Editorial2022-01-01

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Original Article2022-03-01 Clinical Microbiology

SnackNTM: An Open-Source Software for Sanger Sequencing-based Identification of Nontuberculous Mycobacterial Species

Young-Gon Kim , M.D., Kiwook Jung , M.D., Seunghwan Kim , M.D., Man Jin Kim , M.D., Jee-Soo Lee , M.D., Sung-Sup Park , M.D., Ph.D., and Moon-Woo Seong , M.D., Ph.D.

Ann Lab Med 2022; 42(2): 213-248

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Abstract : Background: Sequence-based identification is one of the most effective methods for species-level identification of nontuberculous mycobacteria (NTM). However, it is time-consuming because of the bioinformatics processes involved, including sequence trimming, consensus sequence generation, and public database searches. We developed a simple and fully automated software that enabled species-level identification of NTM from trace files, SnackNTM (https://github.com/Young-gonKim/SnackNTM). Methods: JAVA programing language was used for software development. The SnackNTM diagnostic algorithm utilized 16S rRNA gene sequences, according to the Clinical & Laboratory Standards Institute guidelines, and an rpoB gene region was adjunctively utilized to narrow down the species. The software performance was validated using trace files of 234 clinical cases, comprising 217 consecutive cases and 17 additionally selected cases of unique species. Results: SnackNTM could analyze multiple cases at once, and all the bioinformatics processes required for sequence-based NTM identification were automatically performed with a single mouse click. SnackNTM successfully identified 95.9% (208/217) of consecutive clinical cases, and the results showed 99.0% (206/208) agreement with manual classification results. SnackNTM successfully identified all 17 cases of unique species. In a processing time comparison test, the analysis and reporting of 30 cases, which took 150 minutes manually, took only 40 minutes with SnackNTM. Conclusions: SnackNTM is expected to reduce the workload for NTM identification, especially in clinical laboratories that process large numbers of cases.

Letter to the Editor2021-05-01 Diagnostic Immunology

Algorithm using Neuron-Specific Enolase and Pro-Gastrin-Releasing Peptide to Increase the Diagnostic Accuracy for Small Cell Lung Cancer

Haeyoung Lee , M.D., Ph.D., Sung Dal Park , M.D., Ph.D., Taeyun Kim , M.D., Jehun Kim , M.D., Ph.D., Tae Won Jang , M.D., Ph.D., Hyunji Choi , M.D., and Hyunyong Hwang , M.D., Ph.D.

Ann Lab Med 2021; 41(3): 339-341

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Brief Communication2022-07-01 Clinical Chemistry

Performance Evaluation of the i-SmartCare 10 Analyzer and Method Comparison of Six Point-of-Care Blood Gas Analyzers

Sang-Mi Kim , M.D. and Hyung-Doo Park , M.D., Ph.D.

Ann Lab Med 2022; 42(4): 467-472

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Abstract : Blood gas, electrolyte, glucose, and lactate level measurement have an immediate and critical impact on patient care. We evaluated the performance of i-SmartCare 10 (i-SENS Inc., Seoul, Korea) and conducted a method comparison study of five point-of-care (POC) analyzers with i-SmartCare 10 as the comparator, according to the CLSI guidelines. Ten analytes (pH, pCO₂, pO₂, Na⁺, K⁺, Cl⁻, iCa²⁺, glucose, lactate, and Hct) were tested on six analyzers: i-SmartCare 10, ABL90 FLEX PLUS (Radiometer Medical ApS, Copenhagen, Denmark), i-Stat (Abbott Point of Care Inc., Princeton, NJ, USA), RapidLab 1265 (Siemens Healthcare Diagnostics Inc., Tarrytown, NY, USA), Stat Profile pHOx Ultra (Nova Biomedical, Waltham, MA, USA), and Gem Premier 5000 (Instrumentation Laboratory, Bedford, MA, USA). The total imprecision and linearity (r²>0.99) were excellent, except for a few analytes that narrowly escaped the preset criteria. Interference was noted for Na⁺ in the presence of a high K⁺ level and for iCa²⁺ in the presence of high K⁺ and Mg²⁺ levels. Forty of 48 items demonstrated either a proportional or systematic difference in regression analysis; the relative mean difference (%) of 14/48 items escaped the allowable total error in the difference plot analysis. i-SmartCare 10 shows acceptable performance, and using a single POC blood gas analyzer is recommended for monitoring.

Letter to the Editor2022-07-01 Clinical Microbiology

The First Case of Azorhizobium caulinodans Bacteremia in a Patient with Leukemia

Jae Hyeon Park , M.D., Taek Soo Kim , M.D., and Hyunwoong Park , M.D., Ph.D.

Ann Lab Med 2022; 42(4): 494-496

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Original Article2022-07-01 Clinical Chemistry

Current Status of Serum Insulin and C-Peptide Measurement in Clinical Laboratories: Experience from 94 Laboratories in China

Weiyan Zhou , M.D., Yuhang Deng , M.D., Haijian Zhao , M.D., and Chuanbao Zhang , M.D.

Ann Lab Med 2022; 42(4): 428-437

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Abstract : Background: Accurate measurements of serum insulin and C-peptide are needed for the therapy and classification of diabetes. This study investigated the status of serum insulin and C-peptide measurements in China by analyzing the results of five pooled serum samples measured in 94 laboratories. Methods: Patient serum samples were pooled into five groups according to insulin and C-peptide concentrations and measured in 94 laboratories using different measurement systems. The inter- and intra-laboratory %CV as well as inter- and intra-measurement system %CV were calculated to assess the status of insulin and C-peptide measurements. To verify whether the disagreement between laboratories was due to different calibrators, as reported in previous studies, one low-level and one high-level sample extracted from the five pooled serum samples were used to recalibrate clinical measurement systems. Results: The mean intra-laboratory, intra-measurement system, inter-laboratory, and inter-measurement system %CVs were 2.7%, 4.8%, 21.8%, and 22.4%, respectively, for insulin and 2.3%, 6.7%, 16.4%, and 24.5%, respectively, for C-peptide. The inter- and intra-laboratory %CVs for insulin decreased with increasing concentration. After recalibration with low- and high-level samples, the mean inter-measurement %CV decreased from 22.4% to 17.2% for insulin and from 24.5% to 5.7% for C-peptide. Conclusions: The intra-laboratory and intra-measurement system imprecision values are satisfactory for serum insulin and C-peptide measurements. However, the results from laboratories using different measurement systems were not comparable, and there is still much work needed to achieve the standardization or harmonization of serum insulin and C-peptide measurements.

Letter to the Editor2021-09-01 Clinical Microbiology

Comparison of the AdvanSure RV Plus Real-Time RT-PCR and Real-Q RV II Detection Assays for Respiratory Viruses

Yoo Na Chung , M.D., In Young Yoo , M.D., Ph.D., Sun Ae Yun , M.T., Ji-Youn Kim , M.T., Nam Yong Lee , M.D., Ph.D., and Hee Jae Huh , M.D., Ph.D.

Ann Lab Med 2021; 41(5): 506-509

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Original Article2022-07-01 Transfusion and Cell Therapy

Erythroid Differentiation of Induced Pluripotent Stem Cells Co-cultured with OP9 Cells for Diagnostic Purposes

Juhye Roh , M.D., Ph.D., Sinyoung Kim , M.D., Ph.D., June-Won Cheong , M.D., Ph.D., Su-Hee Jeon , M.S., Hyun-Kyung Kim , M.S., Moon Jung Kim , M.D., Ph.D., and Hyun Ok Kim , M.D., Ph.D.

Ann Lab Med 2022; 42(4): 457-466

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Abstract : Background: Reagent red blood cells (RBCs) are prepared from donated whole blood, resulting in various combinations of blood group antigens. This inconsistency can be resolved by producing RBCs with uniform antigen expression. Induced pluripotent stem cells (iPSCs) generated directly from mature cells constitute an unlimited source for RBC production. We aimed to produce erythroid cells from iPSCs for diagnostic purposes. We hypothesized that cultured erythroid cells express surface antigens that can be recognized by blood group antibodies. Methods: iPSCs were co-cultured with OP9 stromal cells to stimulate differentiation into the erythroid lineage. Cell differentiation was examined using microscopy and flow cytometry. Hemoglobin electrophoresis and oxygen-binding capacity testing were performed to verify that the cultured erythroid cells functioned normally. The agglutination reactions of the cultured erythroid cells to antibodies were investigated to confirm that the cells expressed blood group antigens. Results: The generated iPSCs showed stemness characteristics and could differentiate into the erythroid lineage. As differentiation progressed, the proportion of nucleated RBCs increased. Hemoglobin electrophoresis revealed a sharp peak in the hemoglobin F region. The oxygen-binding capacity test results were similar between normal RBCs and cultured nucleated RBCs. ABO and Rh-Hr blood grouping confirmed similar antigen expression between the donor RBCs and cultured nucleated RBCs. Conclusions: We generated blood group antigen-expressing nucleated RBCs from iPSCs co-cultured with OP9 cells that can be used for diagnostic purposes. iPSCs from rare blood group donors could serve as an unlimited source for reagent production.

Original Article2023-01-01 Diagnostic Genetics

Cost-Effectiveness Analysis of Germline and Somatic BRCA Testing in Patients With Advanced Ovarian Cancer

Jaehyeok Jang , M.D., Yoonjung Kim , M.D., Ph.D., Jae-Hoon Kim , M.D., Ph.D., Sun-Mi Cho , M.D., and Kyung-A Lee , M.D., Ph.D.

Ann Lab Med 2023; 43(1): 73-81

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Abstract : Background: BRCA testing is necessary for establishing a management strategy for ovarian cancer. Several BRCA testing strategies, including germline and somatic testing, are implemented in clinical practice in Korea. We aimed to comparatively evaluate their cost-effectiveness from patients’ perspective. Methods: We developed a decision model comprising five BRCA testing strategies implemented in Korea: (1) germline testing first, followed by somatic tumor testing for patients without a germline variant; (2) somatic testing first, followed by germline testing for patients with a variant detected by somatic testing; (3) both germline and somatic testing; (4) germline testing alone; and (5) somatic testing alone, with no testing as the comparator. One-way sensitivity analysis was conducted to test the uncertainty of key parameters. Results: Assuming a willingness-to-pay of $20,000 per progression-free life-year gain (PF-LYG), all five strategies were considered cost-effective. Strategy 4 was the most cost-effective option, with an incremental cost-effectiveness ratio (ICER) of $2,547.7 per PF-LYG, followed by strategy 1, with an ICER of $3,978.4 per PF-LYG. Even when the parameter values were varied within the possible range, the ICERs of all strategies did not exceed the willingness-to-pay threshold. Conclusions: Considering the importance of knowing a patient’s BRCA gene status, germline testing first, followed by somatic testing, may be a reasonable option.

Letter to the Editor2021-11-01 Diagnostic Genetics

A Novel TTN Gene Variant c.95136T>G (p.Cys31712Trp) and Associated Clinical Characteristics in a Family With Suspected Hereditary Myopathy With Early Respiratory Failure

Yoomi Yeo , M.D., Jong Eun Park , M.D., Ph.D., and Hyuk Sung Kwon , M.D., Ph.D.

Ann Lab Med 2021; 41(6): 604-607

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