Laboratory medicine最新文献

Introduction: Thyroglobulin levels in washout fluids from fine needle aspiration (FNA) biopsies of suspicious thyroid lesions is a well-established tool in diagnosis and follow-up of both papillary and follicular thyroid cancer. Despite the importance of this procedure, there is no standardization of the analytical process. We sought to validate an ultrasensitive thyroglobulin immunoassay not formulated for FNA washout fluids and to assess thyroglobulin stability based on matrix, storage temperature, and elapsed time before analysis.

Methods: Repeatability, limit of blank, limit of detection, and limit of quantification of thyroglobulin in 3 different matrices (kit diluent, serum free, and saline) were determined. Each sample was diluted and assayed immediately or after 14 or 21 days at ‒20 °C.

Results: Low coefficients of variation (s/x¯) × 100 were obtained, while limit-of-detection values for kit diluent and serum-free matrices resulted in values comparable to those reported for serum. Similar values of thyroglobulin were obtained in whole samples tested immediately or after 14 or 21 days of storage.

Conclusions: Analytical validation of the ultrasensitive immunoassay for FNA samples was obtained for 3 matrices; matrix features and sample storage at ‒20 °C do not affect the reliability of thyroglobulin measurements. Use of a protein matrix is recommended for possible presence of samples with low analyte values.

Introduction: Extracellular vesicles (EVs) are emerging as biomarkers with diagnostic potential for tumors, yet EV isolation from plasma remains challenging. In this study, the efficacy of EXODUS for isolating EVs from plasma was evaluated, and the association of these EVs with clinical parameters in patients with glioma and pulmonary tumors were explored.

Methods: Plasma EVs were isolated from 19 patients with glioma, 25 patients with pulmonary tumors, and 16 healthy control individuals using EXODUS. Briefly, EVs were analyzed and confirmed by nanoparticle tracking analysis, transmission electron microscopy, and Western blotting (CD9/Flotillin-1/Alix). In addition, the associations between plasma EVs and clinical measurements, such as biochemical, hematologic, and inflammatory indicators, were examined by Pearson or Spearman tests.

Results: EXODUS was used to isolate EVs of comparable sizes (30-150 nm) across groups from 400 µL plasma. Extracellular vesicle concentrations were much higher in plasma from patients with gliomas and pulmonary tumors than in healthy control samples. The EV protein levels followed similar trends. Plasma EV concentrations strongly correlated with triglyceride levels in patients with gliomas, whereas EV protein levels were negatively correlated with albumin levels in pulmonary tumor/healthy control samples. Compared with blood-based inflammatory markers, EV proteins demonstrated superior diagnostic performance.

Discussion: Our results show that EXODUS is an effective method for isolating EVs from plasma. In this pilot study, an initial investigation of plasma EVs was performed as an auxiliary indicator in cancers for potential clinical application. Plasma EVs with sufficient yield and purity will pave the way for further functional analyses, including proteomics.

Introduction: We sought to identify independent risk factors for stroke in patients with hypercholesterolemia and develop a clinically applicable risk prediction nomogram using a nationally representative dataset.

Methods: Data from 1259 participants with hypercholesterolemia from the US National Health and Nutrition Examination Survey 2017 to 2018 and 2019 to March 2020 were analyzed. Participants were randomly assigned into training and validation sets in a 7:3 ratio (training set, n = 881; validation set, n = 378). Least absolute shrinkage and selection operator regression combined with multivariate logistic regression were employed to identify independent predictors and construct a nomogram model. The model was validated through receiver operating characteristic curve analysis, calibration curves, and decision curve analysis.

Results: Four independent predictors were identified: age, total cholesterol level, serum urea nitrogen level, and white blood cell count. The nomogram demonstrated excellent discriminatory capability, with areas under the curve of 0.811 (95% CI, 0.769-0.853) and 0.835 (95% CI, 0.765-0.902) in the training and validation sets, respectively. Calibration curves revealed high concordance between predicted probabilities and observed outcomes. Decision curve analysis confirmed substantial clinical utility across practical threshold probability ranges.

Discussion: We developed a novel nomogram for stroke risk prediction in patients with hypercholesterolemia that demonstrates robust performance and may facilitate personalized risk stratification and intervention strategies in clinical practice.

The American Society for Clinical Pathology Board of Certification's Research and Development Committee launched a survey to collect data on the Medical Laboratory Technician (MLT) education programs. The survey included MLT program directors, educators, administrators, faculty, and other program-related individuals in university and college programs. The survey gathered information to support MLT program directors and faculty in educating students, especially to clarify current issues and reveal trends that may affect future program resources and the quality of MLT education. Topics in the surveys included demographics; educational level and rank; certification patterns; experience; responsibilities; salaries; retirement; and program-specific areas such as minimum grade point averages (overall and in science) for admission, vacancies, capacity, and clinical sites.

Introduction: Laboratory reference ranges and phlebotomy guidelines are derived from ambulatory individuals, whose values reflect reduced plasma volume from hydrostatic pressure shifts. These conditions may not represent intensive care unit (ICU) patients, who remain supine for extended periods. This study evaluated the impact of posture on routine hematologic and biochemical laboratory tests in ICU patients.

Methods: A prospective, single-center study with a within-subject design enrolled adult, hemodynamically stable ICU patients. Blood samples were collected first in supine patients and again after 15 minutes in upright patients. Paired specimens were compared for differences in routine hematologic and biochemical test values.

Results: Forty-four patients, with a mean (SD) age of 65 (14) years, were included. Statistically significant posture-related differences were observed in red and white blood cell counts, hemoglobin, hematocrit, potassium, carbon dioxide, anion gap, albumin, alkaline phosphatase, and total bilirubin (P ≤ .05). Correlation analyses showed associations between atherosclerosis and white blood cell count, antibiotic use, and hematocrit; liver disease or sepsis was associated with red blood cell distribution width. Potassium levels were correlated with cardiovascular disease, glucose with trauma, and total protein with intracranial hemorrhage.

Discussion: Upright positioning for 15 minutes improves the accuracy of routine laboratory testing in ICU patients and should be considered in phlebotomy protocols.

Introduction: Vitamin D receptor (VDR) variations have attracted attention because of their potential impact on metabolic regulation and liver health. This study aimed to investigate the association between VDR polymorphisms and clinical parameters as well as the risk of metabolic dysfunction-associated steatotic liver disease (MASLD; formerly nonalcoholic fatty liver disease) in a Turkish population.

Methods: The study included 390 participants: 200 patients with MASLD and 190 healthy control individuals. VDR rs1544410, rs2228570, and rs731236 variations were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method.

Results: There was no statistically significant difference in the overall genotype distribution of VDR variants between patients and control individuals. The rs1544410 AA and AG genotypes were associated with higher triglyceride levels. The rs2228570 CT genotype was associated with increased hypertriglyceridemia and hypertension, whereas the CC genotype was more frequent in patients with microvascular complications. The rs731236 CC and CT genotypes were also associated with a higher risk of hypertriglyceridemia.

Discussion: Our study revealed that the VDR rs1544410, VDR rs2228570, and VDR rs731236 variations substantially modulate the risk of hypertriglyceridemia, hypertension, and microvascular complications in MASLD.

Introduction: Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is a disease characterized by positive lupus anticoagulant and decreased prothrombin (plasma coagulation factor II). The primary LAHPS symptom is varying degrees of bleeding. LAHPS is rare, and at present there are no clear recommendations for its management. Some patients with this disease have atypical clinical manifestations that are easily confused with other diseases, resulting in misdiagnosis.

Methods: We report a case of LAHPS in a male child who initially presented with recurrent epistaxis and past history of ecchymosis. Prothrombin and activated partial thromboplastin times were prolonged, plasma coagulation factor II activity was decreased, and lupus anticoagulant was positive. Subsequently, secondary eyeball bleeding, lumbar pain, fever, and other symptoms occurred.

Results: Ultimately, a diagnosis of SLE was made based on his autoantibody results and other tests. Following the administration of methylprednisolone, blood coagulation gradually improved, and no further bleeding was observed.

Discussion: In this report, plasma-mixing studies demonstrated inhibitory and co-factor effects, providing a basis for the disease's subsequent diagnosis and treatment in this patient. This case highlights the laboratory test results analyzed and the reference values for clinical diagnosis and treatment.

Introduction: Toxicologists defend alcohol testing from their laboratories for medicolegal cases.

Methods: A 22-year-old woman drank 144.1 g of alcohol over 8.25 hours at work. Precise details of her drinking (time, volume, and alcohol content) were provided. At her shift's end, her supervisor allowed her to drive home, during which time she caused the death of another driver. Her blood alcohol concentration (BAC) was 2.20 g/L, tested a few hours later. She did not drink alcohol after her work discharge. The decedent's family sued her employer for failure to recognize intoxication. An expert was engaged to perform both theoretical and retrograde BAC estimates based on consumption and the reported BAC, respectively.

Results: Blood alcohol concentration calculations require use of the volume of distribution and the alcohol metabolism rate. The Academy Standards Board recommends reporting a range of BAC calculations. The theoretical and retrograde calculations in this case largely matched each other, suggesting that the driver did not drink after work. Due to the long interval between alcohol intake and her work dismissal, the theoretical calculation produced a wide BAC range (1.4-4.6 g/L). The retrograde calculation range was tighter (2.6-3.1 g/L).

Discussion: A prolonged duration between drinking and testing produces a range of BAC results that can cause ambiguities in legal proceedings.

Machine learning-based solutions to laboratory medicine problems have become commonplace in literature, but real-world implementations remain rare, in no small part because of the substantial investment required to incorporate such solutions into routine clinical care. A crucial step in advancing a machine learning solution from proof of concept into clinical application is a robust and comprehensive evaluation of its performance. In this review, we discuss the common methods, best practices, and potential pitfalls in evaluating machine learning-based solutions to clinical laboratory problems.

Introduction: Diamond-Blackfan anemia (DBA) is a rare disease characterized by macrocytic anemia and congenital malformations.

Methods: We present a familial case of DBA caused by a novel variant in the RPL11 gene. The proband was an 11-month-old Korean boy with macrocytic anemia and erythroid hypoplasia in bone marrow. He had a cleft palate and congenital heart defects.

Results: Massively parallel sequencing analysis identified a novel heterozygous variant, NM_000975.3(RPL11):c.157+1G>C. Laboratory investigation revealed that the father carried the same variant.

Discussion: This report expands our understanding of the intrafamilial variability of DBA. It also highlights the importance of massively parallel sequencing in pediatric patients with anemia.