Serum KL‐6 levels in pulmonary Langerhans’ cell histiocytosis

Abstract

Background Serum Krebs von den Lungen‐6 (sKL‐6) is an high‐molecular‐weight (200 kDa) glycoprotein predominantly expressed by damaged alveolar type II cells, and it has been proposed as a potential biomarker of different ILD. This is a prognostic biomarker for chronic hypersensitivity pneumonitis (cHP) and idiopathic pulmonary fibrosis (IPF), two diseases that share several clinical and radiological features. Little data are available on the potential role of KL‐6 in granulomatous and cystic interstitial lung diseases, including the orphan disease known as pulmonary Langerhans cell histiocytosis (PLCH). Methods For the first time, sKL‐6 concentrations were assayed and compared in 96 patients (17 PLCH, 22 IPF, 34 cHP) and 22 healthy controls. Results Serum KL‐6 concentrations were significantly higher in PLCH (599 ± 594 U/mL), IPF (1645 ± 846 U/mL) and cHP patients (1691 ± 1643 U/mL) than in healthy controls (268 U/mL) (P = .037). Area‐under‐the‐curve values of sKL‐6 were 73.4% between PLCH and healthy controls, 84.5% between IPF and PLCH and 78% between cHP and PLCH. An indirect correlation between sKL‐6 concentrations and peripheral CD1a‐positive cells was demonstrated (r = −0.82; P = .034). Conclusion Serum KL‐6 concentrations were higher in PLCH patients than in controls, reflecting the alveolar damage typical of this rare interstitial lung disease.

Serum KL‐6 concentrations as a novel biomarker of severe COVID‐19

“…Serum samples were obtained from all patients at hospital admission before any biological treatment or infusion of high‐dose intravenous steroids or invasive ventilation. Serum concentrations of KL‐6 (sKL‐6) were measured by KL‐6 reagent assay (Fujirebio Europe, UK), as previously reported 2,4,10 . The principle of the assay is agglutination of sialylated carbohydrate antigen in samples with KL‐6 monoclonal antibody by antigen–antibody reaction.…”

“…It is mainly produced by damaged or regenerating alveolar type II pneumocytes 1 . This mucin protein is recognized as a prognostic bioindicator of ILDs, predicting response to antifibrotic therapies 2‐4 . It has also been proposed as a prognostic marker of ARDS: high KL‐6 concentrations have been demonstrated in ventilated patients and showed a correlation with risk of mortality 5 .…”

Serum Concentrations of KL-6 in Patients with IPF and Lung Cancer and Serial Measurements of KL-6 in IPF Patients Treated with Antifibrotic Therapy

“…Serum samples from all patients were assayed for KL-6 concentrations by KL-6 reagent assay (Fujirebio Europe, Gand, Belgium), as previously reported [6,[24][25][26][27][28][29][30][31]. The principle of the assay is agglutination of sialylated carbohydrate antigen in samples with KL-6 mAb by antigen-antibody reaction.…”

Personalized Approach of Severe Eosinophilic Asthma Patients Treated with Mepolizumab and Benralizumab

“…In severe asthma, the airway remodeling usually consists of abnormal changes of cells with thickness of the walls and scarred [13]. A target of remodeling and diseases activity widely investigated among fibrotic lung diseases is KL-6 [17-19]. Serum KL-6 is a mucin-like glycoprotein, over-expressed in alveolar epithelial cells, reflecting alveolar damage and regeneration of type II pneumocytes [20, 21].…”