While
there have been numerous studies of hepatitis C
in individuals who inject drugs (primarily
heroin), less is known about the effects of non-injection drugs on hepatitis
C virus (HCV) infection. Methamphetamine is a stimulant that may be taken as a
pill, injected, snorted, smoked, or administered anally.
In
the April 2008 Journal of Viral Hepatitis, L. Ye of the University of Pennsylvania
School of Medicine and colleagues reported on a laboratory study looking at whether
methamphetamine inhibits innate immunity in host cells, thereby facilitating HCV
replication in human hepatocytes (liver cells).
Results
•
Methamphetamine inhibited natural intracellular interferon alpha expression in
human hepatocytes, which was associated with increased HCV replication.
•
Methamphetamine also compromised the anti-HCV effect of recombinant interferon
alpha, as used for hepatitis C treatment.
•
Introduction of methamphetamine inhibited expression of the signal transducer
and activator of transcription 1 (STAT-1), a key modulator of interferon-mediated
biological responses.
•
Methamphetamine also down-regulated expression of interferon regulatory factor
5 (IRF-5), a transcriptional factor that activates the interferon pathway.
Conclusion
In
conclusion, the authors wrote, "These in vitro findings that methamphetamine
compromises interferon alpha-mediated innate immunity against HCV infection indicate
that methamphetamine may have a cofactor role in the immunopathogenesis of HCV
disease."
3/07/08
Reference L
Ye, JS Peng, Z Wang, and others. Methamphetamine enhances Hepatitis C virus replication
in human hepatocytes. Journal of Viral Hepatitis 1594): 261-270. April
2008.
Results
