CD8+ T-lymphocytes and CMV retinitis in patients with CD4+ ≤ 50

Purpose: Patients with AIDS and CD4+ T-lymphocytes ≤ 50 cells/ul are at increased risk for cytomegalovirus (CMV) retinitis. We studied patients with CD4+ ≤ 50 cells/ul to determine whether CD8+ T-lymphocyte cell counts help predict CMV retinitis in this subset of patients. Methods: Patients who had a lymphocyte subset analysis with CD4+ ≤ 50 within 2 months before or 2 weeks after a complete eye examination were included. Results of the eye examination and CD8+ cell counts were recorded. Results: 231 patients were studied. 89 of 231 (38.5%) had CMV retinitis. Patients with CMV retinitis had mean CD4+ 17.1; CD8+ 315.8 compared to patients without CMV retinitis, CD4+ 22.1; CD8+ 463.1 (p = 0.007, <0.001, Wilcoxon's rank-sum test). CD4+ and CD8+ cell counts were correlated: all patients, 0.45; patients with CMV retinitis, 0.54; without CMV retinitis, 0.39 (p<0.001 Spearman's Correlation Analysis). By logistic regression, for each cell count decrease in CD4+, CMV retinitis risk increases 1.026 (p=0.01), for each unit decrease in CD8+, 1.002 risk increase (p<0.001). In this group, a unit decrease in CD4+=2% of its total range and a unit decrease in CD8+ = 0.06% range. CD8+ cell count did not provide additional independent information about CMV retinitis in multivariate logistic regression analyses when CD4+ cell count is forced into the model first and similarly with CD4+ cell count. Conclusions: Patients with low CD4+ and CD8+ T-cell counts are at an increased risk of CMV retinitis. Within the subset of patients with CD4+ ≤ 50, CD8+ T-lymphocyte count has a higher predictive value for CMV retinitis than CD4+ cell count. Neither CD4+ nor CD8+ ceil count provide additional predictive information when the other cell count is available.