Journal of Applied Laboratory Medicine最新文献

Background: Most studies found that apolipoprotein B (apo B)-100 is a superior marker for coronary risk to non-high-density lipoprotein (HDL) cholesterol (C). Usually, studies use multivariant analysis with single-point odds/risk ratios. In multivariant analysis, when variables are highly correlated they are difficult to interpret. Effects cannot be well discriminated.

Methods: Brief review and examination of diagnostic sensitivity and specificity by receiver operator characteristic (ROC) curves at decision levels so that discrimination can be well compared. Since apo B has additional expense, clinical value should be compared in an appropriate format. Apo B and cholesterols were measured in 382 angiographically defined patients.

Results: Non-HDLC and apo B were stronger markers than low-density lipoprotein (LDL)C, when examined by logistic regression, but as a result of strong collinearity, non-HDLC appeared weaker than LDLC in the presence of apo B, based on P values. This was true when analyzed with and without nonlipid risk factors. On ROC analysis, apo B and non-HDLC showed stronger C statistics than LDLC and total C. When analyzed alone apo B showed about 6.1% greater sensitivity than non-HDLC. After adjustment for nonlipid risk factors, the C statistics for apo B and non-HDLC were 0.74 and 0.73, and there was little difference in diagnostic specificity.

Conclusions: Risk is calculated from an algorithm that includes nonlipid risk factors similar to those examined here along with cholesterols. When assessed by the 10-year screening algorithm, these data support the view that non-HDLC would be less expensive than apo B with similar clinical efficacy.

Background: While the real-world impact of estimated glomerular filtration rate (eGFR) equation change on clinical outcome in a longitudinal cohort setting is limited, external valuation of equation performance should be performed in different population cohorts. This study aimed to compare differential impacts of eGFR values, calculated by 5 equations in a Korean patient population, on clinical outcomes.

Methods: This retrospective longitudinal follow-up cohort study analyzed 23 246 participants with standardized creatinine/cystatin C assay-based laboratory results. The primary exposure was baseline eGFR calculated by 5 different equations including the recently developed 2021 race-free Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Clinical outcomes including all-cause mortality, renal replacement therapy, and albuminuria were analyzed to estimate the hazard ratio of the eGFR on clinical outcomes.

Results: Among the 5 equations, CKD-EPI 2021 with creatinine and cystatin C (CKD-EPI 2021-CrCys) showed an earlier increase in hazard ratios for all clinical outcomes, while CKD-EPI 2012 with cystatin C showed a higher hazard ratio for all-cause mortality at low eGFR. Replacing CKD-EPI 2012 with CKD-EPI 2021-CrCys, 5.4% of patients with mortality and 3.3% of patients who received renal replacement therapy were reclassified to a lower risk stage.

Conclusions: The 2021 CKD-EPI equations were acceptable in a Korean population, with better predictive power for clinical outcomes when compared to previous equations. The updated race-free factors for eGFR calculation improved identification of patients at risk for clinical outcomes.

Elevated human chorionic gonadotropin (hCG) of unknown etiology is often a diagnostic dilemma. Determination of its source is vital in order to provide proper medical treatment and prevent possible unneeded therapeutic interventions. The differential diagnosis for elevated hCG is broad and includes pregnancy, chronic kidney disease, heterophile antibody, macro-hCG, exogenous hCG administration, pituitary secretion, tumor-associated secretion, etc. One entity that is emerging in the published literature as a cause of elevated hCG is familial hCG syndrome. This syndrome is characterized by persistently elevated concentrations from a yet to be determined source in individuals of the same family. In this special report, we review a recently published case of elevated hCG in a 56-year-old male proposed to be due to familial hCG syndrome. We discuss why we feel the presented case is not consistent with familial hCG syndrome and explore other possible explanations for the patient's elevated hCG concentrations.

Background: Procalcitonin (PCT) measurement is useful for guiding antibiotic therapy and risk assessment in lower respiratory infections and/or sepsis. This study evaluated clinical and analytical performance of the Vitros® Immunodiagnostic Products B·R·A·H·M·S PCT assay (Vitros PCT).

Methods: Precision, limits of blank (LoB), detection (LoD), and quantitation (LoQ) were determined for Vitros PCT, along with method comparison and clinical concordance with the B·R·A·H·M·S PCT™-sensitive KRYPTOR™ assay (KRYPTOR PCT). All-cause 28-day mortality was evaluated according to the change in PCT values (ΔPCT) from day 0 through day 4 in samples from 598 intensive care unit patients with sepsis.

Results: Comparison of Vitros PCT and KRYPTOR PCT results yielded a Deming regression slope of 1.057, intercept of -0.010, and correlation coefficient (r) of 0.994. Precision analysis demonstrated within-laboratory coefficients of variation for Vitros PCT ranging from 3.1% to 6.4%. The LoD and observed LoQ were determined as 0.007 and 0.013 ng/mL, respectively. Overall agreement between assay methods was 98.5%, 98.0%, 97.4%, and 97.8%, at PCT clinical decision cutoffs of 0.100, 0.250, 0.500, and 2.00 ng/mL, respectively, with Cohen's Kappa coefficients (κ) > 0.91. ΔPCT values ≤80% vs >80% were associated with increased 28-day-all-cause mortality (P = 0.006).

Conclusions: Vitros PCT compares well with KRYPTOR PCT, showing excellent agreement at relevant clinical decision cutoffs that have been used for antibiotic decision-making and assessment of risk for sepsis progression. ΔPCT values determined with Vitros PCT were useful for evaluation of 28-day mortality risk in patients with severe sepsis.

Background: Analytical criteria for laboratory analysis based on biological variation are considered state-of-the-art. While biological variance should ideally be measured in patient populations for whom the tests are relevant, data are mostly only available from healthy individuals. We determined the biological variance of activated partial thromboplasmin time (APTT), prothrombin time (PT), fibrinogen, and trough dabigatran levels in patients with atrial fibrillation (AF) who were treated with dabigatran.

Methods: Between 2019 and 2022, patients with AF treated >3 months with dabigatran were included. Blood was collected monthly up to 10 times for the measurement of APTT, PT, fibrinogen, and trough dabigatran levels. Between-subject variance (CVG), within-subject variance (CVI), and analytical variance (CVA) were calculated.

Results: Eighteen participants (median age 65.8 years, 22.2% women) were included, with 130 samples in total. For APTT, the CVG was 11.5%, the CVI 8.8%, and the CVA 1.1%. For PT, these values were 5.2%, 4.0%, and 1.0% and for fibrinogen 13.6%, 11.8%, and 1.6%, respectively. For the dabigatran levels, the percentages were 37.9%, 33.0%, and 3.4%, respectively.

Conclusions: We assessed the biological variance of APTT, PT, fibrinogen, and dabigatran in a patient population with long-term dabigatran use. The analytical performances of coagulation laboratory tests in patients with AF treated with dabigatran were comparable to those in healthy volunteers.CCMO Registration Number: NL67304.078.18.

Background: Clinician-ordered peripheral smear review by pathologist (CPSR) is commonly ordered and has been recommended for decades. However, the clinical utility of this labor-intensive test in the reference laboratory has not been examined. The objective of this study is to assess hematologic abnormalities identified in CPSR orders and to correlate them with complete blood count (CBC) and laboratory-derived smear review (LDSR) in the reference laboratory.

Methods: Two hundred consecutive CPSRs with corresponding CBCs from April 2023 were run by Sysmex® XN-11 analyzers, and their peripheral smears were examined by a board-certified hematopathologist. Hematologic abnormalities of CPSRs were assessed, and the correlation between CPSR and CBC/LDSR was reviewed.

Results: Nearly one-third of CPSRs (29%) had normal peripheral smears and CBCs. The majority of CPSRs showed nonspecific quantitative abnormalities. When compared against CPSR results, LDSR criteria identified 100% of hematologic abnormalities appropriately. Samples that were not flagged for review by LDSR rules were also reviewed (n = 174) to rule out clinically meaningful false negatives. One minor discrepancy (0.6% of cases) of small platelet aggregates was observed in a patient with a reported platelet count of 139 K/uL that was missed by the LDSR process.

Conclusions: In the reference laboratory setting, our findings demonstrate that LDSR adequately detects significant hematologic abnormalities and, therefore, CPSR should be discontinued.

Background: Laboratory medicine has and continues to undergo significant transformation. This paper reviews top trends associated with laboratory medicine using insights, evidence, and outcomes derived from the UNIVANTS of Healthcare ExcellenceTM award program.

Methods: Seventy-two judge-approved best practices of measurably better healthcare were assessed for trends and insights related to outcomes and opportunities for highlighting the value of laboratory medicine.

Results: Ten industry-relevant and insightful takeaways are identified that span stakeholders and key performance indicators.

Conclusion: With evidence that spans 5 years, the findings not only substantiate the critical value of laboratory medicine, but reveal trends associated with award-winning teams, proven integrated clinical care initiatives, and the measurement of their associated outcomes.