USE OF A RADIORECEPTOR ASSAY IN THE ASSESSMENT OF CUSHINGOID FEATURESIN PATIENTS WITH JUVENILE RHEUMATIC DISEASES

A marked variation has been observed in severity of cushingoid appeara nce in patients with rheumatic diseases (RD) following steroid adminis tration. We studied ten children with RD to determine if a relationshi p exists between cushingoid features and an individual's steroid activ ity as measured by prednisolone equivalents using a radioreceptor assa y. Cushingoid features were clinically assessed by a "cushing score" a ccording to the method of Bergrem. Patients were assigned to either th e cushingoid (C) or noncushingoid (NC) group at study entry according to their cushing score. Blood was drawn prior to prednisolone ingestio n and then at 30, 60, 90, 120, 240, and 360 minutes and each sample wa s assessed for prednisolone equivalents and also for free and total co rtisol. Group comparisons of dose-adjusted area under curve (AUC) and peak response are reported. Cushingoid patients had higher plasma pred nisolone equivalents (PE) than noncushingoid patients as measured by p eak PE and AUC. The PE . 6 h/L average AUC for C patients was 248-mu-g PE . 6 h/L versus 134-mu-g PE . 6 h/L for NC patients. This nearly tw ofold difference was also noted between mean peak values (C 82-mu-g/L vs. NC 44-mu-g/L). Spearman correlations of Cushing scores with these two parameters indicated significant (p < 0.05) relationships. A patie nt's Cushing score correlated best with peak response (r(s) = 0.78) an d also with AUC (r(s) = 0.72). Measurement of plasma peak PE or AUC co uld be valuable for individualizing steroid dosing in children with RD .