The incidence of acute hepatitis C virus (HCV)
co-infection has increased in recent years at the largest HIV clinic in Japan,
with almost all cases occurring among men who have sex with men, according to a
poster presented at the 53rd Interscience Conference on
Antimicrobial Agents and Chemotherapy (ICAAC) last month in Denver. For those treated
early with pegylated interferon plus ribavirin the cure rate was 80%.
Since the early 2000s, researchers have reported
outbreaks of acute HCV infection amongst HIV-positive gay and bisexual men,
first in large cities in the UK and continental Europe, followed by Australia
and the US. But there have been few reports on acute hepatitis C in East Asia.
Masahiro Ishikane with the National Center for
Global Health and Medicine and colleagues conducted a retrospective cohort
study looking at people with acute hepatitis C at the AIDS Clinical Center in
Tokyo, the largest HIV clinic
Acute hepatitis C was defined as alanine transaminase (ALT)
elevation >100IU/l accompanied by HCV antibody seroconversion. Acute
hepatitis C is often asymptomatic and many people are not aware they are
infected. People with HIV typically undergo regular liver enzyme testing to
monitor toxicity of antiretroviral drugs, however, and unexpected ALT rises may
signal new HCV infection.
analysed medical records from 34 patients diagnosed with acute hepatitis C between
January 2001 and December 2012. All but one were men and the median age
was 39 years.
The overall incidence
of acute HCV infection was 2.1 cases per 1000 person-years. Incidence increased
slightly over time, as shown by a higher rate in the past five years compared
with the past seven years (2.6 vs 1.5 per 1000 person-years, respectively).
All but two cases
of acute HCV infection (94%) occurred among HIV-positive men who have sex with men (MSM). Most (82%) were on antiretroviral
therapy with suppressed HIV viral load and they had a median CD4 cell count
of 366 cells/mm3,
indicating moderate immune suppression, at the time of HCV diagnosis.
this rate is similar to that seen among HIV-positive gay men in the mostly European CASCADE cohort in 1990, before it increased by more
than ten-fold in the late 2000s. Rates of 20 to more than 100 cases per 1000
person-years or higher have also been seen in Amsterdam and in the Swiss HIV Cohort. However, a recent analysis of HIV-positive MSM in the US Multicenter AIDS Cohort Study found a rate of
only about 5 per 1000 person-years between 2005 and 2011.
Five people (15%)
in the Japanese cohort reported a history of injecting drug use, but the route
of HCV transmission was classified as 'undetermined' in all cases.
Studies of acute
HCV infection among HIV-positive gay men in Europe, Australia and the US point
to probable sexual transmission. HCV infection has been associated with various
factors in different studies – including fisting, anal intercourse, group sex,
use of non-injected recreational drugs and having other sexually transmitted
infections – but data have been inconsistent and the exact mechanism of HCV sexual
transmission is not fully understood.
(82%) were asymptomatic and were diagnosed with HCV by chance at a routine clinic
visit. Six people experienced symptoms including fatigue (18%) and jaundice, or
yellowing of the skin and eyes due to elevated bilirubin (6%). About two-thirds
(68%) had HCV genotype 1b, the most common type in Japan, whilst one-quarter
had genotypes 2a or 2b.
(15%) cleared HCV spontaneously without treatment. This group had significantly
higher peak bilirubin levels than those who did not naturally clear HCV.
patients (35%) started treatment with pegylated interferon plus ribavirin
within 48 weeks of HCV diagnosis, with a median interval of four months between
initial ALT elevation and starting therapy. The remaining 17 participants (50%)
did not receive treatment and progressed to chronic HCV infection.
treatment lasted a median of 45 weeks (range 11 to 72 weeks). Although only
about one-quarter experienced rapid virological response at week 4 of therapy,
the 24-week post-treatment sustained virological response (SVR) or cure rate
was high, at 80%. This far exceeds the SVR rate seen in most studies of HIV/HCV
co-infected patients treated for chronic hepatitis C.
"Early treatment with [pegylated interferon plus ribavirin] should
be considered for favourable response in HIV-infected patients with [acute
hepatitis C]," the researchers concluded.