Variability of peripheral blood lymphocyte beta-2-adrenergic receptor density in humans

β2-adrenergic receptor (βAR) density on peripheral blood lymphocytes has been used as an index to reflect the βAR state of the body. Lymphocytes βARs 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 βAR density could vary with changes in CD4+ and CD8+ cell concentrations. We examined the individual and intersubject variance of βAR 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 β2-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 βAR variance was greater (coefficient of variation 22.4%). However there was a significant correlation between βAR 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 βAR in humans.