[Evolution of CD4 and CD8 lymphocyte subsets in HIV seronegative and seropositive hemophiliacs]

To asses the evolution over time of the CD4, CD8 and total lymphocyte counts in both HIV seronegative and HIV seropositive haemophiliacs.

A total of 124 haemophilic patients (77 HIV seropositive and 47 HIV seronegative) regularly controlled at our Hospital were studied. All patients have had several (range 2-15) CD4 and CD8 lymphocyte counts, with a minimum interval of 2 or more years between the first count and the last one (median 7.7 years). A linear regression analysis of the serial cell counts against the time was made and the corresponding slopes were estimated for each patient and expressed as a percentage of the initial values (standardized slopes).

In HIV seronegative patients the number of CD4, CD8 and total lymphocytes decreased (p < 0.05), but the decrease of the CD4/CD8 ratio was not statistically significant. The decline of the CD4 cells showed a trend to remain above 500 cells/microL. HIV seropositive hemophiliacs had also a substantial decline of lymphocyte counts (p < 0.0001), but essentially due to changes of the CD4 cells, which declined with a nearly constant rate during the follow-up (median values decreased from 793/microL to 324/microL). CD8 cell counts diminished in lower grade than the CD4 cells counts, and consequently the percentage of the total lymphocyte number increased from 42% to 55%. The CD4/CD8 ratio decreased with a standardized slope of -5.7% per year. At the initial evaluation the seropositive patients had CD4 cell counts and CD4/CD8 ratios lower than seronegative ones, but CD8 cell counts were higher in the first group. Total lymphocyte counts were not statistically different at this first evaluation between infected and non-infected patients. At the final evaluation, differences on CD4 cell counts and CD4/CD8 ratio increased, and lymphocyte counts were significantly lower in the HIV-seropositive haemophiliacs. However, the final absolute counts of CD8 cells were not dissimilar in the two groups of patients. The median standardized slopes of the total lymphocyte counts, CD4 cell counts, and CD4/CD8 ratios were significantly more negative for the HIV-infected patients (-5.7%, -9.4 and -5.7%, respectively) than were these for the non-infected ones (-2.0%, -3.2% and -2.5%, respectively).

Lymphocyte counts, mainly the CD4 cell counts, decline in treated haemophiliacs independently of their HIV status. In the HIV seronegative patients the CD4 cell counts generally stabilize above 500 cells/microL. However, in the seropositive haemophiliacs these counts show a continuous fall, with a median rate of 9% of the initial value per year.