Department of Medical and Surgical Sciences & Neurosciences, Respiratory Diseases Unit, University of Siena, Siena, Italy.
Department of Rheumatology, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom.
PLoS One. 2024 Oct 3;19(10):e0311357. doi: 10.1371/journal.pone.0311357. eCollection 2024.
Interstitial lung disease (ILD) may complicate the course of systemic autoimmune rheumatic disease (SARD) and diagnostic biomarkers are needed. Krebs von den Lungen-6 (KL-6), ferritin (FER) and interleukin 6 (IL-6) have been involved in the ILD development. Our study aimed to compare KL-6, FER, IL-6 and soluble mesothelin-related peptide (SMRP) concentrations in a cohort of idiopathic and SARD-ILD.
3169 patients were enrolled in the "UK Biomarkers in Interstitial Lung Disease (UK-BILD) Study". We selected patients affected by SARD-ILD and idiopathic ILD (usual interstitial pneumonia-idiopathic pulmonary fibrosis and fibrotic non-specific interstitial pneumonia). Serum marker concentrations were measured through chemiluminescent assays (Fujirebio Europe, Ghent, Belgium).
1013 patients were selected for the study: 520 (51.3%) had idiopathic ILD and 493 (48.7%) SARD-ILD. Idiopathic ILD patients displayed higher KL-6 values than SARD-ILD (p = 0.0002). FER and SMRP, though within normal ranges, were significantly higher in idiopathic ILD (p<0.0001). Logistic regression showed good sensitivity (69.4%) and specificity (80.4%) selecting the variables FER and KL-6 concentrations, age and gender-male correlated with a diagnosis of idiopathic ILD.
Our study showed the excellent diagnostic value of KL-6 for detecting ILD, which irrespective of the final diagnosis and extent of disease, is always elevated and is a reliable biomarker of lung fibrosis in various diseases, ranging from idiopathic to autoimmune forms. Our study proposed an ILD differentiation model including clinical background. In this context, combination of serum markers and clinical data, as seen in our cohort, may lead to a further improvement in diagnostic accuracy for ILD.
间质性肺疾病（ILD）可能会使系统性自身免疫性风湿病（SARD）的病程复杂化，因此需要诊断生物标志物。Krebs von den Lungen-6（KL-6）、铁蛋白（FER）和白细胞介素 6（IL-6）与ILD 的发展有关。我们的研究旨在比较特发性和 SARD-ILD 患者中 KL-6、FER、IL-6 和可溶性间皮素相关肽（SMRP）的浓度。
3169 名患者参加了“英国间质性肺病生物标志物研究（UK-BILD）”。我们选择了患有 SARD-ILD 和特发性 ILD（特发性间质性肺炎-特发性肺纤维化和纤维化非特异性间质性肺炎）的患者。通过化学发光检测法（Fujirebio Europe，根特，比利时）测量血清标志物浓度。
本研究共纳入 1013 名患者：520 名（51.3%）患有特发性 ILD，493 名（48.7%）患有 SARD-ILD。特发性 ILD 患者的 KL-6 值高于 SARD-ILD（p=0.0002）。FER 和 SMRP 虽然在正常范围内，但在特发性 ILD 中明显升高（p<0.0001）。Logistic 回归显示，选择 FER 和 KL-6 浓度、年龄和男性（与特发性 ILD 相关）等变量具有良好的敏感性（69.4%）和特异性（80.4%）。
我们的研究表明 KL-6 对检测 ILD 具有出色的诊断价值，无论最终诊断如何，ILD 患者的 KL-6 水平总是升高的，并且是各种疾病（从特发性到自身免疫性疾病）肺纤维化的可靠生物标志物。我们的研究提出了一个包含临床背景的ILD 鉴别模型。在这种情况下，如我们的队列中所见，血清标志物和临床数据的结合可能会进一步提高 ILD 的诊断准确性。
