HIV-positive individuals who are coinfected with the hepatitis C virus appear to have slightly worse survival than patients who are only infected with HIV, according to data from a study involving HIV-positive patients taking antiretroviral “salvage” regimens presented to the Twelfth Annual Conference of the British HIV Association in Brighton on March 30th. A separate study also presented to the conference revealed that an increasing proportion of HIV-positive patients in the United Kingdom are being tested for hepatitis C and that injecting drug users were more likely to test positive for hepatitis C.
Studies looking at the effect of hepatitis C on the prognosis of individuals with HIV have yielded conflicting results. Investigators from the OPTIMA (Options in Management with Antiretrovirals) study, which is exploring various treatment strategies for patients with limited options, therefore decided to look at the effect of hepatitis C on the incidence of new AIDS events and survival in patients enrolled in their study. The OPTIMA study includes patients receiving care in the United States, Canada and United Kingdom.
A total of 311 individuals were included in the investigators’ analysis. Of these, 72 individuals (23%) were infected with the hepatitis C virus. Over a median of two years of follow-up, 25% of patients coinfected with hepatitis C died compared to 16% of individuals who were only infected with HIV, meaning that patients coinfected with hepatitis C were 79% more likely to die than those who were hepatitis C virus-negative, a statistically significant difference (p = 0.05).
The investigators then looked at how patients had acquired their infection with HIV and hepatitis C. They established that 74% of individuals coinfected with HIV and hepatitis C reported injecting drug use compared to only 24% of patients who were only infected with HIV. When the investigators controlled for mode of transmission, they found that the effect of hepatitis C on survival ceased to be significant (p = 0.13).
Attention was then turned to how many antiretroviral drugs hepatitis C-infected and hepatitis C-negative patients used. After controlling for this, the investigators found that patients coinfected with hepatitis C were 37% more likely to die than patients who only had HIV, but once again, this difference was not statistically significant (p = 0.39).
The durability of antiretroviral therapy in HIV-positive and HIV/hepatitis C coinfected patients was then examined by the researchers. The median duration of the first OPTIMA study regimen was four months for coinfected patients and seven months for hepatitis C-negative individuals.
Finally, the incidence of new AIDS-defining events was examined in the two groups of patients. During follow-up, 25% of individuals who were only infected with HIV developed a new AIDS-defining condition compared to 23% of coinfected patients. This difference was not statistically significant.
The investigators conclude, “coinfection with hepatitis C appears to increase the risk of mortality, but this effect might be partly explained by a shorter time to switching/stopping antiretroviral therapy. One possible reason could be that hepatitis C virus-infected patients are less able to tolerate antiretrovirals.”
Hepatitis C prevalence
A separate study presented to the conference described the prevalence of hepatitis C coinfection in the UK Collaborative HIV Cohort (UK CHIC). Data from seven HIV clinics treating 21,250 patients from 1996 onwards were included in the investigators’ analysis.
A total of 11,357 individuals had had at least one hepatitis C antibody test with 1,045 (9%) testing hepatitis C virus-positive.
Since 2004, the treatment guidelines of the British HIV Association have recommended that all HIV-positive patients are tested for hepatitis C virus soon after their HIV is diagnosed and at intervals thereafter if they have ongoing risk factors for the acquisition of hepatitis C virus infection. The investigators presented evidence showing that there was a trend for more hepatitis C testing over time: in 1995 only 7% of HIV-positive patients, nearly all of whom were injecting drug users, had been tested for hepatitis C, but this had increased to 72% by 2003 with individuals being tested for the infection regardless of their HIV risk factors.
As a result of more widespread and less targeted testing, the proportion of patients who tested positive actually fell over time. In 1995, 26% of the 369 patients tested for hepatitis C antibodies were positive. This fell to 13% of 2,861 individuals in 2000 and 8% of 8,033 patients in 2004.
HIV risk group was significantly associated with the likelihood of infection with hepatitis C, with current or past injecting drug users (p
Turner J et al. Hepatitis C virus coinfection and HIV-infected patients in the UK collaborative HIV cohort. HIV Med 7 (supplement 1), abstract 014, 2006.
Ewings F et al. The effect of hepatitis C virus on HIV progression in a late salvage population: results from the OPTIMA study. HIV Med 7 (supplement 1), abstract 015, 2006.