LTT-Validity in diagnosis and therapeutical decision making of neuroborreliosis: a prospective dual-centre study

Objectives: The key objective of this study was to assess the validity of a commercially available in-house Lymphocyte Transformation Test (LTT) as a diagnostic parameter and indicator of disease activity/therapeutic efficacy in the context of Lyme neuroborreliosis (LNB).

Methods: A prospective dual-centre study was conducted from 05/14 - 01/18. With respect to Borrelia-LTT a comparison was made between patients suffering from confirmed acute LNB and patients being affected by inflammatory neurologic diseases, defining the control group: Bell's palsy, viral meningitis, herpes zoster, Guillain-Barré-Syndrome and Encephalomyelitis disseminate. Furthermore, we investigated the LTT within the LNB group at the time of admission and again 12 weeks (+/- one week) later - after appropriate antibiotic treatment.

Results: Cases included 15 patients with LNB and 58 participants in the control group. With regard to Borrelia-LTT we calculated a low sensitivity of 40% and a moderate specificity of 91% for LNB. Additionally, LTT-levels three months after adequate antibiotic therapy did not correlate with the therapeutic response of LNB patients.

Conclusions: The present study shows that LTT is neither appropriate for LNB detection nor suitable as a follow-up marker.