- The New Treatment of Hepatitis C. Illustrate your essay wi...
The New Treatment of Hepatitis C. Illustrate your essay with specific examples.
Over the past three decades Hepatitis C has become one the most
prevalent causes of liver disease in the world. It now affects over
180 million people worldwide (3% of the population), with over
30,000 new cases being diagnosed in the US alone every year. Though
treatments for hepatitis C exist, only 50% of those treated show
any response resulting in an urgent need for new therapies. This
review will aim to cover the current treatment options available
and the most relevant clinical and pre-clinical trials for the
treatment of hepatitis C.
More than 180 million individuals across the globe are infected
with the hepatitis C virus (HCV) (Waters et al., 2006). Infection
can lead to fatal liver diseases; cirrhosis and primary liver
cancers known as hepatocarcinomas (Waters et al., 2006). Indeed,
HCV is considered by the World Health Organisation to be a silent
but nevertheless deadly epidemic. The Centre for Disease Control
(CDC) has declared that 20-30% of individuals with chronic
hepatitis C will eventually develop potentially fatal symptoms
(Webster et al., 2009). When compared to Human Immunodeficiency
Virus (HIV), the most well known and well publicised viral
infection, HCV is found to be more prevalent. For each individual
infected with HIV, there are more than four infected with HCV
(Webster et al., 2009). In addition, the number of HCV cases in the
developing world is rapidly increasing with 6% of the population of
central Africa infected (Madhava et al., 2002). The scale of the
level of hepatitis infection worldwide has lead to many avenues of
research being pursued. However, though therapies currently exist
for the treatment of HCV, their efficacy is low; effective in only
50% of subjects (Waters et al., 2006). This has driven the
development of more efficacious and less toxic treatments.
Though new strategies for the treatment of HCV show significant
promise for the future, it should also be noted that in those
responsive to combination therapies, 99% of patients had no
detectable virus up to a decade later (Adamek et al., 2007; Lau et
al., 1998). Thus the current combination therapy represents a cure
for the 50% of HCV infected individuals who respond.
The wealth of research continuing into the treatment of HCV
brings significant hope that an effective treatment for this
virulent and widespread virus may be found in the near future.
Inhibitors of viral replication, virus attachment and virus release
are all currently undergoing clinical trials and are likely to
provide the next round of HCV therapeutics. The geographical
diversity of the different genotypes and the significant influence
of genotype on therapy responsiveness mean that trials conducted on
one continent or even in different countries of regions within a
continent are not comparable. Therefore it is likely that a
worldwide single dosing strategy will not be appropriate for all
patients. Differences in genotype and individual responsiveness may
warrant local modifications in interferon dosing. Improvements in
the dosing, dose regime and support infrastructure of patients
receiving pegylated interferon and ribavirin could also
significantly improve response rates. However, further studies are
required to gain a better understanding of the mechanisms of IFN
and ribavirin activity in order to substantially improve their
actions. Recent innovation in the development of a cell-culture
system that allows complete HCV replication may provide further
information on the antiviral mechanisms of IFN activity and
increase the ease with which new antiviral agents can be assessed.
Crucially, novel antivirals may act synergistically with current
therapies by reducing the ability of HCV to replicate and by
increasing its susceptibility to IFN, reducing the level of
non-responders. In summation, these rapidly increasing combinations
of therapeutics hold the promise of greatly improved rates of
response in the treatment of hepatitis C.