The authors wrote that "with the exception of lymphoma," there are "few data concerning the risk of specific opportunistic diseases in patients with and without hepatitis C virus (HCV) infection." In the current study, they evaluated "the correlation between the occurrence of different AIDS-defining illnesses (ADIs) and chronic HCV infection or HCV-related liver cirrhosis" in a large cohort of HIV-positive persons in Italy.
The study subjects were stratified into two groups: patients without HCV co-infection and with persistently normal aminotransferase levels, and patients with HCV co-infection. The patients with HCV co-infection were stratified according to the diagnosis of liver cirrhosis. Incidences of new ADIs were calculated as the number of events per 1,000 person-years of follow-up. A Poisson regression model adjusted for potential confounders was used to compare the rates in the two groups.
"We observed a total of 496 ADIs among 5,397 patients with 25,105 person-years of follow-up (50 percent tested positive for HCV)," the authors wrote. HCV was found to be associated with increased risk of developing an ADI (adjusted relative rate [ARR], 2.61; 95 percent confidence interval [CI], 1.88-3.61), in particular bacterial infection (ARR, 3.15; 95 percent CI, 1.76-5.67), HIV-related disease (ARR, 2.68; 95 percent CI, 1.03-6.97), and mycotic disease (ARR, 3.87; 95 percent CI, 2.28-6.59) but not non-Hodgkin lymphoma (ARR, 0.88; 95 percent CI, 0.22-3.48).
The results indicated that the rates of mycotic infection, bacterial infection, toxoplasmosis and HIV-related ADI among patients with cirrhosis were significantly higher than among patients infected with HIV only, and the risk was greater than that estimated for HCV antibody-positive patients without cirrhosis.
"In conclusion, we found that HIV-HCV co-infected patients in our cohort were at a two-fold increased risk of developing AIDS than were HIV-monoinfected patients," the authors wrote. "Bacterial and mycotic infection and HIV-related disease are the ADIs more strongly associated with positive HCV serostatus and also with HCV-related cirrhosis. Clinicians should take these data into account in their clinical management of HCV-co-infected patients, in particular when deciding when to start antiretroviral therapy."