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Objective To establish a new murine model of experimental autoimmune myositis by immunizing with MYBPC2 protein. Methods The purified Myosin-binding protein C, fast type (MYBPC2) was emulsified with complete Freundˊs adjuvant, then C57BL/6 mice were immunized by multi-point subcutaneous injection (0, 7 days), and intraperitoneal injection of pertussis toxin 2 μg simultaneously. The pathological changes of mice with different immunizing dose at the preconceived time were ex-plored. Mean-while, mice were immunized with 600 μg each time, and the muscle endurance was tested on the 21th day. The expression of major histocompatibility complex (MHC) class-Ⅰ and the surface biomarkers of the inflammatory cells in muscle tissues were observed. Mann-Whitney U test was used for statistical analysis. Results ① With the increase of immunizing dosage, muscle damage and inflammation tended to be more serious. On the 21th and 28th day, muscle lesions were most significant. Muscle fiber degeneration and necrosis and inflammatory cell infiltration could be seen in the experimental group. ② Compared with the control group, muscle endurance of mice in the experimental group decreased significantly [(6.1 ±1.3) min versus (9.2±1.6) min, U=2.00, P=0.017]. The MHC class-Ⅰ on the muscle fiber surface of the experimental group was positive, scattered infiltration of CD4 +, CD8+ T ly-mphocytes and CD68 + macrophages between muscle fibers and around the vascular areas could be observed, and CD20+B lymphocytes mainly distributed in the area around the blood vessels, nevertheless rarely seen between muscle fibers. Conclusion Exper-imental autoimmune myositis models of mice have been successfully induced by immunizing with MYBPC2 in China for the first time, and similar clinical and pathological features of human polymyositis could be observed. This new model can be used for studying the pathogenesis of autoimmune myositis.
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Objective To study the relationship between anti-transcription intermediary factor 1 family proteins (TIF1) autoantibodies profiles and cancer-associated dermatomyositis (CAM) and to define the diagnostic value of different subtypes of anti-TIF1 aotuantibodies for CAM.Methods The sera from 156 patients with dermatomyositis (DM),55 with polymyositis (PM),70 with systemic lupus erythematosus (SLE),60 with rheumatoid arthritis (RA),46 with primary Sj(o)gren syndrome (pSS),14 with systemic sclerosis (SSc),49 with kinds of malignancies and 40 healthy subjects were examined by immunoprecipitation assays followed by western blotting.Statistical analysis were performed using ANOVA,t test Mann-Wittney U and x2 test or Fisher exact test,nonparametric method was used to evaluate the sensitivity and specificity through calculating the area under the receiver operating characteristic curve (ROC).Results In summary,32 of 156 sera from patients with DM (20.5％) were positive for at least one anti-TIF1 autoantibodies.There are four subtypes of anti-TIF1 autoantibodies profiles existed in patients with DM,including 4 patients with only positive anti-TIF1-α (12.5％),20 with only positive anti-TIF1-γ (62.5％),7 with both positive anti-TIF1-α and anti-TIF1-γ (21.9％) and 1 with both positive anti-TIF1-β and anti-TIF1-γ (3.1％).However,only positive anti-TIF1-α (7.3％) was observed in 4 patients with PM.No patients with other CTDs as well as malignancy and healthy subjects were positive for these autoantibodies.The sensitivity and specificity of presence of anti-TIF1-α antibodies for the diagnosis of CAM were 42.9％ and 96.5％,respectively and those of anti-TIF1-β antibodies were 0 and 99.3％,respectively and those of anti-TIF-1-γ antibodies were 64.3％ and 86.6％,respectively.Application of areas of ROC to identify the best performance of test of anti-TIF1 antibodies profiles were 0.70,0.50,0.76,0.74 and 0.71,respectively.Conclusion Joint detection of antiTIF1 autoantibodies profiles can improve the diagnostic capbility for CAM.
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Objective To express the recombinant mouse histidyl-tRNA synthetase (HARS) and maltose binding protein (MBP) gene in Escherichia coli and obtain the purified protein which possesses antigen specificity.Methods Total RNA was extracted from the myocytes of C57BL/6 mouse and reversely transcripted to cDNA.The gene of N-terminal origin of 591 base pairs was amplified,then cloned into pMALc-5e vector.The recombinant plasmid was transformed into Rosetta-gami B,then IPTG was used to induce the expression of HARS-MBP.Fusion protein was purified by affinity chromatograph.The molecular weight (MW) of HARS-MBP was roughly determined by SDS-PAGE.The antigen specificity was identified by Western blotting using anti-Jo-1 serum from patients,commercial anti-HARS and anti-MBP antibodies.Results The recombinant HARS-MBP protein gene was efficiently expressed in Escherichia coli,and the MW was consistent with predicted MW of 66 000.The fusion protein was specifically combined with its antibody.Conclusion The HARS-MBP fusion protein could be efficiently and steadily synthesized in Escherichia coli,which shows satisfactory antigen specificity and provides the key requirement for making a deep study of HARS in the pathogenesis of idiopathic inflammatory myopathy(IIM) and animal modeling of IIM.
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Objective To investigate the serum levels of soluble human leukocyte antigen (sHLA)-G in patients with polymyositis (PM) or dermatomyositis (DM),and to analyze its association with clinical features and possible role in the pathogenesis of PM/DM.Methods Serum sHLA-G levels of 26 patients with PM,70 patients with DM and 35 matched healthy controls were measured by ELISA.The relationship between the sHLA-G levels and clinical features or seroimmunological data in the patients with PM/DM was analyzed.Results Serum levels of sHLA-G in PM/DM patients were significantly higher compared to healthy controls [(44±70) U/ml vs (4±5) U/ml,P＜0.01].There was statistically significant difference between DM patients and PM patients [(54±81) U/ml vs (27±41) U/ml,P=0.004].The incidence of dysphagia was significantly higher in sHLA-G elevated group than those in sHLA-G normal group (P=0.001).Additionally,Spearman rank correlation analysis showed that the serum sHLA-G levels were positively correlated with serum C3 (r=0.284,P=0.021),but negatively correlated with CD3+ T cells (r=-0.233,P=0.047) and CD4+ T cells (r=-0.287,P=0.015) in the peripheral blood in patients with PM/DM.Serum levels of sHLA-G in non-treated PM/DM patients were significantly higher compared to treated patients [(77±99) U/ml vs (34±52) U/ml,P=0.021].No relationship between serum sHLA-G levels and PM/DM disease activity,or different drug therapy was found.Conclusion Serum levels of sHLA-G are increased in PM/DM patients.The increased production of sHLA-G,paralleled with higher incidence of dysphagia and lower level of CD3+ T cells and CD4+ T cells,indicates that sHLA-G may play an important role in the pathogenesis of PM/DM.
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Objective To identify the prevalence of anti-transcriptional intermediary factor (TIF)1-γ antibody in Chinese patients with idiopathic inflammatory myositis and to define its role in the assessment of early diagnosis of cancer associated myositis (CAM) in a large cohort.Methods Sera from 96 Chinese patients with dermatomyositis(DM),50 patients with polymyositis (PM),33 patients with systemic lupus erythem-atosus (SLE),54 patients with rheumatoid arthritis (RA),8 patients with systemic sclerosis (SSc),and 40 healthy controls were examined by immunoprecipitation assays followed by Western blotting.The distribution of these antibodies in each group was assessed and the association between this autoantibody and CAM in a large cohort was further revealed.T test,Mann-Wittney U test,Chi-square test and Fisher exact test were used for statistical analysis.Results Sera from 17 of 96 DM patients (18％),including 1 with juvenile dermatomyositis (JDM) (17％),2 with clinical amyopathic dermatomyositis (CADM) (25％),and 9 with CAM (64％) were found to have anti-TIF1-γ antibody by immunoprecipitation assays followed by Western blotting.Only 1 patient with PM (2％) was observed with anti-TIF1-γ autoantibody,and no patients with other connective tissue disease patients as well as healthy controls were positive for this autoantibody.The risk of -developing CAM in anti-TIF1γ-positive patients was significantly increased compared to the anti-TIF1-γnegative group,with an OR of 17.74 (95％CI,5.68-55.40).In DM,the negative and positive predictive value of anti-TIF1-γ autoantibody for the diagnosis of CAM was 90.8％ and 56.3％,respectively.Anti-TIF1γ-positive DM patients were significantly older than anti-TIF1-γ-negative DM patients (63±11 vs 48 ±14,P＜0.01).Notably,three of the anti-TIF1γ-positive patients had ILD,one patient was classified as having CAM and the other two were DM patients without cancer,but anti-TIF1γ-positive patients still had a significantly lower incidence of interstitial lung disease (19％ vs 54％,P＜0.05).In contrast to anti-TIF1-γγ-negative DM patients,anti-TIF1-γ antibody-positive patients were more frequently (81％ vs 50％,P＜0.01).There was no significant difference between these groups in terms of other clinical and laboratory parameters.Conclusion Anti-TIF1-γ antibodies may act as a useful diagnostic serological marker for early diagnosis of CAM in Chinese patients.For patients with DM,anti-TIF1-γ antibodies should be assessed at the time of disease diagnosis.This antibody may have impo-rtant significance in the early diagnosis of tumor and improving prognosis.
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ObjectiveTo investigate the clinical significance of peripheral blood lymphocyte subsets in patients with idiopathic inflammatory myopathy (ⅡM).MethodsPeripheral blood lymphocyte subsets was determined by flow cytometry in 89 patients with polymyositis(PM ) or dermatomyositis ( DM ).The association between clinical features and peripheral blood lymphocyte subsets was analyzed by F test,t test and x2 test.ResultsPatients with active DM showed significant decreases in counts of CD3+ cell,CD3+CD4+ cell and CD3+CD8+ cell[(8±4),(5.4±2.8) and (2.6±1.6) ×108/L respectively],compared with those in inactive DM [(16±6), (10.4±5.6) and (5.6±3.8) ×108/L respectively] and healthy controls [(14±4), (8.3±2.8) and (4.6±1.7) ×108/Lrespectively](F=12.901,8.257,7.084; P＜0.05).Logistic regression analysis indicated that myositis disease activity could influence the counts of peripheral blood CD3+ cell,CD3+CD4+ cell and CD3+ CD8+ cell (b=0.211,0.344,0.289; P＜0.05 ).ILD in ⅡM could influence the counts of CD3+ cell and the ratio of CD3+CD4+cell (b=0.928,1.974; P＜0.05 ).Logistic regression analysis indicated that the count of CD3+CD8+ cell was risk factor for death,and the relative risk was 0.989(b=-0.011 ; P＜0.05).ConclusionPeripheral blood lymphocyte subsets may be regarded as useful laboratory parameters for monitoring RA disease activity.Decreased CD8+ T cell may predict a poor outcome of patients with IIM.
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Objectives To investigate serum levels of B cell activating factor(BAFF)in Chinese patients with polymyositis(PM)or dermatomyositis(DM),and analyze the correlation of BAFF with autoantibodies and clinical phenotypes.Methods Serum BAFF levels of 28 PM patients and 30 DM patients(study group),and 25 matched healthy controls(control group)were measured by ELISA.Serum anti-Jo-1 antibody levels were also measured by ELISA in all the subjects.The results of the two groups were compared by unpaired t test and the relevance was analyzed by Pearson's correlation analysis.Results Serum levels of BAFF in PM/DM patients were significantly higher compared to healthy controls(P =0.000),but there was no statistically significant difference between the PM and DM patients(P ＞ 0.05).Patients with interstitial lung disease(ILD)had significantly higher serum BAFF level than the patients without ILD(P =0.000)or the controls(P =0.000).Serum BAFF levels of patients with positive antinuclear antibody(ANA)were significantly higher than those with negative ANA(P =0.003).For patients with anti-Jo-1 antibodies,the serum BAFF levels were correlated with the serum concentration of anti-Jo-1 antibodies(r =0.799,P =0.006).Conclusions Serum levels of BAFF are increased in Chinese PM/DM patients.These findings indicate that BAFF may be possibly enrolled in the pathogenesis of PM/DM.Detecting serum BAFF levels could have some implication for the diagnosis and treatment of PM/DM.
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ObjectiveTo determine the serum level of anti-aminoacyl-tRNA synthetase (ARS)antibody in patients with polymyositis (PM) and dermatomyositis (DM) and to investigate the value of anti-ARS antibody for diagnosing interstitial lung diseases(ILD) in patients with PM/DM compared with anti-Jo-1 antibody.MethodsSerum anti-ARS antibody concentrations were measured by ELISA in 109 adult PM/DM patients,20 patients with SLE,20 patients with RA and 50 healthy controls.T test,Mann-Whitney U test,chi-square test or Fisher exact test were used to compare the sensitivity and specificity for diagnosing ILD in PM/DM patients between anti-ARS antibody and anti-Jo-1 antibody.Moreover,McNemar test was employed to analyze the correlation between the clinical features and anti-MDA5 antibody in PM/DM patients.Results The serum positive rate of anti-ARS antibody was 37.9％,7.8％,10％,0 and 0 in PM/DM patients with ILD and without ILD,patients with SLE and RA and healthy controls,respectively.Serum anti-ARS antibody levels and positive rate in the PM/DM patients with ILD were significantly higher when compared with PM/DM patients without ILD,patients with SLE and RA and healthy controls (X2=-13.5,5.45,10.57,15.17; P＜0.01 ).Anti-ARS antibody presented a significantly higher sensitivity for diagnosing ILD in patients with PM/DM compared to anti-Jo-1 antibody (P＜0.01).The rate of fever and ILD were significantly higher in anti-ARS positive group than anti-ARS negative group(X2=12.55,13.53; P＜0.05),while heliotrope rash and shawl sign occurred more often in anti-ARS negative group(X2=5.7,5.8; P＜0.05).Additionally,follow-up study showed that the serum anti-ARS antibody were all negative in nine patients who died of PM/DM with ILD (P＜0.05).ConclusionSerum anti-ARS antibody is a stronger predictor for early diagnosis of PM/DM with ILD compared to anti-Jo-1 antibody.The detection of anti-ARS antibody can be widely applied to clinical practice.
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ObjectiveTo determine the serum MDA5 levels and their clinical associations in patients with polymyositis/dermatomyositis (PM/DM).MethodsSerum anti-MDA5 antibody was detected by ELISA in 119 adult PM/DM patients,30 patients with systemic lupus erythematosus(SLE),30 patients with rheumatoid arthritis (RA),15 patients with primary Sj(O)gren's syndrome (SS),21 patients with pulmonary infection and 50 healthy controls.t-test,Mann-Whitney U test or chi-square test or Fisher exact test as well as Logistic multivariate regression analysis were carried out to compare the results of this study.ResultsSerum antiMDA5 antibody positive rate in DM patients(22.6％) were significantly higher compared with that of patients with PM (0,P＜0.01),patients with SLE (3.3％,X2=5.68,P＜0.05),RA (3.3％,X2=5.68,P＜0.05),pSS (0,P＜0.05) and pulmonary infection(0,P＜0.05) and healthy controls (0,P＜0.01).In the DM subgroup,CADM patients presented a higher positive anti-MDA5 antibody rate than classic DM patients.The incidence of arthritis,fever,vrash raised CEA and CA153 level,and serum concentration of GGT and ferritin were significantly higher in the anti-MDA5 positive DM group than anti-MDA5 negative DM group (X2=4.08,8.06,6.357,32.4,4.867; Z=-2.86,-2.44; P value of all these tests were less than 0.05 ),while the rate of serum positive ANA,serum level of CK and T,NK cell counts in the peripheral blood were much lower than those in anti-MDA5 negative DM group(X2=4.08; Z=-2.072,-2.013,-2.907; all P＜0.05).Moreover,the incidence of acute/subacute interstitial pneumonia(A/SIP) was significantly higher in anti-MDA5 positive DM patients than anti-MDA5 negative DM patients.The sensitivity and specificity of anti-MDA5 antibody for diagnosing A/SIP in DM patients were 88.2％ and 94％ respectively.Additionally,logistic multivariate analysis showed that anti-MDA5 was an independent risk factor for death of interstitial lung diseases (ILD) in DM (OR=8.46,95％CI 1.77～40.36,P＜0.01).ConclusionIn Chinese PM/DM patients,serum anti-MDA5 antibody is mainly present in DM patients and is a strong predictor for poor prognosis diagnosis of DM with A/SIP and is an independent risk factor for death of ILD in DM.
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ObjectiveTo evaluate the correlation between serum anti-Jo-1 antibody level and myositis disease activity in polymyositis/dermatomyositis.MethodsAnti-Jo-1 antibody levels in serum from 148 polymyositis/dermatomyositis patients and 130 healthy controls were measured by both ELISA and immunoblot assay.Disease activity of the anti-Jo-1 antibody positive patients was assessed by the global myositis disease activity score (visual analogue score,VAS) established by the International Myositis Assessment and Clinical Studies(IMACS) Group.The correlation between disease activity and level of serum antiJo-1 antibody was assessed.Comparisons between groups were performed by x2 test or t test.ResultsThe positive rate of ELISA and EUROLINE was 24.3％(36/148) and 27.0％(40/148) respectively.Fever,ILD,arthritis/arthralgia were found to be more predominant in anti-Jo-1 antibody positive patients than those who were anti-Jo-1 antibody negative patients.There was significant positive correlation between the global myositis disease activity score (VAS) and serum level of anti-Jo-1 antibody (r=0.874,P=9.000).Serum antiJo-1 antibody levels,together with global disease activity,were significantly decreased in the 7 patients after treatment.ConclusionAnti-Jo-1 antibody level measured by ELISA is associated with disease activity of PM/DM,and could be a marker of disease activity.
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Objective To study the clinical, laboratory, X-ray and the pathological features of Parkinson disease patients with rheumatoid-like deformities. Methods One patient was described and the relevant English literature in recent 50 years were reviewed. Results Rheumatoid-like deformities in Parkinson disease was mostly observed in women. The ratio between male and female was about 1:5.6. Joint deformities occurred after 7.6 years of Parkinson's disease in average. The manifestations of joints included the flexion of the metacarpophalangeal (MCP) joints, hyperextension of the proximal interphalangeal (PIP) joints, flexion of the distal interphalangeal (DIP) joints, and ulnar deviation of wrists and bilateral feet hallux valgus. Whole-blood analysis, biochemistry profile, erythrocyte sedimentation rate, C -reactive protein were all in normal range. Rheumatoid factor and ANA, anti-ENA profile, AKA, anti-cyclic citrullinated peptide (anti-CCP) antibody and antiperinuclear factor (APF) were all negative. Periarticular erosion was not observed in plaint X -ray films. Synovial pathology showed non -specific infla -mmation without classical syno vial membrane proliferation and pannus formation. NSAIDs and DMARDs were uneffective, but on the contrary, anti -parkinson' s disease therapy could relieve joints symptoms. Conclusion Parkinson disease can be accompanied with rheumatoid-like deformities which may be misdiagnosed as RA and should be differentiated from RA by laboratory, radiographs and synovium pathology examination.