Clinical Usefulness of Serum Krebs von den Lungen-6 for Detecting Chronic Aspiration in Children with Severe Motor and Intellectual Disabilities

Objective To determine whether the serum level of Krebs von den Lungen-6 (KL-6), a circulating high-molecular weight glycoprotein and a diagnostic biomarker of interstitial lung diseases, is a clinically useful biomarker for detecting chronic aspiration in children with severe motor and intellectual disabilities (SMIDS). Study design Children with SMIDS undergoing videofluorography for assessment of dysphagia were prospectively evaluated. Based on the videofluorography results, the participants were classified into aspiration and non-aspiration groups. Age, sex, white blood cell count, and serum levels of C-reactive protein, lactate dehydrogenase, albumin, and KL-6were compared between the 2 groups. Binary logistic regression was performed to identify factors independently associated with the presence of aspiration. Results A total of 66 patients participated in this study, 37 who were classified as the aspiration group and 29 as the non-aspiration group. The serum KL-6 level in the aspiration group was significantly higher than that in the nonaspiration group (median, 344 U/mL vs 207 U/mL, P < .01). Logistic regression modeling showed that the number of prescribed antiepileptic drugs (OR, 1.978; 95% CI, 1.217, 3.214; P < .01) and serum KL-6 level (OR, 1.012; 95% CI, 1.005, 1.019; P < .01) were independent predictors of aspiration. Conclusions The study demonstrated that the KL-6 level is significantly higher in children with SMIDS who aspirate than in those who do not. KL-6 shows promise as a biomarker for chronic lung disease due to aspiration in these children.