Objective The aim of the present study was to evaluate the plasma vitamin D (vit D) levels and their association with the disease activity in patients with ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (uSpA) compared with healthy populations. Methods This study included 161 spondyloarthritis patients (113 uSpA patients and 48 AS patients) attending our rheumatology out-patient clinic, along with 92 controls. Results The plasma vit D levels were 18 μg/L (8-38) in the AS group, 20 μg/L (4-92.3) in the uSpA group and 24.3 μg/L (7.2-76.8) in the control group. The plasma vit D levels of the AS patients were significantly lower than those of the patients in the control group (p=0.004). The men in the AS group had significanly lower vit D levels than those in the control group (p=0.005). On the other hand, the women in the uSpA group had significanly lower vit D levels than those in the control group (p=0.011). The vit D levels were inversely related to both erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in the AS patients (p=0.002, R=-0.428; p<0.001, R=-0.592, respectively). This correlation was not demonstrated in the uSpA patients. The vit D levels were not found to correlate with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) levels in either the AS or uSpA patients. Conclusion 25-hydroxy-vit D deficiency is frequently observed in patients with SpAs. In this study, vit D deficiency was much more prominent in the male AS patients. On the other hand, among women, the uSpA patients exhibited much more prominent vit D deficiency than the control group subjects. The acute phase response may inversely affect the vit D levels in AS patients.

Aim: To define the prevalence of polyautoimmunity (PAI) among celiac disease (CD) patients and to compare clinical and laboratory features of CD patients with or without PAI in order to determine the risk factors for PAI in CD. Material and Method: Patients diagnosed with CD in our clinic between 2007 and 2014 with at least 1 year of follow-up were retrospectively evaluated. Totally 145 patients were included in the study. Information on patient demographics and laboratory data were obtained from patient records. The study participants were divided into 2 groups. Group 1 was the CD-alone group consisting of patients without any other autoimmune diseases (AIDs), while group 2 was the PAI group consisting of patients with accompanying one or more AIDs. Results: The mean age of 145 CD patients (106 female and 39 male) included in the study was 37.2 ± 12.3 years. Of the 145 patients included, 48 (33.1%) were in the PAI group. When two groups were compared with each other in terms of the demographic features and laboratory data, the following were identified as risk factors for PAI: female gender, family history for AIDs, antigliadin IgG positivity, vitamin D deficiency, antinuclear antibody positivity ≥1/80 titer and having any musculoskeletal disease. Conclusion: To the best of our knowledge, this is one of the largest studies in the literature on CD patients for the PAI prevalence and related risk factors. Identification of the risk factors in early stages is important to explore PAI among CD patients. Larger, prospective studies are warranted about the risk factors and autoimmune characteristics of CD.