Shipment impairs lymphocyte proliferative responses to microbial antigens

Lymphocyte proliferation assays (LPAs) are widely used to assess T-lymphocy te function of patients with human immunodeficiency virus infection and oth er primary and secondary immunodeficiency disorders. Since these assays req uire expertise not readily available at all clinical sites, specimens may b e shipped to central labs for testing. We conducted a large multicenter stu dy to evaluate the effects of shipping on assay performance and found signi ficant loss of LPA activity. This may lead to erroneous results for individ ual subjects and introduce bias into multicenter trials.