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 immunodefi ciency virus (HIV)-infected subjects with or without CMV retinitis and CD4(+) cell counts of <0.050 x 10(9)/L. Cell surface markers on perip heral blood lymphocytes were evaluated using Bow cytometry. Patients w ith CMV retinitis had significantly lower levels of CD8(+) cells (medi an: 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 molec ule CD28 and lymphocyte function-associated antigen-1 (LFA-1) express ion was observed in patients versus controls (CD28: 0.048 x 10(9)/L v s. 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-re gulation of CD28 and LFA-1 accessory molecules are associated with an increased risk of CMV retinitis in HIV-infected patients.