T cell subsets and cytomegalovirus retinitis in human immunodeficiency virus-infected patients

A case-control study was done to investigate the relationship between T cell subsets and cytomegalovirus (CMV) retinitis in human immunodeficiency virus (HIV)-infected subjects with or without CMV retinitis and CD4(+) cell counts of <0.050 x 10(9)/L. Cell surface markers on peripheral blood lymphocytes were evaluated using Bow cytometry. Patients with CMV retinitis had significantly lower levels of CD8(+) cells (median: 0.152 x 10(9)/L) compared with levels for controls (median: 0.296 x 10(9)/L, P<.001). Significant down-regulation of costimulatory molecule CD28* and lymphocyte function-associated antigen-1 (LFA-1) expression was observed in patients versus controls (CD28*: 0.048 x 10(9)/L vs. 0.143 x 10(9)/L, p<.001; LFA-1: 0.238 x 10(9)/L vs. 0.499 x 10(9)/L, p<.001), but no significant differences were noted for NK cells. We propose that progressive loss of the CD3* CD8* cell subset and down-regulation of CD28 and LFA-1 accessory molecules are associated with an increased risk of CMV retinitis in HIV-infected patients.