Benign Multiple Sclerosis Is Characterized by a Stable Neuroimmunologic Network

Abstract

Objectives: Patients diagnosed with multiple sclerosis (MS) but without disability (Expanded Disability Status Scale score <2) form a specific group within those patients suffering from relapsing-remitting MS. Several neuroimmunologic effectors, including cytokines and melatonin, are known for their influence on the initiation of relapses and progression of the disease. Methods: We evaluated 41 female patients with benign MS with respect to their clinical course, treatments and neuroimmunological parameters, including cytokines and melatonin. One subgroup was followed up for 7 years, and another group was evaluated during acute clinical relapse. Results: The benign MS course in this homogeneous group of young patients was demonstrated by mild disease progression in 16% over 7 years. Initially, patients treated with azathioprine (AZA) revealed significantly reduced melatonin serum levels (p = 0.04) compared to untreated patients, but not at follow-up. During acute relapse, treatment with corticosteroids (CS) resulted in increased levels of type 2 cytokines as well as reduced type 1 cytokine levels. Conclusions: Our study supports the functional role of CS acting as an antiinflammatory protagonist during MS relapse, by inducing a shift towards predominance of type 2 cytokines. AZA showed a more subtle modulation of immune functions, reflected by reduced levels of the immune active hormone melatonin. During follow-up, it became apparent that stabilized levels of the interacting Th1/Th2-derived cytokines and melatonin are maintained in concordance with the benign course of MS. These findings are in accordance with the hypothesis that benign MS is characterized by a balanced cytokine and neuroendocrine network, which is supported by immune-modulating therapies.