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

In this article, the authors adapt and extend the methodology of Phillips (Phillips et al. J. Acquir Immune Defic Syndr 1992;5:148-52) to estimate the distribution of CD4(+) T-cell number at the time of acquired immunodeficiency syndrome (AIDS) and to estimate the correlation between CD4(+) T-cell number at AIDS and CD4(+) T-cell number prior to human immunodeficiency virus infection. Using data from the Los Angeles portion of the Multicenter AIDS Cohort Study, the authors find that the median CD4(+) T-cell count at the time of AIDS is 67 cells/mm(3) with 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 infection to be 0.71 with a 95% confidence interval of 0.21-0.94. This very high correlation is suggestive of biologic hypotheses concerning possible control of the circulating CD4(+) T-cell number. The high correlation can also be useful in determining when to start prophylactic treatment.