The relationship between oxidative burst and severity of multiple sclerosis

• Published in: Multiple sclerosis 2008-09, Vol.14, p.S236-S236
• Main Authors: Mossberg, N, Movitz, C, Bergstroem, T, Hellstrand, K, Nilsson, S, Andersen, O
• Format: Article
• Language: English
• ISSN: 1352-4585

Background: Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase reduces oxygen in phagocytic cells during elimination of pathogens to form a number of reactive oxygen species. This process, known as the respiratory burst, is an important effector function of the innate immune system. We have recently shown that the respiratory burst is significantly lower in patients with severe Guillain-Barre syndrome. Objective: To determine if the level of respiratory burst in patients with multiple sclerosis (MS) influences disease severity. Methods: We here examined the respiratory burst in leukocytes isolated from 61 patients with relapsing-remitting MS (RRMS) and secondary-progressive MS (SPMS) and 61 age-matched healthy controls. The severity was also evaluated by a Multiple Sclerosis Severity Score (MSSS) and by onset characteristics predicting the subsequent course of MS. Leukocytes were activated by formyl-Met-Leu-Phe (fMLF), Trp-Lys-Tyr-Met-Val-Met-NH2 (WKYMVM) or phorbol myris-tate acetate (PMA), and superoxide anion production was measured with isoliminol/luminol-enchanced chemiluminescence (CL). Myeloperoxidase (MPO) activity in isolated leukocytes was measured spectrophotometrically. Results: A lower superoxide anion production was found after stimulation with fMLF (p=0.025), PMA (p=0.026) and WKYMVM (p=0.047) in patients with more severe course, evaluated with the MSSS. There was no difference in superoxide anion production between patients with RRMS and SPMS, or between cases with different predictors at onset. No significant differences in superoxide radical production were found between patients and controls after stimulation with fMLF, WKYMVM and PMA. There were no differences in MPO activity between patients and controls, nor between subgroups of patients. Conclusions: The present study indicated a relationship between the respiratory burst, which is a part of the innate immune response, and the severity of MS. This suggests that the individual capacity to generate oxygen radicals, in analogy with findings in the Guillain-Barre syndrome, may determine the severity of MS.