| Objective1.To assess the profile of myositis specific antibodies(MSAs)in Chinese patients with idiopathic inflammatory myopathy(IIM)and explore associations of antibody profile with clinical characteristics,laboratory data and prognosis.2.To assess anti four and a half LIM domain 1(FHL1)antibody in serum of Chinese patients with idiopathic inflammatory myopathy(IIM)and explore clinical significance of anti FHL1.Methods1.178 patients with IIM were enrolled.12 MSAs were measured by immunoblotting.Associations between antibody profile and clinical manifestations were determined by statistical analyses.Further logistic regression analyses were performed to identify if MSAs profile were risk factors for specific clinical features.2.Serum samples were collected from 76 IIM patients,patients with other autoimmune diseases(including rheumatoid arthritis,systemic lupus erythematosus,sjogren syndrome,scleroderma)and healthy people.Anti FHL1 antibody in serum were detected by enzyme-linked immunosorbent assay(ELISA).Statistical analysis was conducted with clinical data.Results1.The most frequent MSAs were anti aminoacyl t RNA synthetase(ARS,including anti Jo-1,anti PL-7,anti PL-12,anti EJ,anti OJ)(34.8%),followed by anti MDA5(32.6%),anti TIF1γ(11.8%)and anti SRP(11.8%).Anti ARS-positive patients demonstrated significantly higher prevalence of interstitial lung disease(ILD)and mechanic’s hand(90.3%vs 66.4%,P<0.001,16.1%vs 4.3%,P=0.007).Compared with those who were anti MDA5-negative,patients with positive anti MDA5 had higher incidence of ILD,Gottron sign,malar rash and arthritis(all P<0.05)and low incidence of muscular weakness and dysphagia(55.2%vs 78.3%,P=0.001,8.6%vs 23.3%,P=0.018).Anti TIF1γwas more prevalent in patients older than 65 years(25.9%vs 9.3%,P=0.032)and associated with tumor(19.0%vs 3.2%,P=0.01).Patients with positive anti SRP have higher incidence of muscular weakness and higher levels of CK,LDH and AST(all P<0.05).The patients with positive anti Mi-2βhave less frequency of ILD(40.0%vs 77%,P=0.003).Logistic regression analysis revealed that anti MDA5 and anti Jo-1 were significantly independent risk factors for ILD.Anti TIF1γwere significantly independent risk factors for dysphagia.The survival time of anti MDA5 positive patients was significantly less than those who were negative(5.0 vs 14.0,months,P=0.001).2.A total of 76 patients with IIM were enrolled,including 65 with dermatomyositis and11 with polymyositis.17 patients with IIM were found to be positive for anti FHL1antibody,with a positive rate of 22.4%.Most samples from patients with other autoimmune diseases and healthy people were negative.Statistical analyses revealed that anti FHL1-positive patients showed significantly higher prevalence of dysphagia(41.2%vs 10.2%,P=0.009).Log-Rank test suggested patients with positive anti FHL1 antibody had shorter survival time(3.0 months vs 21.0 months,χ~2=3.765,P=0.052).Conclusions1.Anti ARS is the most common MSA.Some subtype of MSAs were associated with distinct clinical manifestations and might serve as independent risk factor for specific clinical features.Detection of MSAs was helpful for diagnosis,treatment and prognosis of patients with inflammatory myopathy.2.Anti FHL1 antibody was associated with specific clinical manifestation in IIM and serves as a promising biomarker in assisting clinical diagnosis and prognosis. |
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