Low levels of vitamin D and the relationship between vitamin D and Th2 axis-related cytokines in neuromyelitis optica spectrum disorders

Abstract

ObjectiveThe impact of vitamin D have been studied in neuroinflammation disorders, and as the newly discovered Th2-related cytokines, IL-25, IL-31 and IL-33 may also play important roles in the lesions of neuromyelitis optica spectrum disorders (NMOSD). This study sought to investigate the clinical profiles of vitamin D and Th2 axis-related cytokines and their relationships in patients with NMOSD. MethodsEighty-four NMOSD patients and 84 healthy controls (HC) were evaluated for serum levels of the total vitamin D [25(OH)D], 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] by means of high performance liquid chromatographytandem mass spectrometry (HPLC-MS/MS). Meanwhile, serum AQP4-IgG (n = 84) were detected by an AQP4-transfected cell-based assay (CBA) and IL-25, IL-31, IL-33 (n = 32) were performed using enzyme-linked immunoassay (ELISA) method. ResultsThe serum levels of 25(OH)D, 25(OH)D2 and 25(OH)D3 were significantly lower in NMOSD group as compared to HC group. There were also significant differences in serum vitamin D levels between the acute phase group and remission group except the 25(OH)D2 levels (p = 0.070). No correlations were detected between vitamin D and disease activity or vitamin D and disease disability. Furthermore, serum 25(OH)D, 25(OH)D2, and 25(OH)D3 levels were not correlated with serum IL-25, IL-31, and IL-33 levels, the location of lesions and the number of lesion locations. ConclusionOur result showed hypovitaminosis D in NMOSD patients. The activity of 25(OH)D3 seemed to be closer to 25(OH)D than 25(OH)D2. Low levels of 25(OH)D/25(OH)D3 might represent a risk factor for the disease activity in patients with NMOSD.