ABSTRACT
Background & objectives: To examine ß-D-mannuronic acid (M2000) effects on L-selectin shedding and leucocyte function-associated antigen-1 (LFA-1) expression as mechanisms of action of this drug in patients with ankylosing spondylitis (AS). Methods: To investigate the molecular consequences of ß-D-mannuronic acid on L-selectin shedding, flow cytometry method was used. Furthermore, the effect of it on LFA-1 gene expression was analyzed by using quantitative real time (qRT)-PCR technique. Results: The LFA-1 expression in patients with AS was higher than controls (P=0.046). The LFA-1 expression after 12 wk therapy with ß-D-mannuronic acid was meaningfully decreased (P=0.01). After 12 wk treatment with ß-D-mannuronic acid, the frequency of CD62L-expressing CD4+ T cells in patients with AS, was not considerably altered, compared to the patients before therapy (P=0.5). Furthermore, after 12 wk therapy with ß-D-mannuronic acid, L-selectin expression levels on CD4+ T-cells in patients with AS, were not remarkably changed, compared to the expression levels of these in patients before treatment (P=0.2). Interpretation & conclusions: The results of this study for the first time showed that ß-D-mannuronic acid can affect events of adhesion cascade in patients with AS. Moreover, ß-D-mannuronic acid presented as an acceptable benefit to AS patients and could aid in the process of disease management.