Updated total IgE reference intervals in Norwegian adults

It is important and expected of laboratories to provide updated reference intervals to the clinician. As no recent publications report adult total IgE reference intervals on a Scandinavian population, the aim of our study was therefore to provide an estimate on healthy Norweigian adults.

A reference interval study was conducted in accordance to CLSI guidelines. Samples were collected from n = 252 presumably healthy adult participants enrolled through the regional blood donation program. Total IgE measurements were performed on the ImmunoCAP^TM platform (Thermo Fisher Diagnostics) traceable to the WHO-reference standard (75/502) for total IgE measurements.

An upper 95% total IgE reference limit was estimated to 302 kU/L (90% CI 177-388 kU/L), and the 97.5% percentile was estimated to 391 kU/L (90% CI 344-560 kU/L). No significant differences were found between participants who self-reported having an allergic disease and participants who did not self-report having an allergic disease.

Our results and other recent publications find markedly higher values than adult reference intervals established four decades ago which still remain widely used by clinical laboratories. We therefore recommend total IgE reference intervals should be critically reviewed and updated.