Most Read
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Review Article2022-05-01 Transfusion Medicine
Abstract : Blood is lifesaving; however, it can neither be limitlessly acquired nor artificially produced. The supply and use of blood, as an invaluable biological commodity, necessitate systematic and rational management under governmental guidance to ensure safe and reliable transfusions. Despite Korea’s blood donation rate of 5.04%, which is higher than the 3.15% in high-income countries as reported by the WHO, the demand for blood exceeds the availability. This is due to the birthrate decline, dearth of young donors, and growing and aging recipient population. This review outlines the Korean blood management system, with a focus on blood service data from 2020, with the aim to delineate the current state of Korea’s blood management system and the policies established to address the imminent blood shortage. Each policy is described in detail to provide helpful information for blood management services in other countries.
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Original Article2022-03-01 Clinical Microbiology
Clinical Differences in Patients Infected with Fusobacterium and Antimicrobial Susceptibility of Fusobacterium Isolates Recovered at a Tertiary-Care Hospital in Korea
Myungsook Kim
Ann Lab Med 2022; 42(2): 188-195, Ph.D., Shin Young Yun
, M.D., Yunhee Lee
, B.D., Hyukmin Lee
, M.D., Dongeun Yong
, M.D., Kyungwon Lee
, M.D.
Abstract : Background: Fusobacterium species are obligately anaerobic, gram-negative bacilli. Especially, F. nucleatum and F. necrophorum are highly relevant human pathogens. We investigated clinical differences in patients infected with Fusobacterium spp. and determined the antimicrobial susceptibility of Fusobacterium isolates. Methods: We collected clinical data of 86 patients from whom Fusobacterium spp. were isolated from clinical specimens at a tertiary-care hospital in Korea between 2003 and 2020. In total, 76 non-duplicated Fusobacterium isolates were selected for antimicrobial susceptibility testing by the agar dilution method, according to the Clinical and Laboratory Standards Institute guidelines (M11-A9). Results: F. nucleatum was most frequently isolated from blood cultures and was associated with hematologic malignancy, whereas F. necrophorum was mostly prevalent in head and neck infections. Anti-anaerobic agents were more commonly used to treat F. nucleatum and F. varium infections than to treat F. necrophorum infections. We observed no significant difference in mortality between patients infected with these species. All F. nucleatum and F. necrophorum isolates were susceptible to the antimicrobial agents tested. F. varium was resistant to clindamycin (48%) and moxifloxacin (24%), and F. mortiferum was resistant to penicillin G (22%) and ceftriaxone (67%). β-Lactamase activity was not detected. Conclusions: Despite the clinical differences among patients with clinically important Fusobacterium infections, there was no significant difference in the mortality rates. Some Fusobacterium spp. were resistant to penicillin G, ceftriaxone, clindamycin, or moxifloxacin. This study may provide clinically relevant data for implementing empirical treatment against Fusobacterium infections.
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Review Article2022-03-01 Clinical Chemistry
Review of the Use of Liquid Chromatography-Tandem Mass Spectrometry in Clinical Laboratories: Part I-Development
Ann Lab Med 2022; 42(2): 121-140Abstract : The process of method development for a diagnostic assay based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) involves several disparate technologies and specialties. Additionally, method development details are typically not disclosed in journal publications. Method developers may need to search widely for pertinent information on their assay(s). This review summarizes the current practices and procedures in method development. Additionally, it probes aspects of method development that are generally not discussed, such as how exactly to calibrate an assay or where to place quality controls, using examples from the literature. This review intends to provide a comprehensive resource and induce critical thinking around the experiments for and execution of developing a clinically meaningful LC-MS/MS assay.
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Original Article2021-07-01 Diagnostic Genetics
Accuracy and Performance Evaluation of Triplet Repeat Primed PCR as an Alternative to Conventional Diagnostic Methods for Fragile X Syndrome
Hyunjung Gu
Ann Lab Med 2021; 41(4): 394-400, M.D., Man Jin Kim
, M.D., Dahae Yang
, M.D., Ji Yun Song, M.T., Sung Im Cho
, M.T., Sung Sup Park
, M.D., Ph.D., and Moon-Woo Seong
, M.D., Ph.D.
Abstract : Background: Conventional diagnosis of fragile X syndrome (FXS) is based on a combination of fragment analysis (FA) and Southern blotting (SB); however, this diagnostic approach is time- and labor-intensive and has pitfalls such as the possibility of missing large number alleles. Triplet repeat primed PCR (TP-PCR) is a current alternative used to overcome these limitations. We evaluated the diagnostic usefulness of TP-PCR compared with the conventional diagnostic protocol consisting of FA and/or SB in terms of allele categorization, repeat number correlation, and zygosity concordance in female genetic carriers. Methods: From November 2013 to March 2018, 458 patients (326 males, 132 females) were simultaneously examined using FA and/or SB and TP-PCR by detecting CGG repeat numbers in FMR1 gene and diagnosed as per American College of Medical Genetics guidelines. Results: The TP-PCR results showed high concordance with the FA and/or SB results for all three aspects (allele categorization, repeat number correlation, and zygosity concordance in female genetic carriers). TP-PCR detected CGG expansions ≥200 in all full mutation (FM) allele cases in male patients, as well as both the normal allele (NL) and FM allele in female carriers. In premutation (PM) allele carriers, the TP-PCR results were consistent with the FA and/or SB results. In terms of zygosity concordance in female genetic carriers, 12 NL cases detected by TP-PCR showed a merged peak consisting of two close heterozygous peaks; however, this issue was resolved using a 10-fold dilution. Conclusions: TP-PCR may serve as a reliable alternative method for FXS diagnosis.
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Original Article2022-01-01 Clinical Chemistry
Comprehensive Laboratory Data Analysis to Predict the Clinical Severity of Coronavirus Disease 2019 in 1,952 Patients in Daegu, Korea
Eun-Hyung Yoo
Ann Lab Med 2022; 42(1): 24-35, M.D., Ph.D., Soon Hee Chang
, M.D., Ph.D., Do-Young Song
, M.D., Ph.D., Chae Hoon Lee
, M.D., Ph.D., Gyu Young Cheong
, M.D., Ph.D., Sunggyun Park
, M.D., Ph.D., Jae Hee Lee
, M.D., Ph.D., Sooin Lee
, M.D., Ph.D., Sang-Gyu Kwak
, Ph.D., Chang-Ho Jeon
, M.D., Ph.D., and Kyung Eun Song
, M.D., Ph.D.
Abstract : Background: Laboratory parameter abnormalities are commonly observed in COVID-19 patients; however, their clinical significance remains controversial. We assessed the prevalence, characteristics, and clinical impact of laboratory parameters in COVID-19 patients hospitalized in Daegu, Korea. Methods: We investigated the clinical and laboratory parameters of 1,952 COVID-19 patients on admission in nine hospitals in Daegu, Korea. The average patient age was 58.1 years, and 700 (35.9%) patients were men. The patients were classified into mild (N=1,612), moderate (N=294), and severe (N=46) disease groups based on clinical severity scores. We used chi-square test, multiple comparison analysis, and multinomial logistic regression to evaluate the correlation between laboratory parameters and disease severity. Results: Laboratory parameters on admission in the three disease groups were significantly different in terms of hematologic (Hb, Hct, white blood cell count, lymphocyte%, and platelet count), coagulation (prothrombin time and activated partial thromboplastin time), biochemical (albumin, aspartate aminotransferase, alanine aminotransferase, lactate, blood urea nitrogen, creatinine, and electrolytes), inflammatory (C-reactive protein and procalcitonin), cardiac (creatinine kinase MB isoenzyme and troponin I), and molecular virologic (Ct value of SARS-CoV-2 RdRP gene) parameters. Relative lymphopenia, prothrombin time prolongation, and hypoalbuminemia were significant indicators of COVID-19 severity. Patients with both hypoalbuminemia and lymphopenia had a higher risk of severe COVID-19. Conclusions: Laboratory parameter abnormalities on admission are common, are significantly associated with clinical severity, and can serve as independent predictors of COVID-19 severity. Monitoring the laboratory parameters, including albumin and lymphocyte count, is crucial for timely treatment of COVID-19.
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Review Article2021-11-01 General Laboratory Medicine
Early Laboratory Preparedness of the Korea Disease Control and Prevention Agency and Response to Unknown Pneumonia Outbreak from Wuhan, China, in January 2020
Il-Hwan Kim
Ann Lab Med 2021; 41(6): 532-539, Ph.D., Byung-Hak Kang
, Ph.D., Seung Hee Seo
, M.S., Ye Eun Park
, M.S., Gab Jung Kim
, Ph.D., Sang Won Lee
, Ph.D., Jun Hyeong Jang
, Ph.D., Su Kyoung Jo
, M.S., Jun Ho Jeon
, Ph.D., Jeong-Min Kim
, Ph.D., Yoon-Seok Chung
, Ph.D., Myung-Guk Han
, Ph.D., Sang-Oun Jung
, Ph.D., Junyoung Kim
, Ph.D., Kyu-Jam Hwang
, Ph.D. , Cheon-Kwon Yoo
, Ph.D., and Gi-eun Rhie
, Ph.D.
Abstract : We report the response process of the Laboratory Analysis Task Force (LATF) for Unknown Disease Outbreaks (UDOs) at the Korea Disease Control and Prevention Agency (KDCA) during January 2020 to coronavirus disease 2019 (COVID-19), which developed as a UDO in Korea. The advanced preparedness offered by the laboratory diagnostic algorithm for UDOs related to respiratory syndromes was critical for the rapid identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and enabled us to establish and expand the diagnostic capacity for COVID-19 on a national scale in a timely manner.
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Original Article2021-11-01 Clinical Microbiology
Disk Diffusion Susceptibility Testing for the Rapid Detection of Fluconazole Resistance in Candida Isolates
Suhak Jeon
Ann Lab Med 2021; 41(6): 559-567, M.D., Jong Hee Shin
, M.D., Ph.D., Ha Jin Lim
, M.D., Min Ji Choi
, Ph.D., Seung A Byun
, M.S., Dain Lee
, M.S., Seung Yeob Lee
, M.D., Eun Jeong Won
, M.D., Soo Hyun Kim
, M.D., and Myung Geun Shin
, M.D.
Abstract : Background: Given the increased fluconazole resistance (FR) among Candida isolates, we assessed the suitability of disk diffusion susceptibility testing (DDT) for the early detection of FR using well-characterized Candida isolates. Methods: In total, 188 Candida isolates, including 66 C. albicans (seven Erg11 mutants), 69 C. glabrata (33 Pdr1 mutants), 29 C. parapsilosis (15 Erg11 mutants), and 24 C. tropicalis (eight Erg11 mutants) isolates, were tested in this study. FR was assessed using DDT according to the standard CLSI M44-ED3 method, except that two cell suspensions, McFarland 0.5 (standard inoculum) and 2.5 (large inoculum), were used, and the inhibition zones were read at 2-hour intervals from 10 hours to 24 hours. Results: DDT results for the standard inoculum were readable after 14 hours (C. albicans, C. glabrata, and C. tropicalis) and 20 hours (C. parapsilosis) for >95% of the isolates, whereas the results for the large inoculum were readable after 12 hours (C. glabrata and C. tropicalis), 14 hours (C. albicans), and 16 hours (C. parapsilosis) for >95% of the isolates. Compared with the results produced using the CLSI M27-ED4 broth microdilution method, the first readable results from the DDT method for each isolate exhibited an agreement of 97.0%, 98.6%, 72.4%, and 91.7% for the standard inoculum and 100%, 98.6%, 96.6%, and 95.8% for the large inoculum for C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis, respectively. Conclusions: DDT using large inoculum may detect FR rapidly and reliably in the four most common Candida species.
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Original Article2021-11-01 Diagnostic Immunology
Combination of a SARS-CoV-2 IgG Assay and RT-PCR for Improved COVID-19 Diagnosis
Kotaro Aoki
Ann Lab Med 2021; 41(6): 568-576, Ph.D., Kunitomo Takai
, M.H.E.S., Tatsuya Nagasawa
, M.M.S., Katsuhito Kashiwagi
, M.D., Nobuaki Mori
, M.D., Ph.D., Keiji Matsubayashi
, M.S., Masahiro Satake
, M.D., Ph.D., Ippei Tanaka
, Ph.D., Nanae Kodama
, M.S., Takahiro Shimodaira
, M.M.S, Yoshikazu Ishii
, Ph.D., Taito Miyazaki
, M.D., Toshiaki Ishii
, M.M.S, Toshisuke Morita
, M.D., Ph.D., Toru Yoshimura
, Ph.D., and Kazuhiro Tateda
, M.D., Ph.D.
Abstract : Background: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is generally diagnosed by reverse transcription (RT)-PCR or serological assays. The SARS-CoV-2 viral load decreases a few days after symptom onset. Thus, the RT-PCR sensitivity peaks at three days after symptom onset (approximately 80%). We evaluated the performance of the ARCHITECT® SARS-CoV-2 IgG assay (henceforth termed IgG assay; Abbott Laboratories, Lake County, IL, USA), and the combination of RT-PCR and the IgG assay for COVID-19 diagnosis. Methods: In this retrospective study, 206 samples from 70 COVID-19 cases at two hospitals in Tokyo that were positive using RT-PCR were used to analyze the diagnostic sensitivity. RT-PCR-negative (N=166), COVID-19-unrelated (N=418), and Japanese Red Cross Society (N=100) samples were used to evaluate specificity. Results: Sensitivity increased daily after symptom onset and exceeded 84.4% after 10 days. Specificity ranged from 98.2% to 100% for samples from the three case groups. Seroconversion was confirmed from 9 to 20 days after symptom onset in 18 out of 32 COVID-19 cases with multiple samples and from another case with a positive result in the IgG assay for the first available sample. Conclusions: The combination of RT-PCR and IgG assay improves the robustness of laboratory diagnostics by compensating for the limitations of each method.
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Original Article2022-01-01 General Laboratory Medicine
Economic Evaluation of Total Laboratory Automation in the Clinical Laboratory of a Tertiary Care Hospital
KyungYi Kim
Ann Lab Med 2022; 42(1): 89-95, M.S., Sang-Guk Lee
, M.D., Ph.D., Tae Hyun Kim
, Ph.D., and Sang Gyu Lee
, M.D., Ph.D., M.B.A.
Abstract : Background: Total laboratory automation (TLA) is an innovation in laboratory technology; however, the high up-front costs restrict its widespread adoption. To examine whether the capital investment for TLA is worthwhile, we analyzed its clinical- and cost-effectiveness for the expected payback period. Methods: Clinical chemistry tests and immunoassays performed in the clinical laboratory of a tertiary care hospital were divided into a post-TLA group, including 1,182,419 tests performed during December 2019, and a pre-TLA group, including 1,151,501 tests performed during December 2018. Laboratory information system data were used to measure clinical effectiveness, and depreciation data were used to calculate TLA costs. Results: Laboratory performance improved after TLA adoption in all four key performance indicators: mean turn-around time (TAT), representing the timeliness of result reporting, decreased by 6.1%; the 99th percentile of TAT, representing the outlier rate, decreased by 13.3%; the TAT CV, representing predictability, decreased by 70.0%; and weighted tube touch moment (wTTM), representing staff safety, improved by 77.6%. Based on these effectiveness results, economic evaluation was performed using two approaches. First, the incremental cost-effectiveness ratio and wTTM were used as the most cost-effective performance indicators. Second, the expected payback period was calculated. Considering only staff cost reduction, it was anticipated that 4.75 yrs would be needed to payback the initial investment. Conclusions: TLA can significantly enhance laboratory performance, has a relatively quick payback period, and can reduce total hospital expenses in the long term. Therefore, the capital investment for TLA adoption is considered to be worthwhile.
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Review Article2022-09-01 Diagnostic Hematology
Unreliable Automated Complete Blood Count Results: Causes, Recognition, and Resolution
Gene Gulati, Ph.D., Guldeep Uppal, M.D., and Jerald Gong, M.D.
Ann Lab Med 2022; 42(5): 515-530Abstract : Automated hematology analyzers generate accurate complete blood counts (CBC) results on nearly all specimens. However, every laboratory encounters, at times, some specimens that yield no or inaccurate result(s) for one or more CBC parameters even when the analyzer is functioning properly and the manufacturer’s instructions are followed to the letter. Inaccurate results, which may adversely affect patient care, are clinically unreliable and require the attention of laboratory professionals. Laboratory professionals must recognize unreliable results, determine the possible cause(s), and be acquainted with the ways to obtain reliable results on such specimens. We present a concise overview of the known causes of unreliable automated CBC results, ways to recognize them, and means commonly utilized to obtain reliable results. Some examples of unreliable automated CBC results are also illustrated. Pertinent analyzer-specific information can be found in the manufacturers’ operating manuals.
