Clinical Study On The Correlation Between Serum Calprotectin Levels And Disease Activity Of Rheumatoid Arthritis

Objective:To detect the level of serum calprotectin(S100A8 /A9)in patients with rheumatoid arthritis(RA),and to investigate the relationship between serum calprotectin(S100A8 / A9)level and the activityofrheumatoid arthritis(RA).Methods:55 patients with rheumatoid arthritis and 25 healthy volunteers were enrolled in this study.According to DAS28 scores,55 patients with RA were divided into two groups.The active group was defined as having a DAS28 score of ?2.6 points,a total of 34 cases.The remission group was defined as a DAS28 score of <2.6 points,a total of 21 cases.Serum levels of calprotectin were measured by Enzyme Linked Immunosorbent Assay(ELISA).The serum calprotectin levels between RA patients and healthy group,active group and remission group were compared.The correlations between serum protein level and clinical indices were also analyzed.Using SPSS17.0 statistical software for data statistics and analysis.The independent sample T test was used to compare the serum levels of calprotectin between RA patients and healthy controls,RA patients active and remission group,RA patients active group and healthy control group,RA patients remission group and healthy control group.The correlation between the two samples with normal distribution was analyzed by Pearson correlation analysis,The correlations between the levels of calprotectin and the laboratory and clinical indexes such as ESR,CRP,PLT,Ig G,DAS28 score,joint deformity count and joint tenderness count were an5 alyzedrespectively.Result:1.The level of serum calprotectin in RA patients was higher than that in healthy controls[(251.38 ± 48.72)pg / ml vs(216.53 ± 40.95)pg / ml,P <0.01)],the difference was statistically significant.2.The levels of ESR,CRP,PLT and Ig G in RA patients were significantly higher than those in healthycontrols(P <0.01).3.The level of serum calprotectin in RA activity group was higher than that in remission group[(278.75 ± 37.80)pg / ml vs(207.07 ± 26.77)pg / ml,P <0.01],the difference was statistically significant.4.Serum calprotectin levels in RA patients were positively correlated with erythrocyte sedimentation rate(ESR),C reactive protein(CRP),platelet count(PLT),immunoglobulin G(Ig G),diseaseactivity index DAS28 score,swollenjointcount and tenderjointcount.5.In this study,the receiver operating characteristic curve(ROC)was used for analysis,and the cut-off value for evaluating RA disease activity or remission was tentatively discussed.When calprotectin was taken at 229.51 pg/ml,the area under the curve was 0.928.At this time,the sensitivityof RAwas91.2%andthespecificity was88.3%.Conclusion:1.Thelevelofserumcalprotectin in RApatients was higherthanthatinhealthycontrols.2.The level of serum calprotectin in RAactivity group was higher than that in remission group,suggesting that abnormally elevated serum calprotectin level correlated with disease activity in RApatients.3.Serum calprotectin levels in RA patients were positively correlated with ESR,C reactive protein(CRP),platelet(PLT),immunoglobulin G(Ig G),disease activity index DAS 28 score,swollen joint count and tender joint count,Suggesting that calprotectin may be involved in the chronic inflammatory process of RA and may be one of the indicators for evaluating disease activity.4.In this study,the receiver operating characteristic curve(ROC)was used for analysis,and the cut-off values used to evaluate RAdisease activity or remission were tentatively explored.When calprotectin was taken at 229.51 pg/ml,the area under the curve was 0.928.The sensitivity of RA was91.2%andthespecificitywas88.3%.