Lesley Tetlow

Radioimmunoassay for the measurement of thrombospondin in plasma and breast cyst fluid: Validation and clinical application

Thrombospondin is an adhesive protein that has been implicated in malignancy, specifically in tumour progression and angiogenesis. We developed a radioimmunoassay for the measurement of thrombospondin in plasma and breast cyst fluid. The assay exhibited high accuracy, with recoveries of 102-136% and acceptable imprecision, with an intra-assay coefficient of variation (CV) of < 7·5% across the analytical range 30-1000 ng/mL and inter-assay CV of 4·4% and 7·7% at 152 and 224 ng/mL, respectively. Thrombospondin measured in the breast cyst fluid of patients with gross cystic disease of the breast showed that patients with type II (Na+) cysts had significantly higher concentrations than type I (K+) cysts. The plasma thrombospondin reference range was determined as 131-274 ng/mL. Patients with breast cancer had significantly higher plasma thrombospondin concentrations than normal individuals or patients with benign breast disease. Plasma thrombospondin was higher in breast cancer patients with lymph node involvement.

No evidence of an increase in early infant mortality from congenital adrenal hyperplasia in the absence of screening

Objective Congenital adrenal hyperplasia (CAH) is not currently included in the UK newborn screening programme. We investigated the hypothesis that, owing to non-specificity of symptoms, a proportion of males affected by salt-wasting (SW) CAH have died in infancy without being diagnosed. Design Stored newborn screening blood spot samples were analysed for 17α-hydroxyprogesterone (17-OHP) in the following groups: Infants born in the North West of England, 1994 to 2006, who had died by 6 months age; (n=1198), a neonatal reference group (full-term n=100; preterm n=100) and a CAH positive control group. A newborn blood spot sample collected before diagnosis was available in 29/61 CAH patients recruited. SW CAH was present in 18/29 patients (16 males and 2 females). Samples from the deceased group with elevated 17-OHP were analysed for 8 common mutations in the 21-hydroxylase gene (CYP21A2). Setting North West of England. Results Grouped by gestational age, mean (maximum) blood spot 17-OHP in nmol/L was as follows. Deceased full-term n=279, 6 (107); deceased premature n=365, 28 (251); deceased unknown gestational age n=553, 13 (>394). In the SW positive control group, the lowest level of 17-OHP was 179 nmol/L and 14 had levels greater than the highest standard (>268 to >420 nmol/L). All samples from the deceased group with 17-OHP results >179 nmol/L (n=6) and a further 13 samples underwent mutation analysis. No mutations were identified. Conclusions Our findings do not support the hypothesis that, in our unscreened population, males affected by SW CAH are dying prior to diagnosis.

Newborn Screening for Primary Congenital Hypothyroidism: Estimating Test Performance at Different TSH Thresholds.

Abstract Context Active surveillance of primary congenital hypothyroidism (CH) in a multiethnic population with established newborn bloodspot screening. Objective To estimate performance of newborn screening for CH at different test thresholds and calculate incidence of primary CH. Design Prospective surveillance from June 2011 to June 2012 with 3-year follow-up of outcomes. Relative likelihood ratios (rLRs) estimated to compare bloodspot TSH test thresholds of 6 mU/L and 8 mU/L, with the nationally recommended standard of 10 mU/L for a presumptive positive result. Setting UK National Health Service. Patients Clinician notification of children aged <5 years investigated following clinical presentation or presumptive positive screening result. Main Outcome Measure(s) Permanent primary CH status determined by clinician report of continuing T4 requirement at 3-year follow-up. Results A total of 629 newborns (58.3% girls; 58.7% white ethnicity) were investigated following presumptive positive screening result and 21 children (52.4% girls; 52.4% white) after clinical presentation; 432 remained on treatment at 3-year follow-up. Permanent CH incidence was 5.3 (95% CI, 4.8 to 5.8) per 10,000 infants. With use of locally applied thresholds, sensitivity, specificity, and positive predictive value were 96.76%, 99.97%, and 66.88%, respectively. Compared with a TSH threshold of 10 mU/L, positive rLRs for 8 mU/L and 6 mU/L were 1.20 (95% CI, 0.82 to 1.75) and 0.52 (95% CI, 0.38 to 0.72), and negative rLRs were 0.11 (95% CI, 0.03 to 0.36) and 0.11 (95% CI, 0.06 to 0.20), respectively. Conclusions Screening program performance is good, but a TSH threshold of 8 mU/L appears superior to the current national standard (10 mU/L) and requires further evaluation. Further research should explore the implications of transient CH for screening policy.

Paediatric Anti-Müllerian Hormone measurement: Male and female reference intervals established using the automated Beckman Coulter Access AMH assay

Anti‐Müllerian Hormone (AMH) concentration is high at birth in males, demonstrating the presence of functional testicular tissue in the prepubertal period, and acting as a useful marker in the investigation of paediatric reproductive disorders. AMH also provides a tool in the investigation of female virilization, premature ovarian failure and polycystic ovarian syndrome in childhood. Robust, assay‐specific paediatric AMH reference intervals are therefore required for clinical interpretation of results. The aim of this study was to derive age‐specific AMH reference intervals for males and females aged 0‐18 years.