Baseline T cell reactivity in multiple sclerosis is correlated to efficacy of interferon-β

Background: Measuring proliferative responses of T lymphocytes is a simple, reproducible and widely used assay of immune competence. Evidence suggests a role of T cell reactivity in autoimmune diseases. Interferon (IFN)-beta blocks in vitro proliferation of human T cells. Objectives: To assess (i) the relation between T cell proliferation and disease characteristics of MS patients, (ii) differences in T cell proliferation between subgroups and HC, and (iii) the predictive value of T cell proliferation for efficacy of IFN-beta. Methods: Proliferative responses were measured in phytohaemagglutinin (PHA), anti-CD2/CD28 and anti-CD3 stimulated whole blood of 189 MS patients and 249 healthy controls (HC). Forty-eight Patients started treatment with IFN-beta. Based on EDSS progression, number of relapses and steroid interventions, patients were classified as either clinical responder or nonresponder to IFN-beta. Results: Significant differences between MS subgroups and HC were found in T cell responses upon both PHA stimulation (RR>HC: p = 0.001 and SP>HC: p = 0.001) and CD2/CD28 stimulation (RR>HC, SP>HC and PP>HC: all p values <0.001). No significant differences were found between the MS subgroups. A probability of 88% (95% Cl, 71-95%) for a favorable response to IFN-beta was found with increased baseline proliferative T cell responses to PHA; a probability of only 16% (95% Cl, 7-33%) with decreased values. Conclusion: Our results suggest that the level of T cell proliferation in whole blood predicts efficacy of IFN-beta in MS. (C) 2002 Elsevier Science B.V. All rights reserved.