Clinical

GB virus C not predictive of HIV-1 infection outcome

Last Updated: 2004-05-03 14:39:18 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Contrary to published reports, a study conducted in Sweden suggests that the presence of GB virus C (GBV-C) at diagnosis of HIV-1 does not predict a favorable outcome of HIV-1 infection.

"For the evaluation of patients newly diagnosed with HIV infection, GBV-C RNA testing cannot be used to predict the natural disease course," Dr. Per Bjorkman and colleagues from Malmo University Hospital write in the April 9th issue of the journal AIDS.

Several research groups have observed a strong association between GBV-C viremia and improved survival in HIV-infected patients. (See Reuters Health reports February 13 and May 1, 2003)

Dr. Bjorkman's team studied the longitudinal course of GBV-C viremia and its association with HIV-1 disease progression in a prospective cohort study of 230 patients for whom a serum sample was obtained within 2 years of HIV-1 diagnosis. They followed the group for a median of 4.3 years until either initiation of antiretroviral therapy, death, or their last clinic visit.

They tested baseline and follow-up serum samples from 163 patients for GBV-C RNA and antibodies against GBV-C envelope E2 protein (anti-E2), signifying resolved GBV-C viremia.

At baseline, 62 patients (27%) had GBV-C viremia and 69 (30%) had anti-E2. According to the team, baseline GBV-C status did not correlate with all-cause mortality (p = 0.12), HIV-related mortality (p = 0.18), or progression to AIDS (p = 0.84).

"GBV-C viremia was rare in patients with AIDS," the authors report, "and tended to disappear without occurrence of anti-E2 in patients with progressive disease."

Fourteen of 44 (32%) of patients with GBV-C viremia at baseline had no detectable evidence of the virus at follow-up and 11 of these subjects lost GBV-C RNA and did not show anti-E2 seroconversion.

These 11 subjects had significantly higher all-cause mortality (p = 0.018), HIV-related mortality (p = 0.007), and were more likely to progress to AIDS (p < 0.001) compared with anti-E2-negative subjects with persistent absence, presence, or acquisition of GBV-C viremia.

"Our findings suggest that GBV-C viremia in HIV-1 infected individuals may represent a phenomenon secondary to the rate of HIV-1 progression rather than an independent prognostic factor," the authors write.

The observation in this cohort that loss of GBV-C viremia without detectable anti-E2 seroconversion is associated with increased HIV progression "merits further investigation," they conclude.

AIDS 2004;18:877-886.