Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Dr Gottlieb and colleagues and Dr Lima and colleagues suggest that the results of our study may simply represent variability in the measurement of HIV RNA and CD4 T-cell count. We recognize that there is significant imprecision in these assays and we provided an adjustment for this additional source of variability, after which a large proportion of the person-to-person variation in rate of CD4 cell loss remained to be explained. As Gottlieb et al indicate, our study was not designed to address the relationship of viral replication with time to occurrence of AIDS or death, and we make no claims to that effect. Indeed, more precise and prolonged measurements of both viral replication and immune competence, were they available, would likely reveal a tighter association, indicating a greater role of the virus in driving immune response than suggested by our analysis. This possibility, however, does not contradict our results, which are based on those measurements commonly used in the clinic.
Rodriguez B, Lederman MM, Sethi AK, Cheruvu VK, Bosch RJ, Martin J, Deeks S. Presenting Plasma HIV RNA Level and Rate of CD4 T-Cell Decline—Reply. JAMA. 2007;297(8):805-807. doi:10.1001/jama.297.8.806