Al Rubaye A M, Sharquie I K, Gorial F I
University of Baghdad, College of Medicine, Department of Microbiology and Immunology, Baghdad, Iraq.
University of Baghdad, College of Medicine, Department of Medicine, Baghdad, Iraq.
Med J Malaysia. 2023 Sep;78(5):609-615.
Interleukin (IL)-40 is a recently identified cytokine with a novel role in the pathogenesis of inflammatory diseases. Since systemic lupus erythematosus (SLE) is an autoimmune disease characterised by a pro-inflammatory response, it is likely that IL-40 contributes to the underlying disease processes of this disorder. The aim of the current study was to evaluate the potential of IL-40 to act as a diagnostic biomarker for SLE.
The study included 99 patients with SLE who attended the Rheumatology Unit at Baghdad Teaching Hospital. These subjects were divided into three subgroups according to disease status: inactive, n = 33; active moderate, n = 33; and active severe, n = 33. Additionally, 33 matched controls were studied. Full medical histories, body mass index, gender and clinical disease activity, the latter evaluated with the SLE disease activity index, were collected. Laboratory parameters measured included anti-dsDNA antibodies, C3 and C4 levels, erythrocyte sedimentation rate and C-reactive protein titres. Serum IL-40 levels were quantified using an enzyme-linked immunosorbent assay.
IL-40 levels were significantly higher in patients (12.5420 ± 3.00575 ng/L) than in controls (6.1138 ± 0.59452 ng/L; p < 0.01). Mean serum IL-40 concentration was highest in the active severe group (15.2291 ± 2.26540 ng/L) and decreased, in order of disease severity, in the remaining cohorts: active moderate, 13.0643 ± 1.23927 ng/L; inactive, 9.3325 ± 1.62807 ng/L (P < 0.01); controls, 6.1138 ± 0.59452 ng/L. Serum IL-40 levels showed excellent validity for the diagnosis of SLE with a cut-off value of ≥ 9.3 ng/ml and area under the curve of 0.987. Sensitivity, specificity and accuracy were 99%, 90.9% and 96.97%, respectively (P < 0.001).
Serum IL-40 levels were elevated in SLE patients. It is therefore proposed that IL-40 is a novel cytokine which is associated with SLE and positively linked with disease severity.
白细胞介素（IL）-40是一种最近发现的细胞因子，在炎症性疾病的发病机制中具有新的作用。由于系统性红斑狼疮（SLE）是一种以促炎反应为特征的自身免疫性疾病，IL-40可能参与了该疾病的潜在病理过程。本研究的目的是评估IL-40作为SLE诊断生物标志物的潜力。
该研究纳入了99名在巴格达教学医院风湿病科就诊的SLE患者。这些受试者根据疾病状态分为三个亚组：非活动期，n = 33；活动中度，n = 33；活动重度，n = 33。此外，还研究了33名匹配的对照。收集了完整的病史、体重指数、性别和临床疾病活动度（后者用SLE疾病活动指数评估）。检测的实验室参数包括抗双链DNA抗体、C3和C4水平、红细胞沉降率和C反应蛋白滴度。使用酶联免疫吸附测定法定量血清IL-40水平。
患者的IL-40水平（12.5420±3.00575 ng/L）显著高于对照组（6.1138±0.59452 ng/L；p < 0.01）。血清IL-40平均浓度在活动重度组最高（15.2291±2.26540 ng/L），并按疾病严重程度依次降低，其余队列：活动中度，13.0643±1.23927 ng/L；非活动期，9.3325±1.62807 ng/L（P < 0.01）；对照组，6.1138±0.59452 ng/L。血清IL-40水平对SLE诊断具有良好的有效性，截断值≥9.3 ng/ml，曲线下面积为0.987。敏感性、特异性和准确性分别为99%、90.9%和96.97%（P < 0.001）。
SLE患者血清IL-40水平升高。因此，提出IL-40是一种与SLE相关且与疾病严重程度呈正相关的新型细胞因子。
