Comparison of lipemia interference created with native lipemic material and intravenous lipid emulsion in emergency laboratory tests.

Introduction: This study aimed to investigate the effects of lipemia on clinical chemistry and coagulation parameters in native ultralipemic (NULM) and intravenous lipid emulsion (IVLE) spiked samples. Materials and methods: The evaluation of biochemistry (photometric, ion-selective electrode, immunoturbidimetric method), cardiac (electrochemiluminescence immunoassay method) and coagulation (the viscosity-based mechanical method for prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen and the immunoturbidimetric method for D-dimer) parameters were conducted. In addition to the main pools, five pools were prepared for both types of lipemia, each with triglyceride (TG) concentrations of approximately 2.8, 5.7, 11.3, 17.0 and 22.6 mmol/L. All parameters' mean differences (MD%) were presented as interferographs and compared with the desirable specification for the inaccuracy (bias%). Data were also evaluated by repeated measures of ANOVA. Results: Prothrombin time and APTT showed no clinically relevant interference in IVLE-added pools but were negatively affected in NULM pools(P < 0.001 in both parameters). For biochemistry, the most striking difference was seen for CRP; it is up to 134 MD% value with NULM (P < 0.001) at the highest TG concentration, whereas it was up to - 2.49 MD% value with IVLE (P = 0.009). Albumin was affected negatively upward of 5.7 mmol/L TG with IVLE, while there was no effect for NULM. Creatinine displayed significant positive interferences with NULM starting at the lowest TG concentration (P = 0.028). There was no clinically relevant interference in cardiac markers for both lipemia types. Conclusions: Significant differences were scrutinized in interference patterns of lipemia types, emphasizing the need for careful consideration of lipemia interferences in clinical laboratories. It is crucial to note that lipid emulsions inadequately replicate lipemic samples.

Dose-dependent effects of ghrelin and aberrant anti-Mullerian hormone levels in the prevention of ovarian damage caused by cisplatin in Wistar-albino rats.

PURPOSE: Ghrelin has previously been proven to have anti-inflammatory and antioxidant properties in preventing cisplatin-induced ovarian damage. The aim of this study was to evaluate the potential effects of this hormone in preventing this damage in rats using histopathological and biochemical methods. METHODS: Twenty-eight Wistar-albino rats were randomly divided into four groups. While no drug was given to Group 1 (sham group), acylated ghrelin was intraperitoneally administered to Group 2 at 0.5 nmol/kg and Group 3 at 2 nmol/kg for 21 days. Group 4 received only saline solution. On the 15th day, a single dose of 5 mg/kg cisplatin was intraperitoneally administered to each rat in Groups 2, 3 and 4. Serum anti-Mullerian hormone (AMH) values were measured on days 0, 15 and 21. Then, laparotomy and bilateral oophorectomy were performed, and the ovaries were histopathologically examined. RESULTS: The number of primordial and primary follicles was significantly higher in Group 3 than in the saline solution + cisplatin group. In Group 4, cisplatin caused significantly higher follicle damage in the primordial, primary and secondary phases compared to the sham group. The AMH level of the SF + cisplatin group was significantly lower than that of the sham group and the high-dose ghrelin + cisplatin group, and the AMH level of the sham group was significantly higher than that of the low-dose ghrelin + cisplatin group. CONCLUSION: High-dose ghrelin was effective in preventing cisplatin-induced ovarian damage by preserving the number of primordial and primary follicles. Larger randomized studies are needed to determine the optimal dosage and duration of ghrelin.

HDL subgroups and their paraoxonase-1 activity in the obese, overweight and normal weight subjects.

BACKGROUND: Obesity and overweight are significant public health problems because of higher risk for coronary artery disease (CAD). It is very important to determine new predictive markers to identify the CAD risk in obese and overweight. To aim this, we analysed HDL-C subgroups (HDL2-C and HDL3-C) and their paraoxonase-1 (PON-1) activity in obese, overweight and normal weight subjects. METHOD: 71 obese, 40 overweight and 30 healthy subjects as a control group were enrolled the study. Serum lipids levels were determined with enzymatic colorimetric method. Further, PON-1 activities and HDL-C levels were determined by spectrophotometric methods. Non-HDL3-C concentrations were calculated with the subtraction of HDL3-C from total HDL-C. RESULTS: The mean serum levels of total HDL-C, HDL3-C, Non-HDL3-C and ApoA1 were higher in control group than obese and overweight groups. There were a statistically significant difference between obese and control group in terms of Lp(a), hsCRP and HOMA index. Higher total PON-1, non-HDL3 PON-1 and HDL3 PON-1 activities were found in the control group compared with obese and overweight groups. Total HDL was weakly negative correlated with the HOMA index, BMI and waist circumference. There was a weak negative correlation between non-HDL3-C and waist circumference. CONCLUSION: Altered HDL-subgroups pattern and decreased PON-1 activities may cause increased risk for CVD in obese and overweight individuals. Therefore determination of HDL subgroups and their PON-1 activity may improve risk prediction compared with measuring total HDL-C levels and its PON-1 activity alone. Body weight and insulin resistance appear to have a role in the decreased HDL-C levels and PON-1activity in obese. Further studies should be conducted to shed more light on impacts of these markers in CVD.

Sample size, power and effect size revisited: simplified and practical approaches in pre-clinical, clinical and laboratory studies.

Calculating the sample size in scientific studies is one of the critical issues as regards the scientific contribution of the study. The sample size critically affects the hypothesis and the study design, and there is no straightforward way of calculating the effective sample size for reaching an accurate conclusion. Use of a statistically incorrect sample size may lead to inadequate results in both clinical and laboratory studies as well as resulting in time loss, cost, and ethical problems. This review holds two main aims. The first aim is to explain the importance of sample size and its relationship to effect size (ES) and statistical significance. The second aim is to assist researchers planning to perform sample size estimations by suggesting and elucidating available alternative software, guidelines and references that will serve different scientific purposes.

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.

Biological variation of peripheral blood T-lymphocytes.

BACKGROUND: Flow cytometric analysis of the lymphocyte subsets has become one of the most commonly used techniques in the routine clinical laboratory. It is frequently used in monitoring lymphocyte recovery after hematopoietic stem cell transplantation (HSCT), as well as diagnosis and treatment of acquired immunodeficiency syndrome (AIDS). Reliable biological variation (BV) data is needed for safe clinical application of these tests. In this study, similar preanalytical and analytical protocols to the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) checklist were followed and a stringent statistical approach was applied to define BV of T-lymphocytes. METHODS: During the 10 weeks study period, weekly blood samples were obtained from 30 healthy individuals (20 females, 10 males) and analyzed with Facs Canto (BD Biosciences, San Jose, CA, USA) analyzer using 4-colour BD Multitest CD3/CD8/CD45/CD4 reagents. Data were assessed in terms of normality, tendencies, outliers and variance homogeneity prior to applying coefficient of variance (CV)- analysis of variance (ANOVA) test. Sex-stratified within-individual (CVI) and between-individual (CVG) BV estimates of CD3+, CD3 + CD4+, CD3 + CD8+, and CD3 + CD4 + CD8+ T lymphocytes were calculated. RESULTS: No difference was found between males and females. Except for the CD3 + CD4 + CD8+ subset, stable BV was found for CD3+, CD3 + CD4+, and CD3 + CD8+ subsets. CONCLUSSION: Instead of using the conventional reference ranges of CD3+, CD3 + CD4+ and CD3 + CD8+ counts for monitoring HIV positive or post-HSCT patients, RCV should be used. Because individualityis characteristic of lymphocytes subsets RCVs should be used instead of RIs for patient monitoring.

Biological variation estimates of prothrombin time, activated partial thromboplastin time, and fibrinogen in 28 healthy individuals.

BACKGROUND: Although tests of global hemostasis prothrombin time (PT) and activated partial thromboplastin time (aPTT) should not be used for prediction of bleeding risk, these tests are often used by many clinicians in daily practice particularly as a preoperative screening test. Robust biological variation (BV) data are needed for safe clinical applications of these tests. In this study, a stringent protocol was followed to estimate the BV's for PT, aPTT, and fibrinogen levels. METHODS: Weekly blood samples were obtained from 28 healthy individuals (18 females, 10 males) during 10 weeks study period. All measurements were performed with Stago STA-R coagulation analyzer. Prior to coefficient of variation (CV)-analysis of variance (ANOVA), the data were assessed for normality, trends, outliers, and variance homogeneity. Sex-stratified within-individual (CVI ) and between-individual (CVG ) BV estimates were determined for PT, aPTT, and fibrinogen tests. RESULTS: No difference was found between male and female estimates of BV. The observed CVI and CVG estimates were found to be lower than those previously published. Only for fibrinogen, CVI was higher than CVG . CONCLUSION: Following a meticulous protocol, our study results provide up-to-date and more stringent BV estimates of global hemostasis tests.

What should be the laboratory approach against isolated prolongation of a activated partial thromboplastin time?

BACKGROUND: This study is a retrospective evaluation of patients who were subject to mixing study in our laboratory due to prolonged APTT. The preliminary diagnoses, clinical manifestations, and results of additional ordered tests were reviewed. The study aims to investigate whether repeating APTT test with a different assay prior to performing mixed study in patients with prolonged APTT would be a better alternative algorithmic approach in order to save both time and costs. METHODS: We retrospectively evaluated 166 patients (65 females and 101 males) who were subject to mixing study due to isolated prolonged APTT. Additional ordered tests to identify the etiology and clinical findings were reviewed. All patients who had prolonged APTT as a result of testing with Hemosil Synthasil APTT reagent in ACL TOP analyzer were repeated with Stago Cephascreen APTT reagent in STA-R coagulation analyzer. RESULTS: APTT test was requested preoperatively in 72.2% of cases. Only 6.6% of the cases had history of bleeding. Correction with mixing study was achieved in 122 (73.5%) cases, among which 75 (45%) cases were found to have APTT test results within reference range when tested with Cephascreen reagent. In 44 (26.5%) cases, mixing study did not result in correction. Only 4 cases were confirmed to have lupus anticoagulants (LA), while 4 cases were diagnosed with hemophilia with inhibitors. CONCLUSION: Prolonged APTT results should always be retested using a different assay prior to mixing study. The clinician and the laboratory specialist should collaborate at the postanalytical phase.

Comparison of Widely Used Biochemical Analytes in the Serum and Saliva Samples of Dialysis Patients.

BACKGROUND: The aim of this study is to determine whether the saliva analysis is an alternative to routine biochemical and immunoassay analyses in patients undergoing perito - neal dialysis (PD) or hemodialysis (HD). METHODS: Study group consisted of 40 healthy control, 44 PD and 44 HD patients. Routine biochemical analytes, thyroid stimulating hormone (TSH), free T3, free T4, vitamin B12, ferritin and folic acid were measured. RESULTS: Compared to pre-HD, urea, creatinine, uric acid, potassium levels were lower in post-HD, and calcium, magnesium, vitamin B12 levels were higher in post-HD both in saliva and serum. Positive correlations between saliva and serum were found for TSH and ferritin in control; urea, LDH, K in PD; urea, creatinine, alkaline phosphatase in pre-HD, and gamma-glutamyl transferase, iron, TSH in post-HD. There was a negative correlation only for creatine kinase and Mg in pre-HD and calcium in post-HD. In all groups, a positive correlation was found for urea, creatinine and a negative correlation was found for magnesium. CONCLUSIONS: Our study showed higher salivary urea and creatinine levels in patient groups, consistent with serum levels. Based on these results, salivary urea and creatinine levels may be useful in the evaluation of azotemia in dialysis patients.

A Pathway to National Guidelines for Laboratory Diagnostics of Chronic Kidney Disease - Examples from Diverse European Countries.

The principal benefit of guidelines is to improve the quality of care received by patients. In the 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (KDIGO) was released and it is designed to provide information and assist decision making. This review gives a brief overview of a various national CKD guidelines that rely on the newly released KDIGO guidelines. All of the included countries (France, Turkey, Norway and Croatia) are non-English speaking countries and they differ in population and socio economic aspects. Examples shown in this review may provide valuable experience for countries that are in process of creating their national CKD guidelines.

Is Turkish MEFV Mutations Spectrum Different Among Regions?

BACKGROUND: Familial Mediterranean fever (FMF) is an autosomal recessive inherited inflammatory disease. The gene responsible for the disease, called MEFV, encodes a protein called pyrin or marenostrin. According to recent data, MEFV mutations are not the only cause of FMF, but genetic analysis of MEFV gene is needed for confirming the diagnosis of FMF. In the present study, we aimed to evaluate the molecular testing results of MEFV mutations. METHODS: Molecular testing results of 1,435 patients were retrospectively evaluated over the last 4 years. These patients were identified as having FMF clinical symptoms. Patients were tested for 12 common mutations in the MEFV gene using a strip assay technique. RESULTS: From all 1,435 patients, MEFV mutations were found in 776 patients (54.08%) and 659 patients (45.92%) did not carry any mutations. Patients with mutations were classified as homozygotes (n = 148), compound heterozygotes (n = 197), heterozygous (n = 427), and complex genotypes (n = 4, patients with three mutations). Allelic frequencies for the four most common mutations in the mutation-positive groups were 48.79% (M694V), 14.86% (M680I G/C), 13.70% (E148Q), and 12.35% (V726A). The remaining alleles (10.3%) showed rare mutations that were R761H, P369S, A744S, K695R, F479L, and M694I. No patient showed a I692del mutation that is sometimes evident in other Mediterranean populations. CONCLUSION: It was found that the most common four mutations (M694V, M680I [G/C], E148Q, V726A) were similar to those previously reported from different regions of Turkey and this study might add some knowledge to the mutational spectrum data on FMF.

Relationship between high sensitivity troponins and estimated glomerular filtration rate.

BACKGROUND: Diagnosis of acute coronary syndrome may be challenging because of high troponin concentrations in patients with chronic kidney disease. OBJECTIVE: the aim of this study is to investigate the difference between high sensitivity troponin T and troponin I in four groups of patients separated according to eGFR values and the effect of renal function both on troponin T and troponin I. METHODS: 119 outpatients were divided into 4 groups according to their eGFR values as Group 1: eGFR<30, Group 2: eGFR between 30 and 60, Group 3: eGFR between 60 and 90 and Group 4: eGFR >90mL/min/1.73m(2). The cardiac troponin T and I concentrations were measured concurrently. RESULTS: Troponin T values of all patients who have eGFR values lower than 30mL/min/1.73m(2) were above the decision point, but cTnI values of only 2 patients were above the decision limit (40ng/L) in this group. There was a strong and significant negative relationship between eGFR and hs-cTnT [log(y)=2.3-0.72log(x); R(2)=0.625] whereas there was no significant relationship between eGFR and hs-cTnI [log(y)=1.28-0.08log(x); R(2)=0.013] when eGFR was taken into consideration as a continuous variable. CONCLUSION: In this study, we found that cTnT increases with decreasing eGFR values, but cTnI is not affected by the change in eGFR values.

Falsely Elevated Glucose Concentrations in Peritoneal Dialysis Patients Using Icodextrin.

BACKGROUND: Peritoneal dialysis (PD) is used as an alternative to hemodialysis in end-stage renal disease (ESRD). Icodextrin has been used as a hyperosmotic agent in PD. The aim of the study was to assess two different point-of-care testing (POCT) glucose strips, affected and not affected by icodextrin, with serum glucose concentrations of the patients using and not using icodextrin. METHODS: Fifty-two chronic ambulatory peritoneal dialysis (CAPD) patients using icodextrin (Extraneal®) and 20 CAPD patients using another hyperosmotic fluid (Dianeal®) were included in the study. Duplicate capillary and serum glucose concentrations were measured with two different POCT glucose strips and central laboratory hexokinase method. Assay principles of glucose strips were based on glucose dehydrogenase-pyrroloquinoline quinone (GDH-PQQ) and a mutant variant of GDH (Mut Q-GDH). The results of both strips were compared with those of hexokinase method. RESULTS: Regression equations between POCT and hexokinase methods in icodextrin group were y = 2.55x + 1.12 mmol/l and y = 1.057x + 0.16 mmol/l for the GDH-PQQ and Mut Q-GDH methods, respectively. The mean difference between the results of hexokinase and those of GDH-PQQ and Mut Q-GDH in icodextrin group was 3.41 ± 1.56 and 0.72 ± 0.64 mmol/l, respectively. However, the mean differences were found much lower in the control group; 0.64 mmol/l for GDH-PQQ and 0.52 mmol/l for Mut Q-GDH. CONCLUSION: Compared to GDH-PQQ, glucose strips of Mut Q-GDH correlated better with hexokinase method in PD patients using icodextrin.

Is there a relationship between small, dense LDL and lipoprotein--associated phospholipase A2 mass in dialysis patients?

BACKGROUND: We aimed to measure small, dense LDL (sdLDL) and lipoprotein-associated phospholipase A2 (Lp-PLA2) concentrations and to evaluate their relationship with other risk factors of atherosclerotic heart disease in dialysis patients. METHODS: Study group consisted of 30 peritoneal dialysis and 20 hemodialysis patients with 20 healthy control subjects. sdLDL was measured by homogeneous LDL assay after precipitation of Apo B containing lipoproteins with heparin-magnesium. Lp-PLA2 mass was measured by immunoturbidimetric assay. RESULTS: sdLDL concentrations in the samples collected before hemodialysis and peritoneal dialysis treatment were significantly higher than the control group (p < 0.05). Lp-PLA2 concentrations of both pre-hemodialysis and peritoneal dialysis groups were higher than control group (p < 0.05). There was not a significant correlation between sdLDL and Lp-PLA2. sdLDL concentrations are significantly decreased after a hemodialysis session. CONCLUSIONS: sdLDL and Lp-PLA2 concentrations are increased independently in the end stage renal failure patients who are receiving dialysis treatment.

A multicenter nationwide reference intervals study for common biochemical analytes in Turkey using Abbott analyzers.

BACKGROUND: A nationwide multicenter study was organized to establish reference intervals (RIs) in the Turkish population for 25 commonly tested biochemical analytes and to explore sources of variation in reference values, including regionality. METHODS: Blood samples were collected nationwide in 28 laboratories from the seven regions (≥400 samples/region, 3066 in all). The sera were collectively analyzed in Uludag University in Bursa using Abbott reagents and analyzer. Reference materials were used for standardization of test results. After secondary exclusion using the latent abnormal values exclusion method, RIs were derived by a parametric method employing the modified Box-Cox formula and compared with the RIs by the non-parametric method. Three-level nested ANOVA was used to evaluate variations among sexes, ages and regions. Associations between test results and age, body mass index (BMI) and region were determined by multiple regression analysis (MRA). RESULTS: By ANOVA, differences of reference values among seven regions were significant in none of the 25 analytes. Significant sex-related and age-related differences were observed for 10 and seven analytes, respectively. MRA revealed BMI-related changes in results for uric acid, glucose, triglycerides, high-density lipoprotein (HDL)-cholesterol, alanine aminotransferase, and γ-glutamyltransferase. Their RIs were thus derived by applying stricter criteria excluding individuals with BMI >28 kg/m2. Ranges of RIs by non-parametric method were wider than those by parametric method especially for those analytes affected by BMI. CONCLUSIONS: With the lack of regional differences and the well-standardized status of test results, the RIs derived from this nationwide study can be used for the entire Turkish population.

Can routine automated urinalysis reduce culture requests?

OBJECTIVES: There are a substantial number of unnecessary urine culture requests. We aimed to investigate whether urine dipstick and microscopy results could accurately rule out urinary tract infection (UTI) without urine culture. DESIGN AND METHODS: The study included a total of 32,998 patients (11,928 men and 21,070 women, mean age: 39 ± 32 years) with a preliminary diagnosis of UTI and both urinalysis and urinary culture were requested. All urine cultures were retrospectively reviewed; association of culture positivity with a positive urinalysis result for leukocyte esterase (LE) and nitrite in chemical analysis and pyuria (WBC) and bacteriuria in microscopy was determined. Diagnostic performance of urinalysis parameters for detection of UTI was evaluated. RESULTS: In total, 758 (2.3%) patients were positive by urine culture. Out of these culture positive samples, ratios of positive dipstick results for LE and nitrite were 71.0% (n=538) and 17.7% (n=134), respectively. The positive microscopy results for WBC and bacteria were 68.2% (n=517) and 78.8% (n=597), respectively. Negative predictive values for LE, nitrite, bacteriuria and WBC were very close to 100%. CONCLUSIONS: Most of the samples have no or insignificant bacterial growth. Urine dipstick and microscopy can accurately rule out UTI. Automated urinalysis is a practicable and faster screening test which may prevent unnecessary culture requests for majority of patients.

Serum soluble fas ligand levels in familial Mediterranean fever.

INTRODUCTION: Fas/FasL system plays an important role in the regulation of cell life and death, and circulating levels of sFasL have been shown to increase in some inflammatory conditions. However, there is no sufficient information about the levels of sFasL in patients with FMF. This study was designed to evaluate the serum sFasL levels in patients with FMF during attack and attack-free periods. METHODS: Twenty-five FMF patients in attack and forty-four in free-attack period, and 20 age-, sex-, and BMI-matched healthy controls were included in this study. Participants with any chronic diseases were excluded. Blood samples were obtained within the first 24 h of the attack period and between febrile attacks, and levels of WBC, ESR, Fibrinogen, hsCRP and sFasL were determined. RESULTS: The levels of traditional acute phase reactants during the attack were significantly higher than the attack-free and controls (p < 0.05). The serum sFasL levels in the FMF study groups did not differ from the control group (0.70 ± 0.08 vs. 0.73 ± 0.12; 0.70 ± 0.08 vs. 0.83 ± 0.14; 0.73 ± 0.12 vs. 0.83 ± 0.14, respectively, p > 0.05). Moreover, the sFasL levels during the attack were not significantly different from those in attack-free patients (0.70 ± 0.08 vs. 0.83 ± 0.14, p > 0.05). CONCLUSION: In this study, we demonstrated that serum sFasL levels were not markedly affected in FMF and cannot be used as a supportive marker to differentiate attacks from attack-free periods. However, further studies are needed to determine its usefulness as a marker in clinical practice.

Performance of different screening methods for the determination of urinary glycosaminoclycans.

BACKGROUND: The study aim was to compare the performance of three different methods used for determining urinary glycosaminoglycans (GAG) levels in spot and 24-h urine samples. METHODS: Performance characteristics were studied for cetylpyridinium chloride (CPC), and manual and automated dimethylmethylene blue (DMB) methods. RESULTS: For automated DMB method, within-run precisions were 9.10% and 1.98%, and between-day precisions were 13.0% and 5.81% in low- and high-urine pools, respectively. The method was linear up to 100 mg/L of GAG concentration. The detection limit of the method was 0.71 mg/L. Mean recovery was 95.7%. CONCLUSIONS: The automated DMB method was found to give better performance characteristics than cetylpyridinium chloride (CPC) and manual DMB methods. It is a fast, cheap, simple and reliable method and can be applied in many diseases in which GAG is used as a screening test.