Flow cytometry of cerebrospinal fluid (CSF) lymphocytes: Alterations of blood CSF ratios of lymphocyte subsets in inflammation disorders of human central nervous system (CNS)

Flow cytometry was adapted to measure lymphocytes in human cerebrospinal fl uid (CSF). The method was sufficiently precise, reproducible and accurate d espite low cell counts. In lumbar CSF of controls with 500 to 3500 (10(3)/I ) leukocytes, lymphocyte counts correlated with those in corresponding veno us blood: blood/CSF ratios of approximate to 2000 : 1 were found for total T cells (CD3(+)) and CD3(+) HLA-DR-, CD3(+)4(+), CD3(+)8(+) subsets, ratios were increased for the lymphocyte subsets CD3(+) HLA-DR+ less than or equa l to; CD3(+)16(+)56(+) < CD16(+)56(+)3(-) < CD8(+)3(-) much less than CD19( +); CD8(+)4(+) ratio was half of CD3(+) ratio. Data indicate selective barr iers (blood-brain and blood-CSF barriers) tio blood lymphocyte subsets whic h favor the transfer of T subsets. Correlation of the subset ratios to the CD3(+) ratio indicates distinct barrier properties which changed differentl y with acute and subacute inflammations and neuroimmunological diseases of central nervous system (CNS) in lumbar or ventricular CSF, but not with sim ple protein barrier disturbance. HLA DR+ T ratios were higher than HLA DR- T ratios only with controls and some neuroimmunological diseases. Lymphocyt e barrier characteristics were related tot protein leakage situated at the same barriers, indicating far the lymphocyte subsets selective transfer rou tes in control subjects and non-selective routes in patients with CNS infla mmation where altered ratios revealed a mixture of both routes.