R.D.P. Corp., Armonk, NY, USA). Results Patient characteristics and vitamin D3 supplementation effectiveness In all, 53 RRMS patients completed the SOLARIUM study (F/M?=?35/18; mean age?=?37.5 (8.2) years; median disease duration?=?7.3 (4.4C12.0) months; mean 25(OH)D?=?56.0 (24.5) nmol/L), of which 30 were in the vitamin D3 group and 23 in the placebo group (Supplementary Table S1). After 48?weeks, an increase in serum 25(OH)D-levels was observed in the vitamin D3 group (60 (38C85) to 231 (162C250) nmol/L; p?p?=?0.380).18 Vitamin D3 supplementation selectively reduces anti-EBNA-1 IgG levels All patients were EBV-seropositive (92% were positive for EBNA-1, 98% were positive for VCA, and none were negative for both), whereas 38% of the patients were CMV-seropositive. No significant differences in IgG levels against EBNA-1, VCA, and CMV were found between the groups at T0 or T1 (data not shown). However, anti-EBNA-1 IgG levels were significantly reduced at T1 compared to T0 in the vitamin D3 group (p?p?=?0.626). No significant change between T1 and T0 was instead present for anti-EBV VCA and anti-CMV IgG levels in either group CC-115 (Table 1). Moreover, when comparing the T1CT0 differences in anti-EBNA-1 IgG between the groups, the median difference was significantly larger in the vitamin D3 group (?88 (?397 to ?5)?U/mL) than in the placebo group (0 (?66 to +48)?U/mL; p?=?0.023; Physique 1). These effects remained unchanged when outliers with very high anti-EBNA-1 IgG levels were removed from the analysis (not shown). Within the size limits of the patient cohort, further analyses around the patients in the vitamin D3 group with the most pronounced decreases of anti-EBNA-1 IgG did not reveal differences in 25(OH)D levels, EBV viral load, or EBV-specific CD8+ T cell response (see below). Table 1. Plasma IgG levels of the patients with RRMS.
Anti-EBNA-1 IgG (U/mL)432 (351C1280)429 (297C1290)0.626526 (368C1683)455 (380C1148)<0.0010.023Anti-VCA IgG (U/mL)643 (234C1140)581 (216C1230)0.976374 CC-115 (180C752)411 (171C732)0.3110.615Anti-CMV IgG (U/mL)9 (5C79)13 (5C79)0.2335 (5C73)5 (5C81)0.4070.617 Open in a separate window EBNA-1: EpsteinCBarr nuclear antigen 1; IgG: immunoglobulin G; VCA: viral capsid antigen; CMV: cytomegalovirus; T0: baseline; T1: week 48; Q1CQ3?=?25thC75th percentile. *Between-group comparisons of the T1CT0 differences. Open in a separate window Physique 1. Anti-EBNA-1 IgG levels of patients with RRMS before and after treatment. (a) Within-group comparisons at T0 and T1 in the placebo group CC-115 (n?=?23), (b) within-group comparisons at T0 and T1 in the vitamin D3 group (n?=?30), and (c) between-group comparisons of the anti-EBNA-1 IgG level differences between T1 and T0. Gray lines indicate the medians with interquartile ranges. T0: baseline; T1: week 48. Vitamin D3 supplementation does not influence EBV viral load in PBMC or EBV-specific CD8+ T cells We further explored the potential mechanisms underlying the selective reduction of anti-EBNA-1 IgG upon vitamin D3 supplementation. We hypothesized that vitamin D could reduce antigens available to trigger anti-EBNA-1 antibody responses by promoting eradication of EBV-infected cells (as measured by EBV viral load in PBMCs) via an increase in the cytotoxic T cell response against EBV (as measured by the number of EBV-specific CD8+ T cells). However, median EBV DNA copies in PBMC samples did not significantly change over 48?weeks in either of the groups (Table 2). PBMCs from 15 vitamin D3-supplemented and 15 placebo-administered patients were available for detection of activated EBV-specific CD8+ T cells secreting IFN-. We found that 11 vitamin D3 and 9 placebo patients were positive responders to the EBV peptide pool. The median amount Cav2 of SFC/106 PBMC was comparable for both groups at both time points. Also, no significant changes were found within groups (Physique 2). Therefore, we found no evidence supporting an effect of vitamin D.