Matrix Selection for Measurement of Zinc Levels

INTRODUCTION: Measurement of blood zinc levels is frequently used in the diagnosis of a few conditions such as growth retardation, immunodeficiency, infertility, neurological disorder, and acrodermatitis enteropathica. The serum matrix is the most preferred one to determine zinc levels due to the ease of analysis with other tests and cost-effectiveness of blood collection tubes used to obtain serum samples. In our study, we aimed to compare serum and plasma zinc test results for accurate and reliable zinc measurement in plain tubes with clot activator and gel and in heparin-free tubes, which specifically produced for trace element analysis. METHODS: Twenty-seven randomly selected patients were included in the study. Blood samples drawn simultaneously from patients were pipetted into tubes with clot activator and gel (SST) (SST II Advance, Vacutainer, Becton Dickinson and Company, USA) as well as into trace element tubes with sodium heparin (NH) (NH Trace Elements Sodium Heparin, Vacuette, Greiner Bio-One GmbH, Austria). After the centrifugation process, zinc levels in serum and plasma samples were analyzed by colorimetric method using an autoanalyzer. Bias between serum and plasma zinc levels was evaluated according to the allowable bias criterion based on biological variation and regression analysis performed. RESULTS: The mean and standard deviation of serum and plasma zinc levels were 49.0+-11.5 μg/dL and 46.4+-12.0 μg/dL, respectively, and a statistically significant difference was determined (p=0.012) in between. Besides, the bias between serum and plasma was 6.8%, which was above the allowable bias (3.3%) and considered as clinically significant. No systematic or random errors detected. DISCUSSION AND CONCLUSION: When selecting a blood collection tube for trace element analysis, the structural differences between tubes and the matrix effect should be considered carefully

Usefulness of laboratory parameters and chest CT in the early diagnosis of COVID-19

In the present study, the importance of laboratory parameters and CT findings in the early diagnosis of COVID-19 was investigated. To this end, 245 patients admitted between April 1st, and May 30th, 2020 with suspected COVID-19 were enrolled. The patients were divided into three groups according to chest CT findings and RT-PCR results. The non-COVID-19 group consisted of 71 patients with negative RT-PCR results and no chest CT findings. Ninety-five patients with positive RT-PCR results and negativechest CT findings were included in the COVID-19 group; 79 patients with positive RT-PCR results and chest CT findings consistent with COVID-19 manifestations were included in COVID-19 pneumonia group. Chest CT findings were positive in 45% of all COVID-19 patients. Patients with positive chest CT findings had mild (n=30), moderate (n=21) andor severe (n=28) lung involvement. In the COVID-19 group, CRP levels and the percentage of monocytes increased significantly. As disease progressed from mild to severe, CRP, LDH and ferritin levels gradually increased. In the ROC analysis, the area under the curve corresponding to the percentage value of monocytes (AUC=0.887) had a very good accuracy in predicting COVID-19 cases. The multinomial logistic regression analysis showed that CRP, LYM and % MONO were independent factors for COVID-19. Furthermore, the chest CT evaluation is a relevant tool in patients with clinical suspicion of COVID-19 pneumonia and negative RT-PCR results. In addition to decreased lymphocyte count, the increased percentage of monocytes may also guide the diagnosis

The local clinical validation of a new lithium heparin tube with a barrier: BD Vacutainer® Barricor LH Plasma tube

Introduction: Although serum-providing blood tubes with a barrier are still widely used due to their significant advantages, the use of blood tubes with a barrier to provide plasma is becoming widespread. We compared 22 analytes in a BD Vacutainer® Barricor LH Plasma tube for local clinical validation of this new lithium heparin tube with a barrier. Materials and methods: Samples from 44 volunteers were collected in different tubes (Becton Dickinson and Company): Z tube without additive (reference), clot-activator tube with gel (SST), lithium heparin tube without gel (LiH), and lithium heparin tube with barrier (Barricor). Analyte concentrations in different tubes were compared with the reference tube. All tubes were also evaluated according to additional testing (different centrifugation durations, blood-sampling techniques and individual differences). Results: Aspartate aminotransferase (AST), glucose (Glc), potassium (K), lactate dehydrogenase (LD), sodium (Na), and total protein (TP) had a significant bias in Barricor (9.19%, - 3.24%, - 4.88%, 21.60%, - 0.40%, 5.03%, respectively) relative to the reference tube. There was no statistical difference between different centrifugation durations and individual differences for AST, K and LD in LiH and/or Barricor (P > 0.05). There was a significant bias for LD between LiH and Barricor in terms of blood-sampling techniques (21.2% and 12.4%, respectively). Conclusions: Recently, the use of plasma has become prominent due to some of its advantages. In this study, plasma AST, K, LD, Glc and TP levels in Barricor were clinically different in comparison to serum. The results of additional tests showed that higher levels of LD in Barricor did not result from haemolysis, and they might be related to other factors including number of platelets, cellular fragility, or functional environment

Tiroid Fonksiyon Testlerinde Diürnal Ritm ve Postprandial Değişim

Amaç: Tiroid fonksiyon testleri (TFT) klinisyenler tarafından en sık istenen biyokimyasal parametrelerinden biridir ve günün herhangi bir saatinde analiz edilebilmektedir. Bu nedenle hastaların tanı ve takibinde doğru ve güvenilir bir karar vermek için diürnal varyasyon ve açlık-tokluk durumunun TFT üzerine etkisini değerlendirdik. Gereç ve Yöntem: 16 sağlıklı erişkin gönüllüden (11 erkek, 5 kadın), 9.00, 10.00, 11.00, 12.00, 15.00, 18.00 ve 24.00 saatlerinde kan alındı. Saat 09.00'da alınan örnekler bazal düzey olarak kabul edildi. Diğer saatlerdeki tiroid uyarıcı hormon (TSH), serbest triyodotironin (fT3) ve serbest tiroksin (fT4) düzeyler, bazal düzeyler ile istatistiksel ve klinik olarak karşılaştırıldı. Bulgular: Gün boyunca fT4 düzeylerinde istatistiksel ve klinik olarak anlamlı bir varyasyon bulunmazken, TSH düzeyleri bazale göre (-%27.37)-(%48.95) arasında klinik olarak anlamlı değişim gösterdi. fT3 düzeylerinin ise sadece saat 15.00 ve 18.00’deki değişimi (-%5.59) klinik olarak anlamlı bulundu. Sonuç: TSH ve fT3 test sonuçları değerlendirilirken diürnal varyasyonunun da göz önüne bulundurulması ve değilse sabah aynı saatlerde kan örneklemi yapılması gerektiği düşünüldü

Kritik COVID-19 Hasta PrognozununDeğerlendirilmesinde Akut FazProteinlerinin Önemi

Amaç: Yoğun bakım ünitesine ilk kabulde kötü prognoz riskine sahip COVID-19 hastalarını belirlemenin çeşitli tanısal zorlukları vardır. Karaciğer tarafından sentezlenen akut faz proteinlerinin konsantrasyonu inflamasyon ve enfeksiyonu takiben serumda artar veya azalır. Bu çalışmada, kritik COVID-19 hastalarında akut faz proteinlerinin prediktif değerini belirleme ve yoğun bakım ünitesinde mortalite riskini öngörmede inflamatuar belirteçlerin etkinliğini değerlendirme amaçlanmaktadır. Gereç ve Yöntem: Retrospektif olarak tasarlanan bu çalışma yoğun bakım ünitesinde tedavi gören kritik COVID-19 hastalarında yapıldı. Çalışmaya yoğun bakım ünitesine kabulün ilk 24 saatinde ARDS ve/veya çoklu organ disfonksiyonu olan 123 hasta dahil edildi. Yoğun bakım ünitesindeki 28 günün sonunda sağ kalan (n=54) ve ölen (n=69) hasta grupları veya invaziv mekanik ventilasyon (n=83) uygulanan ve uygulanmayan (n =40) hasta grupları oluşturuldu. Gruplar arasında akut faz proteinleri olan serum amiloid A, C-reaktif protein, albümin ve prealbüminin yoğun bakım ünitesine kabulün ilk 24 saat içerisindeki değerleri karşılaştırıldı. Bulgular: Albümin ve prealbümin düzeyleri ölen (sırasıyla p=0.011, p<0.001) ve mekanik ventilasyon uygulanan (sırasıyla p=0.010, p=0.006) hastalarda anlamlı olarak azaldı. Mekanik ventilasyonlu hastalarda serum amiloid A düzeyleri anlamlı olarak arttı (p=0.022). Sonuç: Yoğun bakım ünitesine kabul sırasında düşük prealbümin ve albümin seviyeleri ve yüksek serum amiloid A seviyeleri, hastalık şiddeti ve mortalitenin prognostik bir belirteci olarak kullanılabilir

HLA-B VARIATIONS AND HLA-B*57:01 PREVALENCE IN HIV-1 INFECTED TURKISH PATIENT

ntroduction: Human Leukocyte Antigen (HLA)-B*57:01 is associated with a hypersensitivity reaction to abacavir used in antiretroviral therapy in patients infected with human immunodeficiency virus (HIV)-1. In this study, we aimed to investigate the prevalence of HLA-B*57:01 and HLA-B alleles that may pose a risk in the Turkish population. Material and Methods: In this retrospective study, 500 HIV-1 infected patients who applied to the Tissue Typing Laboratory and 500 healthy bone marrow donors as the control group were examined. HLA-B genotyping was performed before starting abacavir therapy. 451 (90.2%) of HIV-1 positive patients and 264 (52.8%) control group were male (p<0.001). HLA-B genotyping was performed using the sequence-specific primer (SSP) HLA-B kit or the HLA-B sequence-specific oligonucleotide probe hybridization (SSO) kit. The presence or absence of the HLA- B*57:01 specific allele in individuals with B*57 allele was detected using the HLA-B*57:01 SSP kit. Result: The HLA-B*57:01 allele frequency was found to be 1.5% (n=15) in HIV-1 positive patients and 1.6% (n=16) in controls. The prevalence of HLA-B*57:01 allele in the Turkish population was calculated as 3.1% (n=31). Also HLA-B*7 (p=0.013, OR: 1.761), HLA-B*14 (p=0.016, OR: 2.592), HLA-B*18 (p=0.001, OR: 2.106), HLA-B* 49 (p=0.035, OR: 1.626) alleles were associated with susceptibility to HIV-1. Conclusion: The prevalence of HLA-B*57:01, which we found as 3.1% in our society, is lower than the Caucasian ethnic group (5-8%) . Our results will shed light on the cost-effectiveness analysis studies to be conducted on HLA B*57:01 screening in HIV-1 positive patients and will contribute to the literature

Evaluation of D-dimer levels measured by different analytical methods in COVID-19 patients

Clinicians experience some challenges due to the lack of standardization of test, although D-dimer is a prognostic marker for COVID-19. We compared the clinical and analytical performances of D-dimer results obtained from different devices, kits and methods in patients with a diagnosis of COVID-19. Thirty-nine patients with a diagnosis of COVID-19 and 24 healthy individuals were included in the study. D-dimer levels were measured with Innovance D-DIMER kit (immunoturbidimetric method) on Sysmex CS-2500 and BCS XP and VIDAS D-Dimer Exclusion II kit (enzyme-linked fluorescence method) on mini VIDAS. The studies of precision, method comparison and clinic performance were performed. The variation coefficients in all systems were within the acceptable imprecision (7.8%). Bias%(12.5%) between BCS XP and Sysmex CS-2500 was lower than the acceptable Bias%(15.5%). Bias% values (19.2% and 33.3%, respectively) between Mini VIDAS with BCS XP and Sysmex CS-2500 were higher than the acceptable Bias%. The correlation coefficients among all systems were 0.89-0.98. For 500 ng/ml FEU, there was almost perfect agreement between BCS XP and Sysmex CS-2500, a moderate agreement between Mini VIDAS and BCS XP and Sysmex CS-2500. The cut-off values for distinguishing between individuals with and without COVID-19 were Mini VIDAS, Sysmex CS-2500 and BCS XP 529, 380 and 390 ng/ml FEU, respectively. The immunoturbidimetric method can be used as an alternative to the enzyme-linked fluorescent method because of satisfactory agreement at the different thresholds proposed for venous thromboembolism. However, it is recommended to follow up COVID-19 with the D-dimer results obtained by the same assay system

Evaluation of Postprandial Total Antioxidant Activity in Normal and Overweight Individuals

WOS: 000396415800012Aim: Postprandial changes acutely alter some mechanisms in body. There are many studies showing blood oxidative status changes after food intake and supplementation. The aim of the present study was to evaluate the effects of a standardized meal on serum total antioxidant activity (TAA) in normal weight and overweight individuals. Material and Method: Fourteen normal weight and twelve overweight individuals were given a standardized meal in the morning after an overnight fast. Serum TAA, glucose, total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride concentrations were measured at baseline, 3rd hour and 6th hour after the meal in both groups. Results: In both normal and overweight groups, the difference between baseline and 3rd hour was significant for TAA. The TAA of the overweight group was also significantly lower than the TAA of the normal weight group at 3rd hour. However, there was no significant correlation between lipid parameters and TAA levels. Discussion: The present study shows that postprandial oxidative stress occurs more prominently in overweight individuals than in normal weight individuals. Postprandial changes acutely induce oxidative stress and impair the natural antioxidant defense mechanism. It should be noted that consuming foods with antioxidants in order to avoid various diseases and complications is useful, particularly in obese subjects

Effects of Lutein on Brain Damage and Vasospasm in an Experimental Subarachnoid Hemorrhage Model

© 2020 Elsevier Inc.Objective: Vasospasm developing after subarachnoid hemorrhage (SAH) is an important cause of mortality and morbidity. Lutein is a carotenoid with antioxidant and anti-inflammatory properties. The aim of present study was to investigate effects of lutein on the basilar artery and nerve tissues. Methods: Wistar rats were randomly divided into 3 groups: control (group 1), SAH (group 2), and SAH treated with lutein (group 3). Lutein was administered for 3 days by means of orogastric gavage. Basilar artery lumen area, wall thickness, serum total antioxidant status, serum total oxidant status, and oxidative stress index were calculated. Histopathologic and immunohistochemical analyses were conducted. Results: No statistically significant difference was found between groups in terms of wall thickness; lumen area; and serum total antioxidant status, serum total oxidant status, and oxidative stress index values. A statistically significant difference was found between groups colored with terminal deoxynucleotidyl transferase dUTP nick end labeling (P < 0.005). Post hoc analysis was used to examine the results between groups. Results of group 1 and group 3 were equal (P = 1) and lower than group 2 (P = 0.04 and P = 0.006, respectively). Conclusions: Lutein was found to have a positive effect on width of the basilar artery lumen area. Therefore, positive effects of lutein on vasospasm might be statistically significant if lutein is administered at higher doses. Lutein was found to be effective in preventing brain damage after SAH. To our knowledge, this study is the first in the literature to examine the effect of lutein on vasospasm and brain damage after SAH