Biochemia medica最新文献

This commentary discusses the prognostic relevance of leukocyte telomere length and paraoxonase-1 activity in small-cell lung cancer (SCLC) patients undergoing chemotherapy. It emphasizes the importance of integrating telomere biology and oxidative stress assessment in prognostic modeling. The discussion also considers the modifying effects of lifestyle, treatment regimens, and genetic background, advocating for research that combines clinical, biochemical, and molecular data to enhance prognostication in SCLC.

Proper preanalytical handling of blood samples is critical to ensure the reliability of laboratory results, particularly in patients undergoing hemodialysis, where biochemical monitoring is essential for assessing dialysis adequacy and guiding treatment decision. We reported three cases of abnormal post-dialysis gel separator flotation in blood collection tubes from patients undergoing hemodiafiltration: in each case, the gel migrated to the top of the tube, with plasma trapped below and blood cells remaining at the bottom. Marked hyperproteinemia and hypercalcemia were observed in the plasma, inconsistent with the patient's clinical status and pre-dialysis values. These findings raised suspicion of a preanalytical error potentially associated with the hemodialysis procedure. On-site investigations conducted in collaboration with the dialysis center for four additional patients, combined with a better understanding of the principles of hemodiafiltration and the potential sampling sites, confirmed that the gel migration anomaly was secondary to unsuitable sampling from the venous line (outflow line) of the dialysis circuit instead of the arterial one (inflow line). In conclusion, we highlighted the critical role of adhering to the appropriate sampling site when performing post-dialysis blood tests: the arterial line was identified as the appropriate site for post-dialysis blood sampling, while the venous line should be reserved exclusively for infusion or reinjection purposes and must never be used for blood collection at the end of dialysis.

Introduction: The Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) Key Incident Monitoring and Management EQA Program (KIMMS) aims to monitor the laboratory quality system's pre- and post-analytical phases. The purpose of this paper is to describe the most common incidents from 2024.

Materials and methods: The KIMMS program has four surveys a year, collecting data from the previous three months, with preanalytical and postanalytical incident reporting of 35 incident types. Participants are asked to capture the number of episodes and the number of incidents per quarter of the year.

Results: The four 2024 surveys received an average of 111 responses, with 55,329,998 episodes recorded and 1,496,708 incidents identified. The findings from the 2024 program are that the incident "No specimen received" appears to have the highest 80th percentile across the patient sources. The commonest site of error is the Emergency Department (ED), with an 80th percentile overall.

Conclusions: The KIMMS data provide valuable, regular and reproducible benchmarking data for the pre- and post-analytical phases of the total testing cycle.

Introduction: Microscopic examination of peripheral blood smears remains essential step in hematology diagnostics, requiring reliable and standardized staining techniques. This study evaluated performance of Aerospray Hematology PRO Slide Stainer (ELITechGroup Inc., Utah, USA) in comparison with manual May-Grünwald-Giemsa (MGG) technique.

Materials and methods: Forty K₂EDTA-whole-blood smears were prepared in duplicate and stained using both methods. Hundred samples flagged by Siemens Advia 2120i for atypical lymphocytes (ATYPS), immature granulocytes (IG), blasts and nucleated red blood cells were analyzed for diagnostic accuracy. Precision was assessed using three K₂EDTA-whole-blood samples, where 12 smears per sample were evaluated. Manual differential counts of 100 white blood cells (WBC) per slide were performed by experienced laboratory scientist. Data distribution was assessed using Kolmogorov-Smirnov test. Method comparison was performed using Bland-Altman and Passing-Bablok analyses, while sensitivity and specificity were calculated for ATYPS, IG and blasts.

Results: Precision results met acceptable criteria for all WBC subpopulations. No significant differences were observed for mature WBCs: intercept - 4.0 (- 13.8 to 3.0) slope 1.0 (0.9 to 1.2) for neutrophils; intercept - 1.5 (- 9.3 to 1.9), slope 1.1 (0.9 to 1.3) for lymphocytes; intercept 1.0 (- 2.0 to 1.6), slope 1.0 (0.9 to 1.4) for monocytes; intercept 0.0 (- 1.5 to 1.3), slope 1.0 (0.5 to 1.7) for eosinophils. Staining of mature WBCs was comparable, showing no significant differences in nuclear or cytoplasmic morphology. While immature WBCs, particularly myelocytes, displayed fewer granules and lighter nuclear staining with Aerospray. Diagnostic accuracy was unsatisfactory for classifying ATYPS (Se = 73%, Sp = 60%), IG (Se = 63%, Sp = 50%) and blasts (Se = 63%, Sp = 100%), whereas erythrocyte and platelet morphology were unaffected.

Conclusions: Aerospray Hematology PRO is suitable for mature WBC populations. However, manual MGG staining remains necessary for reliable evaluation of immature and pathological cells.

Introduction: This study established laboratory and trimester specific indirect reference intervals (RIs) for thyroid stimulating hormone (TSH).

Materials and methods: A retrospective observational study was performed at a tertiary-care laboratory's hospital during 12 months. Between February 2023 and February 2024, TSH results from 2166 women in their first trimester of pregnancy were retrieved. Only outpatients coming from primary care were included in the study. After applying exclusion and outlier criteria, TSH results from 1300 patients were analyzed to establish new RIs using the 2.5th and 97.5th percentiles by the non-parametric percentile method. These RIs were verified by an indirect method analyzing 486 TSH results from a cohort of pregnant women that were extracted from April to June 2024, and a direct prospective study of 28 pregnant women from a primary care center. All TSH tests were measured using a Cobas 8000 e801 system (Roche, Basel, Switzerland).

Results: The TSH RIs were 0.60-4.33 mIU/L. Both verification methods met the requirements of the CLSI guidelines.

Conclusions: The indirect method could be used to establish and verify local RIs for TSH in first trimester pregnant women. This may reduce misclassification of pregnant women undergoing thyroid function tests.

Introduction: Glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) are increasingly used biomarkers in the evaluation of mild traumatic brain injury (mTBI), primarily to reduce the frequent overuse of head computed tomography (head CT). However, their specificity may be compromised by orthopedic trauma, which commonly accompanies mTBI. The aim of this study was to assess whether orthopedic trauma is associated with higher serum concentrations of GFAP and UCH-L1 in CT-negative mTBI patients, thereby potentially reducing their specificity for detecting CT-positive mTBI.

Materials and methods: This prospective observational study included 67 CT-negative mTBI patients, of whom 29 (0.43) had orthopedic trauma and 38 (0.57) had none. Blood samples were obtained within 12 hours of injury and serum concentrations of GFAP and UCH-L1 were measured using a chemiluminescent microparticle immunoassay (CMIA) on the Alinity analyzer, following the manufacturer's instructions. Statistical analysis included Mann-Whitney U test, chi-square test, Kruskal-Wallis test, post-hoc Dunn's test and logistic regression analysis with P < 0.05 considered significant.

Results: Serum GFAP concentrations were significantly higher in patients with orthopedic injuries (median (IQR): 70.0 (30.8 to 226.5) pg/mL) than in those without (24.95 (5.52 to 49.15) pg/mL; P < 0.001). Similarly, UCH-L1 concentrations were higher in the orthopedic injury group (median (IQR): 2494.3 (670.1 to 5708.1) pg/mL) compared with those without trauma (262.8 (153.8-595.3) pg/mL; P < 0.001).

Conclusions: Orthopedic trauma is associated with higher serum concentrations of GFAP and UCH-L1 in CT-negative mTBI patients, which may reduce the specificity of these biomarkers for ruling out intracranial injury.

Introduction: Prostate-specific antigen (PSA) can circulate bound to extracellular vesicles (EVs) and its measurement (ev-PSA) can be useful in prostate cancer. Although not designed with that purpose, total PSA assays react with ev-PSA. We evaluated the analytical performance of several total PSA assays in ev-PSA quantification and the impact of ev-PSA on total PSA measurement.

Materials and methods: Extracellular vesicles were isolated from 83 serum samples from prostate cancer patients by size exclusion chromatography or ultracentrifugation. PSA was quantified in serum, EVs, International Standard for PSA 17/100 from the World Health Organization (WHO IS 17/100) and exosomes from lymph node carcinoma of the prostate (LNCaP) cell line, using commercial immunoassays (Elecsys, Atellica, Immulite, Liaison and Kryptor).

Results: Nanoparticle tracking analysis showed that the WHO IS 17/100 contains significantly less EVs than serum (P < 0.001). The sensitivity to detect ev-PSA followed this order: Elecsys ~ Atellica > Immulite > Liaison > Kryptor. Ev-PSA could be detected in all serum samples with Elecsys and Atellica, but not with Immulite (87.8%), Liaison (58.5%) or Kryptor (48.8%). Bland-Altman analysis showed a proportional bias in ev-PSA quantification between Elecsys and other methods. Addition of ev-PSA to serum samples caused a proportional bias in PSA measurement between Elecsys and Immulite methods, with a relationship (r² = 0.99; P < 0.001) between ev-PSA and the difference in total PSA concentration between both methods.

Conclusions: While ev-PSA can be measured using commercial kits, notable differences exist between methods, which could lead to potential discrepancies in serum total PSA results across various assays.

Introduction: Lipoprotein(a) (Lp(a)) is an independent cardiovascular risk factor, primarily determined by genetic factors. This study assessed Lp(a) concentrations in presumably healthy subjects and evaluated its association with age, sex, and cardiometabolic risk factors.

Materials and methods: The study included presumably healthy 1046 adults and 276 children. Laboratory parameters: lipid profile, Lp(a), apolipoprotein B (apoB), glucose, HbA1c, C-reactive protein and creatinine were measured. Contributions of Lp(a)-apoB to apoB (%Lp(a)/apoB) and of Lp(a)-cholesterol to LDL-cholesterol (%Lp(a)-C/LDL-C) were calculated.

Results: Lipoprotein(a) concentrations were significantly higher in adults than in children (P = 0.014) and in women than in girls (P = 0.003), but showed no overall sex differences. In women, Lp(a) was higher after age 50, while in men a slight rise occurred after age 60. Lipid indices %Lp(a)/apoB and %Lp(a)-C/LDL-C declined in men until their 40s and was higher after 50 in both sexes. In a multivariable logistic regression model increased LDL-C concentration was a significant predictor of Lp(a) ≥ 0.30 g/L in women (odds ratio, OR = 1.77; P = 0.021) and children (OR = 2.83; P = 0.009). Boys had twofold higher probability of Lp(a) ≥ 0.30 g/L than girls (OR = 2.17; P = 0.024).

Conclusions: Lipoprotein(a) concentrations increase with age, especially after 50 in women and 60 in men, and are significantly associated with LDL-C. Rising %Lp(a)/apoB and %Lp(a)-C/LDL-C alongside falling apoB and LDL-C suggest greater atherogenicity in older individuals, particularly men. These findings support including Lp(a) in lipid profile for better cardiovascular risk assessment.

Introduction: Many clinical laboratories rely on manufacturer-provided reference intervals (RIs) because of logistical and financial constraints of direct RI estimation. Indirect estimation methods offer a practical alternative for deriving RIs from laboratory data. This study aimed to estimate RIs for eight serum enzymes using the R-based algorithm reflimR, and to compare them with refineR, manufacturer's instructions for use (IFU), and direct methods.

Materials and methods: Data from adult outpatients tested between January 2021 and May 2022 were retrospectively analyzed for alkaline phosphatase (ALP), alanine aminotransferase (ALT), amylase, aspartate aminotransferase (AST), creatine kinase (CK), gamma-glutamyl transferase (GGT), lactate dehydrogenase and lipase. Reference intervals were estimated using reflimR and refineR, and compared with IFU and direct RIs. Overlap between lower and upper limits was evaluated using a color-coded scheme. Data distribution was tested with Shapiro-Wilk; and Mann-Whitney U and Spearman's correlation tests were used for group comparisons and correlations.

Results: Sex-specific RIs were required for ALP, ALT, AST, CK and GGT. ReflimR generally produced wider intervals than refineR. Agreement of reflimR with refineR, parametric, and IFU-based RIs was 88.5%, 72.7%, and 62.5%, respectively. The lowest agreement was observed with the non-parametric method (55.0%).

Conclusions: ReflimR provides a practical approach for indirect RIs estimation from routine data. Its performance was comparable to refineR and parametric methods, supporting its use for verifying or updating local RIs, especially where population-specific RIs are unavailable. To our knowledge, this is the first study to apply reflimR to the Turkish population and directly compare its performance with refineR and IFUs.

Effect size measures are important complements to P values, providing information about the magnitude and practical relevance of research findings. While widely discussed in the context of parametric tests, effect size estimation for nonparametric tests remains less explored. This article reviews standardized effect size measures applicable to four common nonparametric tests: Mann-Whitney, Wilcoxon signed-rank, Kruskal-Wallis, and Friedman. Commonly suggested classifications for these effect sizes are also discussed. This article aims to support researchers in reporting and interpreting effect sizes more effectively in nonparametric contexts.