Laboratory medicine最新文献

Objective: To compare platelet count results of specimens that yield platelet clump flags to platelet count results on these specimens after vortexing.

Method: Specimens that generated platelet count flags on Sysmex XN 3000 instruments were vortexed and rerun. Only data from specimens demonstrating elimination of platelet clump flags were used in this study. Pearson r analysis was performed on data.

Results: Comparison of complete blood count results (white blood cell count, red blood cell count, hemoglobin, hematocrit, and platelet count) all yielded Pearson r scores >0.9.

Conclusion: Additional patient comfort and safety concerns, as well as concerns over additional specimen collection and processing costs, may be avoided by vortexing and rerunning specimens flagged for platelet clumps when the platelet count is normal.

We present 3 cases of discordant results from screening hemoglobin A1c (HbA1c) measured by ion-exchange high-performance liquid chromatography (HPLC) all due to various forms of interference and flagged by the instrument as "suspected hemoglobin E (HbE)." The first case was due to a rare hemoglobin variant, later confirmed to be hemoglobin Hoshida, the second due to "true" heterozygous HbE, and the third a result of analytical artifact causing splitting of the HbA1c peak without an underlying variant hemoglobin. We examine the similarities in these cases along with the laboratory work-up to classify each cause of interference to demonstrate the wide array of potential causes for the suspected HbE flag and why it warrants proper work-up. Because there is no standardized method of reporting out hemoglobin variant interference in HbA1c measurement, we discuss our laboratory's process of investigating discordant HbA1c measurements and reporting results in cases with variant interference as 1 possible model to follow, along with discussing the associated laboratory, ethical, and clinical considerations. We also examine the structure of hemoglobin Hoshida, HbE, and conduct a brief literature review of previous reports.

Objective: To assess the diagnostic value of urinary transferrin (Tf) in early diabetic nephropathy (DN) to propose a more sensitive and noninvasive biomarker for screening and monitoring DN in clinical practice.

Methods: We searched 3 databases from their inception to May 2023, to identify studies investigating the diagnostic value of Tf in patients with DN. Meta-DiSc software, version 1.4, and Stata software, version 15.1 (StataCorp) were used to conduct a meta-analysis and evaluate the diagnostic accuracy of urine Tf levels for DN.

Results: The meta-analysis included 6 relevant studies investigating the diagnostic value of Tf level for DN. Urinary Tf as a diagnostic marker demonstrated a combined sensitivity of 0.82 (95% CI, 0.71-0.89) and specificity of 0.88 (0.84-0.92). the positive diagnostic likelihood ratio was 7.07 (4.57-10.93), the negative diagnostic likelihood ratio was 0.20 (0.12-0.35), and the diagnostic odds ratio was 34.49 (13.61-87.44). Also, the area under the receiver operating characteristic curve was 0.92 (0.89-0.94), indicating that urinary Tf has a decent discriminative ability in diagnosing DN.

Conclusion: Tf level is a valuable biological marker for early diagnosis and monitoring of DN in clinical practice. It has statistically significant predictive value for patients in the early phases of DN.

Background: A substantial number of patients with multiple myeloma (MM) who have bone destruction are initially admitted into the orthopedic service at the hospital. However, routine laboratory testing usually fails to identify these patients, thus delaying optimal therapy. Therefore, there is a clear medical need for early diagnosis of MM in these patients.

Methods: Between 2019 and 2021, 42 patients receiving treatment for orthopedic conditions had normal hemoglobin (Hb), total protein (TP), albumin (ALB), creatinine (CREA), and blood calcium (Ca) levels before their surgical procedure(s) but were subsequently pathologically confirmed to have MM, based on their presenting orthopedic symptoms. During the same period, 52 patients with orthopedic conditions were pathologically excluded from the diagnosis of MM and were recruited into our control group. Serum free light chain (sFLC) testing was performed in 94 consecutive patients in the orthopedic service using Siemens N Latex FLC kits. The levels of Hb, TP, ALB, CREA, and Ca were also measured. All 42 patients with MM were divided into group A (n = 25: κ proliferation) and group B (n = 17: λ proliferation) by the pathology department.

Results: There were no significant differences in levels of Hb, TP, ALB, CREA, and Ca between group A and group B and the control group. However, the sFLC κ/λ ratio of group A and B was also significantly different from that of the control group (P < .001). The results of serum immunofixation electrophoresis (IFE) testing demonstrated negative results in 14 cases (58.3%) in group A and 4 cases (25.0%) in group B.

Conclusions: Some patients with orthopedic conditions who do not have typical MM laboratory results, such as those with abnormal Hb, TP, ALB, CREA, and Ca levels before their operation(s), actually have MM. MM should be highly suspected in patients with unexplained bone lesions and with an abnormal sFLC κ/λ ratio. Further tissue or bone marrow biopsy is needed in these patients even if serum and urine IFE results are negative and light chain ratio is normal.

Objective: Low-density lipoprotein cholesterol (LDL-C) has been commonly calculated by equations, but their performance has not been entirely satisfactory. This study aimed to develop a more accurate LDL-C prediction model using machine learning methods.

Methods: The study involved predicting directly measured LDL-C, using individual characteristics, lipid profiles, and other laboratory results as predictors. The models applied to predict LDL-C values were multiple regression, penalized regression, random forest, and XGBoost. Additionally, a novel 2-step prediction model was developed and introduced. The machine learning methods were evaluated against the Friedewald, Martin, and Sampson equations.

Results: The Friedewald, Martin, and Sampson equations had root mean squared error (RMSE) values of 12.112, 8.084, and 8.492, respectively, whereas the 2-step prediction model showed the highest accuracy, with an RMSE of 7.015. The LDL-C levels were also classified as a categorical variable according to the diagnostic criteria of the dyslipidemia treatment guideline, and concordance rates were calculated between the predictive values obtained from each method and the directly measured ones. The 2-step prediction model had the highest concordance rate (85.1%).

Conclusion: The machine learning method can calculate LDL-C more accurately than existing equations. The proposed 2-step prediction model, in particular, outperformed the other machine learning methods.

Background: Diagnostic accuracy of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) in identification of intracranial abnormalities detected by computed tomography (CT) in mild traumatic brain injury (mTBI), and in patients with mild neurological symptoms not caused by head trauma but suspected with a neurological disorder, was examined.

Methods: GFAP and UCH-L1 were determined using the chemiluminescence immunoassays on the Alinity i analyzer (Abbott Laboratories).

Results: Significantly higher GFAP (median 53.8 vs 25.7 ng/L, P < .001) and UCH-L1 (median 350.9 vs 153.9 ng/L, P < .001) were found in mTBI compared to non-head trauma patients. In mTBI diagnostic sensitivity (Se) and specificity (Sp) for the combination of GFAP and UCH-L1 were 100% and 30.9%, respectively, with area under the curve (AUC) 0.655. GFAP alone yielded Se 85.7%, Sp 41.8%, and AUC 0.638, while UCH-L1 yielded Se 57.1%, Sp 56.4%, and AUC 0.568. In non-head trauma patients, the combination of GFAP and UCH-L1 showed Se 100%, Sp 87.9%, and AUC 0.939, while GFAP alone demonstrated Se 100%, Sp 90.9%, and AUC 0.955.

Conclusions: If these results are reproduced on a larger sample, GFAP and UCH-L1 may reduce CT use in patients with mild neurological symptoms after systemic causes exclusion and neurologist's evaluation.

Background: Medical laboratory science (MLS) professionals play a crucial role in health care teams. However, research culture in the profession has not been well developed or studied. It is necessary to characterize attitudes toward research and scholarly activities among MLS professionals and identify ways to promote research in the profession.

Methods: A cross-sectional survey was administered through American Society for Clinical Laboratory Science channels. Survey responses were summarized using descriptive statistics, and linear regression models were constructed to identify characteristics that predicted 2 research attitudes: "valuing the role of research" and "perceived research environment" in the profession.

Results: Of the 116 MLS professionals in this study, 53% reported currently participating in research activities. Opinions toward research were generally positive, although many respondents were not currently conducting research. Individuals with education and research practice focuses tended to place greater value on research, and education level was a significant predictor of perceived research environment. Dedicated research time and mentorship were cited as effective ways for employers to promote research in MLS.

Conclusion: Overall, respondents had favorable attitudes toward research in MLS, but approximately half of participants noted a lack of incentives to conduct research. This study highlights several initiatives that may be effective for promoting increased research activity among MLS professionals.

Background: Plasma circular (circ)RNAs detected by droplet digital polymerase chain reaction (ddPCR) may be ideal markers for liquid biopsy. However, ddPCR detection of circRNAs in plasma for diagnosis of lung adenocarcinoma has been rarely reported.

Methods: An RNA sequencing analysis was performed in plasma from patients with early lung adenocarcinoma and healthy individuals. Droplet digital PCR was used to verify the differentially expressed genes.

Results: The copy numbers of circle RNALZIC (circLZIC)and circle RNACEP350 (circCEP350) in the plasma of lung adenocarcinoma patients were significantly higher than in plasma of healthy people, and the copy numbers in postoperative plasma of the same patients were significantly lower than those in preoperative plasma. CircLZIC and circCEP350 alone and in combination had diagnostic value in lung adenocarcinoma and early lung adenocarcinoma. CircLZIC and circCEP350 had more binding sites with multiple microRNAs. Their target genes were enriched in several signaling pathways.

Conclusion: The copy numbers of circLZIC and circCEP350 were higher in plasma of lung adenocarcinoma patients than in plasma of healthy controls, significantly correlated with tumor size and TNM stage, and closely related to the occurrence and development of tumors. These circRNAs may serve as molecular markers for the diagnosis of lung adenocarcinoma.

Background: Rejected samples lead to prolonged turnaround time and delayed diagnosis and treatment of patients. This study was conducted to determine minimum acceptable sample volume in Sarstedt brand coagulation tubes to reduce high sample rejection rate.

Methods: Blood samples were drawn from 20 participants (10 healthy volunteers and 10 patients receiving oral anticoagulant) into coagulation tubes. Six samples were taken from each participant, with tube fill volumes of 100%, 90%, 80%, 70%, 60%, and 50%. Prothrombin time (PT), active partial thromboplastin time (aPTT), and fibrinogen tests were analyzed.

Results: According to quality performance specifications, the tube fill volume must be at least 70% for PT and aPTT and 50% for fibrinogen. There was no statistical difference in samples from healthy volunteers for PT, aPTT, and fibrinogen tests when the minimum tube fill volume was at least 80%, 90%, and 50%, respectively. These percentages were 50%, 70%, and 60%, respectively, in patients receiving oral anticoagulant.

Conclusions: Sarstedt tubes meet quality standard specifications at a 70% fill rate for PT and aPTT and a 50% fill rate for fibrinogen. Comprehensive studies with larger populations are needed to accept these values as sample acceptance criteria for the laboratory.

Background: Biannual instrument-correlation studies are required for nonwaived assays performed on multiple instruments.

Objective: To determine the feasibility of using College of American Pathologists (CAP) Quality Cross Check-Chemistry and Therapeutic Drug Monitoring (CZQ) to assess instrument correlations among multiple analyzers, analyzer models, and Clinical Laboratory Improvement Amendments (CLIA) licenses for 55 unique analytes.

Methods: Instrument correlation studies were performed on 9 Abbott ARCHITECT instruments (c4000 [n = 4], c8000 [n = 2], and c16000 [n = 3]) over 3 CLIA licenses using CZQ materials. The mean (SD) values, concentration difference, percent bias, and peer data for each individual level of CZQ were determined for each individual analyzer. Acceptable concentration and percentage for each analyte were set using criteria from CAP or other reputable sources such as the American Association of Bioanalysts or the Royal College of Pathologists of Australasia. Peer data were provided by CAP with the CZQ kit.

Results: Correlations using CZQ materials showed that 94.5% of assays studied were within the acceptability criteria by percent bias only and 98.2% were within acceptability criteria by concentration difference.

Conclusions: The use of CZQ provides support to standardized correlation studies among instruments within and across separate CLIA licenses. However, widespread adoption of CZQ may be limited due to concerns regarding matrix effects, analyte ranges, and ease of data analysis.