ABSTRACT
Objective To explore the expression of interferon-inducible genes (IFIG) in idiopathic inflammatory myopathies (IIM) patients and its clinical significance.Methods Peripheral blood mononuclear cells from 52 IIM patients and 20 healthy controls were extracted.The transcriptional levels of six IFIG genes:oligoadenylate synthetase 1 (OAS-1),IFN-induced protein with tetratricopeptide repeats 1(IFIT1),IFIT4,interferon-inducible-protein 44 (IFI44),radical S-adenosyl methionine domain containing protein 2 (RSAD2) and myxo-virus resistance gene 1 (MX-1) were detected by real-time polymerase chain reaction (PCR).Interferon scores were calculated and compared.The correlations between interferon scores and clinical features of IIM patients were investigated.Non-parametric Mann-Whitney and Spearman analysis were used for statistical analysis.Results In IIM patients,the transcriptional levels of OAS-1 [90.4(40.2,350.8)],IFIT1 [112.7(49.8,151.1)],IFIT4 [127.8(110.4,200.2)],IFI44 [100.3(39.5,160.7)],RSAD2 [100.9(50.2,559.2)] and MX-1 [110.7(60.3,298.9)] were greatly higher than those in healthy controls [4.5(2.1,27.8),21.5(0.4,31.4)i 21.5(0.8,51.2),5.2(0.4,27.8),27.8(17.5,33.5),25.1(15.7,31.8),respectively] (Z=-5.121,-4.359,-5.301,-4.906,-4.348,-4.151; P＜0.01).Meanwhile,interferon scores were significantly elevated in IIM patients [65.7(3.6,136.9),Z=-5.778,P＜0.01],compared with healthy controls [1.2(0.1,3.1)],especially in those with interstitial lung disease [89.3(41.9,176.7),Z=0.544,P＜0.05].Interferon scores were correlated positively with ESR (r=0.234,P＜0.05).Conclusion The mRNA levels of OAS-1,IFIT1,IFIT4,IFI44,RSAD2 and MX-1 are significantly increased in patients with IIM.Interferon score might be used as a new biomarker for IIM patients.