Volume 49, Issue 5

This paper offers a comprehensive examination of the current landscape of standardized training for laboratory medicine resident physicians in China. It explores key elements including training objectives, methodologies, content, and evaluation criteria. Based on a critical analysis of existing strengths and limitations within the current system, targeted recommendations are proposed to guide the cultivation of highly qualified professionals in laboratory medicine. These suggestions aim to improve the overall quality of residency training and address growing clinical demands and evolving trends within the discipline.

Objectives In 1 H nuclear magnetic resonance spectroscopy (NMR), a single measurement can yield insights into hundreds of metabolites. The use of NMR is expanding in research, with comprehensive datasets readily available. To fully leverage the spectral data, e.g. for amino acid (AA) detection, evaluating the quality of NMR quantification is crucial. For this, we compared the results for 15 AAs obtained from 1 H NMR and a clinical HPLC platform. Methods 1 H NMR and HPLC measurements of 15 AAs from 90 samples are compared by Spearman correlation coefficients and Passing-Bablok analysis. Imprecision is evaluated by coefficients of variation based on duplicates. Results 1 H NMR measurements of two AAs show high correlation and good agreement to HPLC measured levels (phenylalanine, alanine). Three more AA measurements reveal high correlation but systematic bias (tyrosine, valine, glycine). NMR results of six investigated AAs are less comparable (ornithine, threonine, histidine, isoleucine, leucine, lysine). Four measurands could not be evaluated (glutamine, glutamic acid, asparagine, methionine). Conclusions Analytical quality varies considerably among the investigated AAs. A limited number of AAs show good concordance with results from HPLC supporting selective use of NMR spectra for AA analysis. While NMR holds promise in both research and clinical settings, it is currently not suitable for comprehensive AA monitoring for diagnostic purpose.

Objectives The results obtained for zinc levels by different laboratory measurement procedures vary because zinc is not yet a harmonized test. Firstly, we aimed to determine reference intervals for serum zinc that had been measured by two different kits on two different clinical chemistry analyzers, employing various statistical methodologies, and secondly to make a comparison between zinc deficiency prevalences according to the determined reference intervals and the manufacturer’s reference intervals. Methods The results of the serum zinc levels that were measured by spectrophotometric method, using Improgen ® and Archem ® zinc kits across a range of time intervals, were obtained retrospectively. The indirect reference intervals for zinc were determined using the Bhattacharya, RefineR and ReflimR methods for both assays. The prevalence of zinc deficiency was evaluated according to the two different kit manufacturers’ recommendations and our established reference intervals. Results The reference intervals determined by all three methods were found to be lower than those recommended by the manufacturers with the exception of Archem ® kit in children. Although the determined reference intervals and lower reference limits were different, the prevalence of zinc deficiency has decreased substantially after the implementation of established reference intervals for both kits and has reached almost same level (20.0–4.6 % and 8.5–4.7 %). Conclusions The establishment of appropriate and accurate zinc reference intervals is of paramount importance in order to avoid the overdiagnosis of zinc deficiency, the unnecessary laboratory testing and the administration of supplements to individuals without underlying deficiencies.

Objectives Chronic hepatitis B infection is a major cause in Vietnam of developing hepatocellular carcinoma (HCC). HCC surveillance for hepatitis B patients is recommended to detect tumors early for effective treatment and survival extension. The novel Elecsys ® GAAD algorithm (Roche Diagnostic) was generated by using serum PIVKA-II and alpha-fetoprotein (AFP) measurements with age and biological sex factors for more effective HCC screening expectations. This study was conducted to validate the GAAD algorithm for HCC surveillance in Vietnamese hepatitis B patients. Methods A cross-sectional study with 337 hepatitis B patients divided into 142 HCC and 195 non-HCC including benign liver tumors, liver fibrosis and cirrhosis was performed in Vietnam. The Elecsys ® GAAD score was computed by Elecsys ® AFP, Elecsys ® PIVKA-II and patient’s age, gender. The clinical evaluation of the GAAD algorithm was accessed by sensitivity, specificity at recommended cut-off, and the AUC of the receiver operating characteristic curve. Results The GAAD showed moderate performance with an AUC of 0.767 (95 % CI 0,716–0,818), but was more effective than AFP alone in the general detection of HCC, and more useful than PIVKA-II in the detection of HCC at an early stage with tumors ≤ 2 cm and in distinguishing benign liver tumor from HCC. It did not provide more benefit than PIVKA-II to detect HCC at all stages or cirrhosis background. Conclusions The study showed that GAAD had moderate performance, but appeared to be more effective than AFP alone in general HCC surveillance and may be superior to PIVKA-II for detecting early-stage HCC with tumors ≤2 cm, and for distinguishing HCC from benign liver tumors in chronic hepatitis B patients.

Objectives Circulating tumor DNA (ctDNA) assays play an increasingly important role in cancer management. A new version of TruSight Oncology 500 (TSO500) ctDNA, v2, was recently released, and the recommended DNA input was decreased to 20 ng from 30 ng in the prior version. This study aimed to assess the analytical and clinical performance of TSO500 ctDNA v2 using varying input DNA. Methods Four replicates of two reference materials were prepared with varying DNA input. Nine residual clinical samples that were tested using TSO500 ctDNA v1 were also prepared with reduced DNA input compared to the initial tests. A total of 17 samples were subjected to library preparation, sequencing, and bioinformatics analysis according to the manufacturer’s protocol. The effects of varying DNA input on quality measures and variant detection accuracy were analyzed. Results The depth of coverage and variant detection sensitivity of the reference material gradually decreased with reduced DNA input. The total number of reads was unaffected, while the mean family size increased with the reduction in DNA input, attributing the decreased performance to reduced library complexity. Among the 61 single nucleotide variants and 17 indel variants previously detected using TSO500 ctDNA v1 with 30 ng of input DNA, only 45 (73.8 %) and 7 (41.2 %) were detected using v2 with 20 ng of input DNA, respectively. Conclusions The DNA input is a critical factor that determines assay performance and an input higher than recommended by the manufacturer should preferably be used for TSO500 ctDNA v2 for its optimal performance.

Objectives ddPCR is a tool improving the detection and clinical management of critical infections. This prospective study verified ddPCR’s application value in pathogen detection for abdominal sepsis. Methods It was conducted in the First Affiliated Hospital of Chongqing Medical University from January 2021 to December 2022. And 164 patients with abdominal sepsis were enrolled. Strengths and weaknesses of abdominal sepsis pathogen detection via drainage fluid culture versus ddPCR were analyzed. Results In abdominal sepsis patients, 86 % of them detected pathogens using ddPCR, compared with 71.3 % using traditional methods. 208 bacterial strains were found by ddPCR, including 58.7 % (122/208) Gram-negative and 41.3 % (86/208) Gram-positive bacteria. 182 strains of bacteria (56.6 % Gram-negative, 43.4 % Gram-positive) and 15 strains of fungi were detected by the conventional method. Notably, 67.7 % of the patients were positive for both ddPCR and culture, and 10.4 % were negative. Using culture as the gold standard, for infections with two or more pathogens, ddPCR demonstrated 95.31 % sensitivity and 98 % specificity. Reporting time of the drainage fluid culture (40.85 ± 1.61 h) was significantly longer than ddPCR (6.86 ± 0.12 h) (p<0.001). A total of 52 patients were identified as carriers of drug-resistant genes through ddPCR analysis, of which 39 had their anti-infection treatment plans modified during the course of therapy. Conclusions ddPCR is a rapid and sensitive tool for the etiological detection of abdominal sepsis. However, it currently detects only specific pathogens and cannot differentiate between viable microorganisms and those that have already undergone apoptosis.