New, Simple, Fast, Whole Blood Intraoperative PTH Assay – Laboratory and Clinical Validation

Abstract Introduction IOPTH monitoring is a reliable method of predicting cure during the surgery for Primary Hyperparathyroidism (PHPT) but current methods are slow and require presence of laboratory staff. NBCL Connect is the first Analyser which can be used by theatre staff and measures whole blood PTH in 5 minutes. Aim Laboratory and Clinical validation of new IOPTH assay in patients undergoing surgery for PHPT. Methods Intra and inter assay variability using BioRad Liquichek Specialty Immunoassay, internal quality controls and serum and whole blood PTH concentrations in patients cured by parathyroidectomy for PHPT measured on NBCL and “gold standard” Future Diagnostics (FD) and Roche platforms. Pearson coefficient was used for linear correlation between measurements. Results Preliminary precision data confirms good analytical performance of NBCL Analyser which is similar to that of FD platform. Further precision, accuracy, linearity and sensitivity studies are ongoing. Plasma PTH concentration from 4 patients (5 samples each, total 20) measured on NBCL and FD platforms showed good correlation (R 0.90, slope 0.644, IC – 0.68) Whole blood PTH concentration in 2 patients (5 samples each, total 10) measured on NBCL, FD and Roche platforms showed good correlation. 50% reduction in circulating PTH, main (Miami) criteria confirming biochemical cure, were similar for all 3 platforms Conclusions NBCL Connect Analyser assay showed good laboratory and clinical performance able to predict biochemical cure in patients undergoing surgery for PHPT. Our preliminary data suggests that this straightforward to operate and fast system is a promising technology which can be used widely during parathyroid surgery.