HIV and HCV treatment for people with coinfection
When should HIV be treated first?
Generally, HIV treatment should be started first if CD4 count is less than 200 cells/mm3, and probably started first if it is between 200-350 cells/mm3.
People with serious liver damage may need HCV treatment even when their CD4 count is lower than this. HIV treatment may be started at higher CD4 counts if the CD4 count is falling, and HCV treatment will be used soon.
Using HCV treatment depends on:
- Willingness/readinessto start HCV treatment.
- Need for treatment.
If liver disease is mild, HCV treatment can be delayed.
If it is moderate to serious, HCV treatment is recommended.
The most important aspects of HIV treatment are just as relevant for people who also have HCV, including choice of treatment, adherence, side effects and resistance.
When should HCV be treated first?
If HCV treatment is needed, people on a stable HIV regimen should be treated, even if their CD4 cell count is under 200 cells/mm3.
Older studies, that used standard interferon to treat HCV, reported that it was less effective for people with low CD4 counts.
However, in a small group of people studied so far, PEG interferon plus ribavirin works at both high and low CD4 counts.
It is best not to start treatment for both HIV and HCV at the same time. This is because side effects from both treatments make this too difficult.
HIV treatment concerns in people with coinfection
The main differences in HIV treatment for someone who also has HCV relate to:
- Timing of HIV treatment.
- Concern for liver toxicity/damage as a side effect of HIV drugs.
- The choice of HIV drugs.
Some drugs are less liver-friendly than others. It is not clear though whether small increases in liver enzymes increase the risk of clinical disease.
Caution is clearly important. HIV drugs should be selected carefully, and liver enzyme levels monitored regularly.
Some side effects occur more frequently in people with HCV coinfection, including lipodystrophy (fat accumulation or fat loss) and abnormal blood fat and insulin levels.
HCV increases the risk of developing diabetes and this risk is higher in HIVpositive people.Use of HIV protease inhibitors and nucleoside analogues, especially d4T (stavudine, Zerit), has been linked with an increased risk for high blood sugar and diabetes.
However, this risk should never be used as a factor to withhold HIV treatment.
Drug interactions between HCV treatment and HIV medicines
ddI (didanosine, Videx) should not be used during HCV treatment, because of a serious interaction with ribavirin that can cause lactic acidosis, pancreatitis, and the risk of liver failure in people with advanced cirrhosis.
AZT is not recommended because of the increased risk of anaemia.
d4T (stavudine) in some studies was linked with an increased risk for significant weight loss and lipoatrophy (fat loss) in people using ribavirin.
Abacavir may reduce the chance of a good response to HCV treatment because of a negative drug interaction with ribavirin, and should be avoided if there are other options for HIV treatment.
HCV treatment and CD4 cell count
Even if you are on HIV treatment, interferon can cause your CD4 count to drop. However, your CD4 percentage usually remains the same, or may even increase. This shows that the drop in the count is unlikely to reflect a real change in your immune system.
To support this, the three major HCV treatment trials in HIIV-positive people did not find more opportunistic infections (OIs) among people with low CD4 counts (under 200 cells/mm3).
- There have been some reports of oesophageal candida and TB in HIV-positive people using HCV therapy. In some cases, treatment to prevent certain OIs may be recommended.
- After HCV treatment is ended, the CD4 cell count usually returns to the pre-treatment level within a few months.
- In someone whose CD4 count is already strong (above 500 cells/ mm3) there is no need to use HIV treatment before HCV treatment.