Lymphocyte Proliferation Assay in Lyme Disease

De Souza et al. recently reported that spleen cells from naive, uninfected mice readily proliferate in response to in vitro exposure to Borrelia burgdorferi . This observation, indicating that B. burgdorferi spirochetes can nonspecifically stimulate mononuclear cells, led these investigators to advise caution in interpreting the results of spirochete-induced lymphocyte proliferation. An initial report of such an assay as a diagnostic test suggested that mononuclear cells from patients with late Lyme disease (including seronegative individuals) proliferate in a specific fashion to B. burgdorferi . However, two subsequent studies have indicated that this test lacks specificity or is perhaps potentially useful in a small subset of patients with late disease. We tested mononuclear cells from 11 healthy, seronegative laboratory controls and 11 patients with a clinical diagnosis of Lyme disease.