Increased interferon-inducible gene expression, an useful marker in the diagnosis and disease activity evaluation of systemic lupus erythematosus / 中华风湿病学杂志

ABSTRACT

Objective To study the role of the expression levels of 5 type Ⅰ interferon (IFN)-inducible genes (LY6E, OAS1, OASL, MX1, and ISG15) in the diagnosis and disease activity evaluation of systemic lupus erythematosus (SLE). Methods Peripheral blood was obtained from 68 SLE patients, 50 patients with other connective tissue diseases and 26 normal controls, and total RNA was extracted and reverse transcribed into complementary DNA. Real-time PCR technique was used to determine gene expressions at transcription level. An IFN score for each individual was calculated according to the expression of 5 1FN genes. Comparisons of gene expression and IFN score were made among groups. The genes expression levels in patients with SLE were analyzed using receiver operative characteristic curve. The association between IFN scores and disease activity, as assessed by the SLEDAI scores and 24 h proteinuria, was analyzed using Spearman correlation analyses. Results ① The expression levels of MX1, OASL, OAS1, ISG15 and LY6E mRNA in SLE patients were significantly increased as compared with normal controls and disease controls (P all＜0.01 ).② IFN scores in SLE patients (17.9±29.1) were significantly increased as compared with normal controls (0±3.3)and disease controls (3.0±8.1) (P all＜0.01 ). ③ IFN scores area under the ROC curve (AUCROC) was 0.846. When The IFN scores reached 2.56, its sensitivity and specificity for the diagnosis of SLE were 93.1%and 78.3%, respectively. ④ Levels of IFN score was positively correlated with SLEDAI scores (r=0.256,P＜0.05) and 24 h proteinuria (r=0.337, P＜0.05). Conclusion The 5 IFN-inducible genes are highly expressed in SLE patients. IFN score level is valuable for the diagnosis of SLE and a high IFN score is usually associated with an elevated disease activity.