The Level Of Serum 25 OH D In Patients With Primary Sj?gren's Syndrome And Its Relationship With Systemic Involvement

Objective:Primary Sj?gren's syndrome(pSS)is common in diffuse connective tissue diseases and mainly affect middle-aged women.The disease is featured by infiltration of a large number of lymphocytes,plasma cells and other inflammatory cells in exocrine glands,leading to functional and structural damage.The typical clinical manifestations are dry mouth and dry eyes,often combined with multiple systemic involvements,such as lungs,liver,kidneys,hematological system and nerve system.Many factors contribute to the pathogenesis of the disease,including heredity,infection,immunity,environment and so on.Vitamin D is known as a new kind of neuroendocrine-immune regulating hormone nowadays.An increasing number of studies show that the metabolic disorders of vitamin D are related with many rheumatic diseases including pSS,but the relationship of the level of serum vitamin D and systemic involvements in pSS patients is unclear.The purpose of this study is to explore the role of vitamin D in the pathogenesis of pSS by evaluating its relationship with systemic involvements,clinical parameters,and laboratory indicators,thus providing a new way of thinking for the prevention and treatment of systemic involvements in pSS.Methods:1 41 cases of first-visit pSS patients have been enrolled as experimental group.They all came from Department of Rheumatology,Hebei General Hospital from January 2016 to October 2016 and met the International Classication Criteria for pSS in 2002.39 cases of healthy people were taken as control,matched with pSS patients in age,sex and the date of blood collection.2 The level of serum 25 OH D(including 25 OH D2 and 25 OH D3)was detected by Electro-chemiluminescence Immunoassay(ECLI).The basicinformation of pSS patients was recorded,including clinical symptoms,physical signs,clinical indicators and systemic involvements.The clinical indicators included blood routine examination,erythrocyte sedimentation rate(ESR),serum globlin(GLB),immune globulin(IgA,Ig G and IgM),rheumatoid factor(RF),antinuclear antibodies(ANA),antiextractable nuclear antigens(ENA).3 Biopsy of labial salivary gland tissues was performed and stained by HE.The tissues were graded into 0-IV according to lymphocyte infiltration by the Chisholm criteria.4 The disease activity was assesed according to Sj?gren's syndrome disease activity index(SSDAI)established in 2007 by Vitali.5 SPSS 21.0 software was used for statistical analysis.Results:1 The level of serum 25 OH D in p SS patients: The level of 41 pSS patients was 19.55±6.70ng/ml,while that was 25.05±9.20ng/ml in control group.The difference is statistically significant between the two groups(P<0.05);2 The level of serum 25 OH D in pSS patients with systemic involvements: The systemic involvement was defined as having at least one of the following organs or systems damage: lungs,liver,kidneys,nerve system,hematological system,while the non-systemic involvement was defined as having no organ or system damage.The 25 OH D level of systemic involvement group and non-systemic involvement group were18.38±6.78ng/ml and 21.14±4.95ng/ml respectively,with no significant statistical difference(P>0.05).The level of serum 25 OH D in renal involvement group was 15.77±4.25ng/ml,which was significantly lower than that in non-systemic involvement group(21.14±4.95ng/ml).The difference between the two groups had stastistical difference(P<0.05);3 Relationship between the level of serum 25 OH D and clinical symptoms: The pSS patients were divided into different groups according to whether they had following symptoms: dry mouth,dry eyes and joint pain.Nostastistical difference was found in each pair(P>0.05);4 Relationships between the level of serum 25 OH D and the expression of autoantibodies in pSS patients: The pSS patients were divided into anti-Ro antibody positive and negative group,anti-La antibody positive and negative group,RF positive and negative group.No stastistical difference was found between each pair of antibodies positive and negative group.According to ANA titers,the p SS patients were divided into four groups: ANA1:100,ANA1:320,ANA1:1000 and ANA1:3200 group.The levels of serum 25 OH D were 23.93±3.17 ng/ml,22.96±7.00 ng/ml,19.45±4.79 ng/ml and 19.23±7.42ng/ml respectively.No stastistical difference was found among the four groups(P>0.05);5 Correlation between the level of serum 25 OH D and clinical indicators:The level of serum 25 OH D had negative correlation with IgG(r=-0.684,P<0.05)and no correlation with serum GLB,ESR,IgM,IgA,Hb,WBC or PLT(P>0.05).There were no correlation between the level of serum 25 OH D and the proportion of CD3+CD4+T cell subsets or CD19+B cells in pSS patients(P>0.05);6 Relationship between the level of serum 25 OH D and Chilshom grades of labial salivary glands in pSS patients: The levels of serum 25 OH D in pSS patients with grade III and grade IV were 17.84±7.32 ng/ml and 20.23±6.96ng/ml respectively.No stastistically significant difference was found beween the two groups(P>0.05);7 Correlation between the the level of serum 25 OH D and Sj?gren's Syndrome Disease activity index(SSDAI): There was negative correlation between the level of serum 25 OH D and SSDAI in pSS patients(r=-0.623,P<0.05).Conclusions:1 The level of serum 25 OH D in pSS patients is lower than healthy individuals,especially in patients with renal involvement.This suggests that vitamin D supplement may improve the condition of pSS,especially the occurrence of renal involvement.2 The level of serum 25 OH D in pSS patients had negative correlation with IgG and SSDAI.This suggests that the level of 25 OH D is associated with disease activity,Vitamin D supplement may improve the active condition of pSS.