In-house standards derived from doping peptides: Enzymatic and serum stability and degradation profile of GHRP and GHRH-related peptides.

Matrix effect and sample pretreatment significantly affect the percentage recovery of peptides in biological matrices, affecting the method robustness and accuracy. To counteract this effect, an internal standard (IS) is used; however, in most cases this is not available, which limits the analytical method. It is important to identify short peptides that can be used as ISs in the quantification of peptides in biological matrices. In this study, doping peptides GHRP-4, GHRP-5, GHRP-6, Sermorelin (1-11), Sermorelin (13-20) and Sermorelin (22-29) were synthesized using solid-phase peptide synthesis. Treatment with human blood, trypsin and chymotrypsin was used to determine the stability of the peptides. Products were evaluated using the high-performance liquid chromatography-diode array detector (HPLC-DAD) method. The analytical methodology and sample pretreatment were effective for the analysis of these molecules. A unique profile related to protein binding and enzymatic stability of each peptide was established. GHRP-4, GHRP-6 and Sermorelin (22-29) can be considered as in-house ISs as they were stable to enzyme and blood treatment and can be used for the quantification of peptides in biological samples. Peptides GHRP-6 and Sermorelin (22-29) were used to analyse a dimeric peptide (26 [F] LfcinB (20-30)2 ) in four different matrices to test these peptides as in-house IS.

Análisis clínicos en pediatría: la necesidad de minimizar las horas de ayuno / Clinical analysis in pediatrics: the need to minimize fasting hours

Los informes de laboratorio tienen impacto en las decisiones médicas. El ayuno es un factor preanalítico "controlable" que influye en los distintos parámetros bioquímicos. El objetivo del presente trabajo es poner en discusión la realización en pediatría de análisis clínicos con la indicación de un ayuno fisiológico , analizando resultados obtenidos por diferentes autores y evaluando las diferencias clínicas encontradas según los criterios de calidad establecidos por el laboratorio de Química Clínica. La mayoría de los individuos durante el día se encuentran en estado postprandial. Los resultados del perfil lipídico en ayunas no representan las concentraciones reales promedios de los lípidos plasmáticos de un paciente. El ayuno no sería crítico en la etapa de pesquisa , pero puede ser relevante para establecer un diagnóstico certero o inicio de tratamiento. En el caso de la glucemia si se indica en el control rutinario del paciente, y no hay sospecha de alteraciones en el metabolismo de los hidratos de carbono la glucemia sin ayuno puede ser solicitada comparando la misma con valores de corte adecuado. Las diferentes guías nacionales e internacionales recomiendan que la elección de la métrica para la evaluación, control y seguimiento de pacientes con diagnóstico de diabetes se realicen según el objetivo terapéutico. En los trabajos analizados, observamos que varios parámetros bioquímicos presentaron diferencias estadísticas, aunque las diferencias clínicas no fueron relevantes y permanecieron dentro de los intervalos de referencia. El factor limitante para evaluar parámetros bioquímicos sin ayuno es la falta de valores de referencia adecuados. Hay evidencia suficiente para que tanto el perfil lipídico, la glucemia como el resto de los parámetros bioquímicos del laboratorio de química clínica, sean solicitados con la indicación de un ayuno fisiológico de 2, 4 o 6 horas, dependiendo siempre del motivo de consulta y/o la edad del paciente. Es esencial extender la evaluación a otros analitos en población pediátrica, así como evaluar nuevos puntos de corte para parámetros bioquímicos sin ayuno (AU)

Laboratory reports have an impact on medical decision-making. Fasting is a "controllable" preanalytical factor that influences the different biochemical parameters. The aim of this study is to discuss the performance of clinical analyses in pediatrics with the indication of physiological fasting, analyzing results obtained in different disciplines, and evaluating the clinical differences found according to the quality criteria established by the clinical chemistry laboratory. During the day, most patients are in a postprandial state. Fasting lipid profile results do not represent the actual average plasma lipid concentrations of a patient. Fasting would not be critical in the screening stage, but it may be relevant to establish an accurate diagnosis or initiate treatment. Regarding glycemia, if it is indicated in the routine control of the patient and there is no suspicion of alterations in carbohydrate metabolism, non-fasting glycemia can be requested, comparing it with adequate cut-off values. Different national and international guidelines recommend that the choice of metrics for the evaluation, control, and follow-up of patients with diabetes should be made according to the therapeutic objective. In the studies analyzed, we found that several biochemical parameters presented statistical differences, although the clinical differences were not relevant and remained within the reference range. The limiting factor in the evaluation of biochemical parameters without fasting is the lack of adequate reference values. There is sufficient evidence that the lipid profile, glycemia, and the remaining biochemical parameters of the clinical chemistry laboratory should be requested with the indication of a physiological fast of 2, 4, or 6 hours, always depending on the reason for consultation and/or the patient's age. It is essential to extend the evaluation to other analytes in the pediatric population, as well as to evaluate new cut-off points for biochemical parameters without fasting (AU)

Analytical validation of 39 clinical chemistry tests and 17 immunoassays on the Alinity analytical system.

The aim of this study was to perform the analytical validation of Alinity c and i analyzers (Abbott Laboratories, Chicago, IL, USA) for 39 clinical chemistry tests and 17 immunoassays. Precision was evaluated at least at two concentration levels for 5 days in quintuplicate, following CLSI EP15-A3. Method comparison included parallel analysis of leftover routine samples on Alinity analyzers and the previously used Cobas c501 and e601 (Roche Diagnostics, Mannheim, Germany). Linearity was tested by preparing sequential sample dilutions with high analyte concentration, following the CLSI EP6 document. For clinical chemistry tests, within-run coefficients of variation (CV) were up to 6.0% (beta-2-microglobulin), while between-run CVs up to 5.4% (immunoglobulin M). Among immunoassays, the highest within-run CV was obtained for vitamin B12 (6.9%), while between-run for CA 19-9 (4.3%). Complete agreement with Roche analyzers was observed for 16 (41%) clinical chemistry assays and 6 (35%) immunoassays. Half of all evaluated assays did not meet the desirable biological variation criteria for bias, being especially exceeded for alpha1-antitrypsin, apolipoprotein A1, ceruloplasmin, complement C3 and C4, hemoglobin A1c, lipoprotein (a) and myoglobin, as well as some tumor markers (CA 125, CEA, fPSA, AFP, and ferritin), hormones (cortisol, DHEA-S, insulin) and vitamins (25-OHD). Linearity in the tested ranges was confirmed. Overall, this study revealed that precision criteria derived from manufacturer's claims were not satisfied for all assays while comparison study for some assays yielded differences that imply the need for additional assay evaluation prior to introduction into routine practice.

Comparison of Five Common Analyzers in the Measurement of Chemistry Analytes in an Authentic Cohort of Body Fluid Specimens.

OBJECTIVES: Interpretation of body fluid (BF) results is based on published studies and clinical guidelines. The aim of this study is to determine whether the assays from five common commercial vendors produce similar results in BFs for 12 analytes in a BF cohort. METHODS: BFs (n = 25) and serum (n = 5) were analyzed on five instruments (Roche cobas c501, Ortho 5600, Beckman AU5800 and DXI800, Siemens Vista 1500, and Abbott Architect c8000) to measure albumin, amylase, total bilirubin, cholesterol, creatinine, glucose, lactate dehydrogenase (LDH), lipase, total protein, triglycerides, urea nitrogen, and carcinoembryonic antigen. Deming regression and Bland-Altman analysis were used for method comparison to Roche. RESULTS: Results were significantly different from Roche for LDH and lipase on Ortho and lipase on Siemens but similar for both BFs and serum. BF differences were larger than serum differences when measuring creatinine, glucose, and urea nitrogen on Ortho and glucose on Siemens. CONCLUSIONS: Five instruments used to perform BF testing produce results that are not significantly different except for lipase and LDH measurements. Bias of similar magnitude observed in both BF and serum should not affect interpretation. Further investigations into Ortho and Siemens measuring glucose and Ortho measuring creatinine and urea nitrogen are warranted.

Dynamic Tests in Pituitary Endocrinology: Pitfalls in Interpretation during Aging.

Aging and age-related diseases represent hot topics of current research. Progressive damage in morphology and function of cells and tissue characterizes the normal process of aging that is influenced by both genetic and environmental factors. The ability of each individual to adapt to these stressors defines the type of aging and the onset of age-related diseases (i.e., metabolic syndrome, inflammatory disorders, cancer, and neurodegenerative diseases). The endocrine system plays a critical role in this process because of its complex relationships with brain, immune system, and skeletal muscle; thus, alterations in hormonal networks occur during aging to maintain homeostasis, with consequent under- or overactivity of specific hypothalamic-pituitary-peripheral hormone axes. On the other hand, the increase in life expectancy has led to increasing incidence of age-related diseases, including endocrine disorders, which may prompt assessment of endocrine function in aging individuals. In this context, there is growing awareness that natural changes of endocrine physiology and physiopathology occurring with increasing age may necessitate age-driven diagnostic cutoffs requiring validation in the elderly. This review aims to analyze the available literature on the hormone response to the most important dynamic tests currently used in the clinical practice for the screening of anterior pituitary-related diseases to underline pitfalls in interpretation during aging.

Validação de intervalos de referência de exames bioquímicos do laboratório de análises clínicas de um hospital universitário / Validation of reference intervals for biochemical tests at the clinical analysis laboratory of a university hospital

Introdução: Os intervalos de referência (IRs) disponibilizados em laudos de exames laboratoriais orientam a interpretação dos resultados, respaldando a avaliação clínica realizada por profissionais de saúde. Objetivo: Validar IRs de parâmetros bioquímicos, com base nas características da população local, bem como em informações disponíveis nas bulas dos reagentes e na literatura científica. Material e Métodos: Foi realizado um estudo observacional, descritivo e transversal para padronização de IRs de trinta e quatro parâmetros bioquímicos, executados pelo laboratório de análises clínicas de um hospital universitário. Participaram do estudo quarenta indivíduos adultos, pareados pelo sexo, que responderam um questionário sobre o estado geral de saúde. Uma amostra de sangue foi coletada de cada participante e analisada conforme os padrões do laboratório. Resultados: Os dados obtidos com os voluntários saudáveis permitiram a validação dos IRs de albumina, alanina aminotransferase, amilase, aspartato aminotransferase, bilirrubina direta, bilirrubina indireta, bilirrubina total, cálcio iônico, capacidade total e latente de fixação de ferro, creatinoquinase fração MB, cloro, ferro, fosfatase alcalina, fósforo, gama glutamiltransferase, glicose, lipoproteína de alta densidade, lactato, lactato desidrogenase, lipase, magnésio, potássio, proteínas totais, saturação da transferrina, sódio, triglicerídeos e ureia, de ambos os sexos. Ácido úrico foi validado apenas para o sexo masculino e creatinoquinase total (CK) foi validado apenas para o sexo feminino. Conclusão: Os IRs contidos nas bulas destes reagentes representam a população atendida pelo laboratório e podem continuar sendo utilizados. Em contrapartida, os IRs dos analitos colesterol total, lipoproteína de baixa densidade, cálcio, ácido úrico feminino e CK masculino não foram validados e necessitam de novos estudos para a validação dos intervalos de referência utilizados

Introduction: The reference intervals (RIs) provided in laboratory test reports orientate the interpretation of results, supporting the clinical evaluation performed by health professionals. Objective: Validate RIs of biochemical parameters, based on the characteristics of the local population, as well as on information available in the package inserts of the reagents and in the scientific literature. Material and Methods: An observational, descriptive, and cross-sectional study was carried out for the standardization of RIs of thirty-four biochemical parameters, performed by the Clinical Analysis laboratory of a university hospital. Forty adult individuals, matched by sex, participated in the study, who answered a questionnaire about their general health status. A blood sample was taken from each participant and analyzed according to laboratory standards. Results: Data obtained from healthy volunteers allowed the validation of the RIs of albumin, alanine aminotransferase, amylase, aspartate aminotransferase, direct bilirubin, indirect bilirubin, total bilirubin, ionic calcium, total and latent iron-binding capacity, creatine kinase MB fraction, chlorine, iron, alkaline phosphatase, phosphorus, gamma glutamyltransferase, glucose, high density lipoprotein, lactate, lactate dehydrogenase, lipase, magnesium, potassium, total proteins, transferrin saturation, sodium, triglycerides and urea, of both sexes. Uric acid has been validated for males only and total creatine kinase (CK) has been validated for females only. Conclusion: The RIs contained in the package inserts of these reagents represent the population assisted by laboratory and can continue to be used. The RIs of total cholesterol, low-density lipoprotein, calcium, female uric acid and male CK analytes were not validated and require further studies to validate the reference intervals used

Comparación clínica y laboratorial de la fiebre amarilla severa versus dengue grave en Perú / Clinical and laboratory differences between severe yellow fever and severe dengue in emergency patients

En los centros de Emergencia con poco apoyo de laboratorio, es difícil diferenciar a los pacientes con dengue grave y fiebre amarilla severa. El objetivo fue comparar el perfil clínico y de laboratorio de los pacientes con dengue grave y fiebre amarilla severa en Urgencias. Se realizó un estudio observacional retrospectivo de pacientes con diagnóstico confirmado de dengue y fiebre amarilla en el período 2018 a 2020 atendidos en la Unidad de Emergencia del Hospital Carrión, Huancayo-Perú. Se evaluaron un total de 35 pacientes, 11 pacientes (31,4%) fueron diagnosticados con fiebre amarilla severa y 24 pacientes (68,5%) con dengue grave. La media de los resultados de laboratorio con fiebre amarilla severa fueron bilirrubina indirecta 4,7 ml/dL, aspartato transaminasa 4463 UI/L, transaminasa aminotransferasa 4329 UI/L, creatinina 4,9 mg/dl. En pacientes con dengue grave el hematocrito promedio fue 51,8, hemoglobina 17,6 g/dl, plaquetas 24 × 103/mm. En pacientes con síndrome ictérico-febril la presencia de bradicardia, bilirrubina indirecta elevada y transaminasas muy elevadas debe hacer sospechar de fiebre amarilla; mientras que los pacientes que acuden por ascitis, derrame pleural, aumento de hematocrito y deficiencia de plaquetas, se debe tratar como dengue grave sobre todo en Unidades de Emergencia con poco apoyo de laboratorio(AU)

In Emergency centers with little laboratory support, differentiating patients with dengue and yellow fever is difficult. The Aim was to compare the clinical and laboratory profile of patients with severe dengue and severe yellow fever in the Emergency unit. We conducted a retrospective observational study of patients with a confirmed diagnosis of dengue and yellow fever in the period 2018 to 2020 treated in the Emergency Unit of the Carrión hospital, Huancayo-Peru. A total of 35 patients were evaluated, 11 patients (31.4%) were diagnosed with severe yellow fever and 24 patients (68.5%) with severe dengue. The mean laboratory results in patients with severe yellow fever were indirect bilirubin 4.7 ml/dL, aspartate transaminase 4463 IU/L, transaminase aminotransferase 4329 IU/L, creatinine 4.9 mg / dl. In patients with severe dengue were hematocrit 51.8, hemoglobin 17.6 g / dl, platelets 24 × 103 / mm. In patients with syndrome jaundice and fever the presence of bradycardia, elevated indirect bilirubin, and very elevated transaminases should be suspicious for yellow fever; while in patients who come for ascites, pleural effusion, increased hematocrit and platelet deficiency, it should be treated as severe dengue especially in Emergency Units with little laboratory support(AU)

Application of Sigma metrics in the quality control strategies of immunology and protein analytes.

BACKGROUND: Six Sigma (6σ) is an efficient laboratory management method. We aimed to analyze the performance of immunology and protein analytes in terms of Six Sigma. METHODS: Assays were evaluated for these 10 immunology and protein analytes: Immunoglobulin G (IgG), Immunoglobulin A (IgA), Immunoglobulin M (IgM), Complement 3 (C3), Complement 4 (C4), Prealbumin (PA), Rheumatoid factor (RF), Anti streptolysin O (ASO), C-reactive protein (CRP), and Cystatin C (Cys C). The Sigma values were evaluated based on bias, four different allowable total error (TEa) and coefficient of variation (CV) at QC materials levels 1 and 2 in 2020. Sigma Method Decision Charts were established. Improvement measures of analytes with poor performance were recommended according to the quality goal index (QGI), and appropriate quality control rules were given according to the Sigma values. RESULTS: While using the TEaNCCL , 90% analytes had a world-class performance with σ>6, Cys C showed marginal performance with σ<4. While using minimum, desirable, and optimal biological variation of TEa, only three (IgG, IgM, and CRP), one (CRP), and one (CRP) analytes reached 6σ level, respectively. Based on σNCCL that is calculated from TEaNCCL , Sigma Method Decision Charts were constructed. For Cys C, five multi-rules (13s /22s /R4s /41s /6X , N = 6, R = 1, Batch length: 45) were adopted for QC management. The remaining analytes required only one QC rule (13s , N = 2, R = 1, Batch length: 1000). Cys C need to improve precision (QGI = 0.12). CONCLUSIONS: The laboratories should choose appropriate TEa goals and make judicious use of Sigma metrics as a quality improvement tool.

A nomogram based on clinicopathological features and serological indicators predicting breast pathologic complete response of neoadjuvant chemotherapy in breast cancer.

A single tumor marker is not enough to predict the breast pathologic complete response (bpCR) after neoadjuvant chemotherapy (NAC) in breast cancer patients. We aimed to establish a nomogram based on multiple clinicopathological features and routine serological indicators to predict bpCR after NAC in breast cancer patients. Data on clinical factors and laboratory indices of 130 breast cancer patients who underwent NAC and surgery in First Affiliated Hospital of Xi'an Jiaotong University from July 2017 to July 2019 were collected. Multivariable logistic regression analysis identified 11 independent indicators: body mass index, carbohydrate antigen 125, total protein, blood urea nitrogen, cystatin C, serum potassium, serum phosphorus, platelet distribution width, activated partial thromboplastin time, thrombin time, and hepatitis B surface antibodies. The nomogram was established based on these indicators. The 1000 bootstrap resampling internal verification calibration curve and the GiViTI calibration belt showed that the model was well calibrated. The Brier score of 0.095 indicated that the nomogram had a high accuracy. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was 0.941 (95% confidence interval: 0.900-0.982) showed good discrimination of the model. In conclusion, this nomogram showed high accuracy and specificity and did not increase the economic burden of patients, thereby having a high clinical application value.

The case for the repeatability intra-class correlation as a metric of precision for salivary bioscience data: Justification, assessment, application, and implications.

Best practice standards for measuring analyte levels in saliva recommend that all biospecimens be tested in replicate with mean concentrations used in statistical analyses. This approach prioritizes minimizing laboratory-based measurement error but, in the process, expends considerable resources. We explore the possibility that, due to advances in salivary assay precision, the contribution of laboratory-based measurement error in salivary analyte data is very small relative to more important and meaningful variability in analyte levels across biological replicates (i.e., between different specimens). To evaluate this possibility, we examine the utility of the repeatability intra-class correlation (rICC) as an additional index of salivary analyte data precision. Using randomly selected subsamples (Ns=200 and 60) of salivary analyte data collected as part of a larger epidemiologic study, we compute the rICCs for seven commonly assayed salivary measures in biobehavioral research - cortisol, alpha-amylase, c-reactive protein, interlekin-6, uric acid, secretory immunoglobulin A, and testosterone. We assess the sensitivity of rICC estimates to assay type and the unique distributions of the underlying analyte data. We also use simulations to examine the bias, precision, and coverage probability of rICC estimates calculated for small to large sample sizes. For each analyte, the rICCs revealed that less than 5% of variation in analyte levels was attributable to laboratory-based measurement error. rICC estimates were similar across all analytes despite differences in analyte levels, average intra-assay coefficients of variation, and in the distributional properties of the data. Guidelines for calculating rICC are provided to enable investigators and laboratory staff to apply this metric and more accurately quantify, and communicate, the magnitude of laboratory-based measurement error in their data. By helping investigators scale measurement error relative to more scientifically meaningful variability between biological replicates, the application of the rICC has the potential to influence research strategies and tactics such that resources (e.g., finances, effort, number/volume of biospecimens) are allocated more efficiently and effectively.

Evaluation of a flow cytometric test for G6PD-deficient erythrocytes.

OBJECTIVE: Glucose-6-phosphate dehydrogenase (G6PD) deficiency, an X-linked recessive disorder, is the commonest erythrocytic enzymopathy worldwide. Reliable diagnosis and severity prediction in G6PD-deficient/heterozygous females remain challenging. A recently developed flow cytometric test for G6PD deficiency has shown promise in precisely identifying deficient females. This paper presents our experiences with this test in a subtropical setting and presents a modification in flow cytometric data acquisition strategy. METHODS: The methaemoglobin reduction + ferryl Hb generation-based flow cytometric G6PD test was compared with the screening methaemoglobin reduction test (MRT) and confirmatory G6PD enzyme activity assay (EAA) in 20 G6PD-deficient males, 22 G6PD-heterozygous/deficient females and 20 controls. Stained cells were also assessed for bright/dim G6PD activity under a fluorescent microscope. RESULTS: Flow cytometry separated and quantified %bright cells in heterozygous/deficient females, objectively classifying them into 6 normal (>85% bright cells), 14 intermediate (10-85%) and two G6PD-deficient (<10% bright cells). Concordance with MRT was 89% (55/62 cases) and with EAA was 77% (48/62 cases). Fluorometrically predicted violet laser excitation (405-nm) with signal acquisition in the 425-475 nm region was a technical advancement noted for the first time in this paper. CONCLUSION: Flow cytometry/fluorescence microscopy represent technically straightforward methods for the detection and quantification of G6PD-deficient erythrocytes. Based on our results, we recommend their application as a first-line investigation to screen females who are prescribed an oxidant drug like primaquine or dapsone.

Laboratory-wide association study of survival with prostate cancer.

BACKGROUND: Estimates of overall patient health are essential to inform treatment decisions for patients diagnosed with cancer. The authors applied XWAS methods, herein referred to as "laboratory-wide association study (LWAS)", to evaluate associations between routinely collected laboratory tests and survival in veterans with prostate cancer. METHODS: The authors identified 133,878 patients who were diagnosed with prostate cancer between 2000 and 2013 in the Veterans Health Administration using any laboratory tests collected within 6 months of diagnosis (3,345,083 results). Using the LWAS framework, the false-discovery rate was used to test the association between multiple laboratory tests and survival, and these results were validated using training, testing, and validation cohorts. RESULTS: A total of 31 laboratory tests associated with survival met stringent LWAS criteria. LWAS confirmed markers of prostate cancer biology (prostate-specific antigen: hazard ratio [HR], 1.07 [95% confidence interval (95% CI), 1.06-1.08]; and alkaline phosphatase: HR, 1.22 [95% CI, 1.20-1.24]) as well laboratory tests of general health (eg, serum albumin: HR, 0.78 [95% CI, 0.76-0.80]; and creatinine: HR, 1.05 [95% CI, 1.03-1.07]) and inflammation (leukocyte count: HR, 1.23 [95% CI, 1.98-1.26]; and erythrocyte sedimentation rate: HR, 1.33 [95% CI, 1.09-1.61]). In addition, the authors derived and validated separate models for patients with localized and advanced disease, identifying 28 laboratory markers and 15 laboratory markers, respectively, in each cohort. CONCLUSIONS: The authors identified routinely collected laboratory data associated with survival for patients with prostate cancer using LWAS methodologies, including markers of prostate cancer biology, overall health, and inflammation. Broadening consideration of determinants of survival beyond those related to cancer itself could help to inform the design of clinical trials and aid in shared decision making. LAY SUMMARY: This article examined routine laboratory tests associated with survival among veterans with prostate cancer. Using laboratory-wide association studies, the authors identified 31 laboratory tests associated with survival that can be used to inform the design of clinical trials and aid patients in shared decision making.

New trimester-specific reference intervals for clinical biochemical tests in Taiwanese pregnant women-cohort of TMICS.

BACKGROUND: Because there are no published biochemical reference intervals (RI) for pregnant Taiwanese women, we used an established islandwide birth cohort, the Taiwan Maternal and Infant Cohort Study, to establish RIs for important biochemical parameters in women during their 3rd trimester in Taiwan. Additionally, we compared the differences in these biochemical parameters between early third trimester (weeks 28 to 31) and late third trimester (weeks 37 to 40) of pregnant women as well as the differences in them between the third trimester and after delivery. METHODS: Between 2012 and 2015, we recruited a total of 2,136 pregnant women from nine hospitals located in northern (n = 3), central (n = 3), southern (n = 2), and eastern Taiwan (n = 1) to receive regular prenatal health examinations during their third trimester (weeks 28 to 40). After exclusion, samples obtained from 993 eligible pregnant women were analyzed. RESULTS: There were increases in both lower and upper normal limits for blood neutrophil, thyroid profile (triiodothyronine (T3) and thyroxine (T4)), testosterone, estradiol, and progesterone and decreases for RBC, hemoglobin (Hb), alanine aminotransferase (ALT) and creatinine (Cr) during their third trimesters. Women in their late third trimester (n = 378) had higher median RBC, Hb, aspartate aminotransferase (AST), Cr, thyroid-stimulating hormone (TSH), testosterone, estradiol, and progesterone and lower median platelet and insulin, compared with those in their early third trimester (n = 490). Twenty-three of the women had both third trimester and post-pregnancy data. After delivery, the women had lower median AST, ALT, insulin, T3, T4, testosterone, estradiol, and progesterone and higher median Cr, free T4, FSH, and luteinizing hormone (LH), compared to their third trimesters. CONCLUSIONS: Gestation-related changes in important biochemical parameters should be considered when evaluating clinical laboratory values in pregnant women.

A blood-based biomarker panel (NIS4) for non-invasive diagnosis of non-alcoholic steatohepatitis and liver fibrosis: a prospective derivation and global validation study.

BACKGROUND: Non-invasive tests that can identify patients with non-alcoholic steatohepatitis (NASH) at higher risk of disease progression are lacking. We report the development and validation of a blood-based diagnostic test to non-invasively rule in and rule out at-risk NASH (defined as non-alcoholic fatty liver disease [NAFLD] activity score [NAS] ≥4 and fibrosis stage ≥2). METHODS: In this prospective derivation and global validation study, blood samples, clinical data, and liver biopsy results from three independent cohorts with suspected NAFLD were used to develop and validate a non-invasive blood-based diagnostic test, called NIS4. Derivation was done in the discovery cohort, which comprised 239 prospectively recruited patients with biopsy-confirmed NASH (NAFLD NAS ≥3; fibrosis stage 0-3) from the international GOLDEN-505 phase 2b clinical trial. A complete matrix based on 23 variables selected for univariate association with the presence of at-risk NASH and avoiding high multi-collinearity was used to derive the model in a bootstrap-based process that minimised the Akaike information criterion. The overall diagnostic performance of NIS4 was externally validated in two independent cohorts: RESOLVE-IT diag and Angers. The RESOLVE-IT diag cohort comprised the first 475 patients screened for potential inclusion into the RESOLVE-IT phase 3 clinical trial. Angers was a retrospective cohort of 227 prospectively recruited patients with suspected NAFLD and clinical risk factors for NASH or fibrosis stage 2 or more according to abnormal elastography results or abnormal liver biochemistry. Both external validation cohorts were independently analysed and were combined into a pooled validation cohort (n=702) to assess clinical performance of NIS4 and other non-invasive tests. FINDINGS: The derived NIS4 algorithm comprised four independent NASH-associated biomarkers (miR-34a-5p, alpha-2 macroglobulin, YKL-40, and glycated haemoglobin; area under the receiver operating characteristics curve [AUROC] 0·80, 95% CI 0·73-0·85), and did not require adjustment for age, sex, body-mass index (BMI), or aminotransferase concentrations. Clinical cutoffs were established within the discovery cohort to optimise both rule out and rule in clinical performance while minimising indeterminate results. NIS4 was validated in the RESOLVE-IT diag cohort (AUROC 0·83, 95% CI 0·79-0·86) and the Angers cohort (0·76, 0·69-0·82). In the pooled validation cohort, patients with a NIS4 value less than 0·36 were classified as not having at-risk NASH (ruled out) with 81·5% (95% CI 76·9-85·3) sensitivity, 63·0% (57·8-68·0) specificity, and a negative predictive value of 77·9% (72·5-82·4), whereas those with a NIS4 value of more than 0·63 were classified as having at-risk NASH (ruled in) with 87·1% (83·1-90·3) specificity, 50·7% (45·3-56·1) sensitivity, and a positive predictive value of 79·2% (73·1-84·2). The diagnostic performance of NIS4 within the external validation cohorts was not influenced by age, sex, BMI, or aminotransferase concentrations. INTERPRETATION: NIS4 is a novel blood-based diagnostic that provides an effective way to non-invasively rule in or rule out at-risk NASH in patients with metabolic risk factors and suspected disease. Use of NIS4 in clinical trials or in the clinic has the potential to greatly reduce unnecessary liver biopsies in patients with lower risk of disease progression. FUNDING: Genfit.

Establishment of reference intervals for immunoassay analytes of adult population in Saudi Arabia.

Background This is a second part of report on the IFCC global multicenter study conducted in Saudi Arabia to derive reference intervals (RIs) for 20 immunoassay analytes including five tumor makers, five reproductive, seven other hormones and three vitamins. Methods A total of 826 apparently healthy individuals aged ≥18 years were recruited in three clinical laboratories located in western, central and eastern Saudi Arabia using the protocol specified for the global study. All serum specimens were measured using Abbott, Architect analyzers. Multiple regression analysis (MRA) was performed to explore sources of variation of each analyte: age, body mass index (BMI), physical exercise and smoking. The magnitude of variation of reference values (RVs) attributable to sex, age and region was calculated by ANOVA as a standard deviation ratio (SDR). RIs were derived by the parametric (P) method. Results MRA revealed that region, smoking and exercise were not relevant sources of variation for any analyte. Based on SDR and actual between-sex differences in upper limits (ULs), we chose to partition RIs by sex for all analytes except for α-fetoprotein and parathyroid hormone (PTH). Age-specific RIs were required in females for ferritin, estradiol, progesterone, testosterone, follitropin, luteotropin and prolactin (PRL). With prominent BMI-related increase, RIs for insulin and C-peptide were derived after excluding individuals with BMI > 32 kg/m2. Individuals taking vitamin D supplements were excluded in deriving RIs for vitamin D and PTH. Conclusions RIs of major immunoassay analytes specific for Saudi Arabians were established in careful consideration of various biological sources of variation.

Sputum trypsin-like protease activity relates to clinical outcome in cystic fibrosis.

BACKGROUND: In cystic fibrosis (CF) airways excessive levels of serine trypsin-like proteases (TLPs) activate the epithelial sodium channel (ENaC) resulting in airways dehydration and promotion of mucus secretion. Despite this the relationship of TLP activity and clinical outcome has not been studied. METHODS: We analysed supernatant (sol) prepared from CF sputum from adult CF patients in two study cohorts (29 and 33 samples, respectively). Protease activities were determined by measuring the hydrolysis of peptide-based substrates or by ELISA. Lung function was assessed by spirometry (FEV1). Mortality data was retrospectively obtained and time in months until death or transplantation used for subsequent survival analysis. RESULTS: TLP activity inversely correlated with percent predicted FEV1 (r = -0.4, p = 0.03) and was greater in individuals who did not survive beyond 5-years from the time of sample collection. A Kaplan-Meier analysis demonstrated significantly reduced survival (p = 0.04) for individuals with high TLP activity [hazard ratio (HR) of 7.21 per log unit TLP activity (p = 0.03)]. In contrast, neutrophil elastase displayed no significant associations with lung function or patient survival. Similar findings were evident in the second study cohort. CONCLUSIONS: Sputum TLP activity may represent a novel non-invasive biomarker and/or therapeutic target for CF lung disease.

Thyroid nodules: diagnostic evaluation based on thyroid cancer risk assessment.

Thyroid nodules are extremely common and can be detected by sensitive imaging in more than 60% of the general population. They are often identified in patients without symptoms who are undergoing evaluation for other medical complaints. Indiscriminate evaluation of thyroid nodules with thyroid biopsy could cause a harmful epidemic of diagnoses of thyroid cancer, but inadequate selection of thyroid nodules for biopsy can lead to missed diagnoses of clinically relevant thyroid cancer. Recent clinical guidelines advocate a more conservative approach in the evaluation of thyroid nodules based on risk assessment for thyroid cancer, as determined by clinical and ultrasound features to guide the need for biopsy. Moreover, newer evidence suggests that for patients with indeterminate thyroid biopsy results, a combined assessment including the initial ultrasound risk stratification or other ancillary testing (molecular markers, second opinion on thyroid cytology) can further clarify the risk of thyroid cancer and the management strategies. This review summarizes the clinical importance of adequate evaluation of thyroid nodules, focuses on the clinical evidence for diagnostic tests that can clarify the risk of thyroid cancer, and highlights the importance of considering the patient's values and preferences when deciding on management strategies in the setting of uncertainty about the risk of thyroid cancer.

Clinical biochemistry test eliminator providing cost-effectiveness with five algorithms.

Objectives: The purpose of this study is to investigate the elimination ratios of requested unnecessary tests and the cost-effectiveness to be achieved by means of 5 different algorithms with clinical validity defined in an artificial intelligence program.Methods: The clinician orders received from the hospital information management system were adapted to eliminate AST, direct bilirubin, chlorine, fPSA and fT3 tests using five different algorithms defined in the ALIN IQ software.Results: In this study, 18387 AST, 9500 direct bilirubin, 61 free PSA, 1127 FT3 and 11172 chlorine tests that were ordered within 45 days were eliminated using 5 different algorithms defined in the ALIN IQ software in the Laboratory of Harran University Faculty of Medicine. USD 5592.76 was saved in 45 days. The annual saving is expected to be 363710 tests and USD 45363.49.Conclusion: Five different tests were successfully eliminated with this study. Open-code smart softwares, which can create indefinite algorithms may be utilized as test eliminators in diagnostic clinical laboratories. Millions of dollars may be saved by means of such artificial intelligence softwares that can be adapted to any analyzer across the world.

Contemporary biochemical analysis of normal pericardial fluid.

OBJECTIVE: Biochemical analysis of pericardial fluid (PF) is commonly performed for the initial assessment of PF, and the results are usually interpreted according to Light's traditional criteria for the differential diagnosis of transudates versus exudates. However, Light's criteria have been formulated for the biochemical analysis of pleural fluid. The aim of the present paper is to evaluate the normal composition of PF in candidates for cardiac surgery. METHODS: Cohort study with analysis of PF from candidates for cardiac surgery. Exclusion criteria were previous pericardial disease or cardiac surgery, prior myocardial infarction within 3 months, systemic disease (eg, systemic inflammatory diseases, uremia) or drug with potentiality to affect the pericardium. RESULTS: Fifty patients (mean age was 67 years; 95% CI 64 to 71, 29 males, 58.0%) were included in the present analysis. Levels of small molecules were similar in blood and PF. Total proteins in PF was, on average, 0.5 times lower than corresponding plasma levels (p=0.041), while the level of pericardial lactate dehydrogenase was, on average, 1.06 times higher than plasma (p=0.55). Moreover, mononuclear cells were more concentrated in PF than plasma (p=0.17). Traditional Light's criteria misclassified all PFs as exudates. CONCLUSIONS: Traditional Light's criteria misclassified normal PFs in candidates for cardiac surgery as exudates. This study suggests their futility for the biochemical analysis of PF in clinical practice.

A Predictive Model for the Identification of Cardiac Effusions Misclassified by Light's Criteria.

OBJECTIVES: The application of Light's criteria misidentifies approximately 30% of transudates as exudates, particularly in patients on diuretics with cardiac effusions. The purpose of this study was to establish a predictive model to effectively identify cardiac effusions misclassified by Light's criteria. METHODS: We retrospectively studied 675 consecutive patients with pleural effusion diagnosed by Light's criteria as exudates, of which 43 were heart failure patients. A multivariate logistic model was developed to predict cardiac effusions. The performance of the predictive model was assessed by receiver operating characteristic (ROC) curves, as well as by examining the calibration. RESULTS: It was found that protein gradient of >23 g/L, pleural fluid lactate dehydrogenase (PF-LDH) levels, ratio of pleural fluid LDH to serum LDH level (P/S LDH), pleural fluid adenosine deaminase (PF-ADA) levels, and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels had a significant impact on the identification of cardiac effusions, and those were simultaneously analyzed by multivariate regression analysis. The area under the curve (AUC) value of the model was 0.953. The model also had higher discriminatory properties than protein gradients (AUC, 0.760) and NT-pro-BNP (AUC, 0.906), all at a P value of <.01. CONCLUSION: In cases of suspected cardiac effusion, or where clinicians cannot identify the cause of an exudative effusion, this model may assist in the correct identification of exudative effusions as cardiac effusions.