MEASUREMENT OF CANDIDA-SPECIFIC BLASTOGENESIS - COMPARISON OF CARBOXYFLUORESCEIN SUCCINIMIDYL ESTER LABELING OF T-CELLS, THYMIDINE INCORPORATION, AND CD69 EXPRESSION

Measurement of the T cell blastogenic response to Candida may be usefu l in the evaluation of patients with suspected immunodeficiency, The c lassic blastogenesis assay is based on uptake of [H-3]thymidine by per ipheral blood lymphocytes stimulated with Candida antigens for 5 days. An alternative approach involves staining peripheral blood lymphocyte s with the intracellular fluorescent dye carboxyfluorescein succinimid yl ester (CFSE) and measuring mitotic activity by the successive twofo ld reductions in fluorescent intensity using flow cytometry (FCM), The two approaches were compared in 16 subjects who demonstrated various proliferative responses to Candida, FCM-derived indices all involved i nitial gating on CD3(+) T cells and included 1) blastic transformation as measured by changes in light scatter, 2) cell division, measured b y CFSE fluorescence, and 3) CD69 expression. A good correlation was fo und between [H-3]thymidine uptake and CFSE-derived indices, irrespecti ve of the analysis algorithm used to interpret CFSE division profiles. Furthermore, significant T cell proliferation occurred only in subjec ts who had had one or more symptomatic episodes of vaginal candidiasis whereas controls with no such history, and patients with chronic vagi nal infection, showed minimal proliferation. The increase in proportio n of CD69(+) T cells in culture also correlated with the blastogenic r esponse to Candida, but less well than mitotic indices, CFSE-derived i ndices of T cell blastogenesis to Candida are equivalent to [H-3]thymi dine-based assays and may allow useful laboratory distinction between subjects who have been exposed to and recovered from vaginal Candida i nfection, who have a strong proliferative response, from those with no exposure or chronic infection who demonstrate a poor response. (C) 19 98 Wiley-Liss, Inc.