Major study of "discordant" response--viral control but incomplete CD4 response.

This important research from the Swiss HIV Cohort Study (1) looks at patients who responded virologically to antiretrovirals (viral load consistently under 1000 for at least five years) to find the differences between those who had an "incomplete" CD4 response (defined as not reaching a CD4 count of 500), vs. those with a "complete" response to at least 500. Older age, lower CD4 baseline, and longer HIV infection were associated with incomplete CD4 recovery. CD4 response during the first three to six months of antiretroviral treatment was a good predictor of who would respond at five years (this study looked only at those who did control viral load to under 1,000 copies).

However, this study in 293 patients did not find a statistically significant difference in number of patients who had AIDS-related events--14.4% of those with "complete" CD4 recovery and 21% incomplete, but this difference was not enough to reach the customary .05 level of statistical significance.

In the future, this kind of research could help doctors and patients know what to expect from current antiretroviral treatment, avoiding unnecessary drug use or regimen switches.

A 3-page editorial summary (2) published with the research report is a good place to start for understanding this study and its importance. The journal, Clinical Infectious Diseases, has made both papers available free to nonsubscribers online. Visit http://www.journals.uchicago.edu/CID/journal/available.html, select volume 41 number 3, and scroll down to click on the articles starting on pages 361 and 373.

References

(l) Kaufmann GR, Furrer H, Ledergerber B and others. Characteristics, determinants, and clinical relevance of CD4 T cell recovery to <500 cellsl/[micro]L in HIV type 1-infected individuals receiving potent antiretroviral therapy. Clinical Infectious Diseases. August 1,2005; volume 41, pages 361-372.

(2) Sasson SC, Kelleher AD, and Cooper DA. The modern ART of HIV infection management: Towards a tailored approach to maximize CD4 T cell reconstitution. [editorial commentary] Clinical Infectious Diseases. August 1, 2005; volume 41, pages 373-375.