CD4(-CELL NUMBER AT THE TIME OF ACQUIRED-IMMUNODEFICIENCY-SYNDROME() T)

In this article, the authors adapt and extend the methodology of Phill ips (Phillips et al. J. Acquir Immune Defic Syndr 1992;5:148-52) to es timate the distribution of CD4(+) T-cell number at the time of acquire d immunodeficiency syndrome (AIDS) and to estimate the correlation bet ween CD4(+) T-cell number at AIDS and CD4(+) T-cell number prior to hu man immunodeficiency virus infection. Using data from the Los Angeles portion of the Multicenter AIDS Cohort Study, the authors find that th e median CD4(+) T-cell count at the time of AIDS is 67 cells/mm(3) wit h a 95% confidence interval of 58-84. The 5th and 95th percentiles of the distribution are 8 and 284, respectively. The authors estimate the correlation between the CD4(+) T-cell number at the time of AIDS and the CD4(+) T-cell number prior to human immunodeficiency virus infecti on to be 0.71 with a 95% confidence interval of 0.21-0.94. This very h igh correlation is suggestive of biologic hypotheses concerning possib le control of the circulating CD4(+) T-cell number. The high correlati on can also be useful in determining when to start prophylactic treatm ent.