Evaluation of ARCHITECT HCV Core Antigen Assay

송두열,강정은,김신영,황상현,김형회,이은엽,손한철 대한진단검사의학회 2010 Annals of Laboratory Medicine Vol.30 No.6

Background : Hepatitis C virus (HCV) core antigen (Ag) levels are known to be well correlating with HCV RNA levels, and may be used as an alternative marker of HCV replication for monitoring the response to HCV treatment. However, the low sensitivity of HCV core Ag assay has been an obstacle for clinical use. In this study, recently developed ARCHITECT HCV Ag assay (Abbott Laboratories, USA) was evaluated for analytical performance and clinical usefulness. Methods : A total of 109 sera from HCV infected patients including various genotypes of HCV (1b, 2, 2a/2c, 2b, and 3a) and 20 sera from healthy donors were used for evaluating the sensitivity, precision, and linearity of the HCV core Ag assay. The cross reactivity with HIV, hepatitis B virus and myeloma proteins (N=5, each) and correlation with HCV RNA PCR assay were also evaluated. Results : The sensitivity of the HCV core Ag assay was 97.2% (106/109) and there were no false positive results and cross reactivity. The within-run, between-run and between-day CVs were 3.0%, 2.5% and 3.0%, respectively. The levels of HCV core antigen showed a good correlation with those of HCV RNA quantification (r=0.940). The HCV Ag assay showed an excellent linearity in the range from 0.63 to 17,114 fmol/L (r=0.999). Conclusions : The ARCHITECT HCV Ag assay was good in sensitivity, precision, and linearity and its results well correlated with HCV RNA levels. This assay could be used as a good marker of viral replication for monitoring the therapy response in chronically HCV infected patients. (Korean J Lab Med 2010;30:654-9)

Selection of Unnecessary Urine Culture Specimens Using Sysmex UF-5000 Urine Flow Cytometer

송두열,이현지,조수연,이선민,장철훈 대한임상미생물학회 2018 Annals of clinical microbiology Vol.21 No.4

Background: Urine culture is one of the most frequently requested tests in microbiology. Automated urine analyzers yield much infection-related information. The Sysmex UF-5000 analyzer (Sysmex, Japan) is a new flow cytometry urine analyzer capable of quantifying urinary particles, including bacteria, WBCs, and yeast-like cells (YLCs) and can provide a Gram stainability flag. In this work, we evaluated how many unnecessary urine cultures could be screened out using the UF-5000. Methods: We compared the culture results of 126 urine samples among 453 requested urine cultures (from sources other than the Urology and Nephrology departments) with urinalysis results. Urine cultures were considered positive if bacterial or YLC growth was ≥104 CFUs/mL. Results: We used urinalysis cut-off values of 50/μL and 100/μL for bacteria and YLC, respectively. Forty eight of the 126 (38.1%, or 10.6% of 453 requested) cultures were below these cut-off values and did not contain any culture-positive samples. Conclusion: Bacteria and YLC counts generated using the UF-5000 analyzer could be used to screen out negative cultures and reduce urine culture volume by ∼10% without sacrificing detection of positive cultures. (Ann Clin Microbiol 2018;21:-79)

Performance Evaluation of Real-Q Enterovirus Quantification Kit for Enterovirus by Real-time PCR

송두열,김신영,조선아,함형일,황상현,임영태,김형회,장철훈,이은엽 대한진단검사의학회 2010 Annals of Laboratory Medicine Vol.30 No.6

Background : Molecular methods have enabled rapid diagnosis of aseptic meningitis and have reduced both unnecessary therapeutic interventions and medical costs. In this study, we evaluated the analytical performance of the recently developed Real-Q Enterovirus Quantification kit (BioSewoom Inc., Korea). Methods : We evaluated the detection limit, precision, linearity, and cross-reactivity of the Real-Q Enterovirus Quantification kit and compared it with the conventional PCR method. From March to September 2009, we tested 91 CSF specimens from patients who visited the pediatrics department of the university hospital with symptoms of aseptic meningitis or infantile sepsis, and we also tested 48 CSF specimens from patients with febrile convulsion for differential diagnosis. Results : The Real-Q Enterovirus Quantification kit showed good linearity (r=0.997) within a range from 3×102 to 3×1010 copies/mL, and the detection limit of the kit was 83 copies/mL. The withinrun, between-run, and between-day CVs were 5.3-7.6%, 9.5-12.3%, and 11.4-13.4%, respectively. There was no cross reactivity between enteroviruses and various microorganisms. Positive results were obtained for 39.1% (25/64) of the patients suspected of aseptic meningitis and 44.4% (12/27)of the patients suspected of infantile sepsis. However, among the 48 children with febrile conversion, only 4 were positive for enterovirus. Further, the concordance with conventional PCR was high (73/74). Conclusions : The Real-Q Enterovirus Quantification kit showed excellent linearity and high reliability with a broad reportable range. It showed good detection rate when used with clinical specimens and also showed a high concordance with the conventional method. Therefore, this assay would be clinically useful not only in diagnosis of aseptic meningitis but also in differential diagnosis of infantile sepsis. (Korean J Lab Med 2010;30:624-30)

도서지역 응급환자 이송을 위한 충남형 닥터 UAM 개발 전략

송두열(Doo-youl Song),김태홍(Taehong Kim) 한국정보통신학회 2021 한국정보통신학회 종합학술대회 논문집 Vol.25 No.2

충청남도 도서지역에 주민들이 정기적으로 이용할 수 있는 공공의료시설은 보건진료소 14개, 건강생활지원센터 1개, 병원선 1척이 전부이며, 이러한 시설과 장비로는 중증외상, 뇌혈관 심혈관 질환 등의 응급환자 발생 시 효과적으로 대응할 수 없다. 가장 신속한 응급환자 이송 수단은 단국대학교병원(천안시 소재)에 배치된 닥터헬기를 이용하는 것이다. 그러나 배치된 닥터헬기는 1대 뿐이고, 야간에는 운항을 할 수 없으며, 충청남도 전 지역을 담당하므로 다수 환자 발생 시에는 신속한 이송에 한계가 있다. 따라서 4차 산업의 한 분야인 도심 항공 모빌리티(UAM) 산업과 도서지역 응급환자 이송체계의 문제점을 보완하는 ‘충남형 닥터UAM 개발’의 필요성을 검토하고자 한다. There are only 14 public medical facilities available to residents regularly in the island area of Chungcheongnam-do, one health life support center, and one hospital ship, and these facilities and equipment cannot effectively respond to emergency patients such as severe trauma, cerebrovascular and cardiovascular diseases. The fastest means of transporting emergency patients is to use a doctor helicopter deployed at Dankook University Hospital (based in Cheonan). However, there is only one doctor helicopter deployed, and it cannot operate at night, and since it is in charge of all areas of Chungcheongnam-do, there is a limit to rapid transport in the event of a large number of patients. Therefore, we would like to review the necessity of “Chungnam-type Doctor UAM Development” to compensate for the problems of the urban aviation mobility (UAM) industry and the emergency patient transport system in islands, a field of the 4th industry.

Bacterial Endocarditis Caused by Abiotrophia defectiva in a Healthy Adult: A Case Report with Literature Review

제형곤,송두열,장철훈 대한임상미생물학회 2019 Annals of clinical microbiology Vol.22 No.1

Infective endocarditis caused by Abiotrophia defectiva is rarely encountered. A 67-year-old male transferred from a local hospital presented with severe dyspnea and pulmonary edema. Preoperative transthoracic echocardiography revealed severe mitral regurgitation with large vegetation. Blood cultures grew A. defectiva, a gram positive, nutritionally deficient streptococcus variant. Emergent mitral valve replacement through right thoracotomy was performed, and after completing six weeks of antibiotic combination therapy (vancomycin, ampicillin, and gentamicin), the patient recovered fully. Because of the need for prompt surgical treatment and long-term antibiotic therapy and lack of laboratory experience with the organism, physicians and laboratory workers should pay close attention to the possibility of A. defectiva infective endocarditis when gram positive cocci are detected in blood cultures. (Ann Clin Microbiol 2019;22:-27)

적혈구 비예기항체 빈도 및 분포의 산출기준에 따른 결과값 비교

김신영,강정은,송두열,김경환,김형회,이은엽,손한철 대한진단검사의학회 2009 Annals of Laboratory Medicine Vol.29 No.2

Background : The frequencies and distributions of unexpected antibodies have been reported using two different criteria, based on either number of persons tested or number of tests performed. But there has been no study that compared the results of analyses based on these two different criteria using the same data set. Methods : Unexpected antibody tests performed in a University Hospital during recent 6 yr (January 2002-December 2007) were retrospectively analyzed: 76,985 tests (59,503 persons) for screening and 875 tests (749 persons) for identification. Data were analyzed using two different criteria, based on ‘persons tested’ and ‘tests performed’. Antibodies had been screened and identified using LISS/Coombs gel cards with DiaMed-ID system (DiaMed AG, Switzerland). Results : Frequencies of unexpected antibodies based on ‘persons tested’ and ‘tests performed’ were 1.32% and 1.34%, respectively (P=0.88). For frequently detected as well as rarely detected antibodies, there were no significant differences in the frequencies based on two different criteria. However, for rarely detected antibodies (anti-Xga and Anti-E & D), the frequencies based on ‘tests performed’ were higher than those based on ‘persons tested’, affecting a change in the order of frequencies of antibodies detected. Conclusions : As there were no significant differences in the frequencies of unexpected antibodies calculated using two different criteria, both criteria can be used together for the patient population in our hospital. However, two criteria should be compared to validate the results for other populations. 배경 : 비예기항체의 빈도와 분포의 후향적 분석에 있어, 국 내에서는 일반적으로‘환자’를 기준으로 분석한 결과(인수기준) 와‘검사결과의 건수’를 기준으로 분석한 결과(건수기준)가 함 께 보고되고 있다. 그럼에도 불구하고, 아직까지 이 두 분석 기 준에 따른 결과 값을 서로 비교한 연구는 없다. 본 논문에서 저 자들은 비예기항체의 빈도와 분포를 두 가지 분석 기준에 따라 각각 분석하고, 서로 비교해보았다. 방법 : 2002년 1월에서 2007년 12월까지, 대학병원에 의뢰된 76,985건(59,503명)의 비예기항체 선별검사와 875건(749명)의 비예기항체 동정검사를‘인수기준’과‘검사기준’으로 후향적 분 석을 하였다. 비예기항체 선별검사와 동정검사는 LISS/Coombs 겔 카드와 DiaMed-ID system (DiaMed AG, Switzerland)을 사용하여 시행하였다. 결과 : 비예기항체의 빈도는‘인수기준’과‘건수기준’이 각각 1.32%와 1.34%로 나타나 통계적으로 유의한 차이를 보이지 않 았다(P =0.88). 비교적 흔한 항체와 상대적으로 드문 항체에서 모두 항체 빈도는 두 기준 간에 유의한 차이를 보이지 않았다. 그 러나, 상대적으로 드문 비예기항체(항-Xga와 항-E&D)들은‘인 수기준’에 비해‘건수기준’에서 높은 빈도를 나타내 검출되는 항체의 빈도 순위에는 두 기준 간에 차이를 보였다. 결론 : 본원의 환자군에서는, 연기준 통계를 실시할 경우, 인 수기준과 건수기준 간에 유의한 차이는 없어, 두 기준의 혼용이 가능할 것으로 사료된다. 그러나, 통계 빈도나 대상군이 변할 경 우, 건수기준의 값은 인수기준으로 확인되어야 할 것이다.

고정 헌혈 장소로써의 3차 의료기관 헌혈자 분석

이현지,신경화,송두열,이선민,김인숙,장철훈,김형회 대한수혈학회 2017 大韓輸血學會誌 Vol.28 No.1

Background: Blood transfusion is important when treating patients with anemia or bleeding; thus, supply of blood components should be stable prior to transfusion. To recruit donors, blood donation sites should be conveniently located. This study evaluated factors responsible for increased donation rates in hospitals and the characteristics of the donors in hospital blood banks without a fixed blood collection site nearby. Methods: We retrospectively reviewed 687 blood donations at a blood donation center in Pusan National University Yangsan Hospital (PNUYH) from March 2011 to June 2016. A total of 3,053,695 blood donors listed in the 2014 Korean Red Cross Annual Report were compared to donors in PNUYH. We analyzed the age distribution of donor at blood donation centers from Korean Red Cross according to presence and number of high school and college. Results: Comparison with total blood donors in Korea revealed that there were more blood donors in their thirties, office workers and business owners at PNUYH (P<0.001). The percentage of younger donors in their twenties differed significantly according to the presence of a college within a 4 km radius of the blood donation center (P=0.03). The presence of a high school did not affect the proportion of teenage donors (P=0.833). Conclusion: The blood donation rate at our medical institution without fixed blood collection sites nearby increased. A regional hospital may be used as a blood collection site to recruit donors in areas in which there are no fixed blood donation centers.

Optimal Phlebotomy Interval to Change Hematocrit Levels in Patients with Polycythemia

이현지,신경화,송두열,이선민,김형회 대한수혈학회 2016 大韓輸血學會誌 Vol.27 No.3

Background: Phlebotomy is used to maintain hematocrit levels <45% to prevent polycythemia-related thrombotic events. However, guidelines for the phlebotomy intervals are lacking. Therefore, we analyzed post-phlebotomy changes in hematocrit and determined the optimal phlebotomy intervals for patients with polycythemia. Methods: Between March 2009 and August 2016, we performed 441 phlebotomies for 48 patients with polycythemia. Patients with high-risk polycythemia vera (PV) or secondary polycythemia with hypertension or arrhythmia were medicated with hydroxyurea. We divided the patients into three groups based on phlebotomy interval: <2 weeks, 2∼4 weeks, and >4 weeks. Results: No patients with secondary polycythemia and 25.8% of the patients with PV had thrombotic events pre-phlebotomy. Post-phlebotomy, none of the patients experienced a thrombotic event. The average decrease in hematocrit level was significantly different between the three groups, being 1.98±1.90% (<2 weeks), 0.73±2.53% (2∼4 weeks), and –0.46±4.80% (>4 weeks). Conclusion: To prevent thrombotic events, phlebotomy is a safe and effective treatment to reduce hematocrit levels in patients with polycythemia, regardless of medication. For the maximum effect, a <2-week phlebotomy interval to reduce and <4-week phlebotomy interval to maintain hematocrit levels could be effective.

국내 임산부의 비예기항체 빈도와 신생아의 예후 분석

양유진,신경화,송두열,이선민,김인숙,김형회,이현지 대한수혈학회 2019 大韓輸血學會誌 Vol.30 No.1

Background: In pregnant women, the frequency of irregular antibodies that cause hemolytic disease of the fetus and newborn (HDFN) vary between study populations. The clinical manifestations of HDFN differ according to the specificities and degree of irregular antibodies. This study examined the frequency and nature of maternal alloimmunization and neonatal outcomes. Methods: Pregnant women, who underwent irregular antibody screening for prenatal testing at an obstetrics clinic in a single center, were enrolled. Those who screened positive for irregular antibodies were selected as the test group, and age- and obstetrics history-matched pregnant women were selected as the control group to evaluate the pregnancy outcomes according to irregular antibodies. Results: The prevalence of irregular antibodies was 2.78% (42/1,508). With the exception of an unidentified antibody, anti-D was the most frequently identified antibody, followed in order by anti-E and anti-Lea. The rate of fetal death was higher in the test group (6/37, 16.2%) than in the control group (1/37, 2.7%) (P=0.047). Eight pregnant women had anti-C or anti-D, one woman had a stillbirth, and four living neonates developed hyperbilirubinemia. Of six pregnant women with anti-E alone or with other alloantibodies, three experienced a spontaneous abortion or stillbirth. Among the six newborns with maternal anti-Lea and anti-Jka, four developed hyperbilirubinemia, but their mothers did not experience a spontaneous abortion or stillbirth. Conclusion: The prevalence of unexpected antibodies among pregnant Korean women was 2.78%. A significant difference in neonatal outcomes was observed, including the death rate, prematurity, and hyperbilirubinemia, depending on the specificity of the unexpected antibody.

말초혈액 줄기세포 채집술의 최적화를 위한 말초혈액 CD34+ 세포 기준치

이현지,신경화,송두열,김신영,김형회,이은엽,손한철 대한수혈학회 2011 大韓輸血學會誌 Vol.22 No.1

Background: Peripheral hematopoietic stem cell mobilization is increasing due to its advantages. For successful engraftment, obtaining sufficient stem cells is prerequisite. The number of CD34+ cells of collected blood are widely used to predict the engraftment potential. To determine the optimal point for collection of peripheral blood stem cell (PBSC), enumeration of the number of CD34+ cells in peripheral blood (PB) is known to be helpful. The purpose of this study is to analyze cutoff value of CD34+ cells in PB. Methods: We analyzed 407 cases of autologous PBSC collection and 107 cases of allogenic PBSC collection during 2004∼2009 in Pusan National University Hospital. Complete blood count, HPC fraction and number,CD34+ cells in PB and product of PBSC collection were analyzed. Results: The each number of mononuclear cells and HPC in PB showed a strong correlation with CD34+ cells in PB. A strong correlation between the number of circulation CD34+ cells in PB on the day of collection and the number of collected CD34+ cells was found. The ROC curve revealed that the cutoff point having the optimal sensitivity and specificity at 8.5/uL for target CD34+ cells ≥1.0×106/kg, 10.5/uL for target CD34+cells ≥1.5×106/kg and 13.5/uL for target CD34+ cells ≥2.0×106/kg in this study. Conclusion: To obtain a sufficient yield of CD34+ cells during PBSC collection, determination of cut off point for each target CD34+ cells/kg is helpful to decide the collection.