재가 정맥영양요법 환자에서 Pantoea ananatis에 의한 균혈증 1예

이지교,박재현,김택수,박현웅 대한진단검사의학회 2022 Laboratory Medicine Online Vol.12 No.1

Pantoea ananatis is a Gram-negative, rod-shaped, non-spore-forming, motile bacterium that belongs to the family Erwiniaceae of the order Enterobacterales. In this study, we report the first Korean case of bacteremia caused by P. ananatis isolated from a 17-year-old female hospitalized due to fever. She had undergone total colectomy and massive intestinal resection due to intestinal pseudo-obstruction. Subsequently, the patient received home parenteral nutrition with a central venous catheter (CVC) for ten years and was hospitalized several times for central line-associated bloodstream infections. Gram-negative rods were isolated from two pairs of CVC blood cultures collected at admission. The isolate was identified as Pantoea spp. (95.0%) by GN ID card of the VITEK 2 system (bioMérieux, USA). It was identified as P. ananatis (score: 2.328) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry using MALDI Biotyper (Bruker Daltonics, Germany). We used universal primers to perform 16S rRNA gene sequence analysis. The sequence was searched in the GenBank database and showed 99.32% identity with P. allii and 99.18% identity with P. ananatis. Since the result was not species-specific, additional cpn60 gene sequencing was performed. The sequence revealed 99.91% identity with P. ananatis and 94.00% identity with P. allii. Consequently, the isolate was confirmed as P. ananatis. To accurately identify Pantoea spp., cpn60 was more reliable than the 16S rRNA gene. This is the first confirmed case of bacteremia caused by P. ananatis in Korea. Pantoea ananatis는 Enterobacterales 목의 Erwiniaceae 과에 속하는 균으로, 비포자형성, 운동성, 그람음성막대균이다. 본 연구에서는 발열을 주소로 입원한 17세 여자 환아에서 분리된 P. ananatis에 의한 국내 첫 균혈증 증례를 보고하고자 한다. 환자는 가성 장폐쇄로 결장전절제술과 광범위 소장절제술을 받았다. 그 뒤, 환자는 10년간 중심정맥관으로 재가 정맥영양요법을 시행하고 있었으며, 수 차례 중심정맥관 관련 혈류감염으로 입원했다. 입원 시 중심정맥관에서 채취한 두 쌍의 혈액 배양병에서 그람음성막대균이 확인되었다. 해당 균주는 VITEK 2 system (bioMérieux, USA)의 GN ID card에서 Pantoea spp. (95.0%)으로 동정되었다. MALDI Biotyper (Bruker Daltonics, Germany)를 이용한 matrix-assisted laser desorption ionization time-of flight mass spectrometry에서는 P. ananatis (score value: 2.328)로 동정되었다. 범용 시발체로 16S rRNA 염기서열분석을 시행했다. 염기서열을 GenBank 데이터베이스에서 검색했고, P. allii와 99.32%의 일치도, P. ananatis와 99.18%의 일치도를 보였다. 결과가 종특이적이지 않았기 때문에, 추가로 cpn60 유전자 염기서열 분석을 시행했다. 염기서열은 P. ananatis와 99.91%의 일치도, P. allii와 94.00%의 일치도를 보였다. 따라서, 해당 균주는 P. ananatis로 동정할 수 있었다. Pantoea 속을 정확히 동정하는데 16S rRNA에 비해 cpn60 유전자를 신뢰할 수 있었다. 이는 국내에서 P. ananatis에 의한 첫 균혈증 증례이다.

Evaluation of Matrix Effect in Body Fluid Chemistry on Roche Cobas 8000 c702 System

서종도,이지교,김승환,남영원,이준희,이경훈,송정한,송상훈 대한진단검사의학회 2021 Laboratory Medicine Online Vol.11 No.4

Background: Analysis of body fluids aids in diagnosis and monitoring disease. However, only a few testing platforms and reagents have been validated for a range of body fluids or analytes. In this study, we evaluated a testing system, which has been approved for blood samples, in analyzing body fluid specimens upon matrix mixing. Methods: Serum and body fluid samples, including cerebrospinal fluid (CSF), ascites, pleural fluid, amniotic fluid, and synovial fluid, were mixed, then the matrix effect and linearity for major analytes, namely amylase, chloride, glucose, LDH, and protein were evaluated (N = 30 serum-body fluid pairs) on the Cobas 8000 c702. The obtained data was compared with that of open reagents evaluated on the Architect c16000. Results: For all analyte-body fluid pairs, the mean percent recovery ranged from 98.4% to 101.7%, and this was within the acceptable range for matrix effect. In the linearity test, maximum non-linearity for each analyte-body fluid pair ranged from -5.0% to +4.2%. In interference test, proteins showed positive hemolytic, icteric, and lipemic interference in CSF and hemolytic interference in amniotic fluid. There was no significant interference in the other analyte-body fluid pairs. Results were highly correlated between the Cobas 8000 c702 and the Architect c16000 system. Conclusions: Our findings revealed that the matrix effect of major analytes in body fluid specimens can be excluded and they also validated the linearity of the analytes in the body fluid specimens. Therefore, reagents specified for blood samples can be readily adopted for the analysis of body fluids.

응급수혈 프로토콜을 통한 적혈구 수혈의 안전성 연구

정기욱,이지교,강지상,박재현,정유선,고대현,김형석,한규섭 대한수혈학회 2021 大韓輸血學會誌 Vol.32 No.3

Background: Pretransfusion testing is vital for safe transfusion. However, in situations without time to perform sufficient testing, all or part of the pretransfusion testing may be skipped to issue blood quickly. This study evaluated the safety of red blood cell (RBC) transfusion released by an emergency blood transfusion protocol through retrospective analysis at a tertiary hospital for eight years. Methods: All RBC transfusions following the emergency blood transfusion protocol from 2011 to 2018 at Seoul National University Hospital were included in the study. Crossmatching and unexpected antibody screening test results conducted after RBC release and the occurrence of hemolytic transfusion reactions were analyzed. Results: A total of 1,541 cases (5,299 RBCs issued) of emergency blood transfusion were identified. RBCs were issued after performing the immediate spin crossmatch without an unexpected antibody screening test in most cases (1,443; 93.64%), while RBCs were issued with no pretransfusion testing in 98 cases (6.36%). Antibody screening tests performed after the issue of RBCs showed that 17 (1.1%) cases were positive. Two units of RBCs from two different cases showed positive antiglobulin crossmatch test results. However, none of them were suspected to be associated with a hemolytic transfusion reaction. Conclusion: The incidence of incompatible RBC release was very low in patients receiving RBC transfusion through the emergency blood transfusion protocol suggesting it can be used safely with minimal risk of hemolytic transfusion reactions caused by incompatible blood transfusions. (Korean J Blood Transfus 2021;32:163-173)

ARKRAY ADAMS A1c HA-8190V 장비의 HbA1c 분석능 평가

신우진,김성민,이지교,이경훈,송상훈,이준희,송정한 대한진단검사의학회 2024 Laboratory Medicine Online Vol.14 No.1

배경: 당화혈색소는 한국에서 점점 더 중요해지는 건강문제인 당뇨병의 진단 및 치료 반응 모니터링에 유의미하게 쓰이는 지표이다. 본 연구에서는 고성능 액체크로마토그래피(HPLC)를 이용하여 HbA1c를 측정하는 ADAMS A1c HA-8190V (ARKRAY Inc., Japan) 장비의 분석능을 평가하였다. 방법: HA-8190V의 정밀도, 직선성, 검체 간 교차오염률을 평가하였다. 120개의 잔여 검체를 사용하여 HA-8190V와 HLC-723 G11 (Tosoh Corporation, Japan) 간의 상관성 분석을 시행하였다. IFCC 표준검사법으로 당화혈색소 수치를 측정한 26개의 교환가능성 물질을 사용하여 장비의 정확도를 평가하였다. 21개의 헤모글로빈 변이형 샘플을 이용하여 헤모글로빈 변이형의 장비에 대한 간섭효과를 평가하였다. 결과: 저농도와 고농도 정도관리물질의 반복정밀도의 변이계수는 각각 0.5%와 0.4%였으며 검사실내정밀도의 변이계수는 각각 1.0%와 0.9%였다. 직선성 평가에서 선형성허용편차 5% 기준을 만족하면서 결정계수(R2)는 0.9988로 3.0%에서 20.2%의 농도 범위 내에서 우수한 직선성을 보였다. 유의미한 검체 간 교차오염률은 관찰되지 않았다. HA-8190V로 측정한 HbA1c값은 G11로 측정한 값과 비교하였을 때, 우수한 상관성을 보였다(r=0.997). 의학적 결정 농도(5.7%와 6.5%)에서 % 바이어스가 모두 허용범위 미만이었다. 헤모글로빈 변이형으로 인한 간섭효과를 평가하였을 때 HA-8190V는 비교적 적은 간섭효과를 보였다. 결론: HA-8190V는 우수한 정밀도, 직선성 및 적은 교차오염률을 보였다. G11과 높은 상관성이 있었으며 다른 HbA1c 측정장비들과 비교하였을 때 헤모글로빈 변이형으로 인한 간섭효과 또한 적은 편이었다. HA-8190V는 HbA1c값을 정확하게 측정하여 당뇨병을 진단, 치료 및 추적하는데 임상 검사실에서 유용하게 사용될 수 있을 것으로 판단된다. Background: Hemoglobin A1c is an important marker used in the diagnosis and treatment monitoring of diabetes mellitus, which is an increasingly significant health problem in South Korea. We evaluated the analytical performance of the HPLC-based ADAMS HA-8190V (ARKRAY, Japan) HbA1c analyzer. Methods: The precision, linearity, and carryover of the HA-8190V device were evaluated. Using 120 residual samples, comparative analysis between the HA-8190V and HLC-723 G11 (Tosoh, Japan) devices was conducted. Accuracy was evaluated using commutable samples with known HbA1c concentrations measured using an International Federation of Clinical Chemistry reference measurement procedure. Interference by common Korean Hb variants was evaluated with 21 known Hb variant samples. Results: The repeatability (%CV) for the low- and high-level controls was 0.5% and 0.4%, respectively, while the within-laboratory precision was 1.0% and 0.9%, respectively. For linearity, the coefficient of determination was 0.9988, with excellent linearity in a range of 3.0–20.2%. No significant carryover was observed. HbA1c concentrations measured by HA-8190V showed good correlation (r=0.997) with the G11. Percentage biases at medical decision levels (5.7% and 6.5%) were within the allowable range. The HA-8190V showed the least interference from Hb variants compared to other instruments in standard mode. Conclusions: HA-8190V showed reliable analytical performance with good precision, linearity, and minimal carryover. Furthermore, HA-8190V showed good correlation with the G11 and was least affected by Hb variants compared to other commercial analyzers. Hence, HA-8190V can be utilized in clinical laboratories to accurately measure HbA1c for the diagnosis and treatment monitoring of diabetes mellitus.