Search

The assessment of anti-mullerian hormone (AMH) pre- and post-gonadotoxic treatment helps define reproductive potential in young female adults facing cancer treatment. Normative childhood AMH levels are not well defined. Our objective was to help establish accurate pediatric reference intervals (RIs) for which AMH can be used to assess AMH in pediatric/adolescent survivors. Healthy female volunteers aged 6-19 years were recruited from the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) cohort. 300 serum samples were analyzed for AMH using an automated assay. Basic demographics and menstrual cycle data on the subjects were recorded at time of sample collection. Serum AMH distribution and RIs (2.5th and 97.5th percentiles) were established in four age groups. One recommended RI (0.98-7.84 ng/mL) was established for females aged 6-19 years after outlier removal. Females 6-9 years demonstrated significantly lower mean AMH concentration than did females 9-12 years (Mean ± SD: 3.18 ± 1.62 and 4.16 ± 2.55 ng/mL, respectively), who in turn demonstrated significantly higher AMH concentrations than those aged 12-15 years (Mean ± SD: 3.75 ± 1.61 ng/mL). Statistical differences are unlikely to be clinically meaningful. Menstrual status and ethnicity did not significantly impact AMH concentrations (p = 0.787 and p = 0.0965, respectively). This is the largest series of its kind using a contemporary, automated, single-batched AMH assay in a healthy pediatric female cohort. In conjunction with future data points and longitudinal data, the RI established may be a useful adjunct to reproductive health counselling delivered to pediatric cancer patients requiring fertility damaging therapies.

Background: 1,25-dihydroxyvitamin D (1,25(OH)2D), the biologically active vitamin D metabolite, plays a critical role in calcium and phosphate homeostasis. 1,25(OH)2D is measured to assess calcium and phosphate metabolism, particularly during periods of profound growth and development. Despite its importance, no reliable pediatric reference interval exists, with those available developed using adult populations or out-dated methodologies. Using the fully automated chemiluminescence immunoassay by DiaSorin, we established 1,25(OH)2D pediatric reference intervals using healthy children and adolescents from the CALIPER cohort. Methods: Serum samples from healthy subjects (0 to 2D using the DiaSorin LIAISON XL assay and age-specific reference intervals were established. The Mann-Whitney U-test was used to determine seasonal differences. Pooled neonatal and infantile samples were quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) to determine if elevated concentrations during the first year of life may be attributed to cross-reacting moieties. Results: Three reference interval age partitions were required with highest levels in subjects 0 to 2D concentration was not significantly affected by seasonal variation or sex. Elevated 1,25(OH)2D concentrations in neonatal and infantile samples may be the result of an interfering substance. The absence of 3-epi-1,25-dihydroxyvitamin D in the pooled samples makes it unlikely to be the interfering moiety. Conclusions: Pediatric reference intervals for 1,25(OH)2D were established to improve test result interpretation in children and adolescents. 1,25(OH)2D is elevated in a proportion of neonates and infants, which may be the result of a cross-reacting moiety.

Objective To evaluate the disease burden of placental maternal vascular malperfusion pathology in a low-risk nulliparous population and test the hypothesis that a multiparameter model in the second trimester can predict maternal vascular malperfusion with high precision. Methods A single-center, prospective cohort study was conducted in healthy nulliparous women. Maternal vascular malperfusion disease burden was estimated by incidence, relative risk (RR), and population-attributable risk percent. Maternal risk factors, serum biomarkers, Doppler, and placental morphologic ultrasonography were examined in isolation and in combination for prediction of this placental pathology. Results The incidence of maternal vascular malperfusion pathology was 8.4% (72/856). Women with pathology had higher risk of preeclampsia (8.33% compared with 1.79%; RR 4.67, 95% CI 1.85-11.77%; population-attributable risk 23.6%, 95% CI 16.9-31.6%), small for gestational age (SGA) (47.22% compared with 9.45%; RR 5.00, 95% CI 3.6-6.93%; population-attributable risk 25.2%, 95% CI 22.1-28.5%), and the composite of adverse outcomes (defined as SGA or preeclampsia) (47.22% compared with 10.59%; RR 4.46, 95% CI 3.25-6.13; population-attributable risk 22.5%, 95% CI 19.8-25.5%). The combination of parameters was superior to individual modalities alone in predicting maternal vascular malperfusion, but achieved only moderate precision (area under the curve 0.77, 95% CI 0.71-0.84). Conclusion One in 12 healthy nulliparous women develop maternal vascular malperfusion placental pathology, and these pregnancies had a 4.5 times higher risk of developing preeclampsia or delivering a SGA neonate compared with those without this pathology. A multiparameter model achieved modest precision to predict placental maternal vascular malperfusion. Importantly, in low-risk pregnancies, maternal vascular malperfusion accounts for one fourth of pregnancy outcomes with SGA or preeclampsia. The low population-attributable risk of this placental pathology for SGA and preeclampsia illustrates the importance of discovering novel associations to reduce the disease burden of these pregnancy complications.

Background The diagnostic utility of laboratory tests in paediatric medicine relies heavily on the availability of appropriate reference intervals (RIs). The Canadian Laboratory Initiative on Paediatric Reference Intervals (CALIPER) has established a comprehensive database of covariate-stratified RIs for many paediatric laboratory tests using a large, healthy reference population. Several automated analysers in widespread use in clinical laboratories have already been studied. Here, we extend the testing to Roche immunoassays and report, for the first time, comprehensive paediatric RIs for 17 endocrine and special chemistry markers. Methods A total of 741 healthy children and adolescents (1 day to Results Reference values for all analytes measured required age partitioning, particularly during early life and throughout adolescence. Of the 17 analytes measured, eight required sex partitioning, including ferritin, thyroid stimulating hormone (TSH), total triiodothyronine (TT3) and all fertility/sex hormones, except prolactin. Conclusions This is the first study to determine accurate paediatric RIs for Roche immunoassays. RIs were generally similar to those previously published by CALIPER on other analytical platforms, highlighting the reproducibility of age- and sex-specific trends in reference values observed across the paediatric age range. The RIs established in this study will improve the accuracy of test result interpretation and clinical decision-making in clinical laboratories utilising Roche immunoassays.

To the Editor: International societies and expert groups recommend using sex-specific upper reference limits (URLs)1 for interpretation of high-sensitivity cardiac troponin (hs-cTnI/T) assays (1, 2). Despite advances in our understanding of cTn in adults, the effect of age and sex on cTn in pediatric populations is less understood. The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) previously determined 97.5th and 99th percentiles for the Abbott hs-cTnI assay in a healthy pediatric cohort (3). These data represented the first attempt to characterize hs-cTnI in healthy children but did not include neonates nor were sex-specific differences evident. It is unclear, however, what cTnT URLs would be in this population because cTnT is a different protein and there are differences in analytical sensitivity and specificity between hs-cTnT and hs-cTnI assays (1–4). Establishing pediatric reference values for cTn is important because its measurement has several clinical indications in pediatrics, including monitoring children with postoperative myocarditis and congenital pediatric heart disease. Serum samples from 598 children and adolescents were selected from the CALIPER biobank. Samples from participants

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.Methods: Published reports relevant to use of tumor markers for 5 cancer sites—testicular, prostate, colorectal, breast, and ovarian—were critically reviewed.Results: For testicular cancer, α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. α-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

Type 2 diabetes mellitus (DM) is associated with increased cardiovascular risk, in part due to accelerated subclinical atherosclerosis. Electrocardiographic (ECG) and ankle–brachial index (ABI) abnormalities are used to screen for cardiovascular risk in the clinic. However, their capacity to identify patients with type 2 DM with nonobstructive subclinical atherosclerosis is unknown. Associations of ECG and ABI abnormalities with coronary artery calcium (CAC), a measure of coronary atherosclerosis, were examined using multivariable ordinal regression modeling in 589 asymptomatic patients with type 2 DM. Sensitivity, specificity, and positive and negative predictive values were determined. CAC was prevalent (44% CAC >100; 32% CAC >75th percentile score) despite normal electrocardiograms (64%) and ABIs (97%) in most subjects. Neither ECG nor ABI changes predicted CAC after adjusting for age, gender, and race. ECG abnormalities were neither sensitive nor specific for detection of CAC >100, >400, or >75th percentile (sensitivities 0.43, 0.45, and 0.34; specificities 0.69, 0.66, and 0.63, respectively). ABI abnormalities were not sensitive (0.03, 0.04, and 0.03) but had high specificity (0.98, 0.98, and 0.98). In subjects with normal electrocardiograms and ABIs, extensive CAC was remarkably prevalent (CAC >100 in 24%). In conclusion, ECG and ABI abnormalities failed to detect patients with subclinical coronary atherosclerosis and therefore may be of limited value in identifying many asymptomatic patients with type 2 DM at increased risk of cardiovascular disease.

Human kallikrein 6 protein is a newly discovered human kallikrein. We determined the amount of human kallikrein 6 in extracts of 182 ovarian tumours and correlated specific activity (ng hK6 mg−1 total protein) with clinicopathological variables documented at the time of surgical excision and with outcome (progression free survival, overall survival) monitored over a median interval of 62 months. Thirty per cent of the tumours were positive for human kallikrein 6 (>35 ng hK6 mg−1 total protein). Human kallikrein 6-specific immunohistochemical staining of four ovarian tissues that included benign, borderline and malignant lesions indicated a cytoplasmic location of human kallikrein 6 in tumour cells of epithelial origin, although the intensity of staining was variable. Tumour human kallikrein 6 (ng hK6 mg−1 total protein) was higher in late stage disease, serous histotype, residual tumour >1 cm and suboptimal debulking (>1 cm) (P

PURPOSE: Insulin, a member of a family of growth factors that includes insulin-like growth factor (IGF)-I and IGF-II, exerts mitogenic effects on normal and malignant breast epithelial cells, acting via insulin and IGF-I receptors. Because of this and because of its recognized association with obesity, an adverse prognostic factor in breast cancer, we examined the prognostic associations of insulin in early-stage breast cancer. PATIENTS AND METHODS: A cohort of 512 women without known diabetes, who had early-stage (T1 to T3, N0 to N1, and M0) breast cancer, was assembled and observed prospectively. Information on traditional prognostic factors and body size was collected, and fasting blood was obtained. RESULTS: Fasting insulin was associated with distant recurrence and death; the hazard ratios and 95% confidence intervals (CI) for those in the highest (> 51.9 pmol/L) versus the lowest (< 27.0 pmol/L) insulin quartile were 2.0 (95% CI, 1.2 to 3.3) and 3.1 (95% CI, 1.7 to 5.7), respectively. There was some evidence to suggest that the association of insulin with breast cancer outcomes may be nonlinear. Insulin was correlated with body mass index (Spearman r = 0.59, P < .001), which, in turn, was associated with distant recurrence and death (P < .001). In multivariate analyses that included fasting insulin and available tumor- and treatment-related variables, adjusted hazard ratios for the upper versus lower insulin quartile were 2.1 (95% CI, 1.2 to 3.6) and 3.3 (95% CI, 1.5 to 7.0) for distant recurrence and death, respectively. CONCLUSION: Fasting insulin level is associated with outcome in women with early breast cancer. High levels of fasting insulin identify women with poor outcomes in whom more effective treatment strategies should be explored.

Prostate Specific Antigen (PSA) expression by breast epithelial cells is associated with favorable breast cancer prognosis. In preliminary studies, we found that a nucleotide variation (G-->A) at position -158 in the androgen response element (ARE-1) of the PSA promoter was present in four out of 9 breast tumors examined and in a breast carcinoma cell line. We have now determined the nucleotide composition at position -158 of DNA extracted from 148 well-characterized breast tumors and compared tumor genotype with that of controls without cancer, with tumor PSA concentration and with clinicopathological variables, overall survival and disease free survival. The G-->A base change at position -158 is a polymorphism. Allelotypes were similarly distributed in breast cancer patients and controls. The Mann-Whitney U Test showed a significantly higher tumor PSA concentration in tumors that presented a homozygous G as opposed to homozygous A genotype. Genotype at position -158 was not associated with clinicopathological variables in contingency table analysis. Univariate Cox regression models showed a 28% reduction in risk for death in patients with homozygous G genotype compared to those with homozygous A genotype (P = 0.03). However, ARE-1 genotype did not significantly add to the prognostic power in the multivariate model of overall survival. In summary, the base change at position -158 is a polymorphism that may affect breast cancer prognosis, but further studies are required to confirm this possibility and to investigate the relevance of this polymorphism in terms of breast cancer susceptibility.

This study aimed to assess the quantitative impact of maternal weight discrepancy on the screen result for Down syndrome when using Integrated Prenatal Screening and First Trimester Combined Screening.The study population consisted of 78,165 women undergoing prenatal screening in Ontario, Canada, and 158 pregnancies affected with Down syndrome at one Ontario center. The study assessed quantitative alterations of the multiple of the median values of first and second-trimester serum markers and the risks of Down syndrome at a set of theoretical weight discrepancies.Weight discrepancies have the greatest impact on screening results when the initial risk is close to the risk cut-off. When the weight discrepancy is 5 lb or greater and the denominator of the initial risk is within 50 of the risk cut-off, the chance that a screen result will change from positive to negative or from negative to positive is 47-55% for women undertaking Integrated Prenatal Screening. This chance is 33-43% for women undertaking First Trimester Combined Screening.A weight discrepancy of five or more pounds has a significant impact on the risk of Down syndrome; correction of maternal weight would improve the accuracy of the screening test.

Prenatal screening for chromosomal aneuploidies is a fundamental part of routine obstetric care in most countries. Typically, maternal age, weight, ethnicity, serum biomarkers (including pregnancy-associated plasma protein A, human chorionic gonadotropin, α-fetoprotein, inhibin A, and estriol), and sonographic features (i.e., nuchal translucency) are included in a risk algorithm to determine the probability of the fetus being affected. Pregnant women identified as at high risk according to the prenatal screen can then undergo invasive procedures, such as amniocentesis and chorionic villus sampling, to confirm the diagnosis. Current prenatal-screening methods are able to identify approximately 90% of pregnancies affected by trisomy 21 (Down syndrome) at a false-positive rate of approximately 5%. Given that the prevalence of chromosomal aneuploidies is generally quite low, a false-positive rate of 5% means that a large number of women with unaffected pregnancies undergo invasive procedures, putting the fetus at an unnecessary risk for miscarriage. The discovery of fetal cell-free DNA in the plasma of pregnant women 14 years ago opened up the possibility of identifying chromosomal abnormalities noninvasively, through a single blood sample. Approximately 10% of cell-free DNA in the maternal circulation is of fetal origin, and this property was initially exploited to determine rhesus D status and the sex of the unborn fetus. The advent of next-generation DNA sequencing, however, has allowed prenatal detection of chromosomal aneuploidies, including trisomy 21, from maternal blood. In brief, the proportion of chromosome 21 DNA molecules in maternal plasma is measured directly; an increase above a predetermined threshold is indicative of trisomy 21. The clinical performance of this noninvasive prenatal test has been promising, with recent clinical studies having shown a diagnostic sensitivity of 100% and a diagnostic specificity of 98%–99%, compared with full karyotyping by invasive means. When used as a second-tier screening procedure, this technology also has the …

Objective To investigate the associations between four defined adverse pregnancy outcomes and levels of first and second trimester maternal serum markers focusing in particular on how well combinations of markers predict these adverse outcomes. Methods This was a retrospective review of associations between first and second trimester serum markers and adverse pregnancy outcomes among 141 698 women who underwent prenatal screening for Down syndrome in Ontario, Canada. Detection rates (DR), false positive rates (FPR), and odds ratios were estimated using both single and combinations of markers for the adverse outcomes defined. Results Women with decreased second trimester unconjugated oestriol (uE3), deceased first trimester maternal serum pregnancy-associated plasma protein A (PAPP-A), increased second trimester serum alpha fetoprotein (AFP), or increased second trimester total human chorionic gonadotrophin (hCG) were at greater risk of developing adverse pregnancy outcomes. At a 5% FPR, combinations of these markers predicted at best 33.3% of fetal loss and 31.5% of preterm births (PTB) before 32 weeks of gestation. Conclusion There are significant associations between the levels of first and second trimester serum markers and adverse obstetric outcomes. However, even combinations of these markers can only predict adverse obstetric outcomes with modest accuracy. Copyright © 2010 John Wiley & Sons, Ltd.

Currently there is no reliable method suitable for routine measurement of serum free testosterone (FT).To develop such a method involving liquid chromatography tandem mass spectrometry (LC-IDMS/MS) that directly detects and quantifies the FT present in serum.Ultrafiltrate testosterone obtained from 0.5 mL of serum was partially purified by liquid/liquid extraction and quantified using an Agilent 1200 Series HPLC system coupled to an API 5000 mass spectrometer equipped with an atmospheric pressure chemical ionization ion source. Using split samples serum free testosterone was compared between direct ultrafiltration (UF) coupled LC-MS/MS, analogue FT immunoassay, free testosterone calculated from mass action equations (cFT) and with equilibrium dialysis (ED) coupled LC-MS/MS.Total imprecision determined over twenty runs was6% at 67 pmol/L and 158 pmol/L FT. The dynamic response was linear up to at least 2500 pmol/L while physical LLOQ (18 % CV) equaled 16 pmol/L. The UF method agreed poorly with analogue immunoassay (correlation coefficient 0.667; bias -81%), somewhat better against cFT when total testosterone was determined by immunoassay (correlation coefficient 0.816, bias 21% ) and still better yet against cFT when total testosterone was determined by LC-MS/MS (correlation coefficient 0.8996, bias 10%). Agreement was closest with ED method (correlation coefficient 0.9779, bias 2.4%).We present a relatively simple UF coupled LC-MS/MS definitive method that measures serum free testosterone. The method is relatively fast, reliable and is suitable for the routine clinical laboratory practice.

Objectives To evaluate the performance of integrated prenatal screening (IPS) and first trimester combined screening (FTS) for trisomy 21 in a large Canadian urban center. Method Prospective data collection on women having FTS at one center from 1 November 2003 to 31 December 2005, or IPS at another from 1 January 2003 to 31 December 2005. A positive screen was defined as adjusted risk for trisomy 21 ≥ 1/200 at term or nuchal translucency ≥ 3.5 mm. Results 32 227 and 14 487 women were screened in the IPS and FTS programs, respectively. Detection rates (DRs) and positive rates (PRs) for trisomy 21 were 88.4% (95% CI: 81.6–91.5) and 3.3% (95% CI: 3.1–3.5) for IPS, and 83.9% (95% CI: 74.7–93.0) and 4.0% (95% CI: 3.7–4.3) for FTS. DR adjusted for viability bias was 85.2% for IPS and 78.6% for FTS. Applying both the screens to the 78 134 women who submitted prenatal screens in Ontario in 2005, thereby eliminating the effect of differences in the distribution of maternal age between screens, gave a DR (corrected for viability bias) and PR of 81 and 3.1% for IPS, and 76 and 3.4% for FTS. Conclusions Both IPS and FTS perform well and are feasible in a practical clinical setting. Copyright © 2008 John Wiley & Sons, Ltd.

The National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for Use of Tumor Markers are intended to encourage more appropriate use of tumor marker tests by primary care physicians, hospital physicians and surgeons, specialist oncologists, and other health professionals. This introduction accompanies the e-publication of 2 reports summarizing NACB Quality Requirements for use of tumor markers in clinical practice (1) and NACB Guidelines for use of tumor markers in testicular, prostate, colorectal, breast, and ovarian cancers (2). Two further reports will follow, summarizing the NACB Guidelines for use of tumor markers in liver, pancreatic, gastric, bladder, and cervical cancers and the NACB Guidelines for use of tumor markers in parathyroid, thyroid, neuroendocrine and lung cancers, monoclonal gammopathies, and melanoma. Here we report the updating and extension of practice guidelines first proposed in 2002 (3). Undertaken under the direction of a steering committee appointed by the NACB (Table 1⇓ ), this process involved consideration of 16 specific cancer sites, together with quality requirements for well-established tumor markers and tumor markers being developed by use of new technologies (Table 2⇓ ). With its wide scope, this project is one of the most comprehensive and complex of its type to date. The draft guidelines were posted on the NACB website in July 2005 and were presented as an EduTrak at the 2005 Joint AACC/IFCC Annual meeting in Orlando, Florida. Informed comment was also actively sought from individuals, organizations, and other interested parties. View this table: Table 1. Steering committee for NACB Laboratory Medicine Practice Guidelines on Use of Tumor Markers in clinical practice. View this table: Table 2. Subjects and subcommittee members for NACB Laboratory Medicine Practice Guidelines on Use of Tumor Markers in clinical practice. Nineteen subcommittees developed draft guidelines (Table 2⇑ ). Subcommittee members included individuals with extensive expertise in the science, technology, and clinical practice …

Objective To determine using a simplified study design trimester-specific FT4 reference intervals in pregnancy with the Roche Modular immunoassay in routine use. Design and methods Surplus blood from 300 women in each trimester, drawn at documented times in the gestation, and from 40 age-matched nonpregnant women were assayed for FT4, thyroid stimulating hormone (TSH) and antithyroid peroxidase autoantibody (anti-TPO). Results After excluding women positive for anti-TPO and with abnormal TSH, reference intervals were calculated as 12.5–19.1 pmol/L (nonpregnant group), 11–19 pmol/L (first trimester), 9.7–17.5 pmol/L (second trimester) and 8.1–15.3 pmol/L (third trimester). 3rd trimester FT4 was significantly lower than that of the second trimester (p

Melatonin may protect against breast cancer. Light and other factors influence melatonin, but the evidence is limited. The authors conducted a study to determine factors related to melatonin. Women volunteers recruited in Toronto, Canada, from 2002 to 2004 collected urine for three nights (winter and summer), took periodic light measurements, and recorded exposures in a diary. The relation of each variable to log-transformed creatininecorrected 6-sulfatoxymelatonin in overnight urine was determined by use of generalized estimating equation linear regression. The final model was based on 1,054 measurement days from 213 participating women. None of the light variables was related to the log of 6-sulfatoxymelatonin. A significant interaction between season and day length was included in the final model. The most significant factor was duration of exercise (b ¼ 0.072; p ¼ 0.004, two-tailed), which increased the amount of melatonin produced. Exercise duration later in the day was more significant (b ¼ 0.108; p ¼ 0.0009, two-tailed). There was no difference between moderate or strenuous exercise. The failure to find a relation between light brightness and melatonin may be due to the difficulty of measuring this, as well as the importance of the light spectrum, which could not be measured. It is possible that the protective effect of exercise with respect to breast cancer may operate in part through an effect on melatonin. breast neoplasms; exercise; light; melatonin; women

The concentrations of 11 phenols and 5 furans were measured in 12 categories of distilled spirits by HPLC methodology, together with the total antioxidant status (TAS) of the same beverages. Ellagic acid was the phenol present in highest concentration in all beverages. Moderate amounts of syringaldehyde, syringic acid, and gallic acid, as well as lesser amounts of vanillin and vanillic acid, were measurable in most samples of whiskey, brandy, and rum but were largely undetectable in gin, vodka, liqueurs, and miscellaneous spirits. 5-(Hydroxymethyl)furfural was the predominant furan in the former three beverages, notably cognac, with 2-furaldehyde the next highest, but these were undetectable in most of the latter beverages. Highest TAS values were given by armagnac, cognac, and bourbon whiskey, all three of which tended toward the highest concentrations of phenols. Negative TAS values were exhibited by rum, vodka, gin, and miscellaneous spirits in line with the low or undetectable phenol concentrations in these beverages. Wood aging is the most likely source of phenols and furans in distilled spirits. Those beverages exposed to this treatment contain significant antioxidant activity, which is between the ranges for white and red wines, with the potential to augment the antiatherosclerotic functions attributable to the ethanol that they contain.