Croatian laboratories have a good knowledge of the proper detection and management of hemolyzed, icteric and lipemic samples.

BACKGROUND: Endogenous interferences are an important source of biased laboratory results. Hemolysis, lipemia and icteria are the main source of endogenous interference in laboratory medicine. Accreditation according to ISO 15189 improves the overall quality of the laboratory procedures. The aim of our study was i) to assess the level of knowledge of Croatian medical biochemists about the proper detection and management of hemolysis, lipemia and icteria; and ii) to identify possible differences in the level of knowledge respective to the laboratory accreditation status. METHODS: An on-line self-report survey was carried out by the Working Group for Preanalytical Phase of the Croatian Society of Medical Biochemistry and Laboratory Medicine during April to May 2015. Survey included 14 statements (Q1-Q14) about procedures for samples with interferences and participants were asked to assess the degree of agreement with the statement using a 4-point Likert scale. RESULTS: The lowest level of knowledge was observed for statements Q10 (dealing with icteric sample; 40.9% participants agreed with the correct procedure), Q12 (allowable error for interference; 47.2%) and Q11 (dealing with lipemic sample; 60.1%). Almost all participants (97.4%) agreed that laboratories in Croatia should have a harmonized protocol for management of samples with interferences. Participants from accredited laboratories showed higher knowledge of hemolysis detection (p=0.031), rejection of hemolyzed sample (p<0.001), management of icteric samples (p=0.038) and allowable error for interferences (p=0.040). CONCLUSIONS: Croatian laboratories have a good knowledge of the proper detection and management of hemolyzed, icteric and lipemic samples. Accreditation is associated with higher knowledge about management of samples with interferences.

Cancer cachexia, sarcopenia and biochemical markers in patients with advanced non-small cell lung cancer-chemotherapy toxicity and prognostic value.

PURPOSE: Cancer cachexia and sarcopenia are frequently observed in cancer patients and associated with poor survival. The majority of studies of cancer cachexia and sarcopenia have been done in patients with solid tumors of different origins, and there are currently no good predictors of the benefit of chemotherapy or factors that predict survival in advanced cancer. The purpose of our prospective study was to evaluate prevalence of cachexia and sarcopenia using international consensus definition and criteria for diagnosis in patients with diagnosed advanced non-small cell lung cancer (NSCLC) stage IIIB and IV and their relation to chemotherapy toxicity and survival prediction. A secondary aim was to compare several biochemical markers (CRP, IL-6, protein, and albumin) with time to tumor progression in order to assess prognostic value or to guide a treatment. METHODS: Between December 2013 and April 2015, the prospective cohort study of 100 Caucasian patients with advanced NSCLC stage IIIB or IV, who were referred consecutively to Department for Respiratory Diseases "Jordanovac," was evaluated. Anthropometric measurements and biochemical data (CRP, albumin, protein, IL-6, haemoglobin) together with body composition measurements (total muscle cross-sectional area, lumbar skeletal muscle index) were obtained for each patient before starting with platinum-doublet therapy. Skeletal muscle cross-sectional area at the third lumbar vertebra was measured by computerized tomography, and sarcopenia was defined using a previously published cutoff point. Toxicity was assessed after cycle 1 of treatment and time-to-tumor progression was determined prospectively. RESULTS: One hundred patients with advanced lung cancer were recruited: 67 were male and median age was 64 years. The median time to disease progression was 187 days. The prevalence of cachexia and sarcopenia in study cohort was 69 and 47 %, respectively. CRP, IL-6, and albumin concentration in cachectic compared to non-cachectic patients demonstrated statistically significant difference (p = 0.020, p = 0.040, p = 0.003). Cachexia and sarcopenia were not found to be predictors of chemotoxicity nor was time to tumor progression. On the contrary, albumin concentration with established cutoff point of 37.5 g/L was clearly proved as the predictive factor of both chemotoxicity (OR (95 % CI) = 0.85; p < 0.001) and survival (HR (95 % CI) = 0.55). CONCLUSIONS: Albumin level has been shown to be more important predictive marker of chemotherapy toxicity and survival than cachexia and sarcopenia are. This approach in clinical settings can be used to guide the choice of oncologic treatment.

How to assess the quality of your analytical method?

Laboratory medicine is amongst the fastest growing fields in medicine, crucial in diagnosis, support of prevention and in the monitoring of disease for individual patients and for the evaluation of treatment for populations of patients. Therefore, high quality and safety in laboratory testing has a prominent role in high-quality healthcare. Applied knowledge and competencies of professionals in laboratory medicine increases the clinical value of laboratory results by decreasing laboratory errors, increasing appropriate utilization of tests, and increasing cost effectiveness. This collective paper provides insights into how to validate the laboratory assays and assess the quality of methods. It is a synopsis of the lectures at the 15th European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Continuing Postgraduate Course in Clinical Chemistry and Laboratory Medicine entitled "How to assess the quality of your method?" (Zagreb, Croatia, 24-25 October 2015). The leading topics to be discussed include who, what and when to do in validation/verification of methods, verification of imprecision and bias, verification of reference intervals, verification of qualitative test procedures, verification of blood collection systems, comparability of results among methods and analytical systems, limit of detection, limit of quantification and limit of decision, how to assess the measurement uncertainty, the optimal use of Internal Quality Control and External Quality Assessment data, Six Sigma metrics, performance specifications, as well as biological variation. This article, which continues the annual tradition of collective papers from the EFLM continuing postgraduate courses in clinical chemistry and laboratory medicine, aims to provide further contributions by discussing the quality of laboratory methods and measurements and, at the same time, to offer continuing professional development to the attendees.

Compliance of blood sampling procedures with the CLSI H3-A6 guidelines: An observational study by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) working group for the preanalytical phase (WG-PRE).

BACKGROUND: An observational study was conducted in 12 European countries by the European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase (EFLM WG-PRE) to assess the level of compliance with the CLSI H3-A6 guidelines. METHODS: A structured checklist including 29 items was created to assess the compliance of European phlebotomy procedures with the CLSI H3-A6 guideline. A risk occurrence chart of individual phlebotomy steps was created from the observed error frequency and severity of harm of each guideline key issue. The severity of errors occurring during phlebotomy was graded using the risk occurrence chart. RESULTS: Twelve European countries participated with a median of 33 (18-36) audits per country, and a total of 336 audits. The median error rate for the total phlebotomy procedure was 26.9 % (10.6-43.8), indicating a low overall compliance with the recommended CLSI guideline. Patient identification and test tube labelling were identified as the key guideline issues with the highest combination of probability and potential risk of harm. Administrative staff did not adhere to patient identification procedures during phlebotomy, whereas physicians did not adhere to test tube labelling policy. CONCLUSIONS: The level of compliance of phlebotomy procedures with the CLSI H3-A6 guidelines in 12 European countries was found to be unacceptably low. The most critical steps in need of immediate attention in the investigated countries are patient identification and tube labelling.

Serotonin transporter polymorphism (5-HTTLPR) in Croatian population.

Serotonin transporter polymorphism (5-HTTLPR) is a well-studied polymorphism in psychiatric research. The function of serotonin transporter is to control neural stimulation and maintain homeostasis of serotonin in other cells like platelets and enterochromaffin cells. Considering serotonin function in human behavior, and the role of serotonin transporter, 5-HTTLPR has been associated with depression related disorders, anxiety related personality traits, and adverse response to psychotherapy. However, many studies failed to replicate the association of 5-HTTLPR polymorphism with mentioned disorders. The aim of our study was to assess genotype frequencies in Croatian physically and psychologically healthy population and compare our results with previously published data. Genotype distribution in our research was similar to previous studies on Caucasian population regardless of inclusion criteria. Genotype distribution was as follows: LL 38 %; LS 45 %; SS 17 % and allele frequencies for L and S allele were 61 and 39 %, respectively. Obtained results were in an agreement with the Hardy-Weinberg equilibrium. Comparing inclusion criteria from different studies, we noticed a difference in population selection from one study to another. Increased possibility for selection bias, population stratification and complexity of psychiatric disorders might present a source of possible errors in genetic association studies.

Preanalytical quality improvement: in quality we trust.

Total quality in laboratory medicine should be defined as the guarantee that each activity throughout the total testing process is correctly performed, providing valuable medical decision-making and effective patient care. In the past decades, a 10-fold reduction in the analytical error rate has been achieved thanks to improvements in both reliability and standardization of analytical techniques, reagents, and instrumentation. Notable advances in information technology, quality control and quality assurance methods have also assured a valuable contribution for reducing diagnostic errors. Nevertheless, several lines of evidence still suggest that most errors in laboratory diagnostics fall outside the analytical phase, and the pre- and postanalytical steps have been found to be much more vulnerable. This collective paper, which is the logical continuum of the former already published in this journal 2 years ago, provides additional contribution to risk management in the preanalytical phase and is a synopsis of the lectures of the 2nd European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)-Becton Dickinson (BD) European Conference on Preanalytical Phase meeting entitled "Preanalytical quality improvement: in quality we trust" (Zagreb, Croatia, 1-2 March 2013). The leading topics that will be discussed include quality indicators for preanalytical phase, phlebotomy practices for collection of blood gas analysis and pediatric samples, lipemia and blood collection tube interferences, preanalytical requirements of urinalysis, molecular biology hemostasis and platelet testing, as well as indications on best practices for safe blood collection. Auditing of the preanalytical phase by ISO assessors and external quality assessment for preanalytical phase are also discussed.

Visfatin is not associated with inflammatory markers in patients on hemodialysis.

BACKGROUND: Cardiovascular events are a major cause of death in patients with end-stage renal disease. Endothelial dysfunction represents a key event in atherosclerosis development and has been implicated in the pathophysiology of different forms of cardiovascular disease, including chronic kidney disease. In recent years, visfatin, a ubiquitous adipokine, has been described as a potent marker of endothelial inflammation and dysfunction. The aim of the study was to investigate the association of visfatin with well-known markers of inflammation and endothelial dysfunction. METHODS: Serum and plasma samples from 66 patients (40 males and 26 females) treated by hemodialysis were analysed for visfatin, fibrinogen, CRP, PAI-1 levels. Visfatin was determined by ELISA method while CRP, fibrinogen and PAL-1 were obtained by standard laboratory methods. RESULTS: We observed statistically significant correlation between visfatin level and fibrinogen (r = 0.51; p = 0.008) and the time on dialysis in female patients (r = 0.70; p < 0.001). PAI-1 and CRP did not correlate with visfatin in males nor in females. CONCLUSIONS: Visfatin is correlated with time on dialysis and with fibrinogen only in female dialysis patients. To confirm this, further studies are needed with a higher number of patients.

Can cranberry extract and vitamin C + Zn supplements affect the in vivo activity of paraoxonase 1, antioxidant potential, and lipid status?

BACKGROUND: The modern way of life exposes us to substantial oxidative stress, putting the focus on the research of antioxidant effects of dietary supplements. Recent studies have shown that the effectiveness of particular vitamins and herbal preparations might have an effect on paraoxonase activity. Paraoxonase 1 is an HDL associated enzyme which prevents the oxidation of LDL. Several studies have shown the beneficial effect of some dietary components to the activity of paraoxonase. The aim of this study was to analyze the effects of cranberry extract and vitamin C and zinc preparations (vitamin C + Zn) on serum paraoxonase 1 activity, antioxidant status, and glucose and lipid concentration. METHODS: The study included 31 healthy volunteers (median age 24 years). They were divided into 3 groups according to the intervention type and smoking status and exposed to commercially available preparations of the cranberry extract (2 g/day) and vitamin C + Zn (300 mg/day) during 4 weeks. RESULTS: The results have shown that there is a significant increase in the activity of the paraoxonase 1 in nonsmokers after the intervention with the cranberry extract as well as with vitamin C + Zn preparations. Also, total antioxidant status increased in the non-smokers subgroup after intervention with vitamin C + Zn. However, the lipid profile did not change significantly in response to antioxidant preparations. CONCLUSIONS: Our results show that antioxidant supplements can increase the antioxidant potential of an organism as well as paraoxonase 1 activity. This observation is pointing to the potential complementary role of dietary supplements in the primary prevention of atherosclerosis.

Symptomatic cardiac metastases of breast cancer 27 years after mastectomy: a case report with literature review--pathophysiology of molecular mechanisms and metastatic pathways, clinical aspects, diagnostic procedures and treatment modalities.

Metastases to the heart and pericardium are rare but more common than primary cardiac tumours and are generally associated with a rather poor prognosis. Most cases are clinically silent and are undiagnosed in vivo until the autopsy. We present a female patient with a 27-year-old history of an operated primary breast cancer who was presented with dyspnoea, paroxysmal nocturnal dyspnoea and orthopnoea. The clinical signs and symptoms aroused suspicion of congestive heart failure. However, the cardiac metastases were detected during a routine cardiologic evaluation and confirmed with computed tomography imaging. Additionally, this paper outlines the pathophysiology of molecular and clinical mechanisms involved in the metastatic spreading, clinical presentation, diagnostic procedures and treatment of heart metastases. The present case demonstrates that a complete surgical resection and systemic chemotherapy may result in a favourable outcome for many years. However, a lifelong medical follow-up, with the purpose of a detection of metastases, is highly recommended. We strongly call the attention of clinicians to the fact that during the follow-up of all cancer patients, such heart failure may be a harbinger of the secondary heart involvement.

The quality of the extra-analytical phase of laboratory practice in some developing European countries and Mexico - a multicentric study.

BACKGROUND: This cross-sectional multicentric survey study aimed to assess the quality of the extra-analytical phase of laboratory activities in some developing European countries and Mexico. We assessed the quality of the extra-analytical practices in participating laboratories regarding the: a) sample acceptance criteria; b) phlebotomy procedures; c) test results reporting and d) recording non-conformities. METHODS: A survey was performed during the April-May 2009. A total of 15 clinical laboratories from the following countries were included: Bosnia, Croatia, Czech Republic, Hungary, Mexico, Poland, Portugal, Romania, Serbia and Ukraine. Questions were scored (scores from 1-4) and average scores was calculated for each category. RESULTS: The overall score for all respondents (n = 443) was 3.10 ± 0.33. The average score was 3.11 ± 0.56 for sample acceptance criteria, 2.76 ± 0.58 for phlebotomy and 3.34 ± 0.53, for test results reporting (F = 116.49; p < 0.001). Laboratory accreditation was associated with better practices and higher overall quality of the extra-analytical procedures (F = 16.62; p < 0.001). Moreover, the highest scores for sample acceptance criteria (F = 8.32; p < 0.001), phlebotomy procedures (F = 13.28; p < 0.001) and for reporting non-conformities (F = 33.62; p < 0.001) were observed for accredited laboratories or laboratories under preparation for accreditation. CONCLUSIONS: The overall quality of the extra-analytical practices in countries in this survey is not satisfactory. Phlebotomy practices are the most critical extra-analytical activity. Since laboratory accreditation was associated with better practices and higher overall quality of the extra-analytical procedures, we believe that the most significant improvement could be made by implementing the total quality management system and standardizing laboratory procedures.

The association of uric acid with glucose and lipids in general population: Croatian cross-sectional study.

Hyperuricemia may have an important role in metabolic syndrome, cardiovascular diseases and stroke. Elevated serum uric acid concentration has been shown to be the strong predictor of cardiovascular mortality in several recently published studies. Our aim was to determine the prevalence of hyperuricemia in general Croatian population and to investigate the association of serum uric acid with glucose and lipids. This was a retrospective cross-sectional study on 6,476 consecutive adults. Prevalence of hyperuricemia was 13.9% in general population and it was significantly higher in males, than in females (26% vs. 6%; p < 0.001). Median uric acid concentration was higher in males than in females (343 vs. 238 micromol/L; p < 0.001). Age, glucose and lipid parameters did not correlate with uric acid. In hyperuricemic subjects, increased concentrations of glucose (33.1% vs. 13.1%; p < 0.001), triglycerides (46.9% vs. 17.6%; p < 0.001), total cholesterol (69.6% vs. 51.9%; p < 0.001), LDL-cholesterol (64.5% vs. 46.4%; p < 0.001) and decreased concentration of HDL-cholesterol (24.3% vs. 13.0%; p < 0.001) were more prevalent than in subjects with normal serum concentrations of uric acid. Hyperuricemia is highly prevalent in Croatian general population and it aggregates with hyperglycemia and dyslipidemia.

The prevalence of preanalytical errors in a Croatian ISO 15189 accredited laboratory.

BACKGROUND: The preanalytical phase is the most common source of laboratory errors. The goal of this descriptive study was to analyze the prevalence and type of preanalytical errors in relation to the site of sample collection (inpatient vs. outpatient) and the type of laboratory unit (hematology and coagulation vs. biochemistry). For the biochemistry unit, the data were also analyzed relative to the type of the analysis (stat vs. routine). METHODS: We retrospectively analyzed the sample and test request form error rate for a 1-year period, from January to December 2008. RESULTS: The frequency of the sample errors differed significantly between the emergency and routine biochemistry unit (0.69% vs. 2.14%; p<0.0001), and between inpatients and outpatients (1.12% vs. 1.36%; p=0.0006). Hemolysis was the most frequent sample error, accounting for 65% of all unsuitable specimens in the emergency biochemistry unit. The total sample error rate did not differ between hematology and coagulation vs. the biochemistry unit. The frequency of test request form errors differed significantly with respect to the sample collection site (p<0.0001), laboratory unit (p<0.0001) and type of the analysis (p<0.0001). Errors in the test request form were least frequent in the outpatient unit (2.98%) and most frequent in the routine biochemistry unit (65.94%). CONCLUSIONS: Sample and test request form errors in our laboratory are occurring with a frequency comparable to that reported by others. Continuous educational action is needed for all stakeholders involved in laboratory testing to improve the quality of the preanalytical phase of the total testing process.

Efficiency of test report delivery to the requesting physician in an outpatient setting: an observational study.

BACKGROUND: Clinical laboratories accredited according to ISO 15189 quality standards are obliged to implement and continuously monitor quality indicators for evaluation of the laboratory's contribution to patient care. Reporting laboratory results to the requesting physician is one important phase of the clinical laboratory testing process. Failure to report results may indicate the ineffectiveness of the laboratory service. We aimed to analyze the proportion and type of laboratory reports for outpatients that were not delivered to the requesting physician. METHODS: This retrospective observational study was conducted during an 11-month period from January to December 2007 at our outpatient biochemistry laboratory unit. Data on demographic characteristics, request types and laboratory findings for all uncollected reports were retrieved from the laboratory information system and compared with one random 2-week representative period. RESULTS: During the study period our laboratory issued 22,445 patient reports with more than 150,000 biochemistry analyses. Of these, 464 (2.1%) were uncollected laboratory reports. When compared to the representative period, patients who never collected their laboratory reports were younger (p<0.001) or suffering from some chronic disease. Routine biochemistry tests were the most prevalent (>50%). The majority of routine biochemistry tests were almost equally represented during the study and representative period, while molecular diagnostic tests were several times more frequently uncollected (p<0.001). Reports with electrolytes, metabolites and glucose were the least likely to be uncollected (p<0.001). The total cost for those tests was 30% of the average monthly laboratory budget. CONCLUSIONS: A significant amount of the laboratory budget is wasted for tests that never reach the requesting physician. Such misutilization of the laboratory reveals the substantial lack of medical necessity for test requests. Further studies are needed to explore the possible efficiency of the various interventions in reducing the volume of unnecessary and erroneous testing.

Comparison of visual vs. automated detection of lipemic, icteric and hemolyzed specimens: can we rely on a human eye?

BACKGROUND: Results from hemolyzed, icteric, and lipemic samples may be inaccurate and can lead to medical errors. These preanalytical interferences may be detected using visual or automated assessment. Visual inspection is time consuming, highly subjective and not standardized. Our aim was to assess the comparability of automated spectrophotometric detection and visual inspection of lipemic, icteric and hemolyzed samples. METHODS: This study was performed on 1727 routine biochemistry serum samples. Automated detection was performed using the Olympus AU2700 analyzer. We assessed: 1) comparability of visual and automated detection of lipemic, icteric and hemolyzed samples, 2) precision of automated detection, and 3) inter-observer variability for visual inspection. RESULTS: Weighted kappa coefficients for comparability of visual and automated detection were: 0.555, 0.529 and 0.638, for lipemic, icteric and hemolyzed samples, respectively. The precision for automated detection was high for all interferences, with the exception of samples being only slightly lipemic. The best overall agreement between observers was present in assessing lipemia (mean weighted kappa=0.698), whereas the lowest degree of agreement was observed in assessing icterus (mean weighted kappa=0.476). CONCLUSIONS: Visual inspection of lipemic, icteric and hemolyzed samples is highly unreliable and should be replaced by automated systems that report serum indices.

Methodological issues in genetic association studies of inherited thrombophilia: original report of recent practice.

The aims of this article are to evaluate the methodological quality of genetic association studies on the inherited thrombophilia published during 2003 to 2005, to identify the most common mistakes made by authors of those studies, and to examine if overall quality of the article correlates with the quality of the journal. Articles were evaluated by 2 independent reviewers using the checklist of 16 items. A total of 58 eligible studies were identified. Average total score was 7.59 +/- 1.96. Total article score did not correlate with the journal impact factor (r = 0.3971; 95% confidence interval [CI], 0.1547-0.5944, P = .002). Total score did not differ across years (P = .624). Finally, it is concluded that methodological quality of genetic association studies is not optimal, and it does not depend on the quality of the journal. Journals should adopt methodological criteria for reporting the genetic association studies, and editors should encourage authors to strictly adhere to those criteria.

Gentamicin and Vancomycin Interference on Results of Clinical Chemistry Parameters on Abbott Architect c8000.

CONTEXT.­: Gentamicin and vancomycin are nephrotoxic antibiotics. Little is known about the influence of drug concentrations on results of clinical chemistry tests. OBJECTIVE.­: To investigate gentamicin and vancomycin interference on results of 33 commonly measured biochemistry tests. DESIGN.­: The study was carried out in the University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice (Zagreb, Croatia). For each drug, 10 aliquots of pooled serum were prepared. In order to cover toxic concentrations, pool serum samples were spiked with drugs to obtain 0 to 50 µg/mL of gentamicin and 0 to 200 µg/mL of vancomycin. Biochemistry tests were measured in duplicate on the Architect c8000 analyzer, and drug concentrations were measured on Architect i2000 SR (both Abbott Laboratories, Abbott Park, Illinois). For each tested concentration, bias was calculated against the initial measurement. Acceptance criteria were defined as measurement uncertainty of the commercial control with the value close to the measured range of the pool sample. RESULTS.­: For gentamicin, all bias values were below established criteria. For vancomycin, significant changes were observed for potassium, direct bilirubin, and immunoglobulin A. Significant bias was already detected at low vancomycin concentration (2.98 µg/mL) for direct bilirubin (bias = 9.7%; acceptable = 8%). Potassium bias at the highest vancomycin concentration (204.4 µg/mL) exceeded acceptance criteria (bias = 4.5%; acceptable = 4%). For immunoglobulin A, no apparent trend was observed, and bias is attributed to increased method imprecision. CONCLUSIONS.­: Gentamicin did not interfere with the results of clinical chemistry tests. Direct bilirubin concentration is falsely increased in the presence of vancomycin, and potassium is affected at high concentrations.

Patient safety is not compromised by excluding microscopic examination of negative urine dipstick.

Background Microscopic examination of samples with negative dipstick results is not necessary. The aims of this study were to: (i) assess the risk of excluding urine sediment examination with negative dipstick results and (ii) calculate time savings by introducing this process. Methods The risk analysis was done for samples with negative urine dipstick and positive sediment findings. Possible missed elements in sediment were defined as 21 errors. Time saving was calculated as average time for preparation and examination sediments. Data were presented as counts and percentages. Results Out of 2997 samples, negative dipstick results were reported for 926 (30.6%) samples, out of which, microscopic examinations were positive for 527 (17.6%) samples. 18/21 errors were detected, with missing <5 squamous epithelial cells (SQEC) and bacteria 1+ as the most frequent ones (22.7% and 22.4%, respectively). Errors with the intermediate risk for patients were missing to report: ≥5 SQEC, ≥5 transitional epithelial cells, ≥10 hyaline casts (11.9%, 0.21%, 0.32%, respectively). Errors associated with high risk were not detected. Estimated total time saving is more than 25 h/month. Conclusions Microscopic examination of urine samples with negative dipstick results can be excluded without risk for patients and can result with considerable time savings.

The methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and cancer risk: the Croatian case-control study.

OBJECTIVES: Methylation abnormalities appear to be important for the pathogenesis of many cancer types. Since methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the methylation process catalyzing reduction of 5,10-methylenetetrahydrofolate to 5-methyl-tetrahydrofolate, C677T polymorphism, which decreases enzyme activity, may be associated with cancer susceptibility. The aim of this work was to investigate the distribution of MTHFR C677T polymorphism between various types of cancer and cancer-free controls and to assess if there is a difference in frequency. MATERIALS AND METHODS: 269 Cancer cases (95 prostate cancer, PC; 81 head and neck, HN; and 93 breast cancers, BC) and 102 healthy controls, free of cancer, were genotyped for C677T MTHFR polymorphism using the PCR-RFLP method. RESULTS: There was no overall difference in C677T genotype distribution between total cancer cohort and controls (p=0.064). However, a significant difference and protective OR was found for the C/T genotype (OR=0.574, 95% CI=0.352-0.935). In a comparison of different cancer types and respective controls, genotype frequencies were significantly different between head and neck carcinoma and controls (p=0.004), again with protective role of C/T genotype (OR=0.356, 95% CI=0.189-0.671). Moderate overrepresentation of C/T was found in respective male controls when compared with prostate cancer patients (p value was 0.074 for C/T vs. C/C comparison). The OR for heterozygous C/T genotype in prostate cancer group was 0.404, pointing to its putative protective role. Genotype and allelic frequencies did not differ significantly between 93 breast cancer patients and their 65 age-matched female controls. CONCLUSION: Our data indicate that the C677T MTHFR polymorphism does not significantly contribute to the inherited genetic susceptibility to breast and prostate cancer, while we show some evidence for possible genetic contribution of this polymorphism to the development of head and neck carcinoma.

Preanalytical external quality assessment of the Croatian Society of Medical Biochemistry and Laboratory Medicine and CROQALM: finding undetected weak spots.

INTRODUCTION: The aim of this paper is to present results of first two years of preanalytical external quality assessment (EQA) in Croatia. MATERIALS AND METHODS: This paper summarizes results from 6 rounds of preanalytical EQA during 2014-2016 in 161-175 Croatian laboratories (number ranged between cycles). EQA was designed as an online survey of the compliance with National recommendations for phlebotomy (NRP). Forty-seven questions in 5 categories are analyzed (materials and equipment, patient identification, patient preparation, sampling and storage). Additionally, preanalytical cases are presented. Overall performance scores (Question score (Qscore) for compliance with NRP and Case score (Cscore) for preanalytical cases) are calculated for each question/case as a proportion of laboratories with satisfactory procedure (x 100). Qscores and Cscores ≥ 70 were classified as acceptable (maximal score = 100). RESULTS: In investigation of compliance with NRP, acceptable Qscores were obtained for 34/47 questions. The lowest scores were observed for the availability of sterile disposable tourniquets (Qscore = 15) and safe-sharp needles (Qscore = 34), obtaining patients address as an identifier (Qscore = 21), using glycolysis inhibitor tubes for glucose concentration measurement (Qscore = 21) and verification of manufacturers declarations on temperature and time of storage (Qscore = 31). There was no statistically significant difference in overall Qscore according to different categories of phlebotomy procedures (P = 0.284). The results of preanalytical cases showed acceptable Cscore values for all cases (89-96). CONCLUSION: First two years of preanalytical EQA showed good compliance with the NRP and excellent expertise in resolving complex preanalytical issues. Major critical spots are lack of availability of safe-sharp needles, disposable tourniquets and glucose inhibitor tubes.

Does recreational scuba diving have clinically significant effect on routine haematological parameters?

INTRODUCTION: Scuba diving represents a combination of exercise and changes in environmental conditions. This study aimed to evaluate changes in haematological parameters after recreational scuba diving in order to identify clinically significant changes. MATERIALS AND METHODS: The study included males, 17 recreational divers, median age (range) 41 (30-52) years. Blood samples were taken before diving, immediately after diving to 30 meters for 30 minutes, 3 hours and 6 hours after diving. Complete blood counts were analyzed on the Cell Dyn Ruby haematology analyzer. Statistical significance between successive measurements was tested using Friedman test. The difference between the two measurements was judged against desirable bias (DSB) derived from biological variation and calculated reference change values (RCV). The difference higher than RCV was considered clinically significant. RESULTS: A statistically significant increase and difference judging against DSB was observed: for neutrophils immediately, 3 and 6 hours after diving (18%, 34% and 36%, respectively), for white blood cells (WBCs) 3 and 6 hours after diving (20% and 25%, respectively), for lymphocytes (20%) and monocytes (23%) 6 hours after diving. A statistically significant decrease and difference judging against DSB was found: immediately after diving for monocytes (- 15%), 3 and 6 hours after diving for red blood cells (RBCs) (- 2.6% and -2.9%, respectively), haemoglobin (- 2.1% and - 2.8%, respectively) and haematocrit (- 2.4% and - 3.2%, respectively). A clinically significant change was not found for any of the test parameters when compared to RCV. CONCLUSIONS: Observed statistically significant changes after recreational scuba diving; WBCs, neutrophils, lymphocytes, monocytes increase and RBCs, haemoglobin, haematocrit decrease, probably will not affect clinical decision.