The Significance Of Anti-cyclic Citrullinated Peptide Antibodies And Rheumatoid Factor In Patients With Rheumatoid Arthritis

Rheumatoid Arthritis(RA)is a kind of chronic advanced autoimmune disease, which is characterized by damage and deformity of joints, even the disfunction of joints. The morbidity of RA is about 0.32%-0.38% in China. It is reported that joints of 50%-90% RA patients have been damaged in imageology within 2 years after the onset of the disease, and the therapeutic effect is the best with treatment within 1 year, especially within 3 months. Thus, it is very important to diagnose early for holding damage of articulation and improving prognosis. Some report suggest the combined detection of three subtype (IgG-RF,IgA-RF,IgM-RF) of rheumatoid factor (RF) is helpful to early diagnosis, evaluation of pathogenetic condition and therapeutic effect. And the level of RF is proportional to the ratio of progress in RA. Anti-Cyclic citrullinated peptide (CCP) antibody is a new serologic marker with a high specificity and sensitivity (98%,68%) in diagnosis of RA. It is also a index of early diagnosis and prognosis of RA. It is reported that the combined detection of anti-CCP antibody and each subtype of RF can elevate specificity of diagnosis of RA(82%-98% to 98%), and the exist of RF has correlation with severity of disease (bone erosion and articulation dysfunction) in some degree.Objective: To study the significance of combined detection and solo-detection of anti-CCP antibody and subtype of RF and explore the relationship between anti-CCP antibody, subtype of RF and course, severity and activity of RA.Methods: 106 RA patients and 80 other rheumatism patients(including lupus erythematosus systemic 15 cases, ostarthritis 15 cases,ankylosing spondylitis 10 cases , systemic sclerosis 10 cases , multiple myositi/ dermatomyositis 8 cases, mixed connective tissue disease 6 cases, Sjogren's syndrome 4 cases, gout 3 cases, psoriatic arthritis 3 cases, Behcet disease 3 cases) visited in China and Japan Union Hospital affiliated to Jilin University during Oct 2006-Dec 2007 were selected as study objects, 30 healthy staff from our hospital were also selected. The clinical and laboratory data were recorded, including gender, age, course of disease, time of morning stiffness, counts of swelling and painful joint, X-ray photograph and so on. Gathering the blood of Veins of upper extremity of all study objects, which was stored at 4℃. Then detect anti-CCP antibody and subtype of RF (IgG-RF,IgA-RF,IgM-RF. By the use of the Spss13.0 statistical package, calculating the sensitivity and specificity to diagnosis of RA of anti-CCP antibody and IgG-RF,IgA-RF,IgM-RF with the four table method. Measurement data were expressed as x±s, using t test. The variance analysis was adopted to compare the average of multi-groups. X2 test was used to compare the rate. Logistic regression analysis was used in the correlation analysis of the two variables. P<0.05 means the difference has the statistical significance.Results: 1,The sensitivity and specificity to diagnosis of RA of anti-CCP antibody and IgG-RF,IgA-RF,IgM-RF were 79.2%,93.6%;57.54%,92.7%;53.77%,87.27%;71.7%,83.6% respectively. 2,The sensitivity and specificity to diagnosis of RA of anti-CCP antibody combinding with IgG-RF, anti-CCP antibody combinding with IgA-RF, anti-CCP antibody combinding with IgM-RF, RF-IgG combinding with RF-IgA,RF-IgG combinding with RF-IgM,RF-IgA combinding with RF-IgM,ACCP combinding with RF-IgG and RF-IgA and RF-IgM were 51.89%,100%;60.38%,99.1%;64.15%,98.2%;54.72%,97.27%;55.66%,96.36%;63.21%,95.45%;49.06%,100% respectively. 3,The level of anti-CCP antibody and IgG-RF,IgA-RF,IgM-RF will step up with the advancement of disease. But there is no significance about the level of IgG-RF,IgA-RF,IgM-RF among 3 groups (P >0.05). The concentration of anti-CCP antibody just in early RA group was lower than in mid-advanced RA group(p=0.005). 4,Anti-CCP antibody and IgA-RF,IgM-RF were correlation with the counts of damaged joints, and the concentration of anti-CCP antibody and RF-IgG,RF-IgA,RF-IgM in multi-articulation RA group were higher than in oligo-articulation RA group( P-value 0.02,0.1,0.04,0.02 respectively). 5,Anti-CCP antibody and IgA-RF,IgM-RF were correlated with bone erosion, and the concentration of Anti-CCP antibody and IgG-RF,IgA-RF,IgM-RF is higher than in bone erosion group than in non-bone-erosion group(P-value 0.004, 0.064, 0.01, 0.046 respectively). 6,The differences of course of disease, erythrocyte sedimentation rate, X-ray staging and DAS28 between anti-CCP antibody and RF-IgG,RF-IgA,RF-IgM positive RA group and four-antibody negative or one-antibody positive RA group was significant.Conclusion: 1,Compared with subtype RF, the sensitivity and specificity of anti-CCP antibody was higher. The combinded detection of anti-CCP antibody and RF-IgG,RF-IgA,RF-IgM can elevate the accuracy and specificity of diagnosing RA. 2,The concentration of anti-CCP antibody may be related with course of disease. 3,Anti-CCP antibody and IgA-RF,IgM-RF were correlation with the counts of damaged joints, and the three antibodies will raise with increasing of count of damage joints. 4,Anti-CCP antibody and IgA-RF,IgM-RF were correlated with bone erosion, and the concentration of the three antibodies will increase withadvancement of bone erosion. 5,The combinded detection of anti-CCP antibody and RF-IgG,RF-IgA,RF-IgM is helpful to evaluate severity and activity of disease and to prognose turnover of disease. 6,The combinded detection of anti-CCP antibody and RF-IgG,RF-IgA,RF-IgM is helpful to early and much earlier diagnosis of RA.