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Serum ferritin is currently the recommended laboratory test to investigate iron deficiency. There have been efforts to standardise serum ferritin assays with implementation of traceability to the World Health Organization reference standard. We evaluate the analytical bias among five widely used commercial ferritin assays in Australia. The relationship between serum ferritin and erythrocyte parameters was recently explored to derive functional reference limits. Residual patient serum specimens were analysed by five participating laboratories that utilised a different ferritin assay, Abbott, Beckman Coulter, Roche, Siemens, and Ortho. Using data mining approach, functional reference limits for Siemens, Abbott, and Ortho serum ferritin methods were derived and compared. At clinically relevant ferritin decision points, compared to the Beckman method, the Roche assay showed higher results ranging from 6 mug/L (31%) at the lowest decision point to 575 mug/L (57%) at the highest decision point. In contrast, the Ortho method underestimated ferritin results at lower decision points of 20 and 30 mug/L, with estimated ferritin results of 16 mug/L (-19%) and 27 mug/L (-12%), respectively. The Abbott and Siemens assays showed a positive bias which was introduced at differing decision points. The comparison of the Siemens and Ortho methods presents similar inflection points between the two assays in the establishment of functional reference limits for serum ferritin. There remain significant biases among some of the commonly used commercial ferritin assays in Australia. More studies are needed to assess if functional reference limits are a way to overcome method commutability issues.Copyright © 2021 Royal College of Pathologists of Australasia

Objective: Current Endocrine Society Clinical Practice Guidelines use a specific aldosterone/renin ratio (ARR) threshold to screen for primary aldosteronism (a treatable disease causing up to 15% of hypertension in primary care) in all patients. We sought to characterize demographic variations in the ARR, hypothesizing a need for age- and sex-specific reference ranges to improve the accuracy of the test. Design(s): Retrospective cross-sectional analysis of ARR measurements at a single tertiary hospital from December 2016 to June 2018. Patient(s): A total of 442 patients with clinically indicated ARR were included, after excluding those who were on spironolactone or the oral contraceptive pill, were pregnant or had an existing adrenal condition. Measurements: Aldosterone, renin and the ARR. Result(s): Among those aged 20-39 years (n = 74), females had significantly higher median aldosterone (369 vs 244 pmol/L, P =.028), lower median renin (17.0 vs 27.6 mIU/L, P =.034) and higher median ARR (20.7 vs 10.3 (pmol/L)/(mIU/L), P =.001) than males, despite having lower systolic (135 vs 145 mmHg, P =.021) and diastolic (89 vs 96.5 mmHg, P =.007) blood pressure. The >= 60-year age group (n = 157) also had significant sex differences in the ARR. With increasing age (20-39 vs >= 60 years), there was a significant fall in plasma aldosterone in females (369 pmol/L vs 264 pmol/L, P =.005), with no change observed in males. Conclusion(s): For those 20-39 years old, aldosterone and the ARR are significantly higher in females despite a lower systolic and diastolic BP, highlighting the potential for false-positive results. Our findings indicate the need for prospective studies with a control population to define age- and sex-specific ARR reference ranges.Copyright © 2020 John Wiley & Sons Ltd

BACKGROUND: Adrenal vein sampling (AVS) is crucial for accurate lateralization of aldosterone excess but it is technically challenging due to the difficulty of adrenal vein cannulation. The use of adrenocorticotropic hormone (ACTH) to improve cannulation success is controversial and can lead to discordant lateralization outcomes. OBJECTIVE(S): To evaluate the utility of ACTH in two centres with different levels of AVS expertise and formulate a strategy for interpreting discordant results. DESIGN: A retrospective cross-sectional analysis of AVS results and post-operative patient outcomes. SETTING: Two large tertiary hospitals with harmonized AVS protocols where adrenal venous samples are collected both before and after ACTH stimulation. MEASUREMENTS: Cannulation success (measured by selectivity index, SI), lateralization (measured by lateralization index, LI) and post-operative biochemical cure. RESULT(S): Number of AVS procedures judged to have successful bilateral adrenal vein cannulation increased from 53% pre- to 73% post-ACTH. The increase in cannulation success was significantly higher in centre where AVS was performed by multiple radiologists with a lower basal success rate. In both centres, the proportion of cases deemed to display lateralization significantly decreased with the use of ACTH (70% pre- to 52% post-ACTH). Based on post-operative outcomes of patients with discordant results who underwent unilateral adrenalectomy, the combination of LI > 3 pre-ACTH and LI > 2 post-ACTH was predictive of a biochemical cure. CONCLUSION(S): ACTH can increase the rate of cannulation success during AVS at the expense of reduced lateralization. The criteria for lateralization should be carefully determined based on local data when ACTH is used.Copyright This article is protected by copyright. All rights reserved.

Background: Adrenal vein sampling (AVS) is crucial for accurate lateralization of aldosterone excess but it is technically challenging due to the difficulty of adrenal vein cannulation. The use of adrenocorticotropic hormone (ACTH) to improve cannulation success is controversial and can lead to discordant lateralization outcomes. Objective(s): To evaluate the utility of ACTH in two centres with different levels of AVS expertise and formulate a strategy for interpreting discordant results. Design(s): A retrospective cross-sectional analysis of AVS results and postoperative patient outcomes. Setting(s): Two large tertiary hospitals with harmonized AVS protocols where adrenal venous samples are collected both before and after ACTH stimulation. Measurements: Cannulation success (measured by selectivity index, SI), lateralization (measured by lateralization index, LI) and postoperative biochemical cure. Result(s): Number of AVS procedures judged to have successful bilateral adrenal vein cannulation increased from 53% pre- to 73% post-ACTH. The increase in cannulation success was significantly higher in centre where AVS was performed by multiple radiologists with a lower basal success rate. In both centres, the proportion of cases deemed to display lateralization significantly decreased with the use of ACTH (70% pre- to 52% post-ACTH). Based on postoperative outcomes of patients with discordant results who underwent unilateral adrenalectomy, the combination of LI '3 pre-ACTH and LI '2 post-ACTH was predictive of a biochemical cure. Conclusion(s): Adrenocorticotropic hormone can increase the rate of cannulation success during AVS at the expense of reduced lateralization. The criteria for lateralization should be carefully determined based on local data when ACTH is used.Copyright © 2020 John Wiley & Sons Ltd

Objectives: Preanalytical processes in pediatric patients are generally manual and associated with a higher risk of error. The optimized delta check rules for detecting misidentified children samples are examined. Method(s): Relative difference and absolute different delta check limits were applied on original and reshuffled (to simulate sample mislabeling/mix-up) paired deidentified pediatric results of 57 laboratory tests. The sensitivity, specificity, and accuracy of a range of delta check limits were determined. The delta check limit associated with the highest accuracy was considered optimal. Result(s): In general, the delta check limits had poor to moderate accuracy (0.50-0.81) in detecting misidentified patient samples. The sensitivity (rule out misidentified sample) quickly deteriorated at increasing delta check limits. At the same time, the specificity (rule in misidentified sample) of the delta check limit was also low. The performance of the relative difference and absolute difference delta check rules was similar. Conclusion(s): Our findings showed poor delta check performance in the pediatric population. The high false-positive flag rate may lead to wasteful resource-intensive investigations and delay in result reporting. In addition, we observed that the optimized pediatric delta check correlated strongly with within-subject biologic variation, whereas delta check accuracy correlated poorly with index of individuality.Copyright © 2019 American Society for Clinical Pathology. All rights reserved.

Central hypothyroidism is a condition where there is (qualitatively or quantitatively) TSH deficiency, leading to reduced thyroid hormone production. In such patients, serum TSH does not accurately reflect the adequacy of thyroxine replacement, as the log-linear relationship between thyrotropin (TSH) and free thyroxine (FT4) is lost. We aimed to prospectively determine the optimal physiological FT4 treatment range for children treated for primary hypothyroidism, based on their serum TSH concentrations. This information could be used to guide optimal therapy for all children on thyroxine replacement, including those with central hypothyroidism. In total, sixty children (median age: 11 years, range: 11 months to 18 years) were recruited over 21 months. They were prescribed a stable dose of thyroxine for at least 6-8 weeks prior to a thyroid function test that consisted of serum TSH, FT4 and free triiodothyronine (FT3) measurements. The serum sample for the thyroid function tests was collected before ingestion of the daily dose, i.e. the trough concentration, and measured using Beckman Coulter UniCel DxI 800 instrument, Siemens Advia Centaur, Roche Cobas, Abbott Architect, Ortho Clinical Diagnostics Vitros 5600 (Ortho-Clinical Diagnostics, Raritan, NJ) platforms. The FT4 and FT3 reference intervals showed significant inter-method difference. The lower limit of the FT4 reference intervals were generally shifted mildly higher when the TSH concentration of the children were restricted from 0.5-5.0 mIU/L to 0.5-2.5 mIU/L. By contrast, the upper limit of the FT3 and FT4 reference intervals were relatively stable for the different TSH concentrations. Assay-specific target ranges for optimal thyroxine therapy are required until FT4 assay standardisation is realised.

Paracetamol overdose is common and microRNA (miR)-122 expression is increased with liver injury. We aimed to measure miR-122 in the setting of an abbreviated paracetamol overdose treatment regimen. We compared miRNA expression in patients treated for paracetamol poisoning with an abbreviated 12-h intravenous acetylcysteine regimen (200 mg/kg over 4 h, 50 mg/kg over 8 h) or a 20-h regimen (200 mg/kg over 4 h, 100 mg/kg over 16 h) (NACSTOP trial). miR-122 expression is increased (decreased cycle threshold (Ct) values) with paracetamol liver injury. We assessed miR-122 expression in patients receiving the two acetylcysteine regimens and in a separate group with acute liver injury (ALI). We examined 121 blood samples in 38 patients. After 20 h of acetylcysteine, median alanine transaminase (ALT) was 12 U/L (18, 14) versus 16 U/L (11, 21) (p = 0.17) and median miR-122 Ct was 30.1 (interquartile range (IQR): 28.9, 33.3) versus 31.4 (28.9, 33.9) (p = 0.7) in the NACSTOP abbreviated and control groups, respectively. Median normalized miR-122 Ct after 20 h of acetylcysteine was 2.2 (IQR 1.9, 6.4), 1.1 (0.7, 2.9), 63.9 (2.5, 168), 123.2 (40.9, 207.8) in the NACSTOP-abbreviated, NACSTOP-control, ALI and hepatotoxicity groups, respectively. There was no significant difference in ALT or miRNA between NACSTOP treatment groups and no signal of increased liver injury from an abbreviated 12-h acetylcysteine regimen. These findings suggest that an abbreviated acetylcysteine regimen in low-risk patients who have overdosed on paracetamol is safe. Further study is required to validate this finding utilizing miRNA as a comparative biomarker.Copyright © The Author(s) 2019.

BACKGROUND: Ayahausca is an ethnobotanical drink of South America and the compound dimethyltryptamine (DMT) is primarily responsible for the hallucinogenic effects. DMT has a short half-life and its detection in urinary drug screens is challenging. We investigate a simple alternate approach to detect ayahuasca consumption by relying on other constituents of the drink, the beta-carboline harmala alkaloids. METHOD(S): Three commercially sourced harmala alkaloids were characterized and added to a non-targeted high-resolution mass spectrometry urine drug screening method. All analyses were performed on a Waters Xevo G2-XS LC-QTof, in positive electrospray ionization mode. The mass detector was operated in MSE mode and data processed with UNIFITM software. A urine specimen from a patient suspected to have consumed ayahuasca was analyzed by a non-targeted drug screen. RESULT(S): The harmala alkaloids: harmine, harmaline and tetrohydroharmaline (THH) were characterized and their detection data added to the toxicology screening library. Harmaline and THH were detected in the patient's urine specimen. CONCLUSION(S): The inclusion of the harmala alkaloids into the drug screen method library may enable the detection of ayahuasca use in patients that undergo non-targeted drug screen.Copyright © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Objectives: We aimed to determine the physiologically correct free thyroxine (FT4) target range in children on thyroxine for primary hypothyroidism to guide optimal therapy for all children on thyroxine including those with central hypothyroidism. There are biases among current FT4 assays as reflected by the manufacturers' reference intervals. Therefore, we postulate that the ideal FT4 target range for children on thyroxine therapy would also be assay-specific. Method(s): Patients with primary hypothyroidism were prospectively recruited. Patient samples with thyroid-stimulating hormone (TSH) in the normal range (0.4-4.0 mIU/L) on Beckman Coulter DxI were included for analysis. Samples were measured on four other instruments (Siemens Centaur, Roche Cobas, Abbott Architect, Ortho Vitros). FT4 ranges (median (2.5th-97.5th)) were calculated. The results were compared to the manufacturers' quoted reference intervals (e.g. DxI: FT4, 7.9-14.4 pmol/L). Result(s): Results from thirty-two patients aged from 2 to 18 years were analysed. In the thyroxine-treated group (congenital hypothyroidism (n=24) and autoimmune hypothyroidism (n=8)), FT4 was 14.3 pmol/L (11.5-17.3) on DxI, FT4 was 18.5 pmol/L on Centaur. Conclusion(s): This study suggests that target FT4 in children on thyroxine should be well above the manufacturer's quoted reference interval. In thyroxine-treated hypothyroidism with normal TSH, FT4 levels vary as much as 30% among the different assays. Therefore, target FT4 ranges should also be assay-specific.

JAK2-Val617Phe mutation detection involves Taqman allele-specific-probe-based assay generating cycle threshold (Ct) values for wild-type(WT)/Val617Phe(VF). Quantitative BCR-ABL-p210 involves real-time-PCR assay producing Ct values (ABL and BCR-ABL copy numbers). After thermal cycling run, data analysis involves manually exporting raw quantitation data as spreadsheet file and formatting it to include amplification thresholds checks and insertion of several calculation formulas. Calculations/checks include: (JAK2-Val617Phe) input limit, grey zone, delta Ct (VF-WT) for each sample; (BCR-ABL-p210) Ct replicates variation, normalised copy numbers (standardisation to international scale). Manual checks/calculations may take a scientist up to 15-20 minutes with risk of transcription/analytical errors (wrong Results). Aim(s): To develop/validate an 'automated' spreadsheet which analyses raw data from JAK2-Val617Phe and quatitative-BCR-ABL-p210 assays and provides final data with minimal manual work. Method(s): Automated spreadsheets were developed for JAK2-Val617Phe and quatitative-BCR-ABL-p210, using 20 data sets from previous manual-entry spreadsheets. They involved multiple modifications (complex formulas) for error-free/robust spreadsheets. Spreadsheets were validated using further 20 data sets each. Result(s): Data from 'automated' spreadsheets fully agreed with manual-entry spreadsheets during validation. Each analysis took less than 5 minutes. Multiple simulations demonstrated spreadsheets were modification-protected. Discussion(s): Molecular haematology testing has significant clinical implications (diagnosis/management). Use of 'automated' spreadsheets minimises laboratory errors and improves analysis time.Copyright © 2018

Case: A 92-year-old female with past history of dementia presented to hospital after an unwitnessed fall. She was diagnosed with rhabdomyolysis with serum total creatine kinase (CK) of 618 U/L (RR 0-190). However, six weeks later, her serum CK remained unchanged with no significant rise or fall. Cardiac cause for elevated CK was considered. Serum troponin was normal. Serum CKMB by immunoinhibition method was 945 U/L and unexpectedly higher than total CK. Methods and Results: Polyethylene glycol (PEG) precipitation study showed clearly reduced recovery in CK value post-PEG in our patient specimen suggesting presence of macro CK (patient, baseline 476 U/L, post-PEG 138 U/L; control specimen 1, baseline 546 U/L, post-PEG 440 U/L; control specimen 2, baseline 368 U/L, post-PEG 328 U/L). CK electrophoresis showed the predominant CK isoenzyme band (94% of total activity) lying at the electrophoretic mobility usually associated with CKMB. Macro CK can overlie the CKMB band. Gel filtration chromatography was not available to sub-classify the macro CK into type 1 or 2. Discussion(s): Macro CK type 1 may occur in healthy people but is also associated with autoimmune disease. Macro CK type 2 has been reported in mainly ill patients and is associated with malignancy.1 Reference1. Galarraga B, Sinclair D, Fahie-Wilson MN, et al. A rare but important cause for a raised serum creatine kinase concentration: two case reports and a literature review. Rheumatology 2003; 42: 186-8.Copyright © 2018

Context: To compare degree of liver injury and paracetamol metabolite concentrations after treatment with standard of care (20-h) vs. abbreviated (12-h) acetylcysteine regimens used in paracetamol overdose (NACSTOP trial). Method(s): Timed blood samples from a cohort of subjects enrolled in the cluster-controlled NACSTOP trial evaluating a 12-h acetylcysteine regimen (200 mg/kg over 4 h, 50 mg/kg over 8 h) were assayed for paracetamol metabolites as a pilot study, using liquid chromatography/mass spectrometry. Control group subjects received a 20-h course of acetylcysteine (200 mg/kg over 4 h, 100 mg/kg over 16 h). The intervention group received a 12-h acetylcysteine regimen (stopped after at least 12 h of treatment). Positive control groups not in the trial with acute liver injury (ALI) or hepatotoxicity were also studied. Result(s): One hundred and forty-one blood samples were collected from 40 patients receiving acetylcysteine after paracetamol overdose. Median ALT after 20 h of acetylcysteine was 12 U/L (IQR 8.14) in the abbreviated regimen group, compared to the control group 16 U/L (IQR 11.21) (p =.46). There was no significant difference in median metabolite concentrations on presentation and after 20 h of acetylcysteine between these two groups (p >.05). Presentation median sum CYP-metabolite/total metabolite percentages were 2.5 and 3.0 in the abbreviated and control NACSTOP groups, respectively. Conclusion(s): An abbreviated 12-h acetylcysteine regimen for paracetamol overdose used in the NACSTOP trial had similar circulating metabolite concentrations compared to a 20-h regimen in selected subjects with low risk of hepatotoxicity. This suggests that further acetylcysteine may not be needed in the abbreviated group at time of cessation.Copyright © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Introduction: Between-laboratory variation in the quantification of co-migrating paraproteins in the beta-region of serum protein electrophoresis may adversely impact patient care if the patient uses different pathology services. To identify the level of agreement in the reporting of beta-migrating paraproteins, sample exchanges were conducted in five Australian states and New Zealand (NZ). Method(s): A minimum of four samples containing beta-migrating paraproteins were distributed to participating laboratories. Laboratories were invited to report paraprotein concentration using their routine practice and measure involved total immunoglobulin (Ig) using immunochemical methods. Victorian laboratories were requested to also report 'total beta + paraprotein' by densitometry. Result(s): Thirty-one laboratories returned results. Overall, CVs for quantification of the involved total Ig by immunochemical methods performed better than what was routinely reported in the paraprotein field (1.5-13.7% vs 8.2-21.8% for NSW; 4.1-9.0% vs 13-28.6% for NZ; 7.4-29.4% vs 5.7-67.0% for qld; 0.7-7.3% vs 18.2-43.3% for WA; 0.2-7.2% vs 0-23.6% for SA; and 3.2-9.7% vs 13.8-70.5% for VIC). Amongst Victorian laboratories, CVs for 'total beta+paraprotein' quantification were better than what was reported in the paraprotein field (4.0-18.2% vs 13.8-70.5%). Conclusion(s): This study has highlighted the between-laboratory variation in measurement of beta-migrating paraproteins and the need for harmonisation to improve patient care.Copyright © 2018

Background: Familial hypercholesterolemia (FH) is a common monogenic hereditary lipid disorder characterised by increased serum low-density lipoprotein cholesterol (LDL-cholesterol) concentrations and high risk of premature atherosclerotic cardiovascular disease. The prevalence of FH identified in a tertiary hospital laboratory was investigated by performing an opportunistic screen for index cases. Method(s): The prevalence of likely FH based on LDL-cholesterol thresholds >4.9 mmol/L as employed by the Dutch Lipid Clinic Network Criteria (DLCNC) score was evaluated retrospectively in a single tertiary hospital laboratory over a six-month period (July to December 2016). Result(s): 4943 lipid profiles screened, 106 patients (mean age 53.2 +/- 12.9 and 41% male) had LDL-cholesterol of >4.9 mmol/L after exclusion of 5 patients (0.1%) with secondary causes. Possible (n = 90) and probable/definite (n = 16) FH according to DLCNC score was seen in 1.8% and 0.4% of the overall screened population, respectively. Conclusion(s): Point prevalence of screening for FH in patients undergoing lipid profile testing in a tertiary hospital laboratory was comparable with prevalence of FH in general population (based on 1 in 200-250). This supports the benefit of establishing an efficient "alert system" in conjunction with a trigger "reflex testing" to facilitate further formal FH scoring and exclusion of possible secondary causes of hyperlipidemia in potential index FH.Copyright © 2019

Prompt intervention can prevent permanent adverse neurological effects caused by neonatal hypothyroidism. Thyroid function changes rapidly in the first few days of life but well-defined age-specific reference intervals (RIs) for thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free tri-iodothyronine (FT3) are not available to aid interpretation. We developed hour-based RIs using data mining. All TSH, FT4 and FT3 results with date and time of collection from neonates aged <7 days during 2005-2015 were extracted from the Monash Pathology database. Neonates with more than one episode of testing or with known primary hypothyroidism, identified by treating physicians or from medical records, were excluded from the analysis. The date and time of birth were obtained from the medical records. Of the 728 neonates qualifying for the study, 569 had time of birth available. All 569 had TSH, 415 had FT4 and 146 had FT3 results. For age <=24 h, 25-48 h, 49-72 h, 73-96 h, 97-120 h, 121-144 h and 145-168 h of life, the TSH RIs (2.5th-97.5th) (mIU/L) were 4.1-40.2, 3.2-29.6, 2.6-17.3, 2.2-14.7, 1.8-14.2, 1.4-12.7 and 1.0-8.3, respectively; the FT4 RIs (mean +/- 2 standard deviation [SD]) (pmol/L) were 15.3-43.6, 14.7-53.2, 16.5-45.5, 17.8-39.4, 15.3-32.1, 14.5-32.6 and 13.9-30.9, respectively; the FT3 RIs (mean+/-2 SD) (pmol/L) were 5.0-9.4, 4.1-9.1, 2.8-7.8, 2.9-7.8, 3.5-7.2, 3.4-8.0 and 3.8-7.9, respectively. TSH and FT4 were substantially high in the first 24 h after birth followed by a rapid decline over the subsequent 168 h. Use of hour-based RIs in newborns allows for more accurate identification of neonates who are at risk of hypothyroidism.Copyright © 2018 2018 Walter de Gruyter GmbH, Berlin/Boston.

Background: Patients with chronic kidney disease (CKD) are at increased fracture risk. In men without CKD, oestradiol is the predominant sex hormone regulating bone health, but sex hormone binding globulin (SHBG) has also been independently associated with fracture. Gonadal dysfunction is common in men receiving dialysis, however the effect of sex-steroids and SHBG on bone mineral density (BMD) and fracture in these patients is unknown. Aim(s): To examine the relationship between gonadal steroids and SHBG with BMD and fractures in men receiving dialysis pre-transplantation. Method(s): Cross-sectional study of male dialysis patients wait-listed for transplantation. Biochemistry, gonadal steroids (oestradiol, total testosterone (TT), calculated free testosterone (FT)), SHBG, dual-energy X-ray absorptiometry and thoracolumbar X-rays were performed prior to transplantation. Multivariable regression models were used to investigate the associations between gonadal steroids, BMD and fractures. Result(s): 546 males (mean age 45.8 +/- 12.8 years) were included. Pre-existing diabetes mellitus was present in 38% and median time of dialysis was 24 months. 183 patients had non-vertebral fractures (23%), 92 (17%) had vertebral fractures and 59 (11%) had both. After adjusting for age, BMI and dialysis time, higher SHBG levels were associated with non-vertebral fractures, even after adjusting for femoral neck (FN) Z-scores (OR 1.65; 95% CI 1.08-2.53, P = .022). Oestradiol, TT and FT were not associated with vertebral or non-vertebral fractures. SHBG was also associated with lumbar spine (LS) and FN Z-scores using the same adjusted models (beta = -0.181, P = .019 and beta = -0.204 P = .018 respectively). Lower oestradiol levels were significantly correlated with lower LS Z-scores (beta = 0.137, P = .014) and adjusting for diabetes mellitus did not attenuate these associations. Conclusion(s): Fractures occur in about half of men receiving pre-transplantation dialysis and associated w

Introduction: Prompt intervention can prevent permanent adverse neurological effects caused by neonatal hypothyroidism. Thyroid function changes rapidly in the first few days of life but age-related reference intervals (RIs) for TSH, FT4 and FT3 are not available to aid interpretation. This is further complicated by the imprecision of how the days of life are classified, e.g., a neonate who was born just before midnight would be classified as day-1 a few minutes after midnight rather than day-0. We have developed hour-based RIs using data mining. Method(s): All TSH, FT4 and FT3 results (Beckman) with date and time of collection from neonates aged Results: Of the 728 neonates qualifying, 569 had time of birth available. All 569 had TSH, 415 had FT4 and 146 had FT3 results. For age <=24h, 24.1-48.0h, 48.1-72.0h, 72.1-120.0h and 120.0-168.0h of life, the TSH RIs (2.5th-97.5th) (mIU/L) were 4.1-40.2, 3.2-29.6, 2.6-17.3, 1.0-10.3 and 1.0-8.2 respectively; the FT4 RIs (mean +/- 2SD) (pmol/L) were 15.3-43.6, 14.7-53.2, 16.5-45.5, 17.8-39.4, 15.3-32.1, 14.5-32.6, 13.9-30.9 and 14.4-28.6 respectively; and the FT3 RIs (mean +/- 2SD) (pmol/L) were 5.0-9.4, 4.1-9.0, 2.8-7.8, 3.5-7.2, 3.4-8.0, 3.8-7.9 and 3.8-7.2 respectively. Conclusion(s): In most babies, there is a substantial surge in TSH and FT4 shortly after birth followed by a rapid decline over the subsequent 168 hours. The upper limits are manyfold higher than the values for adults. Use of method- and hour-based RIs in newborns allows for correct identification of neonates who are at risk of hypothyroidism. Due to current lack of analytical harmonisation, these RIs must necessarily be method-specific.

Objective: Adrenal vein sampling (AVS) is used to distinguish unilateral from bilateral causes of primary aldosteronism (PA). The use of adrenocorticotropic hormone (ACTH) stimulation during AVS remains controversial. ACTH increases successful cannulation at the expense of producing discordant AVS results. This study compares basal and post-ACTH aldosterone and cortisol values to evaluate the role of ACTH in AVS, and correlates the results of AVS to surgical outcomes in patients with discordant lateralisation. Method(s): An audit was conducted of 127 AVS performed at two tertiary hospitals. Information was collected on patient demographics, screening tests, AVS results pre-and post-ACTH stimulation, adrenal imaging and surgical outcomes including adrenal histology and biochemistry where available. Successful cannulation and lateralization were defined by the selectivity index (SI) and the lateralization index (LI) respectively. The diagnosis of aldosterone producing adenoma was supported by a contralateral suppression index (CSI) <1. Result(s): ACTH increased SI in all cases with more successful cannulations of both adrenal veins and an overall increase in bilateral cannulation success from 43% pre-ACTH to 65% post-ACTH. The number of unilateral cases fell from 71% basally to 55% post-ACTH. Among 10 patients with discordant results, 6 underwent unilateral adrenalectomy of whom 4 were found to have adenoma on histology. Patient who had clinical and/or biochemical improvement either had post-ACTH LI >2 and/or CSI <1. Of all these discordant cases, the majority lateralized to the right side at baseline. Conclusion(s): ACTH increased cannulation success rate in AVS but at the cost of reduced lateralization. Basal LI appears to be the more reliable lateralization indicator, although a lower post-ACTH LI threshold of >2 and contralateral suppression also support the diagnosis of aldosterone-producing adenoma. Discordant cases remain clinical dilemmas so strategies to redu

Background: The saline suppression test (SST) is conducted to confirm the diagnosis of primary aldosteronism (PA) in patients with an elevated aldosterone:renin ratio. Studies have speculated that SST can predict PA subtype as either unilateral (predominantly an aldosterone-producing adenoma) or bilateral (adrenal hyperplasia) [1]. An accurate prediction of bilateral disease may reduce the need for adrenal vein sampling (AVS). Aim(s): To identify SST parameters that distinguish bilateral from unilateral PA. Method(s): A retrospective analysis was performed on 89 patients who underwent the SST at Monash Health (February 2011-May 2017). Clinical information collected included patient demographics, SST, AVS and histology results. A positive SST was defined as plasma aldosterone concentration (PAC) >140 pmol/L at 4 hours post-infusion of 2 L normal saline in the recumbent position [2]. Patients with positive SST results were categorized into three PA subtypes: unilateral, bilateral and undetermined (unsuccessful AVS or no AVS). Results were expressed as median (lower and upper quartiles). Result(s): 84 patients had a positive SST: 25 unilateral, 25 bilateral and 34 undetermined. The unilateral group had significantly higher PAC compared to the bilateral group both at 0 hours, 538 pmol/L (441-748) vs 323 pmol/L (250-429) (P = .004), and at 4 hours, 462 pmol/L (280-764) vs 230 pmol/L (195-298) (P = 0.05). Compared to the bilateral group, the PAC in the unilateral group demonstrated a lower absolute reduction at 4 hours, -69 pmol/L (-178-30) vs -87 pmol/L (-142-44) and a smaller percentage decrease at 4 hours, -17% vs -27%, however these were not statistically significant. Conclusion(s): Unilateral causes of PA had a higher PAC during the SST both at 0 and 4 hours. However, we did not identify a clear SST parameter which differentiated unilateral from bilateral PA. A seated SST which is more sensitive for bilateral PA [3] may be better for predicting PA subtypes.

Objective: MicroRNA (miR)-122 expression increases, and miR-483 decreases with paracetamol liver injury. We compared the clinical safety of an abbreviated 12 hour IV acetylcysteine protocol (200 mg/kg over 4 hours, 50 mg/kg over 8 hours) with a 20-hour regimen (200 mg/kg over 4 hours, 100 mg/kg over 16 hours) in patients with low risk of liver injury after acute paracetamol poisoning (NACSTOP-trial). Method(s): A convenience sample of patients treated with acetylcysteine following paracetamol overdose was recruited from NACSTOP. Patients with a normal ALT at presentation and low paracetamol (<20 mg/L) and normal ALT 12 and 20 hours from the start of acetylcysteine were included. Two comparative groups not enrolled in NACSTOP with acute liver injury (ALI: ALT >50 IU/L and double baseline) or hepatotoxicity (ALT >1000 IU/L) were also included. miR-122 expression (quantification cycle, Cq), miR-483 and a miR-ratio (2-deltaCq miR-122/483) were determined from patient samples. Cq results are inversely proportional to miR-expression. Result(s): Of the 38 patients, eight received the 12-hour (abbreviated) and 20 received the 20-hour (control) NACSTOP acetylcysteine regimens; seven patients with ALI and three with hepatotoxicity were also included. The overall median age was 22 years (IQR 18,32) and 70% were female. Median acetylcysteine duration was 13 hours in those receiving the abbreviated regimen, 20 hours in the control and ALI groups and 60 hours in those with hepatotoxicity. Median time to starting acetylcysteine was 6 hours (IQR 5.5,12), 6.5 (5.6,10.5), 7 (5,12), 24 (12,31); median peak ALT was 13 (IQR 10,20) IU/L, 20 (14,22), 83 (61,100), 2365 (2035,15601); and median peak miR-122 Cq was 29.6 (IQR 28.7,31.0), 29.7 (28.6,32.7), 29.0 (23.1,32.4), 23.7 (21.1,23.8) in the abbreviated, control, ALI, and hepatotoxicity groups, respectively. There was no significant difference in median peak ALT or miR-122 Cq between abbreviated and control NACSTOP groups (p > .05). Ther

Background: The saline suppression test (SST) serves to confirm the diagnosis of primary aldosteronism (PA) whilst adrenal vein sampling (AVS) is used to determine whether the aldosterone hypersecretion is unilateral or bilateral. An accurate prediction of bilateral PA based on SST results could reduce the need for AVS. Aim(s): We sought to identify SST parameters that reliably predict bilateral PA. Method(s): The results from 121 patients undergoing SSTs at Monash Health from January 2010 to January 2018 including screening blood tests, imaging, AVS and histopathology results were evaluated. Patients were subtyped into unilateral or bilateral PA based on AVS and surgical outcomes. Result(s): Of 113 patients with confirmed PA, 33 had unilateral disease whilst 42 had bilateral disease. In those with bilateral disease, plasma aldosterone concentration (PAC) was significantly lower post-SST, together with a significant fall in the aldosterone-renin ratio (ARR). The combination of PAC < 300 pmol/L and a reduction in ARR post-SST provided 96.8% specificity in predicting bilateral disease. Eighteen of 39 patients (49%) with bilateral PA could have avoided AVS using these criteria. Conclusion(s): A combination of PAC < 300 pmol/L and a lower ARR post-SST could reliably predict bilateral PA. An independent cohort will be needed to validate these findings.Copyright © 2018 John Wiley & Sons Ltd

Aims: Disorders of puberty are diagnosed and monitored by measurement of hormones of the hypothalamic-pituitary-gonadal (HPG) axis. As growth and development can influence normal circulating concentrations of these hormones, gender- and Tanner stage-specific gonadotropin ranges are more meaningful than age-specific values. In particular, given the pulsatile nature of gonadotropin release, are baseline luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels using a sensitive assay able to distinguish between prepuberty and the onset of puberty? Methods: LH and'sH results (measured on Beckman Coulter UniCel DxI 800 analyser) betweeen March 2011 and October 2015 were extracted from Monash Pathology laboratory information system. Patients were included where data on Tanner staging were available. Patients with primary gonadal failure and on treatments influencing the HPG axis were excluded. The remaining data were used to calculate genderand Tanner stage-specific LH and'sH ranges (mean +/- 2SD). Result(s): Of 724 records of paired LH and'sH measurements Tanner staging for 185 was available. See table below for gender- and Tanner stage-specific LH and'sH ranges (mean +/- 2SD). Conclusion(s): Results from a cohort of healthy children and adolescents are ideal for calculation of paediatric reference intervals for gonadotropins. Nevertheless, our data from hospital outpatients (after exclusion of any intervention that might alter HPG axis) still provided a useful picture of gonadotropin levels across Tanner stages. More data points are required to establish reference ranges for routine clinical use. There is significant overlap between gonadotropin results between Tanner Stages I and II suggesting that diagnosing the onset of puberty is difficult using baseline measurements, particularly in females, suggesting the need for gonadotropin-releasing hormonestimulated gonadotropins to assess maturity of the HPG axis.

Gonadal hormones impact bone health and higher values of sex hormone-binding globulin (SHBG) have been independently associated with fracture risk in men without chronic kidney disease. People with chronic kidney disease have a greatly increased fracture risk, and gonadal dysfunction is common in men receiving dialysis treatment. Nevertheless, in these men the effect of gonadal steroids and SHBG on bone mineral density (BMD) and fracture risk is unknown. Here we investigate relationships between gonadal steroids, SHBG, BMD and fracture in men on long-term dialysis therapy, awaiting kidney or simultaneous pancreas kidney transplantation. Results of serum biochemistry, SHBG, gonadal steroids (total testosterone, calculated free testosterone and estradiol), BMD by dual-energy X-ray absorptiometry and thoracolumbar X-rays were obtained. Multivariable regression models were used to examine associations between SHBG, gonadal steroids, BMD and fracture of 321 men with a mean age of 47 years. Diabetes mellitus was present in 45% and their median dialysis vintage was 24 months. Prior fractures occurred in 42%, 18% had vertebral fracture on lateral spine X-ray, 17% had non-vertebral fragility fracture within 10 years and 7% had both. After adjustment for age, body mass index and dialysis vintage, higher SHBG levels were significantly associated with nonvertebral fractures [odds ratio 1.81 (1.30-2.53)] and remained significant after adjustment for BMD. Calculated free testosterone and estradiol values were not associated with fracture. Prevalent fracture rates were high in relatively young men on dialysis awaiting transplantation. Thus, SHBG is a novel biomarker associated with fracture, which warrants investigation in prospective studies.Copyright © 2018 International Society of Nephrology

Objective: Circulating CYP450-metabolites have been investigated previously to ascertain risk of liver injury. We investigated the clinical safety of an abbreviated 12-hour IV acetylcysteine protocol (200 mg/kg over 4 hours, 50 mg/kg over 8 hours) with a control group, 20-hour regimen (200 mg/kg over 4 hours, 100 mg/kg over 16 hours) in patients with acute paracetamol poisoning and low-risk of liver injury (NACSTOP-trial) using paracetamol metabolites to predict liver injury. Method(s): A convenience sample, treated with acetylcysteine, following paracetamol overdose was recruited from NACSTOP. Patients with normal ALT at presentation and low paracetamol (<20 mg/L) and normal ALT after 12 hours of acetylcysteine were included. Two comparative groups not enrolled in NACSTOP, with acute liver injury (ALI: ALT >50 IU/L and double baseline) or hepatotoxicity (ALT >1000 IU/L), were also included. Paracetamol metabolites (APAP-Cys, APAP-GSH, APAP-Mer, APAP-Sul, APAPGlu) were assayed. Sum CYP-metabolite percentage (CYS, Mer, GSH)/Total metabolites was calculated. Result(s): Paracetamol metabolites were examined in 40 patients; eight received the 12-hour regimen and 21 received 20-hours of acetylcysteine (NACSTOP-control). Nine patients with ALI and two with hepatotoxicity were also recruited. The overall median age was 22 years (IQR 18,32) and 70% were female. Median acetylcysteine duration was 13 hours in those receiving the 12-hour regimen, 20 hours in the NACSTOP-control and ALI groups and 60 hours in those with hepatotoxicity. Median times to starting acetylcysteine were 6 hours (IQR 5.5,12), 6.5 (5.6,11), 9 (5.5,16), 21 (12,31); median peak ALT was 13 IU/L (IQR 10,20), 19 (14,22), 67 (59,94), 8983 (2365,15601); and presentation sum CYP-metabolites percentage 2.5, 3.0, 2.8, 14.9 in the abbreviated, NACSTOP-control, ALI and hepatotoxicity groups, respectively. There was also a significant difference between presentation sum CYP-metabolite percentage in those with and wi

Contains fulltext : 169928.pdf (publisher's version ) (Closed access), BACKGROUND: Noninvasive prenatal detection of fetal subchromosomal copy number aberrations (CNAs) can be achieved through massively parallel sequencing of maternal plasma DNA. However, when a mother herself is a carrier of a CNA, one cannot discern if her fetus has inherited the CNA. In addition, false-positive results would become more prevalent when more subchromosomal regions are analyzed. METHODS: We used a strategy that combined count- and size-based analyses of maternal plasma DNA for the detection of fetal subchromosomal CNAs in 7 target regions for 10 test cases. RESULTS: For the 5 cases in which CNAs were present only in the fetus, the size-based approach confirmed the aberrations detected by the count-based approach. For the 5 cases in which the mother herself carried an aberration, we successfully deduced that 3 of the fetuses had inherited the aberrations and that the other 2 fetuses had not inherited the aberrations. No false positives were observed in this cohort. CONCLUSIONS: Combined count- and size-based analysis of maternal plasma DNA permits the noninvasive elucidation of whether a fetus has inherited a CNA from its mother who herself is a carrier of the CNA. This strategy has the potential to improve the diagnostic specificity of noninvasive prenatal testing.

Objective: Adrenal vein sampling (AVS) is crucial for differentiating between unilateral and bilateral causes of primary aldosteronism (PA). However, there is a lack of uniform agreement regarding the use of adrenocorticotropic hormone (ACTH) stimulation during AVS. This study compares basal and post-ACTH aldosterone and cortisol values to evaluate the role of ACTH stimulation in AVS. Method(s): An audit was conducted of 127 AVS procedures performed at Austin Health (Jan 2001-Dec 2015) and Monash Health (Jan 2010-Dec 2015). Both centres performed AVS pre- and post-ACTH using sequential catheterization. Patient demographics, screening aldosterone and renin concentrations, AVS aldosterone and cortisol levels pre- and post-ACTH stimulation, adrenal imaging and surgical outcomes including adrenal histology were retrieved. Successful cannulation and lateralization were defined by the selectivity index (SI) and the lateralization index (LI) respectively. Suppression of the non-dominant adrenal site was defined as contralateral suppression index (CSI) <1. Result(s): ACTH significantly increased the rate of successful cannulation (SI > 2 pre- or > 3 post-ACTH), from 70% to 95% on the left (p<0.001), and from 54% to 68% on the right (p=0.029). However, ACTH stimulation significantly lowered the LI (p=0.03). Using LI> 3 pre-ACTH and LI > 4 post-ACTH as thresholds for lateralization, the number of unilateral cases decreased from 71% pre-ACTH to 52% post-ACTH. 6 cases were discordant, whereby the cases would have been re-classified as bilateral despite basal lateralization. Despite being discordant, all underwent unilateral adrenalectomy, 4 of those had adrenal adenomas confirmed on histology and had clinical improvement and normalization or improvement in blood pressure. All 4 patients had post-ACTH LI > 2 and basal CSI<1. Conclusion(s): ACTH stimulation increased the rate of successful cannulation in AVS but masked lateralization in four cases of proven adenoma. Basal LI appe

Purpose: Increased fracture rates are observed in renal transplant recipients (RTRs) compared with the general population. Risk factors include age, diabetes, dialysis vintage, immunosuppression and mineral and bone disorders.1 Low serum phosphorus levels occur post-transplantation; however, its relationship with fracture risk has not been evaluated. The purpose of this study was to evaluate risk factors for fracture in RTRs at a single tertiary referral centre. Method(s): A retrospective cross-sectional analysis of 146 patients (75 M, 71 F) who had been referred for dual energy X-ray densitometry (DXA) post-renal transplantation was performed. Aetiology of end stage kidney disease (ESKD), duration of dialysis, parathyroidectomy history, immunosuppression regimen, bone mineral density (BMD), biochemistry and fractures were documented. Statistical analyses included univariable and multivariable regression. Result(s): The mean age of patients was 54 years and mean time post-transplantation 6.7 years. A total of 79 fractures occurred in 52 patients (35%), with 40 fractures occurring post-transplantation. Ankle/foot fractures were most common (48%). Lower serum phosphorus levels and declining femoral neck (FN) T-score and were associated with fractures in both univariable and multivariable regression analyses after adjusting for age, gender, weight, estimated glomerular filtration rate and pre-transplant history of fracture (P=.011 and P=.042 respectively). The relationship between serum phosphorus and fracture remained significant independent of FN T-score, parathyroid hormone levels, parathyroidectomy status and prednisolone use. Conclusion(s): Fracture was common post-renal transplantation. Lower serum phosphorus levels and declining FN T-scores were associated with fractures. The mechanism of this previously unreported observation requires further evaluation in prospective studies.Copyright © 2017 John Wiley & Sons Ltd

Objective: Adrenal vein sampling (AVS) is crucial for differentiating between unilateral and bilateral causes of primary aldosteronism (PA). However, there is a lack of uniform agreement regarding the use of adrenocorticotropic hormone (ACTH) stimulation during AVS. This study compares basal and post-ACTH aldosterone and cortisol values to evaluate the role of ACTH stimulation in AVS. Method(s): An audit was conducted of 127 AVS procedures performed at Austin Health (Jan 2001-Dec 2015) and Monash Health (Jan 2010-Dec 2015). Both centres performed AVS pre- and post-ACTH using sequential catheterization. Patient demographics, screening aldosterone and renin concentrations, AVS aldosterone and cortisol levels pre- and post- ACTH stimulation, adrenal imaging and surgical outcomes including adrenal histology were retrieved. Successful cannulation and lateralization were defined by the selectivity index (SI) and the lateralization index (LI) respectively. Result(s): ACTH significantly increased the rate of successful cannulation (SI > 2 pre- or > 3 post-ACTH), from 70% to 95% on the left (P < 0.001), and from 54% to 68% on the right (P = 0.03). However ACTH stimulation significantly lowered the LI (P = 0.03). Using LI> 3 pre-ACTH and LI > 4 post-ACTH as thresholds for lateralization, the number of unilateral cases decreased from 70% pre-ACTH to 56% post- ACTH. 17 cases would have been re-classified as bilateral despite basal lateralization. Eight of these patients elected to undergo unilateral adrenalectomy, six of whom were found to have adenomas on histology and had a biochemical cure together with normalization or improvement in blood pressure. All six patients had post-ACTH LI > 2. Conclusion(s): ACTH stimulation increased the rate of successful cannulation in AVS but masked lateralization in six cases of proven adenoma. Basal LI appears to be the more reliable indicator of lateralization although a post-ACTH LI using a lower threshold of >2 also supports the diagnosi