Reliability of lymphocyte proliferation assays

According to the psychoneuroimmunology literature, stressful experiences and psychological stress can alter various immunological parameters. The lymphocyte proliferation response of T cells is known to be variable but no data can be found on the reliability of blastogenesis retesting. To address this problem, 10 healthy volunteer men were tested on four occasions in longitudinal repeated measures design. Immunological parameters were measured from blood samples testing date. Using a doubly multivariate repeated measures design, significant time and concentration effects were observed for both parameters: concanavalin A induced blastogenesis (ConA) and phytohemagglutinin induced response (PHA). An interaction effect between time and mitogen dose was observed. Satisfactory reliability for ConA could not be achieved even in controlling for mitogen dose. Better results were obtained for PHA, but only at dilution 1:100. These data highlight the need for caution in interpreting fluctuations associated with lymphocyte proliferation responses in psychoneuroimmunology.