Association of vitamin D serum levels and vitamin D supplementation with B cell kinetics and disease activity in Multiple Sclerosis patients treated with ocrelizumab: an Italian multi-center study.

BACKGROUND: Several observational studies have shown an association between low circulating levels of 25-hydroxy- vitamin D (25(OH)D) and an increase in inflammatory activity in Multiple Sclerosis (MS). Among its immunomodulatory functions, 25(OH)D suppresses proliferation and immunoglobulin production of B cells. 25(OH)D supplementation has been associated with better radiological outcomes in MS patients treated with interferon (IFN)-B, glatiramer acetate, fingolimod, natalizumab and rituximab. Our study is aimed at analyzing the association of 25(OH)D serum levels and supplementation with B cell kinetics and clinical-radiological outcomes of people with MS treated with ocrelizumab. METHODS: We have retrospectively collected clinical and radiological data from 136 MS patients who have been treated with ocrelizumab, have undergone at least two treatment cycles and for whom data on serum 25(OH)D levels and intake were available. The patients were divided into three groups according to baseline 25(OH)D serum levels: deficient (≤19,9 ng/ml), insufficient (20-29,9 ng/ml), and normal range 25(OH)D (>30 ng/ml). According to 25(OH)D intake, we divided our population into users and non-users. To explore B cell kinetics at six- and twelve-month follow-ups, the patients were divided into two groups: with fast repopulation (FR) and slow repopulation rate (SR), based on the reappearance or non- appearance of CD19 at each time point. RESULTS: When considering the entire population, the mean 25(OH)D serum level (sd) was 26.27 ng/ml (14.15). 43 (31,62%) patients were classified as deficient, 52 (38,24%) were classified as insufficient, and 41 (30,14%) showed 25(OH)D serum levels within the normal range. 60.29% (82/136) of the patients were classified as users, and 39.70% (54/136) as non-users. Over the eighteen-month treatment period, we observed a significant difference between the 25(OH)D users and the non-users as concerns the number of scans with at least one new/enlarging T2 lesion (2% vs 15.38%, respectively; p= 0.025). In the multinomial regression model, 25(OH)D deficiency (serum levels ≤19,9 ng/ml) was significantly associated with a higher likelihood of disease activity during a follow-up of eighteen months (p = 0.029, RRR = 4.84, Confidence Interval (CI) 1.17 - 20.01). After six months, there were 30/136 FR patients (22,05%), whereas only 22/136 (16,17%) showed early B cell reappearance at twelve month follow up. 86.66% of the patients in the FR group showed 25(OH)D levels lower than 30 ng/ml (25(OH)D deficiency or insufficiency), whereas only 65.09% of the SR patients presented vitamin D levels lower than 30 ng/ml (p= 0.024). In the logistic regression model, 25(OH)D serum levels below 30 ng/ml were associated with a higher likelihood of early B cell reappearance at six month follow up (p= 0.042). CONCLUSIONS: 25(OH)D supplementation and serum levels might be associated with B cell kinetics and radiological activity of patients with MS treated with ocrelizumab.

Investigation of low-level laser therapy potentiality on proliferation and differentiation of human osteoblast-like cells in the absence/presence of osteogenic factors.

Several studies have shown that low-level laser irradiation (LLLI) has beneficial effects on bone regeneration. The objective of this study was to examine the in vitro effects of LLLI on proliferation and differentiation of a human osteoblast-like cell line (Saos-2 cell line). Cultured cells were exposed to different doses of LLLI with a semiconductor diode laser (659 nm; 10 mW power output). The effects of laser on proliferation were assessed daily up to seven days of culture in cells irradiated once or for three consecutive days with laser doses of 1 or 3 J/cm(2). The obtained results showed that laser stimulation enhances the proliferation potential of Saos-2 cells without changing their telomerase pattern or morphological characteristics. The effects on cell differentiation were assessed after three consecutive laser irradiation treatments in the presence or absence of osteo-inductive factors on day 14. Enhanced secretion of proteins specific for differentiation toward bone as well as calcium deposition and alkaline phosphatase activity were observed in irradiated cells cultured in a medium not supplemented with osteogenic factors. Taken together these findings indicate that laser treatment enhances the in vitro proliferation of Saos-2 cells, and also influences their osteogenic maturation, which suggest it is a helpful application for bone tissue regeneration.