Objectives: Neuroinflammation represents one of the two major pathological components of multiple sclerosis (MS). The aim of our study was to find the role of the late pro-inflammatory cytokine HMGB1 (high mobility group box) in MS pathogenesis.
Subjects and methods: A total of 165 patients from three MS centers in Slovakia were enrolled in the study. Patients underwent a complex clinical investigation and their plasma levels of HMGB1 were analyzed by a sandwich ELISA test.
Results: MS patients had 4.5 times higher plasma level of HMGB1 (median, 13.529 ng/mL; IQR = 2.330-113.45) than healthy controls (median, 2.999 ng/mL; IQR = 1.686-9.844; P < 0.0001). The concentrations of HMGB1 were significantly associated with increased number of affected areas diagnosed by MRI (P < 0.0001) (the median for one affected area, 4.205 ng/mL; median for five affected areas, 17.843 ng/mL; P < 0.05). Patients with at least one active lesion in any of the affected areas in the brain had significantly higher plasma levels of HMGB1 (median, 20.118 ng/mL; IQR, 3.693-100.12) than those without any active lesion (median, 16.695 ng/mL; IQR, 3.255-113.45; P < 0.0235). We found also a very highly significant association of HMGB1 plasma levels with clinical condition expressed as EDSS (expanded disability status scale) (P < 0.0001); patients with higher EDSS had higher levels of HMGB1 (EDSS ≤ 2.5, 11.648 ng/mL vs. EDSS ≥ 3, 17.549 ng/mL; P = 0.0115).
Conclusion: Our results suggest chronic low-grade inflammation in MS patients that correlates with clinical conditions of MS patients, and for HMGB1 as a possible target molecule in future therapy.
Keywords: EDSS; HMGB1; Immunity; Inflammation; MSSS; Multiple sclerosis.