Serum KL-6 in normal neonates and children without respiratory disease

Abstract

Serum levels of a high molecular weight circulating antigen KL-6, detected by means of a sandwich assay using a monoclonal antibody, had been proved to be a useful marker in monitoring the activity of interstitial lung diseases in adult. However, clinical use of KL-6 in pediatric patients had not been reported. We investigated a series of101children (1mo.-16yr., median 6yr.) who underwent blood testing at our hospital for any reason, except for a respiratory disease, and 40 full term healthy neonates as reference sample groups. The reference interval determined for children was83.7-249.9U/ml (median 149.0U/ml), which was significantly lower than the adult values reported elsewhere. Sex and age difference was not observed. Neither the WBC count nor the CRP value was associated with KL-6levels. But, the serum LDH had a weak positive correlation with KL-6levels. The KL-6levels in neonates were significantly lower than in children. The reference interval determined for neonates was 50.8-226.3U/ml (median 107.2U/ml). Difference with sex, gestational age, route of delivery, birth weight, and the timing of blood sampling was not observed.