Laboratory medicine最新文献

Introduction: Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are novel therapeutic agents for managing anemia in patients with chronic kidney disease (CKD); however, no clinically viable markers for the anemia-improving effect of HIF-PHI have been reported. Therefore, we evaluated changes in iron metabolism markers and identified predictors of anemia amelioration during HIF-PHi treatment.

Methods: We included 48 patients with CKD not undergoing dialysis: 29 patients receiving epoetin β-pegol, an erythropoiesis-stimulating agent (ESA) and 19 patients receiving roxadustat, an HIF-PHi. Markers of iron metabolism, including hepcidin, were measured during treatments using a widely available automated analyzer.

Results: The hemoglobin levels did not differ substantially between the HIF-PHi and ESA groups. Patients treated with HIF-PHI exhibited lower serum iron, ferritin, transferrin saturation, and hepcidin values and higher unsaturated iron-binding capacity at 1 month than did patients receiving the ESA. Reduced hepcidin levels at 1 month were strongly associated with increased hemoglobin levels at 3 months.

Discussion: Our findings suggest that the hepcidin level, as an initial response, can help predict the responsiveness of the HIF-PHi to anemia in patients with CKD. Measuring hepcidin, an integral indicator of iron metabolism, using standard equipment in general hospital laboratories would be beneficial in routine clinical practice.

Introduction: Naegleria fowleri is a pathogenic free-living amoeba that causes primary amoebic meningoencephalitis, a rare and difficult-to-diagnose form of meningitis. By testing patient cerebrospinal fluid (CSF) for ergosterol, a membrane component unique to fungi and amoeba, cases of primary amoebic meningoencephalitis may be distinguished from cases of bacterial and viral meningitis.

Methods: Pooled CSF was fortified with ergosterol, extracted, filtered, and measured by liquid chromatography-tandem mass spectrometry. Measurement method precision, sensitivity, recovery, and stability were evaluated. In vitro cell cultures of N fowleri and a sample (n = 200) of deidentified residual patient CSF specimens were also tested for ergosterol.

Results: Ergosterol remained stable in CSF at 4 °C and -80 °C. The mean variation and total error of the method were 7.4% and 15.8%, respectively. The method limit of quantification (LOQ) was 1.0 ng/mL, which translated to an in vitro LOQ of 2650 cells/mL or higher. A trace of ergosterol, below the LOQ, was detected in a patient specimen positive for cryptococcal meningitis but not in any other CSF specimens.

Discussion: Ergosterol can be reliably detected in spiked human CSF samples and in the supernatant of N fowleri CSF cultures at concentrations of 1.0 to 500 ng/mL. The clinical utility of this method, however, requires further exploration.

Introduction: Artificial intelligence is increasingly used in medical education and testing. ChatGPT, developed by OpenAI, has shown mixed results on various medical exams, but its performance in medical laboratory genetics remains unknown.

Methods: This study assessed ChatGPT-3.5 using 456 publicly available questions from the Polish national specialist exam in medical laboratory genetics. Questions were categorized by topic and complexity (simple vs complex) and submitted to ChatGPT 3 times. Accuracy and consistency were statistically evaluated.

Results: ChatGPT correctly answered 59% of the 456 exam questions, which was statistically significant (P < .001). Accuracy differed by category: 71% for calculation-based questions, approximately 60% for genetic methods and genetic alterations, and only 37% for clinical case-based questions. Question complexity also affected performance: Simple questions had 63% accuracy, while complex questions yielded 43% (P = .001). No statistically significant differences were found across 3 repeated sessions, with performance remaining stable over time (P = .43).

Discussion: ChatGPT-3.5 demonstrated moderate accuracy and stable performance on a specialist exam in medical genetics. Although it may support education in this field, the tool's limitations in complex, domain-specific reasoning suggest the need for further development before broader implementation.

Introduction: Kidney transplant recipients are among the populations at risk for Hepatitis B Virus (HBV) reactivation, and close monitoring is needed for its early detection.

Methods: We describe a case of HBV reactivation in a patient who underwent kidney transplantation more than 30 years ago, with a known serological profile of past HBV infection.

Results: Reactivation occurred as a highly replicative infection that went undiagnosed for 7 years due to negative results for HB surface antigen (HBsAg) and high levels of anti-HBs antibodies. Viral genome sequencing showed a high number of mutations in the major hydrophilic region of HBsAg that could explain such a profile.

Discussion: This case highlights the usefulness of frequent and systematic HBV viral load testing in patients at risk of reactivation, with anti-hepatitis B core antibodies, regardless of HBsAg detection, aminotransferases, and anti-HBs antibody levels.

Introduction: The anti-LW antibody is not considered clinically significant. Yet, it can cause some challenges in differentiating it from the anti-D antibody in pretransfusion testing.

Methods: This case report discusses a 35-year-old patient with nonmalignant gastrointestinal complications who was identified as having anti-LW during pretransfusion testing. We provide a brief history of the LW system and discuss the laboratory methods used to distinguish anti-LW from anti-D.

Results: The patient's prior workup revealed an O RhD-positive blood type and an antibody compatible with anti-D. Auto-control and direct antiglobulin testing with anti-immunoglobulin G were only weakly positive, but the elution was negative. Red blood cell genotyping did not show any RhD variant. Current workup showed the patient's plasma reacting with both RhD-positive and RhD-negative group O cord blood and not reacting with RhD-positive dithiothreitol-treated cells, confirming anti-LW specificity.

Discussion: Clarifying an apparent confusion between a true anti-D and a mimicking anti-LW in pretransfusion blood bank testing remains the basis of providing clinically relevant component therapy. Understanding the basics of the LW Blood Group System serology is fundamental to appropriate problem solving.

Introduction: Snakebite-related deaths are major concerns in populations worldwide that lack access to medical care. Current treatment of snakebites includes administration of polyspecific and polyvalent heterologous equine antiserum. Swift diagnosis of the species of snake responsible is essential to initiate a specific treatment.

Methods: We generated murine monoclonal and rabbit polyclonal antibodies against the venom of the 3 most common venomous snakes in southern India: the Russell viper, the saw-scaled viper, and the Indian cobra. We developed an enzyme-linked immunosorbent assay to distinguish the snake by analyzing the exudates from the snakebite wound.

Results: Monoclonal antibody EC3 reacts specifically with a 45- to 50-kDa venom protein of the saw-scaled viper, antibody NNH6 reacts with 12-kDa venom protein of the Indian cobra, and antibody RVV20 reacts with a 16-kDa venom protein of the Russell viper. We tested the exudates from snakebite wounds in 24 consecutive patients admitted to the Tirunelveli Medical College Hospital with snakebite. Our assay detected 18 patients with Russell viper bite and 1 each for cobra and saw-scaled viper.

Discussion: Our study shows the feasibility of an enzyme-linked immunosorbent assay-based method to identify the 3 major venomous snakes in southern India and holds promise for prompt administration of snake-specific and mechanism-based treatment.

Introduction: CYP2D6 genotyping can guide the appropriate prescription of related drugs, but its complex genetic alterations make clinical implementation challenging. In this study, we evaluated the performance of a custom-made, targeted next-generation sequencing (NGS)-based CYP2D6 genotyping method by comparing it with Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) methods.

Methods: CYP2D6 was included in a customized NGS multigene panel. CYP2D6 genotypes were analyzed in 91 patients, including copy number variations (CNV) analysis based on read depth. For comparison, single-nucleotide variations (formerly single-nucleotide polymorphisms) and CNVs were assessed using Sanger sequencing and MLPA, and the genotype was determined. Differences in genotype and predicted phenotype according to these 2 approaches were evaluated.

Results: The NGS-based results were 100% concordant in single-nucleotide variations compared with Sanger sequencing, but 4 cases (4.4%) were discordant in CNVs with MLPA. Consequently, the NGS-based genotype was 95.6% concordant with the combined Sanger sequencing and MLPA approach. However, the classification of the predicted phenotype was unchanged in the 4 cases with differing assigned genotypes.

Discussion: The NGS-based CYP2D6 genotyping method showed good performance, suggesting its potential utility in clinical practice. Including CYP2D6 in an NGS panel for patients who may use drugs metabolized by CYP2D6 may provide additional useful information.

Introduction: No established criteria exist for assessing the effectiveness of granulocyte transfusion (GTX) or biomarkers for predicting fatal infections in neutropenia. This study aimed to assess whether a novel sepsis marker, presepsin (P-SEP), is a useful prognostic indicator during GTX.

Methods: We collected frozen serum from 8 patients who had undergone GTX between September 2022 and October 2023 and measured their P-SEP levels. We compared these results with clinical records and assessed the alterations before and after GTX and their association with prognosis.

Results: The post-transfusion neutrophil count increased in all cases. In 5 of 8 patients (62.5%), P-SEP levels were reduced 1 day after GTX. Pretransfusion P-SEP levels were statistically significantly lower in the group of patients who survived and overcame infection after transfusion (GTX-survived) than in the group of patients who did not survive (GTX-nonsurvived) (1493 pg/mL vs 6658 pg/mL, P =.04). Transfused cell counts and changes in P-SEP levels 1 day after GTX were better in the GTX-survived group than in the GTX-nonsurvived group, although the difference was not statistically significant.

Discussion: Presepsin is a biomarker that can be assessed in patients undergoing GTX for agranulocytosis. A clinically significant increase in P-SEP levels before GTX may indicate ineffective GTX and an unfavorable prognosis.

Introduction: Anastomotic fistula is the most feared complication in colorectal surgery. It requires early diagnosis followed by urgent treatment. In this study, we analyzed the dynamics of C-reactive protein (CRP) as a marker for early detection of anastomotic fistula.

Methods: A prospective study was conducted among 83 patients who underwent colorectal resection with anastomosis at the First Surgical Department, County Emergency University Clinical Hospital, Cluj Napoca, Romania. The CRP and leukocyte values were recorded at admission and on postoperative days 3, 5, 7, and 9. Total serum protein values were measured on postoperative days 3, 5, and 7, and albumin values were measured on postoperative day 3.

Results: Only CRP values showed substantial postoperative variations. At postoperative days 3, 5, and 7, serum CRP levels in patients with anastomotic fistula were higher than those in patients without anastomotic fistula, with differences at postoperative days 5 (P <.001) and 7 (P <.001) being statistically significant.

Discussion: A steady decrease in CRP values after postoperative day 3 is a strong sign that the development of anastomotic fistula is unlikely. An increase or a flat decrease in CRP value at postoperative days 5 and 7 with a serum value at or close to 100 mg/L suggests an increased probability for development of anastomotic fistula.