Jacobs Journal of Bone Marrow and Stem Cell Research

Krebs von den Lungen 6 (KL6-): A Potential Predictive Biomarker for Bronchiolitis Obliterans in Pediatric and Young Adult Bone Marrow Transplant Recipients

Published on: 2016-12-05


Background:Bronchiolitis obliterans syndrome (BOS) is a serious complication of allogeneic bone marrow transplant (BMT) that is difficult to diagnose. There is a need for a biomarker to detect BOS in transplant recipients. Krebs von den Lungen-6 (KL-6) is a high molecular weight glycoprotein that is expressed on the epithelial surface of type II pneumocytes and bronchiolar epithelial cells in the lungs. We hypothesized that serum KL-6 levels would be elevated in subjects with known BOS.
Methods: This was a multi-center case control study that utilized convenience sampling. Serum samples were obtained from 20 subjects that underwent allogeneic BMT and 20 healthy controls between the ages of 6 months and 30 years. Of the 20 subjects that underwent BMT, 6 met the criteria for BOS. KL-6 levels were determined using a commercially available sandwich-type enzyme linked immunosorbent assay kit.
Results: Mean serum KL-6 levels (+ standard deviation) for BMT subjects with BOS, BMT subjects without BOS and healthy controls were 641.5 (+517.1), 251.5 (+60.6) and 260.8 (+55.3) U/ml respectively. There was an overall difference in KL-6 levels between the three groups (p<0.001). Post hoc tests showed that KL-6 levels in BMT patients with BOS were significantly higher than those in both BMT patients without BOS (p=0.001) and healthy controls (p=0.001). There was no statistically significant difference in KL-6 levels between BMT subjects without BOS and healthy controls (p = .99). 
Conclusion: KL-6 levels were significantly elevated in BMT subjects with BOS as compared those without BOS and healthy controls. KL-6 could serve as a biomarker to detect BOS in BMT recipients


Bronchiolitis Obliterans Syndrome; Stem Cell Transplant; Rare Lung Diseases; Biomarkers; Pediatrics