Endocrine Abstracts

Case 1: A 17-year-old female was referred to the endocrinology outpatients due to abnormal thyroid function tests (TFTs) (as below) detected on routine monitoring for Thyroxine replacement therapy. Following exclusion of pregnancy, possibilities of assay interference due to heterophilic antibodies as well as thyroid hormone resistance were considered. Repeat analysis was arranged at two laboratories using different methods. Results were concordant, excluding assay interference...

Background: The suitability of serum insulin-like growth factor 1 (IGF-1) reference ranges (RR) used locally (manufacturer-derived), were raised as a clinical concern. IGF-1 levels above the RR were reported in patients displaying no clinical signs or symptoms of acromegaly, and in whom growth hormone suppression tests were negative. No analytical issue was evident, and quality performance indicators were satisfactory.Methods: A review of all serum IGF-1...

Background: While investigating hyperandrogenism in women, local laboratory policy dictates adult females with a serum testosterone of >3.5 nmol/l should be confirmed with an alternative method to exclude interference by cross-reacting substances. Patients who were on testosterone replacement or had a previous result in the same year were excluded. We explore the biochemical investigation of discrepant testosterone in females.<strong...

Burosumab has become available as a treatment for children with X-linked hypophosphatemia (XLH) and is a recombinant fully human IgG1 against FGF23. By binding to the active FGF23, burosumab inhibits its effect and symptoms (growth retardation, rickets, enthesiopathy, low phosphate) may improve, however, not in all children. Concomitantly paediatricians are keen to measure FGF23, in treated children, to avoid overtreatment with burosumab, associated with potential calcificatio...