Variability of Peripheral Blood Lymphocyte Beta-2-Adrenergic Receptor Density in Humans

Abstract

Beta2-adrenergic receptor (betaAR) density on peripheral blood lymphocytes has been used as an index to reflect the betaAR state of the body. Lymphocytes betaARs are unequally distributed among lymphocyte subpopulations, with the highest density on CD8+ cells and the lowest on CD4+ cells. Thus, the measurement of peripheral blood lymphocyte betaAR density could vary with changes in CD4+ and CD8+ cell concentrations. We examined the individual and intersubject variance of betaAR density and lymphocyte subpopulations over time in 10 normal subjects, studied on 3 to 5 different d always at approximately 9:00 A.M. over a 4- to 12-wk period. Peripheral blood lymphocytes were isolated and beta2-adrenergic receptor density was determined by specific binding of [125I]-(-)iodopindolol, and lymphocyte subpopulations were measured by flow cytometry. Average receptors per lymphocyte were 776 +/- 183. Whereas the absolute values of CD4+% and CD8+% cell concentrations varied little in individual subjects (coefficient of variation 9.5% and 11.1%, respectively), the individual betaAR variance was greater (coefficient of variation 22.4%). However there was a significant correlation between betaAR and CD4+% and CD8+% cell concentration (correlation coefficients: -0.58, p < 0.001; +0.51, p < 0.001, respectively). This information is relevant to interpretations of changes in peripheral betaAR in humans.