Meeting report: 30th International Conference on Antiviral Research, in Atlanta, GA, USA

Vere Hodge, R Anthony

For years, it has been known that asymptomatic, or set point, VL is correlated with disease progression, but little is known about the impact of the virus itself, or the speed with which it reproduces (replicative capacity or vRC). For example, individuals were followed for five years, starting with widely varying set point VLs and measuring for how long the individuals have CD4 counts remaining >300. For individuals with low VL (10 2 -10 3 ), intermediate VL (10 3 -10 5 ) and high VL (>10 5 ), the proportion retaining more than 300 CD4 cells/mm 3 were 100%, about 25% and virtually 0%, respectively. Indeed, the high VL group reached the end point within three years (p ¼ <0.001). In a similar study comparing individuals infected with low vRC, intermediate vRC and high vRC virus, the latter also lost CD4 cells more rapidly with only $25% with CD4 count > 300. In contrast, 50% low vRC individuals retained CD4 cells above 300. To determine if this detrimental effect of higher vRC was simply an effect on VL, individuals infected with low and high vRC viruses, but with similar set point VLs (3.8 and 4.0 log 10 ), respectively, were compared. About 50 and 25%, respectively, retained CD4 counts (>300) (p ¼ <0.0001). Therefore, the impact of vRC is independent of the effect of set point VL.