Clin Chem Lab Med Research Articles

Longitudinal Blood Count Analysis Reveals That Poor Graft Function after Pediatric Hematopoietic Cell Transplantation Is a Common Complication Associated with Poor Outcome

Background Poor graft function (PGF) is an important complication of allogeneic hematopoietic cell transplantation (allo-HCT), predisposing to infections, bleeding complications and mortality. The reported incidence and outcome of PGF differ between studies, which may partially be explained by differences in patient cohorts and HCT strategies. Pediatric HCT differs from the adults setting in several aspects, such as the underlying disease and use of relatively young donors, including cord blood. To date, however, information on the incidence and outcome of PGF in pediatric HCT recipients is limited. Aim To determine the incidence, risk factors and outcome of poor graft function in pediatric HCT recipients. Methods Longitudinal blood count and transfusion data from 63.219 measurements were retrieved from the Utrecht Patient Oriented Database (ten Berg et al., Clin Chem Lab Med, 2007) to investigate PGF in pediatric recipients of a first HCT. Patients with less than 5 measurements within the first 30 days or 10 measurements within the first 100 days post-HCT were excluded. In line with published definitions, PGF was defined as cytopenia and/or transfusion dependence for 3 consecutive days after day 28 in ≥2 lineages simultaneously, and patients with relapse, grade III-IV GvHD and/or rejection were excluded (Müskens et al., Blood Reviews, 2023). Cytopenias were defined as thrombocytes <20x10 9/L, neutrophils <0.5x10 9/L and hemoglobin <7 g/dL (Kong et al., Biol Blood Marrow Transplant, 2013). Individual and cohort-wide reconstitution patterns of thrombocytes, neutrophils, and hemoglobin after HCT were analyzed and used to identify patients with PGF. Cumulative incidence and survival analyses were conducted using the {survival} R package. Probability of overall survival (OS) and event-free survival (EFS), defined as retransplantation-free, stem-cell-boost free survival, were calculated using the Kaplan-Meier estimate and compared at one year using the log-rank test. Risk factors for PGF and EFS were assessed in univariable and multivariable Cox proportional hazard models. Results Among 348 pediatric recipients who met the inclusion criteria, we identified 53 patients that fulfilled the criteria for PGF, resulting in a cumulative incidence of 0.15 (95% confidence interval (CI): 0.11-0.18). Risk factors for PGF included HCT for hematological disease (p = 0.03) and from an HLA-mismatched donor (p < 0.01). No difference in PGF incidence was observed between recipients of cord blood and bone marrow donors. The one-year OS (1Y OS) of patients in the PGF group was 71% (95% CI: 59-85%), compared to 91% (95% CI: 87-94%) in the good graft function (GGF) group (p < 0.0001, Figure 1A). Infectious disease was the cause of death in 47% in the PGF group, compared to 27% in the GGF group (p = 0.21). The 1Y EFS was 53% (95% CI: 41-68%) in the PGF group, compared to 90% (95% CI: 86-93%) in the GGF group (p < 0.0001, Figure 1B). Conclusion PGF is a common complication in pediatric HCT recipients. No difference in PGF incidence was observed between bone marrow and cord blood grafts. Both patient-specific (underlying disease) and donor-specific (HLA-matching) may contribute to its pathophysiology. PGF patients show a marked reduction in overall and event-free survival, highlighting the need for therapeutic strategies to prevent and/or treat PGF after HCT.

The prognostic value of neurofilament light chain in serum

Interest in the use of fluid biomarkers for monitoring disease course in multiple sclerosis is growing. Neurofilaments are structural proteins, and neurofilament light chain (NfL) is released after neuroaxonal injury. 1 Gafson AR Barthélemy NR Bomont P et al. Neurofilaments: neurobiological foundations for biomarker applications. Brain. 2020; 143: 1975-1998 Google Scholar NfL can be measured in blood by ultrasensitive assays, with good correlation between blood and CSF levels. 1 Gafson AR Barthélemy NR Bomont P et al. Neurofilaments: neurobiological foundations for biomarker applications. Brain. 2020; 143: 1975-1998 Google Scholar , 2 Kuhle J Barro C Andreasson U et al. Comparison of three analytical platforms for quantification of the neurofilament light chain in blood samples: ELISA, electrochemiluminescence immunoassay and Simoa. ClinChemLab Med. 2016; 54: 1655-1661 Google Scholar Serum neurofilament light chain for individual prognostication of disease activity in people with multiple sclerosis: a retrospective modelling and validation studyThe use of sNfL percentiles and Z scores allows for identification of individual people with multiple sclerosis at risk for a detrimental disease course and suboptimal therapy response beyond clinical and MRI measures, specifically in people with disease activity-free status. Additionally, sNfL might be used as an endpoint for comparing effectiveness across drug classes in pragmatic trials. Full-Text PDF

Do Prevotella copri and Blastocystis promote euglycaemia?

Do Prevotella copri and Blastocystis promote euglycaemia?

P229 Standardization of Quantum Blue® rapid TDM assays with WHO international standards for adalimumab and infliximab

Abstract Background Therapeutic drug monitoring of inflammatory bowel disease (IBD) patients under anti-TNF therapy is based on trough level determination of the drug. Rapid assays and multiple ELISAs are available that measure anti-TNF biologics. An international standard is required to improve comparability among different assays. Recently, WHO introduced anti-TNF standards for adalimumab (ADL) and infliximab (IFX). A WHO international reference material (IRM) based standardization is crucial for the harmonization of assays available on the market. Methods The aim of the study was to standardize the BÜHLMANN Quantum Blue® ADL and BÜHLMANN Quantum Blue® IFX based on the WHO IRM for ADL and IFX, respectively. A value transfer from the WHO reference material to the internal calibrator sets for both assays was based on a protocol previously described by Blirup-Jensen et al. (Clin Chem Lab Med 2001; 39(11):1110–1122) and by means of a commercially available ELISA. A method comparison of the ELISA and the rapid test was carried out before the value transfer to guarantee comparability of both assays. Additionally, the correlation of the WHO IRM with the currently used calibrator material was determined for ADL. The correlation of the WHO IFX standard (NIBSC 16/170) with the currently used calibrator material was presented recently (Keller et al. 2020, UEGW 2020). Calibration curves were generated with BÜHLMANN ADL calibrators and with calibrators made from WHO IRM for ADL (NIBSC 17/236). Serum samples, covering a concentration range from 1.0 to 35 µg/mL, were analysed with both calibration curves and compared by Bland-Altman and Passing-Bablok analysis. Results A preliminary value transfer study revealed an relative uncertainty of 12.3% for both drugs. A good comparison of the ADL and IFX rapid test and the ELISA is given: Passing-Bablok correlation coefficient (R) of 0.953 (ADL) and 0.942 (IFX), and a mean bias determined by Bland-Altman of 1.59 µg/mL (ADL) and -0.5 µg/mL (IFX), respectively. The sample values gained with BÜHLMANN calibrators showed an excellent correlation with values gained with the WHO international standard for ADL as calibrator. Passing-Bablok regression analysis revealed a slope of 1.3 and correlation coefficient (R) of 1.0. Conclusion To the best of our knowledge, the Quantum Blue® ADL and Quantum Blue® IFX, are the first commercially available quantitative lateral flow assays comprising a WHO based standardization. Additionally, it was demonstrated that the current standardizations of Quantum Blue® ADL correlates very well with the WHO international standard for ADL.

Микрочастицы клеток крови у больных COVID-19 как маркер активации системы гемостаза.

Введение. Наблюдения за больными COVID-19 показали развитие коагулопатии на фоне тяжелой инфекции, вызванной SARC–CoV-2. Патогенетические механизмы влияния SARC–CoV-2 на систему гемостаза в настоящее время активно исследуются, однако для практического здравоохранения крайне актуальным является поиск маркеров активации системы свертывания крови с целью ранней профилактики тромбоэмболических осложнений у пациентов с COVID-19. Цель исследования: определить количество микрочастиц, отделяющихся от клеток крови, у больных COVID-19 и здоровых индивидуумов и проанализировать корреляцию числа микрочастиц с лабораторными и клиническими характеристиками пациентов. Материалы и методы. Обследованы 10 пациентов с COVID-19, госпитализированных в ФГБОУ ВО СЗГМУ им. И. И. Мечникова Минздрава России в период июнь-июль 2020 г., контрольную группу составили 12 сотрудников ФГБОУ ВО СЗГМУ им. И.И. Мечникова Минздрава России без признаков острого респираторного заболевания, без сердечно-сосудистых и тромбоэмболических эпизодов в анамнезе. У всех обследованных выполнен клинический анализ крови, исследованы маркеры активации и воспаления, а также измерено количество внеклеточных микровезикул — экзосом на проточном цитометре. Результаты. У пациентов с COVID-19 по сравнению с контрольной группой наблюдалось увеличение относительного количества нейтрофилов и снижение тромбоцитов. Такие маркеры как фибриноген, С-реактивный белок, ферритин, интерлейкин-6 и лактатдегидрогеназа значительно превышали верхнюю границу референтных значений. При этом количество экзосом оказалось значимо выше у пациентов с COVID-19 по сравнению со здоровыми лицами (% позитивных событий) — 93,2 [88,7–96,5] против 56,2 [50,5–73,5] соответственно (p = 0,00001) и коррелировало с относительным уровнем нейтрофилов. Среди проанализированных экзосом преобладали микрочастицы тромбоцитарного и лейкоцитарного происхождения. Заключение. Увеличение количества внеклеточных микрочастиц у больных COVID-19 может быть использовано как маркер активации гемостаза и повышенного риска тромботических осложнений на фоне инфекционного заболевания. Background. The monitoring of COVID-19 patients showed the development of coagulopathy in the context of severe infection caused by SARC–CoV-2. The pathogenetic mechanisms of SARC–CoV-2 influence on hemostasis are currently being actively examined, but the search for markers of the blood-clotting system activation for early prevention of thromboembolic complications in patients with COVID-19 is highly relevant for the practical health care. Objectives: to analyze the number of microparticles that separate from blood cells due to the hemostasis activation in COVID-19 patients and in healthy donors and to analyze the correlation between microparticles number and laboratory and clinical characteristics of patients. Patients /Methods. The study included 10 patients with COVID-19 who were hospitalized in Mechnikov North- Western State Medical University in June- July 2020; the control group consisted of 12 employees of Mechnikov North- Western State Medical University without signs of acute respiratory disease, without cardiovascular and thromboembolic episodes in the history. All patients and individuals in the control group had their blood clinically tested on a 5-Diff hematological analyzer, markers for activation and inflammation were examined, and the number of extracellular microvesicles (exosomes) was measured on the flow cytometer. Results. Patients with COVID-19 had an increase in the relative amount of neutrophiles and a decrease in platelets compared to controls. Markers such as fibrinogen, C-reactive protein, ferritin, interleukine-6 and lactate dehydrogenase significantly exceeded the upper reference limit. The number of exosomes was significantly higher in patients with COVID-19 compared to healthy controls (% of positive events) — 93.2 [88.7–96.5] vs. 56.2 [50.5–73.5] respectively (p = 0.00001), and correlated with the relative level of neutrophiles. Among the exosomes analyzed, platelet and leukocyte microparticles prevailed. Conclusions. The increase of extracellular microparticles in COVID-19 patients can be used as a marker of hemostasis activation and increased risk of thrombotic complications in the context of severe infectious disease.

Maternal Hepcidin Suppression Is Essential for Healthy Pregnancy

Iron is essential for maternal and fetal health during pregnancy, and iron requirements increase substantially in the second half of gestation1. However, the molecular mechanisms ensuring increased iron availability during pregnancy are not well understood. Hepcidin is the key iron-regulatory hormone and functions by occluding and degrading the iron exporter ferroportin (FPN) to inhibit dietary iron absorption and mobilization of iron from stores. In healthy human and rodent pregnancies, maternal hepcidin decreases starting in the second trimester and is nearly undetectable by late pregnancy2,3 (Figure A). We explored the role of maternal and embryo hepcidin in regulating embryo iron endowment using mouse models. By generating combinations of dams and embryos lacking hepcidin or not, we showed that in normal mouse pregnancy, only maternal but not embryo or placental hepcidin determines embryo iron endowment4. Maternal hepcidin was inversely related to embryo iron stores, and embryos from hepcidin-deficient dams had significantly higher hepatic iron stores regardless of their own hepcidin genotype. When maternal hepcidin was elevated during the second half of pregnancy in mice by administering a hepcidin mimetic, this led to dose-dependent embryo iron deficiency, anemia, and in severe cases, embryo death4. Embryos were particularly sensitive to maternal iron restriction as they developed iron deficiency in the liver and the brain even when maternal hematological parameters were unaffected. These data highlight the critical role of maternal hepcidin suppression for heathy pregnancy. Yet, the physiological mechanism of maternal hepcidin suppression remains unknown. We showed in mice that maternal hepcidin decreases prior to a significant decrease in liver iron and without any changes in serum iron, suggesting that maternal hepcidin suppression is not driven solely by iron deficiency. Using an in vitro model, we determined that the placenta secretes a hepcidin-suppressing factor. Exposure of primary mouse hepatocytes to supernatants from cultured human placenta cells, but not control media, suppressed hepcidin mRNA more than 10-fold (Figure B) and for up to 48hrs. The suppressive factor in the supernatant was >100kDa in size and not associated with exosomes. Studies to identify the placenta-derived hepcidin suppressor are ongoing. In summary, suppression of maternal hepcidin is essential to ensure adequate iron supply for transfer to the fetus and for the increase in maternal red blood cell mass2, and a placenta-derived hepcidin suppressor likely plays an important role in this adaptation. 1Fisher AL and Nemeth E, Am J Clin Nutr, 2017 2Sangkhae V et al, JCI, 2020 3van Santen S et al, Clin Chem Lab Med, 2013 4Sangkhae V et al, Blood, 2020 Figure 1 Disclosures Ganz: Global Blood Therapeutics: Consultancy; Ionis Pharmaceuticals: Consultancy; American Regent: Consultancy; Rockwell: Consultancy; Vifor: Consultancy; Astellas: Consultancy; Akebia: Consultancy; Gossamer Bio: Consultancy; Silarus Therapeutics: Current equity holder in private company; Sierra Oncology: Consultancy; Ambys: Consultancy; Disc Medicine: Consultancy; Intrinsic LifeSciences: Current equity holder in private company. Nemeth:Intrinsic LifeSciences: Current equity holder in private company; Silarus Therapeutics: Current equity holder in private company; Ionis Pharmaceuticals: Consultancy; Protagonist: Consultancy; Vifor: Consultancy.

ALLERGIC ACUTE CORONARY SYNDROME

SESSION TITLE: Medical Student/Resident Cardiovascular Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Kounis syndrome describes a unique phenomenon of acute coronary syndrome (ACS) in the presence of allergic or anaphylactic reactions. This syndrome is caused by inflammatory mediators - histamine being the most prominent - inducing coronary artery vasospasm. We present a case of allergic ACS in a patient with mast cell activation syndrome (MCAS). CASE PRESENTATION: A 35-year-old woman with a history of MCAS, chronic urticaria, migraines, severe persistent asthma, and recent DVT on therapeutic enoxaparin, was hospitalized for pain and edema concerning for an acute flare of MCAS. She was treated with oral steroids and a continuous intravenous diphenhydramine infusion. The patient later developed sepsis secondary to a staphylococcus aureus line infection and was started on cefazolin. Overnight, she developed asymptomatic diffuse ST elevations in addition to tachycardia with a rate in the 140s (baseline heart rate 100-130) and was found to have elevated troponins. Her initial troponin measurement was 0.28 and declined to 0.26 and 0.21. On physical exam she had scattered urticaria, tachycardia, normal heart sounds without a pericardial friction rub and was saturating well on room air. She was continued on steroids and diphenhydramine infusion with the addition of famotidine. She had no previous cardiac history and no significant family history of cardiovascular disease. TEE done 6 months prior was negative for mural thrombus and showed normal EF; echo the day after the onset of ST elevations showed no significant findings. DISCUSSION: Histamine induced coronary vasospasm may mimic classic ACS in patients undergoing an allergic reaction. Kounis syndrome is suspected to be largely underdiagnosed and should be considered in patients with anaphylactic or other allergic responses. Our patient likely had histamine-mediated ACS after initiation of cefazolin. Her troponin plateau makes ST-elevation myocardial infarction less likely. Other differentials to consider include myopericarditis given the diffuse ST elevations, however, given the onset in close proximity to new antibiotic initiation, her history is suspicious for an allergy mediated process. Furthermore, Kounis syndrome is more commonly found in individuals with other vasospastic conditions such as migraine. Treatment for allergic ACS includes management of underlying allergic response with corticosteroids and antihistamines; calcium channel blockers can also be considered. ACS protocol can be implemented in patients with underlying cardiac disease, but caution should be used with beta-blockers to avoid exacerbation of vasospasm. CONCLUSIONS: Patients undergoing an allergic reaction may experience classic signs and symptoms of ACS induced by histamine-mediated coronary vasospasm. Kounis syndrome is an important differential to consider in any allergy patient with new-onset ST changes or transient angina with or without concomitant urticaria. Reference #1: Kounis NG. Kounis syndrome: an update no epidemiology, pathogenesis, diagnosis and therapeutic management. CCLM. 2016; 54(10):1545–1559 Reference #2: Kounis NG, Zavras GM. Histamine-induced coronary artery spasm: the concept of allergic angina. Br J Clin Pract. 1991;45(2):121-128. Reference #3: Kounis NG. Kounis syndrome: an update on epidemiology, pathogenesis, diagnosis and therapeutic management. Clin Chem Lab Med. 2016;54(10):1545-1559. doi:10.1515/cclm-2016-0010 DISCLOSURES: No relevant relationships by Jennifer Cortes, source=Web Response No relevant relationships by Kelly Roth, source=Web Response

Ten-Month Evaluation of the Routine Application of Patient Moving Average for Real-Time Quality Control in a Hospital Setting.

In recent years there has been renewed interest in patient-based real-time quality control (PBRTQC) techniques. This interest has been stimulated by the availability of new optimization and validation methods. Only a limited amount of research has focused on investigating the true operational value of PBRTQC. Therefore, we have evaluated the performance and value of recently implemented patient moving average quality control (MA QC) procedures. The MA QC settings and protocols were as previously described (Clin Chem Lab Med 2019;57:1329-38) and included MA QCs for 10 chemistry and 6 hematological tests, all performed on duplicate analyzer systems. All MA QC alarms that occurred during the first 10 months of routine clinical application were investigated for assay-specific alarm rate and occurrence in time. Furthermore, the causes of these MA QC alarms were investigated, and alarm relevance was determined on the basis of total allowable bias (TBa) and error (TEa) derived from biological variations. During the 10-month period, 202 individual MA QC alarms occurred, resulting in an overall MA QC alarm rate of 0.030% and a frequency of 4.67 per week. Most alarms were triggered by sodium MA QC. Based on all available fully executed and documented MA QC alarm work-ups, MA QC detected errors that in 26.0% of the alarms exceeded the TBa and in 13.7% the TEa. In 9.2% of the alarms, MA QC alarming triggered instant (technical) corrections. Routine clinical application of MA QC is feasible with maintaining a manageable number of alarms and enabling detection of relevant analytical errors.

MON-070 Cross-Reactivity of Human Insulin and Insulin Analogues in Human Insulin Immunoassay Complicates Case of Medical Child Abuse

Background: Measurement of insulin levels with human insulin immunoassays is important in the investigation of hypoglycemia; however, cross-reactivity with insulin analogues complicates clinical assessment. Clinical Case: A 2-month-old male presented with hypoglycemia. Initial tests were consistent with hyperinsulinemic hypoglycemia: low serum glucose (29 mg/dL, n 70 to 99), elevated insulin (90.1 mU/L, n 3.0 to 19.0), suppressed beta-hydroxybutyrate (0.16 mmol/L, n 0.02 to 0.27), and suppressed free fatty acids (0.27 mmol/L, n 0.50 to 1.60). C-peptide level resulted undetectable (<0.1 ng/mL, n 0.8 to 3.5) raising suspicion for exogenous insulin administration. History revealed an older brother with type 1 diabetes mellitus treated with insulins glargine and lispro. Only one caregiver was present in the hospital, who denied knowledge of exogenous insulin administration. Hypoglycemia persisted despite placement of a continuous 1:1 sitter, high-dose intravenous glucose (glucose infusion rate up to 21.6 mg/kg/min), and treatment with diazoxide. A repeat insulin measurement with the Roche Diagnostics assay specific for human insulin was performed on a critical sample and resulted elevated (13.9 uIU/L, n 2.6 to 24.9), suggestive of endogenous insulin. However, an extensive study of commercial human insulin immunoassays by Heurtault et al., including the Roche Diagnostics assay, has demonstrated cross-reactivity with insulin analogues and their metabolites [1]. Given persistent concern for exogenous insulin administration, the patient’s caregiver was asked to leave the bedside for an extended period of time which resulted in normoglycemia. Diazoxide and dextrose-containing IV fluids were discontinued. Patient maintained normoglycemia for the remainder of the admission and was discharged in the care of child protective services. Conclusions: Cross-reactivity exists in human insulin immunoassays with insulin analogues and their metabolites complicating the determination of endogenous versus exogenous insulin as the cause of hyperinsulinemic hypoglycemia. It is important to know the cross-reactivity of the assay used if a diagnosis of surreptitious insulin administration is suspected. Separation of patient and possible perpetrators and involvement of child protective services is essential in suspected cases of exogenous insulin administration. Evaluation in cases where self-injection of insulin is suspected may be more difficult to decipher, and inclusion of c-peptide measurement at the time of hypoglycemia is critical. Reference: [1] Heurtault B, Reix N, Meyer N, et al. Extensive study of human insulin immunoassays: promises and pitfalls for insulin analogue detection and quantification. Clin Chem Lab Med. 2014; 52:355-362.

COVID-19: Crisis management in congenital heart surgery

COVID-19: Crisis management in congenital heart surgery

Glomerular Filtration Rate Calculation Based on Serum Creatinin and Cystatin C in Type 2 Diabetic Patients

Glomerular Filtration Rate Calculation Based on Serum Creatinin and Cystatin C in Type 2 Diabetic Patients

Hepcidin, Soluble Transferrin Receptor, and Other Biomarkers of Iron Status Distributions in Healthy 2 Years Old Infants from a National Ambulatory Study in France

Background: Adequate evaluation of iron status in young children is of paramount importance given the frequency of iron deficiency (ID) and its potential short- and long-term neurocognitive adverse effects when occurs early. Iron metabolism is complex and the correct evaluation of iron status may be difficult, notably when inflammation is present. Soluble transferrin receptor (sTfR) is not modified by inflammation but lacks specificity in ID, and its combination with serum ferritin (SF) by the TfR-F index (TfR/logSF) has been proposed to improve diagnosis performances [Punnonen Blood 1997]. Hepcidin has been identified in the two last decades has the key regulator of iron homeostasis mainly by controlling iron release from macrophages via ferroportin degradation, as well as enterocytes absorption [Ganz Blood 2011]. Scarce studies have been published on hepcidin in healthy children in industrialized countries [Uijterschout Pediatr Res 2014]. The distribution of sTfR and hepcidin in healthy young children is unknown, including according to gender. Aims: Our objective was to describe hepcidin, sTfR and other iron status biomarkers (serum ferritin [SF], hemoglobin (Hb), transferrin saturation, zinc protoporphyrin [ZnPP]) distributions in a population of healthy infants aged 2 years old. Methods: In a cross-sectional observational study conducted in primary care pediatricians' offices throughout France from 2016 to 2017, infants aged 2 years old were consecutively included to undergo a blood sampling in the morning fasting. They were excluded if they were affected by a chronical disease involving iron metabolism, had fever in the last 15 days or biological inflammation defined as a CRP≥10 mg/L, and had no measurement for hepcidin. Hepcidin and ZnPP in erythrocytes were measured after a &lt;24 hours frozen transport at -80°C in the dark by liquid chromatography-tandem mass spectrometry (LC-MS/MS, limit of detection = 0.75 ng/mL, intra- and inter-assay precision ≤ 12.3% and 9.9% [Lefebvre Clin Chem Lab Med 2015]) and by a fluorimetric method, respectively. Hb and mean corpuscular Hb concentration were measured immediately after the sample by spectrophotometric methods. The other iron biomarkers were immediately measured after refrigerated or frozen transport using immuno-turbidimetric method for transferrin (limit of detection = 0.1 g/L, intra- and inter-assay precision ≤1.2 and 2.6%) and sTfR (limit of detection 0.5 mg/L, intra- and inter-assay precision ≤2.1 and 3.6%), and electro‐chemiluminescence immunoassay for SF (limit of detection = 0.5 μg/L, intra- and inter-assay precision ≤1.1% and 5.7%). The distribution of biomarkers were described, including after classical mathematical transformation. Results: Among the 539 included children, the mean age was 24 months (SD 0.6), 49% were girls. Prevalence of ID (SF &lt;10 µg/L) and anemia (Hb &lt;11 g/dL) was 7% (37/539, 95% CI 4.9-9.3) and 3% (19/536, 95% CI 2.1-5.5), respectively. Hepcidin (ng/mL) median was 3.3 (IQR: 1.0-7.1; min-max: 0.75-104.1) and its mean was 6.7 (SD 10.7). Hepcidin was neither normally nor log-normally distributed (Figure 1.A, 1.B). sTfR median was 4.1 (IQR: 3.6-4.8; min-max: 1.2-13.5) and its mean was 4.2 (SD 1.1). TfR-F index median was 1.2 (IQR: 1.0-1.5; min-max: 0.3-8.4) and its mean was 1.4 (SD 0.6). No statistically significant difference was found between girls and boys for hepcidin, sTfR, and TfR-F index distributions (all p t-tests &gt; 0.3). Distributions of other iron biomarkers were closed to those reported in the literature. Conclusion: We described for the first time in a nationwide ambulatory study hepcidin and TfR/logSF distributions in a population of 2 year-old healthy infants with a low ID prevalence. Hepcidin had a right-skewed distribution and its normalisation was not obtained by usual transformations. Low values, partly corresponding to the limit of detection, were over-represented despite the low proportion of ID defined by SF level. High values were also observed despite the exclusion of infants with CRP&gt;10 mg/L. We did not find significant variations according to gender. Our results will help define normal values at this age to better interpret iron status. Disclosures Sacri: Secteur Francais des Aliments de l Enfance: Research Funding; French Ministry of Health DGOS PHRC regional 2014 no. AOR14053: Research Funding. De Montalembert:Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Addmedica: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Chalumeau:French Ministry of Health DGOS PHRC regional 2014 no. AOR14053: Research Funding; Secteur Francais des Aliments de l Enfance: Research Funding.

Altered Iron Parameters and Hepcidin Levels in a General Population: Lessons from the CHRIS Study

Introduction Environmental and genetic factors may lead to iron accumulation, causing irreversible organ damage. Homozygosity for the C282Y (C282Y +/+) and compound heterozygosity for the C282Y and H63D (C282Y-H63D) mutations of the HFE gene are associated with susceptibility to iron overload (IO). However, their clinical and biochemical expression is heterogeneous, with some patients showing only an increase of transferrin saturation (TSAT) for life, and others developing severe liver disease at a young age. Rarely, IO occurs in subjects without HFE-mutations or other acquired factors (e.g. alcohol intake, hemolysis, etc.). In these cases, non-HFE hemochromatosis is suspected, but the diagnosis is challenging, based on invasive (i.e., liver biopsy) or poorly available (i.e., Next-Generation Sequencing) approaches. A defective production of the iron regulatory hormone hepcidin is the key pathogenetic factor in hereditary hemochromatosis, irrespective of the gene involved, but extensive studies evaluating its potential diagnostic role are still lacking. This project evaluated hepcidin levels in a large subpopulation from the Cooperative Health Research In South Tyrol (CHRIS) study. Here we explored in particular hepcidin levels in subjects with altered iron status parameters, and their role in the identification of subjects at major risk of developing IO. Patients and Methods Study Population. The CHRIS study is a population-based study carried out in South Tyrol (Northern Italy), whose general aims are reported in detail elsewhere (Pattaro C, J Transl Med 2015). Blood samples were tested for several biochemical and genetic parameters, including those related to iron status, such as TSAT, ferritin, and C282Y and H63D mutations. Hepcidin was measured in stored aliquots by a recently updated and validated mass spectrometry-based method in tandem with liquid chromatography (LC-MS/MS), able to distinguish the active hepcidin-25 isoform (Diepeveen LE, Clin Chem Lab Med 2019). Results Among 4,642 participants, 6 were C282Y +/+ and 30 were C282Y-H63D (hereinafter defined as "HFE-H subjects"). HFE-H subjects showed ferritin levels only slightly higher than those with apparent wild-type HFE-H genotype (92.7 vs. 76.0 ng/ml, p=0.29), significantly higher TSAT (46.6 vs. 28.9%, p&lt;0.0001) and lower hepcidin levels (1.41 vs. 2.30 nmol/l, p=0.016) (Table 1). Defective production of hepcidin was suggested by the reduced hepcidin:ferritin ratio (1.53 vs. 3.02 pmol/ng, p&lt;0.0001), which was particularly low in C282Y +/+ (0.65 pmol/ng). Table 2 shows the prevalence of subjects with altered iron parameters (hyperferritinemia and/or increased TSAT), according to the HFE genotype. As concern HFE-H subjects, hyperferritinemia (i.e. &gt;200 or &gt;300 ng/ml in females and males, respectively) was detected in 16.7%, increased TSAT (&gt;45%) in 52.8% and both in 11.1%. A biochemical pattern suggestive of IO (ferritin&gt;500 ng/ml and TSAT&gt;50%) was seen only in 33.3% of C282Y +/+ and in 6.7% of C282Y-H63D, while 41.7% neither had hyperferritinemia nor increased TSAT, confirming the low penetrance of such genotype. Although HFE-H subjects displayed a tendency to increase hepcidin production according to iron deposits (mean level of 1.10 nmol/l in subjects without hyperferritinemia/increased TSAT vs. 3.5 nmol/l of subjects with IO), the hepcidin:ferritin ratio was significantly lower in phenotypically expressed HFE-H subjects (0.49 vs. 2.04 pmol/ng, p=0.014) (Table 3). On the other hand, 540 participants (11.7 percent) without HFE-H genotype had hyperferritinemia, 64 (1.4%) had both hyperferritinemia and increased TSAT, and 12 (0.3 percent) had biochemical signs strongly suggestive of IO (ferritin&gt;500 ng/ml and TSAT&gt;50%). The latters had reduced hepcidin:ferritin ratio (0.92 pmol/ng), a value comparable to that of HFE-H iron loaded subjects (p=0.048). Whole Exome Sequencing data are available for the majority of CHRIS subjects included in this project and will be analyzed in detail in these subpopulations. Conclusions Our data suggest that the hepcidin:ferritin ratio may actually represent a useful indicator of hemochromatosis irrespective of the HFE genotype, possibly driving an optimal use of second level genetic test. Disclosures Girelli: Vifor Pharma: Other: honoraria for lectures; Silence Therapeutics: Membership on an entity's Board of Directors or advisory committees; La Jolla Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy.

The Official Journal of ATTD Advanced Technologies &amp; Treatments for Diabetes Conference Berlin, Germany—February 20–23, 2019

The Official Journal of ATTD Advanced Technologies &amp; Treatments for Diabetes Conference <i>Berlin, Germany—February 20–23, 2019</i>

Impact of the Choice of IGF-I Assay and Normative Dataset on the Diagnosis and Treatment of Growth Hormone Deficiency in Children

Background: The analysis of insulin-like growth factor I (IGF-I) is an important tool for pediatricians in the diagnosis and treatment of growth hormone deficiency in children. However, significant differences exist in IGF-I assays and normative datasets, which can have important clinical consequences. Methods: IGF-I analyses were performed using the IDS-iSYS platform on 1,897 samples from pediatric patients (0.5–18 years old). Z-scores were calculated based on normative IGF-I data from Bidlingmaier et al. (SD-BM) [J Clin Endocrinol Metab. 2014 May; 99(5): 1712–21] and normative IGF-I data from the IGF-I harmonization program in the Netherlands (SD-NL). The differences in Z-scores were analyzed at relevant clinical decision points (–2 SD, +2 SD). These normative datasets were also compared to normative data reported by Elmlinger et al. [Clin Chem Lab Med. 2004; 42(6): 654–64]. Results: The difference in Z-score between SD-BM and SD-NL was highest in males between 0 and 3 years old, exceeding 2 SD. Clinically relevant discordance between both Z-scores at –2 and +2 SD was found in 12.7% of all samples. The IGF-I levels at –2 and +2 SD reported in the normative dataset of Elmlinger et al. were up to 100% higher than the IGF-I levels reported by Bidlingmaier et al. or the Dutch harmonization program. Conclusion: Pediatricians and laboratory specialists should be aware of relevant differences that can exist between IGF-I assays and normative data. Well-defined pediatric reference ranges for the IDS-iSYS platform are highly desirable.

A false positive case of cardiac troponin I identified with CK-MB reflex testing

The assessment of cardiospecific troponins, either troponin I (TnI) or T (TnT), is currently regarded as the mainstay for diagnosing myocardial injury, including acute myocardial infarction (AMI) [ [1] Aldous S.J. Cardiac biomarkers in acute myocardial infarction. Int J Cardiol. 2013; 164: 282-294 Abstract Full Text Full Text PDF PubMed Scopus (84) Google Scholar ]. Although the recent introduction of high-sensitivity troponin immunoassays has contribute to substantially increase the timely and accurate detection of myocardial injury, troponin testing is still plagued by a significant rate of false positive cases, which ultimately contribute to decrease the overall diagnostic specificity of these tests [ [2] Vafaie M. Biener M. Mueller M. et al. Analytically false or true positive elevations of high sensitivity cardiac troponin: a systematic approach. Heart. 2014; 100: 508-514 Crossref PubMed Scopus (34) Google Scholar ]. The leading sources of false positive results of troponin testing include genetic polymorphisms in the TnI and TnT genes which may impair antibody binging [ [3] Lippi G. Cervellin G. Genetic polymorphisms of human cardiac troponins as an unrecognized challenge for diagnosing myocardial injury. Int J Cardiol. 2014; 171: 467-470 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar ], as well as the interference from rheumatoid factor (RF) [ [4] Dupont J. Fromonot J. Franceschi F. et al. A case of false positive troponin elevation: role of the biological laboratory. Int J Cardiol. 2013; 162: e66-e67 Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar ], heterophilic antibodies [ [5] Lippi G. Aloe R. Meschi T. Borghi L. Cervellin G. Interference from heterophilic antibodies in troponin testing. Case report and systematic review of the literature. Clin Chim Acta. 2013; 426: 79-84 Crossref PubMed Scopus (60) Google Scholar ] and spurious hemolysis [ [6] Lippi G. Avanzini P. Dipalo M. Aloe R. Cervellin G. Influence of hemolysis on troponin testing: studies on Beckman Coulter UniCel Dxl 800 Accu-TnI and overview of the literature. Clin Chem Lab Med. 2011; 49: 2097-2100 Crossref PubMed Scopus (26) Google Scholar ].

Determination of lysosomal exoglycosidases in human saliva.

Currently we observe a growing interest in human saliva as a non-invasive material for diagnosis and monitoring of general and oral diseases. The aim of our study was adaptation of the Marciniak et al. (Marciniak J, Zalewska A, Popko J, Zwierz K, 2006, Clin Chem Lab Med 44: 933-937) method for determination of HEX and GLU activity in synovial fluid, and for determination of: HEX and GLU, as well as MAN, GAL, and FUC activity in human saliva. Under optimal conditions, 10 μl of saliva for HEX, and 30 μl for GLU, MAN, GAL and FUC, were sufficient for determination of human salivary exoglycosidases activity with variation coefficient ranging from 0.89 for GLU to 0.99 for GAL. The adapted method for exoglycosidases activity determination in human saliva is sufficiently sensitive and precise to use in clinical diagnosis.

Reply to the article entitled “Identification of an 18 bp deletion in the TWIST1 gene by CO-amplification at lower denaturation temperature-PCR (COLD-PCR) for non-invasive prenatal diagnosis of craniosynostosis: first case report” by Galbiati et al., Clin Chem Lab Med 2014;52(4):505–9

Article Reply to the article entitled “Identification of an 18 bp deletion in the TWIST1 gene by CO-amplification at lower denaturation temperature-PCR (COLD-PCR) for non-invasive prenatal diagnosis of craniosynostosis: first case report” by Galbiati et al., Clin Chem Lab Med 2014;52(4):505–9 was published on July 1, 2014 in the journal Clinical Chemistry and Laboratory Medicine (CCLM) (volume 52, issue 7).

AB1235 Clinical relevance of anti-citrullinated protein antibody for the detection of rheumatoid arthritis in hemodialysis patients

BackgroundHemodialysis (HD) patients are considered to be at increased risk for developing rheumatoid arthritis (RA), as a result of immunologic abnormalities caused by this treatment1). Anti-cyclic citrullinated peptide (anti-CCP) antibody...

AB0735 Antinuclear antibodies in aged people without signs of autoimmune disease

BackgroundAnti-nuclear antibodies (ANA) are a hallmark in the diagnosis of systemic autoimmune rheumatic diseases (SARD). Their occurrence in several diseases like systemic lupus erythematodes (SLE), systemic scleroderma, Sjögren’s syndrome, myositis...