LabMed, Volume 2, Issue 4 (December 2025) – 10 articles

Antibiotic susceptibility testing (AST) reports classify isolates as “susceptible” despite potential undetected resistant subpopulations—a phenomenon termed susceptibility heterogeneity (SH). Found in 15–97% of clinical isolates of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, SH arises from heteroresistance or polyclonal diversity and may evade standard low-inoculum protocols. Clinically, this can lead to treatment failure, particularly in high-risk cases including immunocompromised patients, bloodstream infections, transplant recipients, and situations where minor resistant subpopulations significantly affect outcome. We argue that ethical principles of non-maleficence, transparency, and equity now compel laboratories to acknowledge this limitation. A simple annotation—“Limited susceptibility possible; resistant subpopulations may not be detected”—should accompany “susceptible” results in immunocompromised patients. High-risk cases warrant enhanced testing. This commentary calls for zone inspection, staff training, and Clinical and Laboratory Standards Institute (CLSI)/European Committee on Antimicrobial Susceptibility Testing (EUCAST) guideline updates to reflect SH. Transparency enhances clinical decision-making without implying diagnostic fault. Full article

Alpha-fetoprotein (AFP) is a biomarker commonly used in the diagnosis of various malignancies but may also be elevated in non-neoplastic conditions, including hypothyroidism. We report the case of a 3-year-old girl with Down syndrome (DS) and newly diagnosed hypothyroidism, who presented with a hypoechoic oval lesion adjacent to the thymic parenchyma on ultrasound and markedly elevated AFP levels (169.2 ng/mL). Further investigations, including MRI, excluded the presence of germ cell tumors. Following initiation of levothyroxine therapy, AFP levels normalized in parallel with thyroid function. No evidence of malignancy was detected despite the initial suspicion. This case underscores the association between elevated AFP and hypothyroidism, highlighting the importance of evaluating thyroid status in patients with increased AFP to avoid unnecessary oncological investigations. In particular, elevated AFP in the context of hypothyroidism and DS warrants careful thyroid assessment and follow-up to prevent redundant diagnostic procedures and reduce patient and family anxiety. Thyroid function testing should be considered before extensive oncological evaluation in children with elevated AFP. Full article

Chronic heart failure (CHF) carries high morbidity and mortality. Circulating biomarkers of myocardial stretch, injury, and remodelling aids diagnosis and prognosis, but utility varies, especially in HFpEF, where natriuretic peptide (NP) values may be lower or normal in obesity. We systematically searched PubMed, Scopus, and Web of Science (2010–2025) for primary adult chronic-HF studies evaluating blood-based biomarkers: NPs, high-sensitivity troponins (hs-cTn), galectin-3, soluble ST2 (sST2), and microRNAs. Secondary sources (reviews/meta-analyses/guidelines) informed context only. Acute-HF studies were not pooled with chronic-HF analyses. Where appropriate, log hazard ratios were meta-analysed with random effects models. Twenty-nine studies met criteria. NT-proBNP remained the diagnostic/prognostic reference; across five prognostic cohorts, the pooled HR was 1.68 (95% CI 1.54–1.82; I² ≈ 55%). hs-cTn consistently improved risk stratification. Galectin-3 and sST2 were associated with adverse outcomes but typically provided modest incremental value beyond NPs/hs-cTn; galectin-3 is influenced by renal function, and sST2 is commonly interpreted around ~28–35 ng/mL. MicroRNAs (e.g., miR-21, miR-210-3p, miR-22-3p) showed promising yet heterogeneous signals across platforms and preanalytical workflows; therefore, findings were synthesised narratively without pooling. NT-proBNP and hs-cTn form the evidence-based backbone for biomarker-guided assessment in chronic HF. Galectin-3 and sST2 add adjunct prognostic information, while microRNAs remain investigational, pending standardised methods and external validation. Overall, evidence supports a multimarker, phenotype-tailored approach, with core NPs + hs-cTn and selective adjunct use of sST2/galectin-3 in context (HFrEF vs. HFpEF, obesity, renal function) to refine risk stratification and guide clinical decision-making. Full article

Dried blood spots (DBSs) are a practical tool for diagnosing infectious diseases, especially in remote or resource-limited settings. This study assessed the efficacy of DBS-based serological assays for syphilis screening. EDTA blood samples from 171 syphilis-seropositive and 122 seronegative individuals were used to prepare DBSs by spotting whole blood onto filter paper. After drying, 12 mm disks were punched, incubated overnight in buffered solution, and centrifuged. Syphilis serological screening was conducted using the Liaison^® Treponema Screen assay, Macro-Vue™ Reagin Plasma Rapid (RPR) card test, and Dual Path Platform (DPP) Syphilis Screen and Confirm test. The Liaison^® assay demonstrated 100% sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with an optimized cut-off. The nontreponemal RPR test showed very low sensitivity (2.9%) on DBS but perfect specificity (100%). The DPP test for treponemal antibodies achieved high sensitivity (92.1%) and specificity (98.2%) with microreader adjustment. Visual reading of the DPP test had variable accuracy, with sensitivity reaching 100% but lower specificity (42.1%). Nontreponemal antibody detection by DPP showed moderate sensitivity and specificity. Although nontreponemal testing requires refinement, DBS testing combined with point-of-care tests like DPP holds promise for expanding syphilis screening accessibility and decentralization globally, particularly in resource-constrained environments. Full article

A 39-question survey targeting recent graduates was deployed by the American Society for Clinical Pathology (ASCP) to its membership nationwide by email. Participants were prompted to reflect on clinical educators from whom they had learned the most and least. This survey was open for approximately six weeks with 177 respondents. Participants included medical laboratory scientists (71.8%), medical laboratory technicians (21.8%), phlebotomists (4.5%), blood bank specialists (0.9%) and laboratory administration (0.9%). This paper focuses on three survey questions. The first question asked participants to reflect on clinical educators from whom they had learned the most and explain why. Themes included teaching ability (37.2%), engagement (25.6%), passion (18.6%) and knowledge (16.3%). The second question asked participants to reflect on educators they had learned the least from and explain why. Themes included teaching challenges (48.8%), disengagement (29.3%) and unprofessionalism (19.5%). The third question asked about barriers to clinical training. Main themes included staffing shortages (25.8%), COVID-19-related issues (12.9%) and work culture (12.9%). Little research has been published on the student perspective of clinical training in laboratory sciences. This research provides insight into what students consider helpful in their training and what hinders their learning. Full article

Timely reporting of microbiological results is critical for clinical decision-making, particularly in pediatric hospitals where delays can significantly impact outcomes. Despite advances in laboratory automation, workflow inefficiencies and resistance to change remain barriers to improvement in Latin America. This study aimed to evaluate the effect of implementing a Kaizen-based change management strategy on reducing turnaround time (TAT) in the microbiology laboratory of Hospital Roberto del Río, Santiago, Chile. We conducted a prospective, pre–post intervention study focusing on blood culture processing. The baseline period (July 2022) included 961 cultures processed with the BacT/ALERT^® 3D system. A Kaizen/LEAN intervention was designed, comprising workflow redesign, staff training, and installation of the BACT/ALERT^® Virtuo^® (bioMerieux, Marcy l’Etoile, France) continuous-loading blood culture system. The intervention engaged all technical and professional staff in a five-day Kaizen immersion, followed by eight months of monitoring. Outcomes were assessed by comparing TAT for positive blood cultures before and after implementation (June 2023, 496 samples). Statistical analysis was performed using the Mann–Whitney U test, with p < 0.05 considered significant. The intervention achieved a median reduction in TAT from 68.22 h (IQR 56.14–88.59) pre-intervention to 51.52 h (IQR 41.17–66.57) post-intervention, corresponding to a 24.48% improvement (p < 0.001), surpassing the 20% target. Time to preliminary Gram reporting also decreased, and workflow standardization enhanced staff productivity and culture validation frequency. Implementation of Kaizen principles in a pediatric microbiology laboratory significantly reduced blood culture TAT and improved workflow efficiency. Beyond technological upgrades, active staff engagement and structured change management were key to success. These findings support the applicability of Kaizen-based interventions to optimize laboratory performance in resource-constrained public healthcare systems. Full article

Acute respiratory infections (ARIs) continue to pose a major global health threat, particularly among vulnerable populations. These infections often present with similar clinical symptoms, complicating accurate diagnosis and facilitating unmonitored transmissions. Genomic surveillance has emerged as an invaluable tool for pathogen identification and monitoring of such infectious pathogens; however, its implementation is frequently limited by high costs. The widespread use of high-throughput sequencing during the COVID-19 pandemic has created an opportunity to repurpose existing genomic platforms for broader respiratory virus surveillance. In this study, we evaluated the feasibility of adapting the Illumina COVIDSeq assay—initially designed for SARS-CoV-2 whole-genome sequencing—for use with Influenza A/B, Respiratory Syncytial Virus (RSV), and Rhinovirus. Positive control samples were processed using two approaches for library preparation: four virus-specific multiple workflows and a combined rapid workflow. Both workflows incorporated pathogen-specific primers for amplification and followed the Illumina COVIDSeq protocol for library preparation and sequencing. Sequencing quality metrics were analysed, including Phred scores, read length distribution, and coverage depth. The study did not identify significant differences in genome coverage and genetic diversity metrics between workflows. Genome Detective consistently identified the correct species across both methods. The findings of this study demonstrate that the COVIDSeq assay can be effectively adapted for multi-pathogen genomic surveillance and that the combined rapid workflow can offer a cost- and labour-efficient alternative with minimal compromise to data quality. Full article

Atrial fibrillation (AF), the most prevalent cardiac arrhythmia, significantly elevates the risk of stroke and heart failure. The etiology of AF is complex and multifactorial, involving genetic predisposition, environmental risk factors, and their potential interactions. A previous genome-wide association study (GWAS) of AF in a Korean population has identified an association between the rs3737883 single-nucleotide polymorphism (SNP) in the PPFIA4 gene and an increased risk of AF. However, the association needs to be replicated in other populations. In this paper, we conducted a case–control association study including 724 AF cases and 1475 controls, and successfully validated the association between SNP rs3737883 with the risk of AF in a Chinese population (OR = 1.33 with an adjusted p was 2.83 × 10⁻¹¹). Given that the PPFIA4 variant has been reported to influence high-sensitivity cardiac troponin T (hs-cTnT) levels, we further investigated the relationship between rs3737883 and hs-cTnT in 48 AF patients. Notably, we observed that the risk allele was also associated with elevated hs-cTnT levels. Our findings provide further genetic substantiation for the association of rs3737883 with AF. These results suggest a potential association between the PPFIA4 gene variant, hs-cTnT levels, and AF risk, although further studies are needed to clarify the underlying mechanisms. Full article