Laboratory medicine最新文献

Objective: Identification of instrument failure (IF) represents a point to improve the quality of services provided by medical laboratories. Here, a logistic regression model was created to define the relationship between instrument downtime and laboratory quality management systems.

Methods: Interval-level quality control (QC) and categorical quality assurance data from 3 identical chemistry analyzers was utilized to generate a logistic regression model able to predict IF. A case-control approach and the forward stepwise likelihood-ratio method was used to develop the logistic regression model. The model was tested using a case-control dataset and again using the complete sample.

Results: A total of 650 downtime events were identified. A total of 22,880 QC data points, 187 calibrations, 24 proficiency testing events, and 107 maintenance records were analyzed. The regression model was able to correctly predict 59.2% of no instrument downtime events and 69.2% of instrument downtime events using the case-control data. Using the entire data set, the sensitivity of the model was 69.2% and the specificity was 58.2%.

Conclusion: A logistic regression model can predict instrument downtime nearly 70% of the time. This study acts as a proof of concept using a limited data set collected by the chemistry laboratory.

Objective: Lymphocyte phenotyping is a valuable tool for monitoring the effects of antiretroviral therapy on individuals living with HIV-1. A switch study was conducted to compare T-cell subset quantification performed by a research laboratory and a diagnostic, laboratory to understand the impact on the retrospective and prospective results of a long-term study.

Methods: Using FACSCanto II Flow Cytometers, EDTA anticoagulated peripheral blood from 73 males enrolled in the Multicenter AIDS Cohort Study/Women Interagency HIV Combined Cohort Study was analyzed by both a research (laboratory 1) and a diagnostics laboratory (laboratory 2) for quantification of cluster of differentiation (CD)3, CD4, and CD8 T-cells. There were 47 males living with and 26 living without HIV-1.

Results: Bland-Altman (B-A) analysis was applied to assess the agreement between laboratory 1 and laboratory 2 results. There were 69 out of 73 CD3, 71 out of 73CD4, and 72 out of 73 CD8 T-cell results that fell within acceptable B-A limits of agreement. The mean differences between the 2 laboratories were -1.000, -0.945, and +0.685(%), respectively.

Conclusion: The strong agreement between results from laboratory 1 and laboratory 2 for CD3, CD4, and CD8 T-cell percentage suggests that the difference between laboratories using the same instrumentation and methodology will have a minimal effect on long-term study results.

Objective: The aim of this study was to investigate the relationship between tumor microenvironment markers (myeloid-derived suppressor cells [MDSCs], regulatory T cells [Tregs], programmed cell death 1 [PD-1], and programmed death ligand 1 [PD-L1]) and chemotherapy efficacy and prognosis in advanced gastric cancer, identifying potential monitoring indicators.

Methods: Advanced gastric cancer patients' MDSC and Treg expression was measured by flow cytometry pre- and postchemotherapy; PD-1 and PD-L1 expression in cancer tissues was assessed by immunohistochemistry. Correlations with chemotherapy outcomes and prognosis were analyzed.

Results: Postchemotherapy reductions in MDSC and Treg levels correlated with chemotherapy efficacy (P <.01). Negative PD-1 and PD-L1 expression in cancer tissues predicted better chemotherapy responses (P <.01). Patients with lower MDSC and Treg levels and negative PD-1 and PD-L1 had significantly longer median progression-free survival (PFS) and overall survival (OS) (P <.05).

Conclusion: In advanced gastric cancer, reduced peripheral blood MDSC and Treg levels postchemotherapy and negative PD-1 and PD-L1 expression in tissues are associated with improved chemotherapy efficacy and are independent prognostic factors for PFS and OS.

Introduction: System-wide laboratory internal audits are useful to help laboratories prepare for external audits in addition to being part of the ongoing program for compliance improvement and quality assurance in the laboratory to track and enhance care quality.

Methods: A formal plan was developed and a modified audit checklist was prepared by our laboratory management team, applicable and uniquely tailored for our ambulatory care clinic settings to track operational, quality, and compliance metrics according to the New York State Department of Health Clinical Laboratory Evaluation Program. Two audits were conducted 6 months apart and the conformity documented.

Results: An overall 84% increase in compliance and conformity was observed between first and second audits, which ranged from 63% to 100% across different categories, with 100% improvement (0% nonconformity) in 75% of the sites in the second audit.

Conclusion: A system-wide laboratory internal audit was created and carried out. Staff shortages, rapid turnover, and lack of retraining were found to be contributing factors to sites that did not achieve 100% conformance. Continuous assessment and monitoring are key elements to success in the laboratory quality management system, and through this scheduled audit process, we were able to achieve continual laboratory quality improvement.

Background and aims: Preanalytical errors due to interferences can lead to inaccurate results, necessitating an understanding of potential interferences for each test. This study explores the impact of elevated concentrations of ascorbic acid and glucose on urine analysis, a pivotal diagnostic tool.

Methods: Conducted at the Clinical Institute of Chemistry, KBC Sestre milosrdnice, the research utilized a 24-hour urine sample. Parameters assessed included total proteins, albumin, amylase, sodium, potassium, chlorides, calcium, phosphates, magnesium, creatinine, urea, and uric acid. Various concentrations of added interferents were prepared for duplicate measurements using statistical analysis in Microsoft Excel.

Results: No statistically significant interferences were found in albumin, amylase, sodium, potassium, or phosphate concentrations. However, ascorbic acid interfered with chloride, calcium, and magnesium determinations. Conversely, elevated glucose affected total protein, calcium, magnesium, creatinine, urea, and uric acid determinations. Interference of ascorbic acid with chloride and interference of glucose with total proteins and uric acid displayed a linear relationship.

Conclusions: Results suggest cautious analysis interpretation from certain parameters in patients with elevated glucose and/or ascorbic acid in urine. Whereas ascorbic acid interference may go unnoticed due to its infrequent measurement, routine determination of glucose in urine is crucial, especially for diabetes patients.

Background: Meningiomas are the most common intracranial tumors and their diagnosis relies mostly on neuroimaging and histology. However, the histology grades cannot predict the outcome exactly and some meningiomas tend to recur after resection of even benign tumors. Therefore, it is necessary to explore prognostic and diagnostic molecular targets.

Methods: Differential expression analysis between meningiomas and meninges was performed based on the merged data of GSE43290 and GSE84263. Next, we performed gene set enrichment analysis (GSEA), immune cell infiltration analysis, protein-protein interaction analysis, and survival analysis using public data. The expression level of Synaptosome-associated-protein-25kDa (SNAP25) was verified by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting in meningioma tissues.

Results: There were 263 upregulated and 592 downregulated genes identified in meningiomas by differential expression analysis. GSEA results revealed that meningiomas were negatively related to the pathway of soluble N-ethylmaleimide sensitive factor attachment protein receptor interactions in vascular transport and chemokine signaling. SNAP25 was characterized as a hub gene and downregulated in meningiomas. The Kaplan-Meier plot indicated that high expression of SNAP25 is a favorable factor.

Conclusion: SNAP25 was downregulated and identified as a potential prognostic marker in meningioma.

Objective: We report a rare case of acute hemolytic reactions caused by immunoglobulin (Ig)M anti-M antibody and present a literature review.

Case report: A 61-year-old male patient who underwent blood transfusion developed fever, chills, soy sauce-colored urine, and changes in laboratory test results, including persistently decreased hemoglobin levels, neutrophilia, elevated lactate dehydrogenase level, acute kidney injury, mild acute liver injury, and activation of the coagulation system, indicating acute hemolytic transfusion reaction (AHTR). Antibody screening and major crossmatching results indicated weak positive at 37°C for both posttransfusion and pretransfusion sample. Subsequent serological examinations indicated the presence of IgM anti-M antibodies in plasma but the direct antiglobulin and elution tests were negative. Antibody hemolytic activity assay confirmed AHTR caused by anti-M. The transfused red blood cells were MM and the patient is NN. These signs and symptoms disappeared rapidly and required no additional interventions before discharge.

Conclusion: The accurate diagnosis of anti-M antibody-mediated acute hemolysis is essential for guiding treatment decisions.

Background: Interferences on chemistry and immunoassay results due to paraproteinemia may lead to erroneous diagnoses and treatment. Such interferences are difficult to recognize and even more difficult to deal with. This report describes 1 such case where multiple measurands were affected and how the interferant was overcome.

Case report: Paraproteins present in an immunoglobulin (Ig)G-lambda multiple myeloma specimen interfered with results of total bilirubin, direct bilirubin, inorganic phosphate, iron, ferritin, and total thyroxine measured on 3 platforms: AU5800, Alinity ci, and cobas pure. Repeat testing upon dilution with normal saline or deproteinization by polyethylene glycol precipitation gave unsatisfactory results on some or all the affected measurands. Repeat testing after dilution of the interferant serum with a healthy serum corrected the anomalous results for all the affected measurands.

Conclusion: Dilution of paraproteinemic serum with a healthy serum of known concentrations appears to be the most suitable method to negate the effects of paraproteinemic interferences.

Objective: This study aimed to investigate the utility of neutrophil-related cell population data obtained by automated hematology analyzers in assessing myelodysplastic syndrome cases with decreased granules in neutrophils.

Methods: A total of 108 subjects were classified into normal granule (n = 35), hypogranulation (n = 37), or hypergranulation (n = 36) groups. Neutrophil cell area and granule area were measured by ImageJ. All samples were analyzed on the XR-1000 and UniCel DxH 800, and neutrophil-related parameters were compared among the 3 groups.

Results: Neutrophil cell area and the ratio of the granular area showed significant differences among the 3 groups; they were the highest in the hypergranulation group and lowest in the hypogranulation group. XR-1000 data showed significant differences in NE-SFL and NE-FSC among the 3 groups (P < .0001). NE-SFL and NE-FSC discriminated most accurately hypogranulation group against other groups. UniCel DxH 800 data showed significant differences in MN-V-NE, MN-MALS-N, MN-UMALS-NE, SD-UMALS-NE (P <.01), MN-LMALS-NE, and SD-LMALS-NE (P <.05) among the 3 groups. The combination of SD-V-NE and SD-LMALS-NE discriminated most accurately the hypogranulation group against the other groups.

Conclusion: NE-SFL and NE-FSC and the combination of SD-V-NE and SD-LMALS-NE are useful in detecting cases with decreased granules in neutrophils.