Vitamin D levels in Indian systemic lupus erythematosus patients: association with disease activity index and interferon alpha

• Published in: Arthritis research & therapy Vol. 16; no. 1; p. R49
• Main Authors: Mandal, Manamita, Tripathy, Rina, Panda, Aditya K, Pattanaik, Sarit S, Dakua, Simanchal, Pradhan, Anjan Kumar, Chakraborty, Soumen, Ravindran, Balachandran, Das, Bidyut K
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 10.02.2014; BioMed Central
• Subjects: Adult; Alfacalcidol; Analysis; Arthritis; Calcifediol; Care and treatment; Enzyme-Linked Immunosorbent Assay; Female; Genes; Humans; India; Interferon-alpha - biosynthesis; Interferon-alpha - blood; Interferon-alpha - immunology; Lupus Erythematosus, Systemic - blood; Lupus Erythematosus, Systemic - immunology; Male; Measurement; Medical research; Medicine, Experimental; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Vitamin D; Vitamin D - blood; Vitamin D Deficiency - epidemiology; India
• ISSN: 1478-6362; 1478-6354; 1478-6362
• DOI: 10.1186/ar4479

Low levels of vitamin D have been associated with several autoimmune disorders including multiple sclerosis, rheumatoid arthritis, type 1 diabetes and systemic lupus erythematosus (SLE). The major source of vitamin D is sunlight but exposure of SLE patients to UV rays has been shown to exacerbate disease pathology. Studies in various populations have shown an association between low vitamin D levels and higher SLE disease activity. We enrolled 129 patients who fulfilled American College of Rheumatology criteria in the study. There were 79 treatment-naïve cases and 50 patients who were under treatment for underlying SLE. There were 100 healthy subjects from similar geographical areas included as controls. Plasma 25-OH vitamin D₃ and interferon (IFN)-α levels were quantified by enzyme-linked immunosorbent assay (ELISA). The gene expression level of IFN-α was determined by quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR). Plasma 25-OH vitamin D₃ significantly correlated in an inverse manner with systemic lupus erythematosus disease activity index (SLEDAI) scores (P <0.0001, r = -0.42), anti-dsDNA (P <0.0001, r = -0.39), plasma IFN-α (P <0.0001, r = -0.43) and levels of IFN-α gene expression (P = 0.0009, r = -0.45). Further, plasma levels of IFN-α positively correlated with gene expression of IFN-α (P <0.0001, r = 0.84). Treatment-naïve SLE patients displayed significantly higher plasma levels of IFN-α compared to patients under treatment (P <0.001) and controls (P <0.001). These results suggest an important role of vitamin D in regulating disease activity in SLE patients and the need to supplement vitamin D in their treatment.