Biochemia Medica最新文献

Creatinine and estimated glomerular filtration rate (eGFR) are first-line laboratory parameters in the diagnosis of various renal diseases. In recent decades, cystatin C (cysC) has furthered the laboratory repertoire regarding renal status assessment and has been implemented in many clinical guidelines. Accordingly, with the establishment of cysC as a renal routine biomarker, further opportunities for assessing eGFR have been attained. Nevertheless, various limitations are still associated with cysC and creatinine analysis. Preanalytical errors could cause false results in both biomarkers. In our case, we were confronted with implausibly elevated creatinine levels due to preanalytical errors.

Introduction: Moving average (MA) is one possible way to use patient results for analytical quality control in medical laboratories. The aims of this study were to: (1) implement previously optimized MA procedures for 10 clinical chemistry analytes into the laboratory information system (LIS); (2) monitor their performance as a real-time quality control tool, and (3) define an algorithm for MA alarm management in a small-volume laboratory to suit the specific laboratory.

Materials and methods: Moving average alarms were monitored and analysed over a period of 6 months on all patient results (total of 73,059) obtained for 10 clinical chemistry parameters. The optimal MA procedures were selected previously using an already described technique called the bias detection simulation method, considering the ability of bias detection the size of total allowable error as the key parameter for optimization.

Results: During 6 months, 17 MA alarms were registered, which is 0.023% of the total number of generated MA values. In 65% of cases, their cause was of pre-analytical origin, in 12% of analytical origin, and in 23% the cause was not found. The highest alarm rate was determined on sodium (0.10%), and the lowest on calcium and chloride.

Conclusions: This paper showed that even in a small-volume laboratory, previously optimized MA procedures could be successfully implemented in the LIS and used for continuous quality control. Review of patient results, re-analysis of samples from the stable period, analysis of internal quality control samples and assessment of the analyser malfunctions and maintenance log have been proposed for the algorithm for managing MA alarms.

Introduction: In previous research projects and clinical settings, alcohol analysis in oral fluid (saliva) has been used as an alternative to breath or blood alcohol testing. In this study we examined whether it is possible to obtain clinically relevant data regarding alcohol consumption in individuals who recently consumed alcohol by analysing oral fluid samples when the recommended rinsing of the mouth is impossible before sample collection.

Materials and methods: We conducted a study of 89 nightclub patrons in Norway. Before collecting oral fluid samples and performing breath alcohol testing, participants were required to drink a glass of water to remove residual alcohol from the mouth. Oral fluid samples were collected with the Quantisal oral fluid collection device and analysed using an enzymatic method for alcohol. The alcohol concentration in the neat (undiluted) oral fluid was then calculated. Breath alcohol testing was performed using Lion Alcolmeter 500 instruments.

Results: No false-negative or false-positive results for alcohol were detected in the oral fluid when compared with those in the breath. The Intraclass Correlation Coefficient of 0.40 indicated a poor correlation between alcohol concentrations in the two sample types.

Conclusions: The procedure for collecting oral fluid was suitable for the qualitative determination of alcohol intake but not for quantitative assessment. We recommend that oral fluid samples should not be used for estimating blood or breath alcohol concentrations in people who have recently consumed alcohol or non-alcoholic beverages, as recommended in the instructions for use.

Introduction: Two new formulas, the Martin-Hopkins and the Sampson formula, were recently developed to overcome shortcomings of the Friedewald formula for calculating LDL-cholesterol. We aimed to compare the concordance of the two formulas with apolipoprotein B (apoB), a surrogate marker of the number of LDL particles.

Materials and methods: In a study of serum lipid data of 1179 patients who consulted the AZ St-Jan Hospital Bruges for cardiovascular risk assessment, the correlation and concordance of the Friedewald, Martin-Hopkins and Sampson formulas with apoB concentration, measured by immunonephelometry, were determined and compared.

Results: The Martin-Hopkins formula showed significantly higher correlation coefficient than the Friedewald formula with apoB in the entire dataset and in patients with low LDL-cholesterol < 1.8 mmol/L. Both Martin-Hopkins and Sampson formulas yielded > 70% concordance of LDL-cholesterol with regard to treatment group classification based on population-equivalent thresholds of apoB in hypertriglyceridemic patients (2-4.5 mmol/L), with the highest concordance (75.6%) obtained using Martin-Hopkins formula vs. 60.5% with Friedewald formula.

Conclusion: The Martin-Hopkins (and, to a lesser extent, Sampson) formula is more closely associated with the number of LDL particles than Friedewald formula. This, in combination with literature evidence of lesser accuracy of the Friedewald formula, is an argument to switch from Friedewald to a modified, improved formula.

[This corrects the article DOI: 10.11613/BM.2021.020502.].

Introduction: Automated erythrocyte sedimentation rate (ESR) analysers are based on different methodology than Westergren method. It is questionable whether ESR values obtained from those analysers are comparable with determined values with Westergren method. The aim was verification of the precision, method comparison and accuracy of automated ESR analysers: Roller 20PN (Alifax S.p.A., Polverara, Italy) and iSED (Alcor Scientific, Smithfield, USA).

Materials and methods: Blood samples (N = 752 for Roller 20PN and N = 213 for iSED) were sampled into K₂EDTA (Kima, Italy) tubes for automated and 3.8% Na-citrate tubes (Kima, Italy) for Westergren method. The data was divided into three groups according to the ESR values obtained with the Westergren method: Group Low (L) (ESR ≤ 20 mm), Group Medium (M) (ESR 21-60 mm), and Group High (H) (ESR ≥ 61 mm). Method agreement was assessed by Bland-Altman analysis and Passing-Bablok regression.

Results: Analyser iSED has shown better comparability with Westergren method (bias 0.0 (95%Cl -1.4 to 1.5) range than Roller 20 PN (bias = - 6.4 (95%Cl - 7.1 to -5.7) in the whole measuring. For Roller 20 PN, Passing-Bablok regression has shown constant and proportional difference for Groups L and M, and for iSED only for Group H. Roller 20 PN had lower sensitivity (0.51 (95%Cl: 0.45-0.57) than iSED (0.72 (95%Cl: 0.59-0.80) while they had comparable specificity (> 0.90) and accuracy (≥ 0.80) in comparison with the Westergren method.

Conclusion: Both analysers are not comparable with the Westergren method and should not be used interchangeably.

Introduction: Based on the hypothesis that there is a substantial rate of adults with prediabetes and undiagnosed diabetes mellitus (DM), our aim was to perform haemoglobin A1c (HbA_1c)-based screening in a cohort of Croatian adults and estimate the prevalence of prediabetes and undiagnosed DM according to American Diabetes Association criteria.

Materials and methods: This multi-center, cross-sectional study performed in six Croatian hospitals included 5527 patients aged 40 to 70 years admitted to the Emergency Department or undergoing a primary care check-up. Haemoglobin A1c was measured from leftover whole blood samples using the enzymatic method on either Alinity c or Architect c-series analyser (Abbott Laboratories, Chicago, USA). Haemoglobin A1c between 39-47 mmol/mol was classified as prediabetes, while ≥ 48 mmol/mol as undiagnosed DM.

Results: After exclusion of 435 patients with known DM, the final cohort included 5092 patients (median age 57; 56% males). A total of 882 (17.3%) patients had HbA_1c values between 39 and 47 mmol/mol. There were 214 (4.2%) patients with HbA_1c ≥ 48 mmol/mol. Prediabetes prevalence ranged from 14.2% to 20.5%, while undiagnosed DM from 3.3% to 7.3%, with statistically significant differences among settings (P < 0.001). Age-stratified analysis showed that prediabetes and undiagnosed DM prevalence increase with age (P < 0.001), being 25.4% and 5.8%, respectively, in patients aged 60 to 70 years.

Conclusion: Underlying impairment of glucose metabolism was identified in about one in five adults, with significant number of patients with already overt DM. These results should serve as a starting point for further steps directed towards promotion of preventive measures for DM in Croatia.

Introduction: The detection and prevention of errors in the postanalytical phase can be done through the harmonization and standardization of constituent parts of this phase of laboratory work. The aim was to investigate how well the ongoing management of the postanalytical phase corresponds to the document "Post-analytical laboratory work: national recommendations" in Croatian medical biochemistry laboratories (MBLs).

Materials and methods: All 195 MBLs participating in the national external quality assessment scheme, were invited to undertake a part in a survey. Through 23 questions the participants were asked about management of the reference intervals (RI), delta check, reflex/reflective testing, postanalytical quality indicators and other parts of the postanalytical phase recommended in the national recommendations. The results are presented in numbers and percentages.

Results: Out of 195 MBLs, 119 participated in the survey, giving a response rate of 61%. Not all of the respondents provided answers to all the questions. Delta check has not been used in 59% (70/118) of the laboratories. Only 22/113 (20%) laboratories use reflex and/or reflective testing. In 53% of the laboratories, critical results were reported within 30 minutes of the confirmation of the results. In 34% (40/118) of the laboratories, turnaround time and reporting of critical results are two most often monitored postanalytical quality indicators.

Conclusion: The results showed the critical results reporting and monitoring of postanalytical quality indicators are in the line with the recommendations. However, the management of RI verification, the use of delta check and reflex/reflective testing still must be harmonized among Croatian MBLs.

Introduction: Evaluation of thyroid function is often requested and therefore defining paediatric reference intervals (RIs) is of vital importance. Currently, there is a distinct lack of paediatric RIs for thyroid function tests in Croatia. Thus, we established RIs for thyroid stimulating hormone (TSH), total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3) and free thyroxine (FT4) in the Croatian paediatric population.

Materials and methods: Reference intervals were calculated from 397 apparently healthy children, aged from 2 days to < 19 years. Serum samples were analysed for thyroid function tests on the Abbott Architect i2000. Age- and sex-specific 95% RIs with 90% confidence intervals were established according to Clinical and Laboratory Standards Institute guidelines. To express the magnitude of sex and age variation, standard deviation ratio (SDR) was calculated using two-level nested ANOVA. The criterion for considering partitioning reference values was set to SDR > 0.3.

Results: All thyroid function tests required age partitioning, confirmed by SDR above 0.3. There was no need for sex partitioning, confirmed by SDR below 0.3. Still, FT3 was partitioned due to visually noticeable sex related difference for the oldest group (12 years to < 19 years).

Conclusion: This is the first study to establish RIs for thyroid function tests in the Croatian paediatric population. We propose RIs for widely used Abbott platform, thus giving laboratories method- and population-specific paediatric RIs for thyroid function tests that should improve clinical test interpretation.

Introduction: The data on the coronavirus disease (COVID-19) in solid-organ transplant recipients (SOTRs) in Croatia is unknown. The aim of this study was to analyze the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Croatian SOTRs.

Materials and methods: From 7 September to 27 November 2020 (beginning of the second COVID-19 pandemic wave), a cross-sectional screening for COVID-19 was performed in the adult outpatient liver (LTRs; N = 280) and kidney transplant recipients (KTRs; N = 232). Serum samples were initially tested for SARS-CoV-2 IgG antibodies using a commercial enzyme-linked immunosorbent assay (ELISA; Vircell Microbiologists, Granada, Spain). All positive samples were confirmed using a virus neutralization test (VNT). Data on risk exposure and COVID-19 related symptoms were collected using a questionnaire.

Results: The transplanted cohort's seroprevalence detected by ELISA and VNT was 20.1% and 3.1%, respectively. Neutralizing (NT) antibodies developed in 15.6% of anti-SARS-CoV-2 ELISA IgG positive SOTRs. The difference in seropositivity rates between LTRs and KTRs was not statistically significant (ELISA 21.1% vs. 19.0%, P = 0.554; VNT 3.6% vs. 2.6%, P = 0.082). Overall VNT positivity rates were higher in patients who reported participation in large community events (5.9% vs. 1.0%; P = 0.027) as well as in patients who reported COVID-19 related symptoms in the past six months. In addition, symptomatic VNT positive patients showed significantly higher (P = 0.031) NT antibody titers (median 128, interquartile range (IQR) = 32-128) compared to asymptomatic patients (median 16, IQR = 16-48).

Conclusions: This study showed that 15.6% of anti-SARS-CoV-2 ELISA positive Croatian SOTRs developed NT antibodies indicating protective immunity. Further studies are needed to determine the dynamic of NT antibodies and COVID-19 immunity duration in immunocompromised populations such as LTRs and KTRs.