Different vitamin D status in common multiorgan autoimmune disease patients

Background: Vitamin D plays a key role in calcium homeostasis and contributes to the regulation of the immune system. Furthermore, vitamin D deficiency has been reported to be associated with autoimmune diseases (AIDs), especially with multiorgan AIDs. Various multiorgan AIDs may be different based on the vitamin D status. This study aims to investigate the scrum 25-hydroxyvitamin D (25(OH)D) levels in patients with different common multiorgan AIDS. Methods: A total of 295 patients with multiorgan AIDs treated in our hospital from January 2012 to September 2018 were recruited, including 137 cases of rheumatoid arthritis (RA), 85 cases of systemic lupus erythematosus (SLE), 32 cases of Sjogren's syndrome (SS) and 41 cases of mixed connective tissue disease (MCTD); 47 apparently healthy individuals were also recruited as controls. The serum 25(OH)D levels in patients with different multiorgan AIDS were measured with Roche electrochemiluminescence immunoassay and statistically analyzed the proportion of patients with normal, insufficiency and deficiency in 25(OH)D levels in different multiorgan diseases. The 25(OH)D levels of different multiorgan AID groups and healthy controls were also compared. Results: Incidences of 25(OH)D deficiency in the RA, SLE, SS and MCTD groups were 21.2%, 35.3%, 25.0% and 22.0%, respectively, with significant inter-group differences (p <0.05). The incidence in the SLE group was higher than in the RA, SS and MCTD groups, indicating severe 25(OH)D deficiency in patients with SLE. Significant inter-group differences (p <0.05) were detected in the scrum 25(OH)D levels in different multiorgan AID groups and in the healthy control group. Further pairwise comparison found a significantly higher level of 25(OH)D in the healthy control group than in the SLE, SS, RA and MCTD groups (p < 0.05). Moreover, the 25(OH)D status in the SLE group was significantly lower than that in the SLE, SS, RA and MCTD groups (p <0.05). Conclusions: Serum 25(OH)D deficiency and a low 25(011) D status are commonly seen in patients with different multiorgan AIDs compared to healthy controls, warranting vitamin D supplementation. Severe 25(OH)D deficiency and a lower 25(OH)D status were found in patients with SLE.