Fifty-one patients with erythema migrans were followed up prospectively with serial clinical evaluations, serologic determinations for antiborrelial antibodies, and lymphocyte stimulation responses to Borrelia burgdorferi antigens to determine (i) the factors associated with sustained cellular immune responses and (ii) whether lymphocyte stimulation is a good indicator of prior exposure to B. burgdorferi in patients treated early after erythema migrans. Positive lymphocyte stimulation responses ( > 2 standard deviations above normal control values) were found in 15 (29%) of 51 patients 3 months after treatment for erythema migrans and in 8 (18%) of 44 patients 1 year posttreatment. Heightened lymphocyte responses were not associated with the number or duration of erythema migrans lesions prior to treatment, the mean size of the largest erythema migrans lesion, or the number of symptoms at the time of presentation. The development of Jarisch-Herxheimer reaction, choice of antibiotic, and clinical outcome also were not associated with a positive lymphoproliferation assay result. Changes in the lymphocyte stimulation indices between the two time points assessed (3 months and 1 year posttreatment) also did not correlate with the above variables. When serologic results and lymphoproliferative responses were evaluated as categorical or continuous variables, there were no correlations between values. One year after treatment for early
Lyme disease, lymphocyte reactivity is not a good indicator of prior infection with B. burgdorferi.