ARKRAY ADAMS A1c HA-8180의 분석능 평가

유은형,김병인,조현정 대한진단검사의학회 2014 Laboratory Medicine Online Vol.4 No.3

The hemoglobin A1c (Hb A1c) test is widely used to diagnose diabetes mellitus and monitor glycemic control in patients with diabetes. We evaluated the performance of the ARKRAY ADAMS A1c HA-8180 (ARKRAY KDK, Japan), an automated, HPLC-based Hb A1c analyzer. The ARKRAY ADAMS A1c HA-8180 was evaluated for its linearity and precision and compared to the HLC-723 G7 (Tosoh Corporation, Japan), according to the Clinical and Laboratory Standards Institute’s guidelines. The coefficients of variation (CVs) for within-run precision at low and high levels were 0.6% and 0.3%, respectively, and the total CVs at low and high levels were 0.8% and 0.6%, respectively. The coefficient of determination (R2) was 0.9975, with linearity in the range of 3.0-18.5%. A comparison between the ARKRAY ADAMS A1c HA-8180 and HLC-723 G7 revealed a good correlation (r=0.9955) in the range of 4.8-14.6%. The runtime was 57 s per sample. The ARKRAY ADAMS A1c HA-8180 showed good analytical performance and high throughput. Therefore, it is suitable for routine use for clinical measurements of Hb A1c. 당화혈색소 Hb A1c는 당뇨병의 진단기준과 혈당 조절의 모니터링 지표로 널리 이용되고 있다. 본 연구에서는 Hb A1c 측정 자동화 장비인 ARKRAY ADAMS A1c HA-8180 (ARKRAY KDK, Japan)의 성능을 평가하였다. ARKRAY ADAMS A1c HA-8180의 직선성, 정밀도 및 기존 검사실 장비인 HLC-723 G7 (Tosoh Corporation, Japan)과의 상관성을 CLSI 지침에 따라 평가하였고, 분석속도를 측정하였다. 저농도와 고농도의 Hb A1c 정도관리물질의 검사 내 변이계수는 각각 0.6%와 0.3%였으며, 총 변이계수는 0.8%와 0.6%였다. 직선성은 3.0-18.5% 범위에서 R2=0.9975였다. Tosoh HLC-723 G7과의 상관성 평가에서도 4.8-14.6% 범위에서 r=0.9955의 상관성을 보였고, 분석 속도는 검체 당 57초였다. ARKRAY ADAMS A1c HA-8180는 임상검사실에서 우수한 분석성능으로 대량 검체를 신속하게 검사할 수 있을 것으로 생각된다.

중증열성혈소판감소증후군 환자에서의 치료적 혈장교환술: 단일 기관 경험

유은형,이아진,김상경,전창호 대한수혈학회 2021 大韓輸血學會誌 Vol.32 No.2

Background: Severe fever with thrombocytopenia syndrome (SFTS) is a novel infection caused by the tick-borne SFTS virus. More than 200 patients are reported every year in Korea, but there is no established treatment. In patients with SFTS, therapeutic plasma exchange (TPE) can be applied. Methods: Clinical and laboratory characteristics of patients diagnosed with SFTS who underwent TPE were analyzed. The factors that can differentiate the prognosis between the patients who recovered after TPE and those who died were analyzed. Results: Ten patients were diagnosed with SFTS and treated with TPE. The mean age was 70.8 (49–85) years, with three men and seven females. The laboratory findings showed a decrease in white blood cell (WBC) count, platelet count, and serum albumin and an increase in AST, ALT, LDH, and CK levels. Patients performed an average of three (2∼4) TPE procedures at intervals of 1∼2 days, three of whom died. Compared to the results at admission, the WBC counts increased after TPE, and the platelet counts remained unchanged. The AST, LDH, and CK levels decreased by 2∼6 fold in the recovered patients and increased in those who died. Among them, the change in LDH was statistically significant between the two groups (P=0.0227). Conclusion: TPE has been used as an adjuvant treatment in SFTS patients who do not have a definitive treatment to date. Additional studies, including small-scale studies such as this study, will be needed to establish the timing, interval, and predictive factors of the effect of TPE. (Korean J Blood Transfus 2021;32:83-90)

Utilization of C-Reactive Protein Test as a Predictor of Lung Injury in Patients with Coronavirus Disease 2019

유은형,김상경,김영환,강웅래,정치영,김경찬,홍효림,곽상규,전창호 대한진단검사의학회 2021 Laboratory Medicine Online Vol.11 No.2

Background: C-reactive protein (CRP) test can be used at coronavirus disease 2019 (COVID-19) screening clinics as a point of care test. The aim of this study was to determine whether CRP test can be used as an indicator of lung injury. Methods: In all, 98 patients with COVID-19 were enrolled for this study. We collected medical records and laboratory results of the patients. Chest radiographic findings were classified into five groups. We analyzed the correlation between laboratory tests and the grade of lung injury. Results: In patients with COVID-19, increased CRP and erythrocyte sedimentation rate (ESR), and lymphocytopenia were noted. CRP, ESR, and segmented neutrophils were found to be positively correlated while albumin and lymphocyte were negatively correlated with lung injury grade. CRP levels showed the highest correlation coefficient of 0.858. Based on the chest radiographs, the sensitivity and specificity of CRP was 100% and 77.8%, respectively. Within the reference range of CRP, abnormal chest radiograph was not recognized. In addition, initial and subsequent increase in CRP levels in patients with unremarkable chest radiograph could be associated with aggravated lung injury. Conclusions: CRP test showed a sensitivity of 100% in detection of lung injury, and the level was proportional to the extent of lung lesions. Therefore, CRP test will be useful as a predictor of lung injury in patients with COVID-19.

Correlation between Clinical Severity and Cycle Threshold Values of Real-time RT-PCR at the Time of Admission in COVID-19 Patients

유은형,이아진,김상경,전창호 대한진단검사의학회 2023 Laboratory Medicine Online Vol.13 No.4

Background: The viral load of the patient can be deduced from the cycle threshold (Ct) value. In this study, the correlation between the initial Ct value of the SARS-CoV-2 real-time reverse transcription polymerase chain reaction (RT-PCR) and the clinical features in hospitalized patients in Daegu, South Korea, was explored. Methods: We investigated the clinical and RT-PCR data of 750 patients with COVID-19 (Coronavirus disease-19) at admission in eight hospitals in Daegu, Korea, and assessed the correlation between the Ct values and COVID-19 severity. Results: The Ct values for the four genes showed a statistically significant difference (P<0.001) within the same specimen type. Among the 716 patients classified based on clinical severity, the Ct value was a significant predictor of disease severity at the time of admission. The Ct values of the E, RdRP, and N genes showed significant differences among the eight severity groups (P<0.001). Compared to patients in the non-severe group (categories 1 to 4), those in the severe group (categories 5 to 8) exhibited a relatively lower distribution of Ct values for the E (P<0.001), RdRP (P=0.029), ORF1a (P=0.009), and N genes (P=0.003). Conclusions: The Ct value, which reflects the amount of virus, can serve as a supportive parameter for predicting the severity of COVID-19 in patients at the time of admission.

자가 혈당 측정기 COSMOsensor의 평가

유은형,조현정,기창석,이수연 대한진단검사의학회 2006 Annals of Laboratory Medicine Vol.26 No.1

배경 : 혈당 측정기는 가장 보편적인 현장 검사기기로, 당뇨병환자의 엄격한 혈당 관리와 신속한 검사를 위해 병원과 가정에서널리 사용되고 있다. 저자들은 최근 국내에서 개발된 혈당측정기COSMOsensor (Cosmogenome Inc., Seoul, Korea)의 분석 성능을 기존의 외국산 혈당측정기 3종과 비교하여 종합적으로 평가하고자 하였다.방법 : COSMOsensor에 대해 직선성, 정밀도, 검사자에 따른영향, 상관성 및 분석속도를 평가하였다. 외국산 혈당 측정기,Accu-Chek inform (Roche Diagnostics Ltd., Mannheim, Ger-many), PrecisionTMPCx (Abbott Laboratories, Bedford, MA,USA), SureStepFlexx (LifeScan Inc., Milpitas, CA, USA)에 대해서도 NCCLS 지침에 따라 동일 항목에 대해 평가하였다.결과 : 4종의 혈당기는 우수한 직선성을 보였으며(r≥0.9814),검사중 및 총 변이계수는 3.5% 이내였다. 중앙 검사실 기기 Hit-hachi 7600과도 높은 상관성을 보였다. 참고법과의 혈당 측정치의차이는 만족할만한 결과를 보였으나, 기기마다 다양한 양 또는음의 차이를 보였다.

Frequent CD7 Antigen Loss in Aggressive Natural Killer-Cell Leukemia: A Useful Diagnostic Marker

유은형,이승태,김희진,김원석,김선희 대한진단검사의학회 2009 Annals of Laboratory Medicine Vol.29 No.6

Background : Aggressive natural killer-cell leukemia (ANKL) is a rare neoplasm characterized by systemic proliferation of NK cells. However, the differential diagnosis of NK lymphoproliferative disorders is difficult because of the absence of a distinct diagnostic hallmark. Therefore, to identify diagnostic markers for ANKL, we analyzed the clinical data and laboratory findings obtained for 20 patients with ANKL. Methods : From January 2000 to July 2007, 20 patients were diagnosed with ANKL on the basis of bone marrow studies. We retrospectively analyzed the clinical features and laboratory findings, including the complete blood count, Epstein-Barr virus status, immunophenotype, and the cytogenetic results. Results : The subjects included 6 women and 14 men (median age, 44 yr; range, 2-70 yr). Cytogenetic studies were performed in 18 patients, and karyotypic abnormalities were observed in 9 patients (50%). None of the cytogenetic abnormalities were constantly observed in all the patients. However, 6q abnormalities were observed in 4 patients (4/18, 22%). The immunophenotype of the leukemic NKcells was cytoplasmic CD3+, surface CD3-, CD16/56+, CD2+, and CD5-. Notably, the CD7 antigen was absent in 10 patients (50%). When the CD7 loss was combined with cytogenetic abnormalities, clonal markers could be identified in 75% of the ANKL cases. Conclusions : The CD7 antigen loss was frequently observed in our series of ANKL patients. In conjunction with the cytogenetic findings, this characteristic immunophenotypic finding can serve as a reliable marker for the timely diagnosis of ANKL. Therefore, immunophenotypic analysis of CD7 expression should be included in the diagnosis of NK cell neoplasms.

Experience of percutaneous tracheostomy in critically ill COVID-19 patients

김은진,유은형,정치영,김경찬 대한중환자의학회 2020 Acute and Critical Care Vol.35 No.4

Background: Coronavirus disease 2019 (COVID-19) is a highly contagious disease that causes respiratory failure. Tracheostomy is an essential procedure in critically ill COVID-19 patients; however, it is an aerosol-generating technique and thus carries the risk of infection transmission. We report our experience with percutaneous tracheostomy and its safety in a real medical setting. Methods: During the COVID-19 outbreak, 13 critically ill patients were admitted to the intensive care unit (ICU) at Daegu Catholic University Medical Center between February 24 and April 30, 2020. Seven of these patients underwent percutaneous tracheostomy using Ciaglia Blue Rhino. The medical environment, percutaneous tracheostomy method, and COVID-19 reverse transcriptase-polymerase chain reaction (RT-PCR) results were retrospectively reviewed. After treatment, the COVID-19 infection status of healthcare personnel was investigated by RT-PCR. Results: The ICU contained negative pressure cohort areas and isolation rooms, and healthcare personnel wore a powered air-purifying respirator system. We performed seven cases of percutaneous tracheostomy in the same way as in patients without COVID-19. Five patients (71.4%) tested positive for COVID-19 by RT-PCR at the time of tracheostomy. The median cycle threshold value for the RNA-dependent RNA polymerase was 30.60 (interquartile range [IQR], 25.50–36.56) in the upper respiratory tract and 35.04 (IQR, 28.40–36.74) in the lower respiratory tract. All healthcare personnel tested negative for COVID-19 by RT-PCR. Conclusions: Percutaneous tracheostomy was performed with conventional methods in the negative pressure cohort area. It was safe to perform percutaneous tracheostomy in an environment of COVID-19 infection.

폐암 환자에서 Cyfra 21-1의 진단적 유용성 평가

송성욱,유은형,조현정 대한진단검사의학회 2015 Laboratory Medicine Online Vol.5 No.3

Background: Lung cancer is the most lethal malignant neoplasm in the world. Serum cytokeratin fragment 21-1 (Cyfra 21-1) is a valuable tumor marker for detection of lung cancer, and it has good sensitivity and specificity. The aim of this study was to investigate the diagnostic value of Cyfra 21-1 levels in patients with lung cancer. Methods: We retrospectively reviewed 814 samples from 169 patients with lung cancer, 124 patients with benign pulmonary diseases, and 521 normal controls from health check-up clinic. Serum Cyfra 21-1 levels were determined with Architect CYFRA 21-1 kit (Abbott, USA) using Architect i2000 analyzer. Results: Median levels and interquartile ranges for Cyfra 21-1 in patients with lung cancer (non-small cell lung cancer: 3.16 [1.98, 9.00] ng/mL, small cell lung cancer: 3.32 [2.07, 5.20] ng/mL) were higher than those in patients with benign pulmonary diseases (1.50 [1.17, 2.17] ng/mL; P< 0.01) and in normal controls (1.26 [0.93, 1.75] ng/mL; P<0.01). Sensitivity, specificity, positive predictive value, and negative predictive value for Cyfra 21-1 were 70.4%, 81.2%, 49.6%, and 91.3%, respectively. The area under the curve for Cyfra 21-1 was 0.839 (95% confidence interval, 0.802-0.877). Conclusions: We concluded that Cyfra 21-1 may be useful in the diagnosis of lung cancer. 배경: 폐암은 전 세계적으로 가장 치명적인 암 중의 하나이다. 혈청 사이토케라틴분절 21-1 (Cytokeratin fragment 21-1, Cyfra 21-1) 측정은 폐암의 진단에서 좋은 민감도와 특이도를 지닌 종양 표지자로 알려져 있다. 본 연구에서 폐암의 선별 검사로 Cyfra 21-1의 유용성을 평가하고자 한다. 방법: 연구 대상은 건양대학교 병원을 방문한 폐암 환자 169명, 양성 폐질환자 124명, 정상 건강검진자 521명으로 총 814명을 후향적으로 분석하였다. 혈청 Cyfra 21-1은 Architect CYFRA 21-1 kit를 이용하여 Architect i2000 분석기에서 측정하였다. 결과: 폐암 환자에서 Cyfra 21-1의 중앙값 및 사분범위(비소세포성 폐암: 3.16 [1.98, 9.00] ng/mL, 소세포성 폐암: 3.32 [2.07, 5.20] ng/mL)는 양성 폐질환자(1.50 [1.17, 2.17] ng/mL) 및 정상 군(1.26 [0.93, 1.75] ng/mL)보다 통계적으로 유의하게 높았다(각각 P<0.01). Cyfra 21-1의 민감도, 특이도, 양성 예측치, 음성 예측치는 각각 70.4%, 81.2%, 49.6%, 91.3%였다. 또한 Cyfra 21-1의 곡선하면적은 0.839 (95% confidence interval 0.802-0.877)였다. 결론: 본 연구 결과 Cyfra 21-1은 폐암을 진단하는 데 유용한 종양 표지자임을 확인할 수 있었다.

JAK2 V617F and MPL W515L/K Mutations in Korean Patients with Essential Thrombocythemia

김희정,장자현,유은형,김희진,기창석,김종원,김선희 대한진단검사의학회 2010 Annals of Laboratory Medicine Vol.30 No.5

JAK2 V617F and MPL W515L/K mutations have been reported in approximately 50% and 5% of the patients with essential thrombocythemia (ET), respectively. We investigated the frequency of MPL W515L/K mutations in a series of consecutive patients with ET and post-essential thrombocythemia myelofibrosis (post-ET MF). The study subjects were 63 patients diagnosed either with ET (N=59) or post-ET MF (N=4) at our institution between June 2006 and February 2010. Among them, 35 (55.6%) had the JAK2 V617F mutation. MPL W515L/K mutations were detected by direct sequencing analyses of exon 10, and 2 patients were found to harbor the following MPL mutations: W515L in 1 patient with ET and W515K in 1 patient with post-ET MF. Neither of the patients had the JAK2 V617F mutation. The frequencies of the MPL W515L/K and JAK2 V617F-negative mutations in our subjects with ET/post-ET MF were 3.2% (2/63) and 7.1% (2/28), respectively. This is the first study to report the frequency of JAK2 V617F and MPL W515L/K mutations in Korean patients with ET/post-ET MF. (Korean J Lab Med 2010;30:474-6)

A Case of Resistance to Thyroid Hormone with Thyroid Cancer

김희경,김도이,유은형,이지인,장혜원,Alice Hyun Kyung Tan,허규연,김재현,김광원,정재훈,김선욱 대한의학회 2010 Journal of Korean medical science Vol.25 No.9

Resistance to thyroid hormone (RTH) is an autosomal dominant hereditary disorder that is difficult to diagnose because of its rarity and variable clinical features. The magnitude of RTH is caused by mutations in the thyroid hormone receptor beta (TRβ) gene. We recently treated a 38-yr-old woman with RTH who had incidental papillary thyroid carcinoma. She presented with goiter and displayed elevated thyroid hormone levels with an unsuppressed TSH. She was determined to harbor a missense mutation of M310T in exon 9 of the TRβgene, and diagnosed with generalized RTH. This mutation has not yet been reported in Korea. RTH is very rare and easily overlooked, but should be considered in patients who present with goiter and elevated thyroid hormone levels with an unsuppressed TSH. The association between thyroid cancer and RTH needs further study.