1.
Vitamin D status and the immune assessment in 22q11.2 deletion syndrome.
Legitimo, A, Bertini, V, Costagliola, G, Baroncelli, GI, Morganti, R, Valetto, A, Consolini, R
Clinical and experimental immunology. 2020;(3):272-286
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Abstract
22q11.2 deletion syndrome (22q11.2DS) is characterized by a heterogeneous phenotype, including alterations in phospho-calcium metabolism and immunodeficiency. We analyzed vitamin D status and the immune assessment, focusing on T cell subpopulations and dendritic cells (DCs) in a cohort of 17 pediatric 22q11.2DS patients and 17 age-matched healthy subjects. As antigen-presenting cells, DCs are the main target of vitamin D, promoting a tolerogenic T cell response. Patients were subdivided into three groups according to the parameters of phospho-calcium metabolism and serum levels of 25OHD: normal values, vitamin D deficiency and hypoparathyroidism. Different degrees of T cell deficiency, ranging from normal to partial T cell numbers, were observed in the cohort of patients. The group with vitamin D deficiency showed a significant reduction of naive T cells and a significant increase of central memory T cells compared to controls. In this group the number of circulating DCs was significantly reduced. DC decrease affected both myeloid and plasmacytoid DC subsets (mDCs and pDCs), with the most relevant reduction involving pDCs. A direct correlation between 25OHD levels and recent thymic emigrant (RTE) and DC number was identified. Despite the limited cohort analyzed, our results show that deficiency of the pDC subset in patients with 22q11.2DS may be included among the causative factors of the progressive increase of risk of autoimmune diseases in these patients. As most patients suffer from increased susceptibility to infections and heightened prevalence of autoimmune disorders, we suggest a potential role of vitamin D supplementation in preventing autoimmune or proinflammatory diseases in 22q11.2DS.
2.
Obesity with and without metabolic syndrome: do vitamin D and thyroid autoimmunity have a role?
Agbaht, K, Mercan, Y, Kutlu, S, Alpdemir, MF, Sezgin, T
Diabetes research and clinical practice. 2014;(1):27-34
Abstract
AIMS: To investigate serum levels of thyroid stimulating hormone (TSH), anti-thyroid peroxidase antibody (TPO), and 25(OH)D in the presence or absence of metabolic syndrome in an obese population. METHODS Data from a prospectively generated "Obesity Polyclinic" database that includes socio-demographic characteristics, anthropometric, and laboratory measurements of obese subjects were retrospectively analyzed. Subjects with body-mass index (BMI) ≥30kg/m(2) were eligible. After detailed analysis and exclusion of unavailable cases, subjects diagnosed with and without metabolic syndrome were compared for TSH, anti-TPO, and 25(OH)D. RESULTS Of the study participants (n=548; men/women, 64/484), 277 were diagnosed with metabolic syndrome [Met-S (+)]. Met-S (+) patients had a higher mean BMI (36.4 vs. 32.3kg/m(2), p<.001) and percentage body fat (PBF) (39.2 vs. 35.3%, p<.001), but similar TSH (2.1 vs. 2.2mIU/mL, p=.759), anti-TPO (12 vs. 13IU/mL, p=.483), 25(OH)D (13.2 vs. 12.6ng/mL, p=.409), and calcium-phosphorus product (28.7 vs. 29.5mg/dL, p=0.275), compared to Met-S (-) subjects. When serum TSH, anti-TPO, and 25(OH)D levels were analyzed according to tertiles for comparisons of fasting plasma glucose, triglycerides, high-density lipoprotein cholesterol, BMI, and PBF, only 25(OH)D levels were negatively correlated with BMI and PBF. CONCLUSIONS Although decreased 25(OH)D levels were related to the degree of obesity in obese subjects, serum 25(OH)D levels per se did not seem to be associated with metabolic syndrome. The prevalence of thyroid autoimmunity and hypothyroidism were high in this obese sample; however, neither serum TSH nor anti-TPO levels correlated with metabolic syndrome. Our findings did not support the hypothesis that thyroid autoimmunity and/or vitamin D status have a role in the development of metabolic disturbances in the obese population.