCV infection, 73.5% had concurrent sexually transmitted diseases and 88.0% were receiving combination antiretroviral therapy. The most prevalent HCV genotype was 3a, 2a and 1b in Hong Kong, Taipei and Tokyo respectively. Nine independent clusters belonging to five genotypes (1b, 2a, 2c, 3a and 6a) were identified, each of which occurred in one city without overlapping except for one 3a sequence from Taipei that was closely related genetically to the Hong Kong cluster.

CONCLUSIONS

No international network of HCV transmission was identified among HIV-positive patients in the three Asia-Pacific cities. The transmission dynamics of sexually acquired HCV differed by city, but the risk of intercity clustering should not be ignored.

Ledipasvir-sofosbuvir for treating Japanese patients with chronic hepatitis C virus genotype 2 infection

BACKGROUND & AIMS

Japanese patients with chronic hepatitis C virus (HCV) genotype 2 infection have high rates of sustained virological response (SVR) following 12 weeks of treatment with the nucleotide polymerase inhibitor sofosbuvir in combination with ribavirin, which was the standard of care at the time this study was undertaken. We assessed the efficacy of 12 weeks of treatment with a ribavirin-free regimen of ledipasvir-sofosbuvir.

METHODS

In an open-label, Phase 3 trial we enrolled Japanese patients with chronic HCV genotype 2 infection, with or without compensated cirrhosis. In Cohort 1, participants were randomized 1:1 to receive ledipasvir-sofosbuvir (n = 106) or sofosbuvir + ribavirin (n = 108) for 12 weeks. In Cohort 2, 25 ribavirin-intolerant or -ineligible patients received ledipasvir-sofosbuvir for 12 weeks. The primary endpoint was SVR 12 weeks after therapy (SVR12). In Cohort 1 non-inferiority was assessed with a prespecified margin of 10%.

RESULTS

One-third (33%) of patients were treatment experienced, and 14% had cirrhosis. In Cohort 1, SVR12 rates were 96% (95% CI, 91% to 99%) with ledipasvir-sofosbuvir and 95% (95% CI, 90% to 98%) with sofosbuvir plus ribavirin, thus achieving non-inferiority. Among ribavirin-intolerant/ineligible patients in Cohort 2, SVR12 was 96% (95% CI, 80% to 100%) with ledipasvir-sofosbuvir. Overall, the most common adverse events were nasopharyngitis, anaemia, and headache; anaemia was only observed in patients receiving ribavirin. The percentage of patients who discontinued treatment because of an adverse event was low (1%).

CONCLUSIONS

Among Japanese patients with HCV genotype 2, 12 weeks of treatment with ledipasvir-sofosbuvir resulted in high rates of SVR12 that were non-inferior to sofosbuvir + ribavirin.

Phylogenetic and phylodynamic analyses of hepatitis C virus subtype 1a in Okinawa, Japan

Okinawa Island, located in Southern Japan, has a higher prevalence rate of hepatitis C virus subtype 1a (HCV-1a) infection than that in mainland Japan. Okinawa has a history of US military occupation after World War II. To elucidate the transmission history of HCV-1a in Okinawa, 26 whole-genome sequences were obtained from 29 patients during 2011-2016. Phylogenetic trees were reconstructed to identify the origin and characteristics of HCV-1a in Okinawa with epidemiological information. A phylogenetic tree based on whole-genome sequencing revealed that all of the samples were located below the US branches. Additionally, we identified one cluster comprised of 17 strains (Okinawa, n = 16; United States, n = 1). The majority of the patients in this cluster were people who inject drugs (PWID), indicating the presence of a people who inject drugs (PWID) cluster. Subsequently, Bayesian analyses were employed to reveal viral population dynamics. Intriguingly, a phylodynamic analysis uncovered a substantial increase in effective population size of HCV-1a from 1965 to 1980 and a slight increase in mid-2000, which were associated with an increase in illicit drug use in Okinawa. The estimated divergence time of the PWID cluster was 1967.6 (1964.2-1971.1). These findings suggest that HCV-1a was introduced into Okinawa from the United States in the late 1960s, coincident with the Vietnam War. Subsequently, HCV-1a might have spread among the Japanese population with the spread of injecting drug use. Our study provides an understanding of HCV transmission dynamics in Okinawa, as well as the key role of PWID in HCV transmission.

Global genotype distribution of hepatitis C viral infection among people who inject drugs

BACKGROUND & AIMS

Hepatitis C viral infection (HCV) after injection drug use is very prevalent. The kind of genotype determines the response to treatment. However, no systematic review update on the global genotype distribution of HCV in people who inject drugs (PWID) is currently available.

METHODS

A systematic review was performed by using the keywords: Genotype, Hepatitis C, Injection drug user/Intravenous drug user/Substance user/ PWID, Name of countries in Pubmed, Embase and PsycINFO. The results were compared with the review of Gower et al. in 2014, concerning the distribution of HCV genotypes in the general HCV population.

RESULTS

Using these keywords, 132 studies in 48 countries (from 1995 to 2015) were collected. After grading these results, the data of 48 studies were used to determine the distribution of genotypes in PWID. Genotype 1 is the most prevalent genotype all over the world in PWID. In Europe, genotypes 1, 3 and 4 are highly prevalent. In North and South America and in Australia genotype 1 and 3 are most prevalent. In Asia genotype 2 and 6, and Africa genotype 1a and 4 are mostly observed. Overall, the most important differences comparing with the general population are a lower prevalence of genotype 1b in the PWID population and higher prevalence of genotype 1a and 3.

CONCLUSIONS

There is a different prevalence of genotype distribution in PWID than in the general population. Genotype 3 is especially highly prevalent in the Western countries.

LAY SUMMARY

Hepatitis C viral infection after injection drug use is very prevalent. The most important genotype causing HCV infection in PWID globally is genotype 1, as is the case in the general population, but also genotype 3 is highly prevalent in PWID. Genotype 4 is most prevalent in Africa, spreading into Europe, whereas genotype 2 and 6 are more located in Asia. The most important difference comparing to the general population are generally lower prevalence of genotype 1b, and higher prevalence of genotype 1a and 3 in PWID. As the genotype nowadays still determines the treatment, and as there is a different genotype distribution than in the general population, it is important to identify the genotype also in PWID.

Combination therapy of natural human interferon-beta and ribavirin for chronic hepatitis C patients with injection drug use

AIM

The aim of this study was to evaluate the efficacy and safety of combination therapy using natural human interferon-β and ribavirin (IFN-β/RBV) for chronic hepatitis C patients who were injection drug users (IDU) and resident in the Airin district of Osaka, containing the biggest slums in Japan.

METHODS

Twenty-nine IDU with chronic hepatitis C received combination therapy of IFN-β/RBV. The psychiatrist in charge evaluated the scores of the Zung Self-rating Depression Scale (SDS), a self-rating scale based on 20 questions. Univariate logistic regression analyses were used to determine the factors that significantly contributed to complete treatment and a sustained virological response (SVR).

RESULTS

Thirteen of the 29 patients achieved SVR according to the intention to treat analysis. All patients with a rapid virological response achieved SVR. No patient required a reduced dose of RBV because of a decrease in their hemoglobin level, or of IFN-β because of a low level of white blood cells and platelet count. Two patients had psychological side-effects and stopped the therapy early in the treatment; one patient had depression and the other had anxious depression. Univariate logistic regression analyses indicated that the stage of fibrosis was the only factor that contributed to SVR, and that the SDS test and past drug abuse contributed to completion of the treatment.

CONCLUSION

IFN-β/RBV combination therapy is useful for treating IDU.

Case definitions for acute hepatitis C virus infection: a systematic review

BACKGROUND & AIMS

Case definitions for recent hepatitis C virus (HCV) infection vary considerably between studies. The aim of this systematic review was to characterize case definitions for recent HCV and explore the heterogeneity in studies performed to date.

METHODS

A systematic literature search of MEDLINE, SCOPUS, and ISI Web of Knowledge was performed covering all studies of recent HCV infection cited between January 2000 and June 2011. The criteria used by each study to define cases of recent HCV infection were extracted, structured, and analyzed.

RESULTS

Overall, 195 articles were included, with 87% (n=169) providing a clear case definition for recent HCV infection. The most frequently used individual criteria for defining a case included HCV antibody seroconversion (77%), alanine aminotransferase (ALT) elevation (68%), and HCV RNA detection (63%). In studies using HCV antibody seroconversion, the window period between the last negative and the first positive antibody test varied widely across studies (4 weeks to 4 years). Considerable diversity was also observed with respect to the ALT threshold used to characterize ALT elevations, ranging from 2 to 20 times the upper limit of normal. HCV antibody seroconversion was used as a single criterion in 41% of the studies, while all other studies used at least two criteria (range: 2-9). Epidemiology/surveillance studies mostly used a more sensitive case definition, whereas treatment studies, natural history studies, and diagnosis studies used more specific case definitions.

CONCLUSIONS

Marked heterogeneity in case definitions for recent HCV infection was observed. Although a single case definition for recent HCV is not warranted, a degree of standardization within specific study categories would enable improved cross-study comparison and more uniform evaluation of HCV prevention and management strategies.

Identification and phylogenetic analysis of hepatitis C virus in forensic blood samples obtained from injecting drug users

Injecting drug users (IDUs) are a high-risk group for contracting hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections. In Japan, data on the prevalence of those blood-borne viruses among IDUs are very limited. Blood samples were obtained from 12 cadavers of IDUs sent to Nagoya City University for the purpose of judicious autopsy and two alive IDUs with hepatitis C referred to a local hospital at the same period. The viruses were detected by polymerase chain reaction and phylogenetic analysis was performed. Two (16.6%) of the 12 autopsy cases were positive for HCV, but no case was positive for either HBV or HIV. Phylogenetic analysis of the two HCV isolates revealed that one was classified into genotype 1b and another was genotype 2b. Furthermore, nucleotide sequences of two isolates recovered from IDUs with hepatitis C were identical, that indicated the transmission of HCV between them, and those HCV were phylogenetically classified into genotype 2a. The prevalence of HCV infection among IDUs in Japan, despite the case of judicious autopsy, seems to be high, but HIV infection seems to be rare. The transmission of HCV between IDUs was demonstrated, and this indicates that phylogenetic analysis would applicable to also forensic analysis. HCV isolates identified in this study did not phylogenetically segregate, thus multiple transmission route of HCV among IDUs seems be exist in Japan.