Low levels of vitamin-D are associated with neuropathy and lymphoma among patients with Sjögren's syndrome.

BACKGROUND/PURPOSE: Primary Sjögren's syndrome (SS) is a chronic autoimmune disease primarily involving the exocrine glands. The clinical picture of SS ranges from exocrinopathy to systemic disease affecting the lung, kidney, liver, skin, musculockeletal and nervous systems. The morbidity of SS is mainly determined by extraglandular disease and increased prevalence of lymphoma. Environmental and hormonal factors, such as vitamin-D may play a role in the pathogenic process and disease expression. Thus, we aimed to evaluate levels of vitamin-D and their association with manifestations of SS. METHODS: Vitamin-D levels were determined in 176 primary SS patients and 163 matched healthy volunteers utilizing the LIAISON chemiluminescent immunoassays (DiaSorin-Italy). A correlation between vitamin-D levels and clinical and serological manifestations of SS was performed. RESULTS: Mean vitamin-D levels were comparable between SS patients and control 21.2 ± 9.4 ng/ml and 22.4 ± 10 ng/ml, respectively. Peripheral neuropathy was diagnosed in 23% of SS patients and associated with lower vitamin-D levels (18.6 ± 5.5 ng/ml vs. 22.6±8 ng/ml (p = 0.04)). Lymphoma was diagnosed in 4.3% of SS patients, who had lower levels of vitamin-D (13.2 ± 6.25 ng/ml), compared to SS patients without lymphoma (22 ± 8 ng/ml), (p = 0.03). Other clinical and serological manifestations did not correlate with vitamin-D status. CONCLUSIONS: In this study, low levels of vitamin-D correlated with the presence of peripheral neuropathy and lymphoma among SS patients. The link between vitamin-D and neuropathy or lymphoma was reported in other conditions, and may support a role for vitamin-D in the pathogenesis of these processes. Plausible beneficial effect for vitamin-D supplementation may thus be suggested.

The clinical significance of 25OH-Vitamin D status in celiac disease.

Reduced bone mineral density is frequently found especially in adult celiac disease (CD) and dietary guidelines favor vitamin D supplementation in adults and children with CD. Vitamin D serum levels were investigated in CD populations in order to challenge its routine supplementation. Israeli (61), Spanish (59), CD children (groups 1 and 5, respectively) were compared to children with nonspecific abdominal pain (56), their parents (84) and Spanish adult CD patients (22) (group 2, 3, 4, respectively). 25(OH)-vitamin D was checked by LIAISON chemiluminescent immunoassays. Groups 5 and 1 had the highest levels compared to groups 4 and 3 with the lowest levels. The levels in groups 1 and 2 were comparable. Concerning 25(OH)-vitamin D sera levels, only the difference between group 5 and 4 was statistically significant (30.3 ± 12.3 and 20.2 ± 10.5 ng/ml, respectively p=0.003). When vitamin D was splitted above and below 20 ng/ml level, 54.5% of Spanish adult CD had vitamin D deficiency compared to 16.9% of the local CD children (p=0.001). 29.6% of group 2 had deficient levels compared to their parents with 50% (p=0.019). In conclusion, Vitamin D sera levels negatively correlate with age. Thus, mainly adult CD population should be assessed for vitamin D levels and supplemented accordingly.

Vitamin D and autoimmune thyroid diseases.

The role of vitamin D as an immune modulator has been emphasized in recent years, and low levels of the hormone were observed in several autoimmune diseases including multiple sclerosis and systemic lupus erythematosus. Vitamin D mediates its effect though binding to vitamin D receptor (VDR), and activation of VDR-responsive genes. While VDR gene polymorphism was found to associate with autoimmune thyroid diseases (AITDs), few studies examined levels of vitamin D in these patients and those that did yielded conflicting results. We therefore undertook to evaluate the levels of vitamin D in patients with AITDs compared to patients with non-AITDs and healthy controls. Serum vitamin D (25-OH) levels were measured in 50 patients with AITDs, 42 patients with non-AITDs and 98 healthy subjects, utilizing the LIAISON chemiluminescence immunoassay (DiaSorin, Saluggia, Italy). Vitamin D deficiency was designated at levels lower than 10 ng/ml. Antithyroid antibodies, thyroid functions and demographic parameters were evaluated in all patients. The prevalence of vitamin D deficiency was significantly higher in patients with AITDs compared with healthy individuals (72% versus 30.6%; P<0.001), as well as in patients with Hashimoto's thyroiditis compared to patients with non-AITDs (79% versus 52%; P<0.05). Vitamin D deficiency also correlated to the presence of antithyroid antibodies (P=0.01) and abnormal thyroid function tests (P=0.059). Significantly low levels of vitamin D were documented in patients with AITDs that were related to the presence of anti thyroid antibodies and abnormal thyroid function tests, suggesting the involvement of vitamin D in the pathogenesis of AITDs and the advisability of supplementation.