Sex-related differences in within-subject biological variation estimates for 22 essential and non-essential amino acids.

BACKGROUND: Measurement of serum amino acid (AA) concentrations is important in particular for the diagnosis and monitoring of inborn errors of AA metabolism. To ensure optimal clinical interpretation of AAs, reliable biological variation (BV) data are essential. In the present study, we derived BV data for 22 non-essential, conditionally essential, and essential AAs and assessed differences in BV of AAs related to sex. METHODS: Morning blood samples were drawn from 66 subjects (31 males and 35 females) once a week for 10 consecutive weeks. All samples were analyzed in duplicate using liquid chromatography-tandem mass-spectrometry. The data were assessed for outliers, trends, normality and variance homogeneity analysis prior to estimating within-subject (CVI) and between-subject (CVG) BV. RESULTS: CVI estimates ranged from 9.0 % for histidine (male) to 33.0 % for taurine (male). CVI estimates in males and females were significantly different for all AAs except for aspartic acid, citrulline and phenylalanine, in most cases higher in females than in males. Apart from for arginine, CVG estimates in males and females were similar. CONCLUSIONS: In this highly powered BV study, we provide updated BV estimates for 22 AAs and demonstrate that for most AAs, CVI estimates differ between males and females, with implications for interpretation and use of AAs in clinical practice.

Neutrophil Lymphocyte Ratio, Monocyte Lymphocyte Ratio, Platelet Lymphocyte Ratio in Covid-19 Patients.

BACKGROUND: Covid-19 is a pandemic viral infection with high pathogenicity and contagiousness. Our aim is to evaluate the preliminary hematological findings analyzed during admission in order to determine the diagnostic value of hematological parameters in Covid-19 patients and to reveal their relationship with the severity of the disease. METHODS: Our study includes a total of 169 patients, whose diagnosis was confirmed and 93 of whom were treated in the ward, 76 of whom were treated in the Intensive Care Unit (ICU), and 67 control patients. Neutrophil-to-lymphocyte ratio (NLR), monocyte-lymphocyte (MLR) ratio, platelet-lymphocyte ratio (PLR), mean platelet volume/platelet count ratio (MPV/PLT) data on admission were analyzed retrospectively and compared. RESULTS: ICU patients had significantly higher values of NLR, MLR, PLR, and MPV/PLT (p < 0.001 for each) but had lower values of lymphocyte count and hemoglobin (p < 0.001 for each) compared to that of ward patients. According to the results of ROC analysis, the diagnostic values of NLR, MLR, PLR, and MPV/PLT parameters were statistically significant (p < 0.05). CONCLUSIONS: According to the results of our study, abnormal routine peripheral blood examination results were detected in Covid-19 patients. NLR, MLR, and PLR can be considered as independent, reliable biomarkers for assessing disease severity, hospitalization, and clinical classification in Covid-19. Therefore, it was concluded that fast, cost-effective, easily accessible admission hemogram parameters are reasonably important to predict the prognosis of Covid-19 patients.

Within- and between-subject biological variation data for serum zinc, copper and selenium obtained from 68 apparently healthy Turkish subjects.

OBJECTIVES: Trace elements (TrEL) are nutritionally essential components in maintaining health and preventing diseases. There is a lack of reliable biological variation (BV) data for TrELs, required for the diagnosis and monitoring of TrEL disturbances. In this study, we aimed to provide updated within- and between-subject BV estimates for zinc (Zn), copper (Cu) and selenium (Se). METHODS: Weekly serum samples were drawn from 68 healthy subjects (36 females and 32 males) for 10 weeks and stored at -80 °C prior to analysis. Serum Zn, Cu and Se levels were measured using inductively-coupled plasma mass spectrometry (ICP-MS). Outlier and variance homogeneity analyses were performed followed by CV-ANOVA (Røraas method) to determine BV and analytical variation estimates with 95% CI and the associated reference change values (RCV) for all subjects, males and females. RESULTS: Significant differences in mean concentrations between males and females were observed, with absolute and relative (%) differences for Zn at 0.5 µmol/L (3.5%), Cu 2.0 µmol/L (14.1%) and Se 0.06 µmol/L (6.0%). The within-subject BV (CVI [95% CI]) estimates were 8.8% (8.2-9.3), 7.8% (7.3-8.3) and 7.7% (7.2-8.2) for Zn, Cu and Se, respectively. Within-subject biological variation (CVI) estimates derived for male and female subgroups were similar for all three TrELs. Marked individuality was observed for Cu and Se. CONCLUSIONS: The data of this study provides updated BV estimates for serum Zn, Cu and Se derived from a stringent protocol and state of the art methodologies. Furthermore, Cu and Se display marked individuality, highlighting that population based reference limits should not be used in the monitoring of patients.

Utilization of biological variation data in the interpretation of laboratory test results - survey about clinicians' opinion and knowledge.

INTRODUCTION: To interpret test results correctly, understanding of the variations that affect test results is essential. The aim of this study is: 1) to evaluate the clinicians' knowledge and opinion concerning biological variation (BV), and 2) to investigate if clinicians use BV in the interpretation of test results. MATERIALS AND METHODS: This study uses a questionnaire comprising open-ended and close-ended questions. Questions were selected from the real-life numerical examples of interpretation of test results, the knowledge about main sources of variations in laboratories and the opinion of clinicians on BV. A total of 399 clinicians were interviewed, and the answers were evaluated using a scoring system ranked from A (clinician has the highest level of knowledge and the ability of using BV data) to D (clinician has no knowledge about variations in laboratory). The results were presented as number (N) and percentage (%). RESULTS: Altogether, 60.4% of clinicians have knowledge of pre-analytical and analytical variations; but only 3.5% of them have knowledge related to BV. The number of clinicians using BV data or reference change value (RCV) to interpret measurements results was zero, while 79.4% of clinicians accepted that the difference between two measurements results located within the reference interval may be significant. CONCLUSIONS: Clinicians do not use BV data or tools derived from BV such as RCV to interpret test results. It is recommended that BV should be included in the medical school curriculum, and clinicians should be encouraged to use BV data for safe and valid interpretation of test results.

The use of preanalytical quality indicators: a Turkish preliminary survey study.

OBJECTIVES: The utilization of reliable quality indicators (QIs) proven to be suitable for monitoring and improvement tools is one of the best choices to minimize of the risk of errors in all laboratory processes called as total testing process (TTP). In 2008, a Working Group "Laboratory Errors and Patient Safety" (WG-LEPS) established by International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) developed the Model of Quality Indicators (MQI) complying with requirements of the ISO 15189:2012 standard for laboratory accreditation. They have also been dealing with harmonizing the QIs in most laboratories worldwide since then. The present study was set out to investigate the frequency of using IFCC WG-LEPS' pre-QIs by Turkish laboratories and to assess the conformity of them, by taking into account Turkey's conditions. METHODS: A survey consisting nine questions was applied in 81 laboratories using SurveyMonkey. RESULTS: According to the survey results, most of the laboratories reported they have used pre-QIs in the quality standards of health prepared by Turkish Ministry of Health (MOH). A part of IFCC WG-LEPS' pre-QIs were being utilized by more than 80% of the laboratories, the rest of which only used by 10% of laboratories. CONCLUSIONS: The majority of the medical laboratories have been using the pre-QIs included in the guidelines of Quality Standards prepared by the MOH. The pre-QIs are partially compatible with IFCC WG-LEPS' pre-QIs. The definitions of IFCC WG-LEPS' pre-QIs may also be revised to make them more clear and understandable by IFCC WG-LEPS. The insufficiency of Health Information Management Systems (HIMS) limits the use of pre-QIs proposed by IFCC WG-LEPS. Finally, the education of relevant personnel about the use of HIMS and pre-QIs is very crucial to harmonize and to extend the use of IFCC WG-LEPS' pre-QIs in Turkish medical biochemistry laboratories.

Pre-analytical quality indicators in laboratory medicine: Performance of laboratories participating in the IFCC working group "Laboratory Errors and Patient Safety" project.

Quality indicators (QIs) are key tools for improving the quality of laboratory services, by reducing error rates and safeguarding patient safety. A body of accumulated evidence confirms the relevance of QIs and their impact on the overall quality of laboratory information. The consensus achieved on a list of "harmonized" QIs, along with the system used for data collection and reporting throughout an international benchmarking programme, has enabled achieving realistic performance targets, based on knowledge of the state-of-the-art. Data collected in 2017 and 2018 have been analyzed and performance measures obtained by laboratories participating in the project are summarized in the present article. The laboratory performance measures have been classified into three levels (optimum, desirable or minimum) in agreement with the widely accepted model of analytical quality specifications.

Podocyte Injury in Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND/AIMS: Autosomal dominant polycystic kidney disease (ADPKD) is a tubulointerstitial disease. Different degrees of glomerular affection in ADPKD may affect the further course of disease in which it may hypothetically be secondary to the result of glomerular involvement causing podocyte injury. Our aim was to compare urinary excretion of podocin and podocalyxin, which are biomarkers of podocyte injury, and to assess their relationship with proteinuria and renal function in ADPKD. METHODS: Fifty-six patients with ADPKD and 28 volunteers were enrolled to study. Podocin, podocalyxin protein levels, and proteinuria were measured in urine. Patients were categorized based on their estimated glomerular filtration rate (eGFR). RESULTS: Patients with ADPKD had higher podocin and podocalyxin levels compared to the control group. The levels of podocin and podocalyxin were higher in ADPKD patients both with eGFR ≥60 mL/min/1.73 m2 and with eGFR <60 mL/min/1.73 m2 than in controls. The levels of podocin and podocalyxin were higher in ADPKD patients with eGFR <60 mL/min/1.73 m2 than in ADPKD patients with eGFR ≥60 mL/min/1.73 m2. Podocin and podocalyxin were negatively correlated with eGFR and positively correlated with urine protein to creatinine ratio in ADPKD patients. CONCLUSION: Urine biomarkers of podocytes injury were significantly higher in ADPKD patients even in the early stage of the disease than in the control group. It should be clarified whether these biomarkers can provide new prognostic parameters for disease surveillance.

Tissue Expressions of Soluble Human Epoxide Hydrolase-2 Enzyme in Patients with Temporal Lobe Epilepsy.

OBJECTIVE: We sought to simply demonstrate how levels of soluble human epoxide hydrolase-2 show changes in both temporal the cortex and hippocampal complex in patients with temporal lobe epilepsy. METHODS: A total of 20 patients underwent anterior temporal lobe resection due to temporal lobe epilepsy. The control group comprised 15 people who died in traffic accidents or by falling from a height, and their autopsy findings were included. Adequately sized temporal cortex and hippocampal samples were removed from each patient during surgery, and the same anatomic structures were removed from the control subjects during the autopsy procedures. Each sample was stored at -80°C as rapidly as possible until the enzyme assay. RESULTS: The temporal cortex in the epilepsy patients had a significantly higher enzyme level than did the temporal cortex of the control group (P = 0.03). Correlation analysis showed that as the enzyme level increases in the temporal cortex, it also increases in the hippocampal complex (r2 = 0.06, P = 0.00001). More important, enzyme tissue levels showed positive correlations with seizure frequency in both the temporal cortex and hippocampal complex in patients (r2 = 0.7, P = 0.00001 and r2 = 0.4, P = 0.003, respectively). The duration of epilepsy was also positively correlated with the hippocampal enzyme level (r2 = 0.06, P = 0.00001). CONCLUSIONS: Soluble human epoxy hydrolase enzyme-2 is increased in both lateral and medial temporal tissues in temporal lobe epilepsy. Further studies should be conducted as inhibition of this enzyme has resulted in a significant decrease in or stopping of seizures and attenuated neuroinflammation in experimental epilepsy models in the current literature.

Association of CTLA4 and CD28 Gene Variants and Circulating Levels of Their Proteins in Patients with Breast Cancer.

BACKGROUND/AIM: Breast cancer is one of the most common and lethal types of cancer among women. We focused on the importance of the immune system in the etiology of breast cancer by investigating critical polymorphisms of cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and cluster of differentiation 28 (CD28) gene, and circulating levels of these proteins. MATERIALS AND METHODS: A total of 79 patients with breast cancer and 76 healthy controls were enrolled. Molecular assessment of CTLA4 (rs231775&rs5742909) and CD28 (rs3116496) variants were determined with polymerase chain reaction restriction fragment length polymorphism techniques. Circulating levels of soluble forms of CTLA4 and CD28 were analyzed by ELISA. RESULTS: Although no significant association was found between study groups, CTLA4 +49AA genotypic frequency, and sCTLA4 and sCD28 levels were higher in patients. Some clinicopathological features were also related with CTLA4 and CD28 variants and blood levels. CONCLUSION: While CTLA4 +49AA genotype is increased in patients with breast cancer, the CTLA4 -318T allele may have a prognostic value. In addition, sCTLA4 and sCD28 can be used for diagnostic purposes in patients with breast cancer.

Decreased plasma adiponectin is associated with impaired left ventricular longitudinal systolic function in hypertensive patients: a two-dimensional speckle tracking study.

The influence of plasma adiponectin levels on myocardial contractile function has not been fully examined. We aimed to investigate the relationship between three-directional systolic function and plasma adiponectin levels in asymptomatic hypertensive patients using two- dimensional speckle-tracking echocardiography. The study population consisted of 78 patients with hypertension and 40 healthy controls. Longitudinal strain was significantly reduced in all patients, including those without LV hypertrophy (p=0.009). In multiple-regression analysis, plasma adiponectin levels (ß=-0.273, p=0.008) and LV mass index (ß=0.458, p<0.001) independently correlated with LV longitudinal strain. Decreased plasma adiponectin concentrations were associated with the progression of LV hypertrophy with impaired LV longitudinal systolic function.

Is there any role of thrombin activatable fibrinolysis inhibitor in the development of a hypercoagulable state in gastric cancer.

BACKGROUND: The purpose of this study was to investigate plasma levels of thrombin activatable fibrinolysis inhibitor (TAFI) and TAFI's relationship with coagulation markers (prothrombin fragment 1 + 2) in gastric cancer patients. METHODS: Thirty-three patients with gastric adenocarcinoma and 29 healthy control subjects were prospectively enrolled in the study. Patients who had a history of secondary malignancy, thrombosis related disease, oral contraceptive use, diabetes mellitus, chronic renal failure or similar chronic metabolic disease were excluded from the study. A fasting blood sample was drawn from patients to determine the plasma levels of TAFI and Prothrombin Fragment 1 + 2 (F 1 + 2). In addition, data on patient age, sex, body mass index (BMI) and stage of disease were recorded. The same parameters, except stage of disease, were also recorded for the control group. Subsequently, we assessed the difference in the levels of TAFI and F 1 + 2 between the patient and control groups. Moreover, we investigated the relation of TAFI and F 1 + 2 levels with age, sex, BMI and stage of disease in the gastric cancer group. RESULTS: There were no statistical differences in any demographic variables (age, gender and BMI) between the groups (Table 1). The mean plasma TAFI levels of the gastric cancer group (69.4 ± 33.1) and control group (73.3 ± 27.5) were statistically similar (P = 0.62). The mean plasma F 1 + 2 level in the gastric cancer group was significantly higher than for those in the control group (549.7 ± 325.3 vs 151.9 ± 67.1, respectively; P < 0.001). In the gastric cancer group, none of the demographic variables (age, gender and BMI) were correlated with either TAFI or F 1 + 2 levels. Also, no significant associations were found between the stage of the cancer and either TAFI or F 1 + 2 levels. CONCLUSION: In our study, TAFI levels of gastric cancer patients were similar to healthy subjects. The results of our study suggest that TAFI does not play a role in pathogenesis of the hypercoagulable state in gastric cancer patients.

Variability of serum oxidative stress biomarkers relative to biochemical data and clinical parameters of glaucoma patients.

PURPOSE: The importance of oxidative stress in both the formation and the course of glaucoma has been known. Among the antioxidants, vitamin E possesses the specific effects and regulatory mechanisms of a neurohormone. The serum oxidant/antioxidant profile is reportedly altered in ocular pathologies. In this study, we analyzed the effect of the clinical parameters of glaucoma and biochemical data on antioxidants and serum oxidative stress markers as oxidation degradation products. METHODS: In this multicenter case control study, control and patient groups consisted of 31 healthy individuals and 160 glaucoma patients with no known additional abnormalities, respectively. We analyzed the oxidation degradation products malonyl dialdehyde (MDA), advanced oxidation protein products (AOPP), antioxidants, vitamins E and A, Serine (Ser), superoxide dismutase (SOD), glutathione peroxidase (Gpx), transferrine (TF), and total antioxidant capacity (TADA). All of these parameters and their relationships with serum cholesterol, glucose, protein, albumin, triglyceride levels, age, gender, visual acuities, intraocular pressure (IOP), c/d ratio, gonioscopic findings, medications, presence of pseudoexfoliation (px), central visual field and Optical Coherence Tomography (OCT) data, pachymetry, and Laplace values, were evaluated individually. Statistical comparisons were performed among them, and with the control group as well. RESULTS: TADA, AOPP, SOD, and Gpx were found to be decreased, and MDA, Ser, TF, vitamins A and E increased in the patient group. All data, excluding AOPP, varied significantly. Vitamin E was the most consistent parameter. CONCLUSIONS: In this study, the association between glaucoma and lipid oxidation was shown on a systematic basis, and the significance of vitamin E as a neuroprotective agent has been revealed once more.

Hemodialysis and protein oxidation products.

The presence of a chronic inflammatory state has also been widely documented in end-stage renal disease patients receiving maintenance hemodialysis (HD). It is commonly attributed to the constantly renewed activation of circulating neutrophils and monocytes following blood passage through dialysis circuits and subsequent generation of activated complement components due to contact of plasma with bioincompatible membranes and/or transfer of endotoxins from the dialyzate to the blood compartment. This conjunction leads to a massive generation of reactive oxygen species (ROS), for example, superoxide anion, hydrogen peroxide, hydroxyl radical, and chlorinated oxidants, such as hypochlorous acid by activated neutrophils. The exquisite vulnerability of proteins to ROS is now well documented. Oxidation of amino acid residues, such as tyrosine, leads to the formation of dityrosine, protein aggregation, cross-linking, and fragmentation. Dityrosine-containing protein cross-linking products in the plasma of dialysis patients are named as advanced oxidation protein products (AOPP). In addition, advanced glycation end-products (AGE) is a protein carbonyl compound and produced by protein-ROS interaction. We investigated both the effect of the renewed activation of the immune cells, due to blood-dialyzer interaction over protein oxidation products like AOPP and AGE, among chronic renal failure (CRF) patients receiving maintenance HD, and choice of dialyzers like high flux or the other group on protein oxidation product levels.