Persistent GB virus C infection and survival in HIV-infected men

BACKGROUND: GB virus C (GBV-C), which is not known to be pathogenic in humans, replicates in lymphocytes, inhibits the replication of human immunodeficiency virus (HIV) in vitro, and has been associated with a decreased risk of death among HIV-positive persons in some, but not all, studies. Previous studies did not control for differences in the duration of HIV or GBV-C infection. METHODS: We evaluated 271 men who were participants in the Multicenter Acquired Immunodeficiency Syndrome Cohort Study for GBV-C viremia (by means of a reverse-transcriptase-polymerase-chain-reaction assay) or E2 antibody (by means of an enzyme-linked immunosorbent assay) 12 to 18 months after seroconversion to positivity for HIV (the early visit); a subgroup of 138 patients was also evaluated 5 to 6 years after HIV seroconversion (the late visit). RESULTS: GBV-C infection was detected in 85 percent of men with HIV seroconversion on the basis of the presence of E2 antibody (46 percent) or GBV-C RNA (39 percent). Only one man acquired GBV-C viremia between the early and the late visit, but 9 percent of men had clearance of GBV-C RNA between these visits. GBV-C status 12 to 18 months after HIV seroconversion was not significantly associated with survival; however, men without GBV-C RNA 5 to 6 years after HIV seroconversion were 2.78 times as likely to die as men with persistent GBV-C viremia (95 percent confidence interval, 1.34 to 5.76; P=0.006). The poorest prognosis was associated with the loss of GBV-C RNA (relative hazard for death as compared with men with persistent GBV-C RNA, 5.87; P=0.003). CONCLUSIONS: GBV-C viremia was significantly associated with prolonged survival among HIV-positive men 5 to 6 years after HIV seroconversion, but not at 12 to 18 months, and the loss of GBV-C RNA by 5 to 6 years after HIV seroconversion was associated with the poorest prognosis. Understanding the mechanisms of interaction between GBV-C and HIV may provide insight into the progression of HIV disease.