Significance Of Hidden Rheumatoid Factor IgM,Anti-cyclic Citrullinated Peptide Antibodies,Antikeratin Antibodies,Combined Test In The Diagnosis Of Juvenile Idiopathic Arthritis

Background and ObjectiveJuvenile idiopathic arthritis (JIA) is the most common rheumatic disease of childhood before the age of 16 years.The prognosis of children with JIA is diverse.Some untreated children may be lifelong disability.It is the highest crippling rate of autoimmune diseases in childhood.It is important for the early diagnosis and treatment for improving the joint symptomand .At present the early diagnosis of JIA is mainly based on clinical and X-ray. Lack of effective clinical indexes :ESR,CRP,RF,ANA and so on with poor specificity and sensitivity. There is little significance for X-ray examination in the early of JIA, because the arthropathy is not obvious.It is particularly important for the question to seek the newly serological indexes. The essence of hidden rheumatoid factor IgM(HRF-IgM) is the 19S sedimentation coefficient of IgM in human serum has had a solid combination with the degeneration of 1gG 7S.Because binding sites were closed by 7S of 1gG Fc ,the conventional detection methods could not find them out. It is the unique RF of children.Anti-cyclic citrullinated peptide antibodies and Antikeratin antibodies were the good specificity and the sensitive indexes that found to the diagnosis of RA.To assess the significance of HRF-IgM,anti-CCP,AKA combined test in the diagnosis of JIA. Object and Method1.Object : 60 children with JIA(43boys mean age6.01±2.98, 17girls mean age6.80±2.01), 27 systemic lupus erythematosus(SLE) cases (mean age7.08±1.67), 18 kawaski diseases cases (mean age 2.99±1.29) and 50 healthy children (28boys mean age 6.01±2.98, 22girls mean age 6.80±2.01) who were enrolled to serve as normal controls.2.Specimen collection: Children who did not have breakfast in the morning were drew venous blood 2ml,standing in the room temperature 30min, 2500r/min centrifugalizing to get the upper liquid to AP tube and preserve in -20°C refrigerator.3. Sample detection: The anti-CCP and Rheumatoid Factors (RF) were tested by enzyme linked immunosorbent assay (ELISA). The indirect immumofluorescence method was used to test AKA. Using the QAE-Sephadex-A50 to separate RF then tested HRF-IgM by ELISA.4. Statistical assay: The data were dealt with by SPSS10.0 statistical software. Using fourfold tables material chi-square test to discuss the sensitivity and the specificity of the HRF-IgM, AKA, the anti- CCP in the JIA,SLE and Kawasaki disease' diagnosis. Using contingency table material chi-square test and Pearson's R correlation analysis to discuss the sensitivity and the specificity of the index which combinded by HRF-IgM, anti- CCP and AKA. Using the row(?) column table materialchi-square test to discuss the dependablity and positive rate in different indexes. Alpha =0.05.Results1. The sensitivity of HRF-IgM in the JIA is 65%, the specificity is 85.3%. The positive rates of HRF-IgM were compared between The JIA children and the health comparison group which showed extremely significance (x~2=40.22, P=0.0001, P< 0.01) .2. The sensitivity of Anti- CCP in the JIA is 21.7%, the specificity is 96.8%. The positive rates of Anti- CCP were compared between The JIA children and the health comparison group which showed significance (x~2=7.497, P=0.002, P<0.05) .3. The sensitivity of AKA in the JIA is 21.7%, the specificity is 96.8%. The positive rates of AKA were compared between The JIA children and the health comparison group which showed significance(There is a zero in the actual number, using Fisher's Exact Test P=0.001, P<0.05 ). 4. The sensitivity of HRF-IgM,AKA,Anti- CCP combined test in the JIA is 35%,the specificity is 100%. Using contingency table material chi-square test , X2=90.18, x20.01=16.81, x2>x20.01 , P<0.01. It shows the correlated between JIA and combined indexes.To calculate Pearson's R P=0.9 approach 1. So we could see they had good correlation.Conclusion1. HRF-IgM has a better sensitivity and the specificity in JIA, it can prove to be a valuable reference index for diagnosing JIA.2. AKA and anti- CCP have extremely good specificity but the sensitivity is poor in JIA. They are not suitable used as the diagnosis index of JIA alone.3. HRF-IgM, AKA, and anti- CCP union examination has a better sensitivity in JIA, and the specificity achieves 100%. It is an extremely good index to enhance the diagnosis rate in JIA.