experts estimate that approximately one-quarter to one-third
of people initially infected with HCV will naturally clear the
virus without treatment thanks to an effective immune response.
Among those with persistent infection, however, HCV can over
years or decades cause serious liver disease including cirrhosis
carcinoma, a form of primary liver cancer.
has shown that people with chronic
hepatitis C have a higher risk of liver-related death, but
outcomes among people who were once infected but naturally cleared
the virus have not been extensively studied.
In the present analysis, Lars Haukali Omland and fellow investigators
with the DANVIR Cohort Study examined the association between
chronic HCV replication and mortality among Danish patients
who tested positive for HCV antibodies.
This nationwide cohort study looked at more than 6000 patients
with at least 1 HCV RNA (genetic material) viral load measurement
available after testing positive for HCV antibodies between
1996 and 2005. To capture long-term outcomes, eligible participants
needed to be alive for at least 1 year after HCV RNA assessment.
The researchers estimated mortality rate ratios (MRRs) for overall
mortality and sub-distribution hazard ratios (SDHRs) for cause-specific
mortality, after controlling for patient sex, age, co-existing
conditions, heavy alcohol use, injection drug use, and income.
the 6292 patients in the study, 37% spontaneously cleared
HCV, while 63% developed chronic infection.
5-year survival rates were 92% for participants who cleared
the virus, compared with 86% for those with chronic infection.
HCV infection was associated with higher overall mortality
compared with viral clearance (MRR 1.55).
infection was also associated with a more than a 2-fold
greater risk of liver-related death (SDHR 2.42).
particular, chronic HCV infection greatly increased -- by
more than 16-fold -- the risk of death due to primary liver
cancer (SDHR 16.47).
on these findings, the study authors concluded, "Patients
with chronic HCV infection are at higher risk of death than
patients who cleared the infection."
"The substantial association found between chronic HCV
infection and death from primary liver cancer supports early
initiation of antiviral treatment in chronically HCV-infected
patients," they recommended.
Investigator affiliations: Department of Infectious Diseases,
Rigshospitalet, Copenhagen; Department of Clinical Biochemistry,
Aalborg Hospital; Department of Clinical Epidemiology, Aarhus
University Hospital; Department of Clinical Immunology, Odense
University Hospital; Department of Clinical Immunology and Blood
Bank, Rigshospitalet, Copenhagen; Department of Clinical Immunology,
Viborg Region Hospital; Department of Clinical Immunology, Hospital
of Southern Jutland, Region of Southern Denmark; Department
of Clinical Microbiology, Vejle Hospital; Department of Infectious
Diseases, Odense University Hospital, Denmark; Department of
Epidemiology, Boston University School of Public Health, Boston,
Omland, H Krarup, P Jepsen, and others (DANVIR Cohort Study).
Mortality in patients with chronic and cleared hepatitis C viral
infection: a nationwide cohort study. Journal of Hepatology
53(1): 36-42 (Abstract).