The Relationship Between Plasma Vitamin D₃and B Cells Subsets Of Patients With Primary Sjogren’s Syndrome

Objective To investigate the plasma vitamin D3levels and the relationship to B cellssubsets of patients with primary Sjogren’s syndrome (pSS), and explore the role ofvitamin D3levels in the pathogenesis of pSS.Method The expression of plasma vitamin D3levels of patients with55patients and32healthy controls were measured by ELISA; frequecy of peripheral blood CD19+CD27-na ve B cells, CD19+CD27+memory B cells and CD19+CD27highplasma cells wereanalyzed by flow cytometry of34pSS patients and22controls. The relationship wasanalyzed in pSS patients between the vitamin D3levels and B cell subsets, SSDAI, tearsflow rate, saliva flow rate, Rheumatoid Factor and immunoglobulin.Results①No statistical differences were found in the plasma levels of25(OH)D3between pSS patients and healthy controls (23.15±8.6ng/ml and24.36±7.94ng/ml,P>0.05).②No significant difference was observed in the conditions ofvitaminD3deficiency(<20ng/ml), insufficiency(20-30ng/ml), sufficiency(>30ng/ml)between two groups（X=0.479,p=0.787）.③The level of plasma1,25(OH)2D3wassignificantly lower in pSS patients group than that in the normal control group[24.17pg/ml(22.20,28.41) and41.25pg/ml(23.38,62.18),P<0.05], and that was alsoobviously lower in the active group than that in the normal controlgroup[22.64pg/ml(20.74，24.90) and41.25pg/ml(23.38,62.18),P<0.05],and that wasalso obviously lower in the active group than that in the inactive group[22.64pg/ml(20.74,24.90)and25.39pg/ml(23.16,33.09),P<0.05].However, there was no difference between the inactive and the control group[25.39pg/ml(23.16,33.09) and41.25pg/ml(23.38,62.18),P>0.05].④The percentage of peripheral blood ofCD19+CD27highplasma cells and CD19+CD27+memory B cells in CD19+cells werereduced in pSS patients compared with control group[(0.89±0.30)%and(1.72±0.43)%;(23.74±7.54)%and (34.30±5.28)%, P<0.05], and that was also significantlylower in the active group and inactive group than that in the controls[(1.03±0.59)%and(1.72±0.43)%;(1.00±0.16)%and(1.72±0.43)%;(25.77±9.70)%and(34.30±5.28)%;(25.66±3.07)%and (34.30±5.28),P<0.05], but there was nocorrelation between the active group and the inactive group [(1.03±0.59)%and (1.00±0.16)%;(25.77±9.70)%and (25.66±3.07)%, P>0.05].However, the frequency ofperipheral blood of CD19+CD27-naive B cells in CD19+B cells were increased inpatients with pSS compared with control group[(75.35±7.49)%and (63.92±5.24)%,P<0.05]. and that was also significantly higher in the active group and inactivegroup than that in the controls[(73.40±9.73)%and (63.92±5.24)%;(73.28±2.89)%and (63.92±5.24)%, P<0.05], but this difference was not present between the activegroup and the inactive group④Significant negative correlation was observed between1,25(OH)2D3and the percentage of peripheral blood of CD19+CD27+memory B cells inCD19+cells as well as immunoglobulin G(r=-0.627,p=0.039;r=-0.657,p<0.001)⑤Therewas no correlation between the levels of peripheral CD19+CD27-naive Bcells,CD19+CD27high plasma cells in pSS patients and presence of serum antibodiesagainst Ro (SS-A)、La (SS-B) and Rheumatoid factor, nor serum levels of IgM andIgA, nor exocrine gland function.Conclusion These results demonstrated that the abnormality of vitamin D levels mayplay an important role in the pathogenesis of pSS.