Background Beyond its critical function in calcium homeostasis, vitamin D has recently been found to play an important role in the modulation of the immune/inflammation system. Increasing numbers of study have established that vitamin D insufficiency contributes to a number of diseases, suggesting a range of physiological functions of vitamin D. Recent findings seem to show that low vitamin D levels in patients with Sjogren Syndrom could be associated with severe complications such as peripheral neuropathy.
Objectives The purpose of this study was to evaluate plasma vitamin D level in Primary Sjogren's Syndrome (PSS) and comparing it with healthy controls.
Methods North Africans patients (Tunisian patients) with PSS were diagnosed in an internal medicine department. All patients with PSS meet the revised AECG criteria 2002 and/or ACR proposed criteria 2012. We proceed in this prospective study with a comparison of plasma vitamin D between two groups, with a matched age and sex, one of patients with a Primary Sjogren's Syndrome (PSS) and a second of healthy control subjects. Sixty six patients with PSS were enrolled. Sex ratio was 0.11 (59 female (89.4%) and 7 male (10.6%)).Mean age at diagnosis was 49.07 years ±12.56 (range 26 -73years). Forty eight healthy controls were included. Sex ratio was 0, 14 (42 females (87.5%) and 6 males (12.5%). Registration and statistical analysis of data were done with SPSS. Plasma 25-hydroxyvitamin D (25-OHD) concentrations were measured by a competitive chemiluminescence immunoassay using the Liaison Analyzer (DiaSorin Inc., Stillwater, MN). The inter-assay CV was below 10%. Vitamin D deficiency was defined according to the most recent cut-points defined by The Institute of Medicine as 25-OHD concentrations <10 μg/L.
Results Plasma vitamin D level of PSS patients was insufficient in 42.2% of cases (plasma vitamin D level <30 μg/L) and in 57.8% of cases plasma vitamin D level was lower than 10 μg/L. Plasma vitamin D was lower than 10 μg/L in 66.66% of healthy controls. There is no significant variation of plasma vitamin D levels according to sex, in the PSS group. Plasma vitamin D levels are not significantly decreased in patients with central and/or peripheral neurological manifestations compared to patients with no neurological symptoms. Plasma vitamin D levels are, however; significantly lower in male patients than controls.
Conclusions The incidence of vitamin D deficiency seems more important for PSS patients than healthy controls. It might be interesting to study these patients to examine the outcome of the disease and its severity after a vitamin D supplementation therapy.
Disclosure of Interest None declared