[Relationship between T-subsets and clinical aspects of HIV-associated diseases]

HIV predominantly infects the CD4+ T cells, which during the progression of the disease are eliminated, causing an immune deficiency which renders the patients more susceptible to infections. To evaluate the relevance of the CD4+ T cell elimination and thus the clinical usefulness of CD4/CD8 subset determinations in HIV infected persons, we investigated whether analyses of 667 subset determinations of 365 patients correlated with clinical stages of HIV-infection (CDC classification). Progress of HIV related disease was accompanied by a fall in CD4+ cells and an increase in CD8+ cells, leading to a drastically reduced CD4/CD8 ratio. This change of T-cell subset values correlated well with the clinical classification (CDC). It was, however, only statistically significant if percent values were used, but not if absolute CD4 cell counts, calculated from the peripheral lymphocyte count, were considered. While patients in CDC stage IVC2 (mainly Candida stomatitis) did not differ from stages IIB, IIIB, IVA, we found statistically lower CD4 values if the patients had stage IVA plus IVC2. Stage IVC1 (mainly Pneumocystis carinii pneumonia [PcP, n = 20]) had even lower CD4 values, as PcP appeared almost exclusively in patients with CD4 counts below 20% or 200/microliter. The lowest CD4 counts were observed in patients with Kaposi sarcoma (n = 11) with CD4 cells less than 10% and significant elevated values of CD8 cells (greater than 50%). While the total lymphocyte count correlated with the absolute counts of CD4 and CD8 cells, it was impossible to estimate the T-subset distribution from the absolute lymphocyte count. Our investigations show that a decreased number of circulating CD4 cells correlates well with an increased tendency to develop infections, and thus support the relevance of CD4 cell measurements for the optimal care of asymptomatic HIV infected persons in particular. They also show that the percent values correlate better with clinical stage than the absolute CD4 cell count.