A de novo Proximal 6q Deletion Confirmed by Array Comparative Genomic Hybridization

우광숙,김지은,김경은,김묘징,유재호,안현숙,Lisa G. Shaffer,한진영 대한진단검사의학회 2010 Annals of Laboratory Medicine Vol.30 No.1

Deletions of chromosome 6q, particularly in the proximal region, are relatively rare. Here, we report on a de novo interstitial deletion of (6)(q13q16.2) in a girl with facial dysmorphism, congenital hip dislocation, porencephaly, and brain atrophy. Array comparative genomic hybridization analysis showed arr 6q13q16.2(73,378,824-99,824,130), demonstrating higher resolution than the conventional cytogenetic findings, del(6)(q12q15). The clinical data were analyzed and compared with those of similar patients previously reported in the literature. (Korean J Lab Med 2010;30:84-8)

Outbreak of Pseudomonas Oryzihabitans Pseudobacteremia Related to Contaminated Equipment in an Emergency Room of a Tertiary Hospital in Korea

우광숙,최재임,Bo-Ram Kim,Ji-Eun Kim,김경희,Jeong man Kim,한진영 대한감염학회 2014 Infection and Chemotherapy Vol.46 No.1

Pseudomonas oryzihabitans is frequently found in various sites within hospital settings, including sink drains and respiratorytherapy equipment. Although it rarely causes human infections, P. oryzihabitans has recently been considered a potential nosocomialpathogen, especially in immunocompromised hosts. We report our experience of an outbreak of P. oryzihabitans pseudobacteremia,presumably due to faulty aseptic preparation of a saline gauze canister.

Urinary Neutrophil Gelatinase-Associated Lipocalin Levels in Comparison with Glomerular Filtration Rate for Evaluation of Renal Function in Patients with Diabetic Chronic Kidney Disease

우광숙,최재임,김보람,김지은,안원석,한진영 대한당뇨병학회 2012 Diabetes and Metabolism Journal Vol.36 No.4

Background: Neutrophil gelatinase-associated lipocalin (NGAL) is a promising biomarker of acute kidney injury. There is a growing body of evidence suggesting that NGAL is also a marker of kidney disease and severity in chronic kidney disease (CKD). We studied the utility of urinary NGAL in more accurately predicting renal function in patients with diabetic CKD. Methods: We studied possible relationships between urinary NGAL, estimated glomerular filtration rate (eGFR), and proteinuria in diabetic CKD patients and in healthy populations. Results: Urinary NGAL levels were significantly higher in CKD patients than in healthy controls (96.0 [2.7 to 975.2] ng/mL vs. 18.8 [1.3 to 81.9] ng/mL, P=0.02), and the GFR was lower among CKD patients (49.3 [13.1 to 78.3] mL/min/1.73 m2 vs. 85.6 [72 to 106.7] mL/min/1.73 m2, P<0.0001). The urinary NGAL level showed a significant inverse correlation with GFR (r=-0.5634, P<0.0001). The correlation analyses between urinary protein level and urinary NGAL levels and GFR were as follows: urine protein and urinary NGAL (r=0.3009, P=0.0256), urine protein and GFR (r=-0.6245, P<0.0001), urine microalbumin and urinary NGAL (r=0.1794, P=0.2275), and urine microalbumin and GFR (r=-0.5190, P=0.0002). Conclusion: From these results, we concluded that urinary NGAL is a reliable marker of renal function in diabetic CKD patients. However, urinary NGAL did not provide more accurate information regarding renal function than GFR.

Performance Evaluation of the ELITe InGenius System for Detecting Cytomegalovirus, Epstein- Barr Virus, and BK Virus Infections

우광숙,Jin-Yeong Han 대한임상검사정도관리협회 2022 Journal of Laboratory Medicine And Quality Assuran Vol.44 No.3

Background: The ELITe-MGB Kit (ELITech Group, Italy) is a qualitative and quantitative nucleic acid amplification assay used for the detection and quantification of various viruses, especially in the clinical management of post-transplant infections. In this study, we evaluated the performance of a fully automated cassette-based real-time polymerase chain reaction (PCR) method for cytomegalovirus (CMV), Epstein-Barr virus (EBV), and BK virus (BKV) in comparison with the routine PCR method. Methods: The precision and linearity of each assay using the ELITe InGenius system were evaluated. Comparative studies of the ELITe MGB kit and commercially available real-time PCR assay were performed using clinical patient specimens for each virus. Results: The assay variability of the cycle threshold measurements was ≤1% for all concentrations. The analytical sensitivity of the assay was evaluated using purified control genomic DNA at known concentrations, and the coefficient of correlation was 0.999. Conclusions: The assay showed a good correlation between CMV DNA levels detected by routine PCR assay and excellent validation results. Therefore, the use of the ELITe MGB assay in combination with the ELITe InGenius system allows for rapid, sensitive, and reliable detection and quantification of viral DNA, making early evidence-based intervention possible. However, the clinical value of this assay needs further investigation.

Determination of the Prevalence of Aspirin and Clopidogrel Resistances in Patients with Coronary Artery Disease by using Various Platelet-function Tests

우광숙,김보람,김지은,고리영,Long-Hao Yu,김무현,한진영 대한진단검사의학회 2010 Annals of Laboratory Medicine Vol.30 No.5

Background: Dual therapy with aspirin and clopidogrel has emerged as the gold standard therapy for patients treated with drug-eluting stents (DES). However, there is variability in patients’ responses to this antiplatelet therapy, and some patients continue to show ischemic recurrences after therapy. The purpose of the study was to compare the simultaneously obtained results of various plateletfunction tests for assessing the prevalence of antiplatelet resistance in coronary artery disease patients undergoing DES therapy. Methods: A total of 66 patients were administered a loading dose of aspirin, clopidogrel, and cilostazol at least 12 hr before stenting. The results of VerifyNow (Accumetrics, USA), multiplate analyzer (Dynabyte Medical, Germany), and vasodilator-stimulated phosphoprotein/P2Y12 (Biocytex,France) assays were compared with those of light transmission aggregometry (LTA) analysis. Results: The P2Y12 reaction units and P2Y12% inhibition values obtained using the VerifyNow assay showed strong correlation (r) with the results of the LTA analysis. All tests results showed low concordance in defining the antiplatelet resistance in patients, and the degrees of agreement were as follows: 0 for aspirin reaction units; 0.25, P2Y12% inhibition; 0, aspirin-sensitive patients’ identification test; 0.21, ADPtest; and 0.14, platelet reactivity index, expressed as the k statistics. The prevalence of aspirin and clopidogrel resistances in patients resulted in remarkable variations, from 0%to 22.7% and from 9.1% to 48.5%, respectively. Conclusions: The clinical usefulness of the different assays for the correct classification of patients in terms of antiplatelet resistance remains unclear. Further studies are required to determine the best method for correlating the occurrences of adverse ischemic events. (Korean J Lab Med 2010;30:460-8)

Clinical Usefulness of Serum Cystatin C as a Marker of Renal Function

우광숙,최재임,김보람,김지은,한진영 대한당뇨병학회 2014 Diabetes and Metabolism Journal Vol.38 No.4

Background: Accurate renal function measurements are important in the diagnosis and treatment of kidney diseases. In contrast to creatinine, the production of serum cystatin C has been extensively reported to be unaffected by body muscle mass, age, gender, and nutritional status. Methods: Our study included 37 samples from diabetic chronic kidney disease (CKD) patients for whom serum creatinine tests had been requested and 40 samples from a healthy populations in Dong-A University Hospital between May 2010 and June 2010. The assay precision (i.e., the coefficient of variation) and the reference range of the serum cystatin C test were evaluated. We compared the estimated glomerular filtration rates (GFRs) based on cystatin C with those based on creatinine. Moreover, we investigated the influences of age, gender, weight, and muscle mass on serum creatinine and serum cystatin C. Results: There was a positive correlation between GFR based on creatinine and that based on cystatin C (r=0.79, P<0.0001) among the diabetic CKD patients. Serum creatinine and cystatin C were significantly correlated with body weight and muscle mass, but the strengths of these correlations were greater for serum creatinine. The precision study revealed excellent results for both the high and low controls. The 95% reference interval of cystatin C in the healthy population was 0.371 to 1.236 mg/L. Conclusion: Based on these results, we conclude that, despite the strong correlation between serum creatinine and cystatin C, cystatin C is less affected by weight and muscle mass and might represent a better alternative for the assessment of renal function.

Prevalence and Clinical Associations of Lupus Anticoagulant, Anticardiolipin Antibodies, and Anti-beta2-glycoprotein I Antibodies in Patients with Systemic Lupus Erythematosus

우광숙,김경은,김정만,정원태,김경희 대한진단검사의학회 2010 Annals of Laboratory Medicine Vol.30 No.1

Background : The presence of antiphospholipid antibodies (aPLs) is associated with the clinical features of antiphospholipid syndrome (APS), which comprises venous and arterial thrombosis and pregnancy loss, and systemic lupus erythematosus (SLE). The prevalence of aPLs has been reported to be different in patient populations affected by either of these conditions. We performed a retrospective study to evaluate the prevalence and clinical associations of aPLs, including lupus anticoagulant (LAC), anticardiolipin (aCL), and anti-beta2-glycoprotein I antibodies (anti-beta2-GPI) in a cohort of Korean patients with SLE. Methods : This study included samples from 88 SLE patients for whom aPL testing had been advised between June 2006 and July 2009 at the Dong-A University Hospital. Serum and plasma samples were tested for LAC, aCL (IgG, IgM), and anti-beta2-GPI (IgG, IgM) antibodies. Clinical data from patients were obtained from a review of medical records. Results : LAC was the most common (34.1% of total patients, 30/88) antibody, followed by IgM aCL (31.8%, 28/88), IgG aCL (18.2%, 16/88), and IgM and IgG anti-beta2-GPI (both 5.7%, 5/88 each). Positivity for LAC was strongly associated with venous/arterial thrombosis (P=0.002). Conclusions : LAC was the most common antibody detected in Korean SLE patients and is shown to have a significant association with the presence of venous/arterial thrombosis. The measurement of LAC may be clinically useful in identifying patients with SLE who are at a high risk for venous/arterial thrombosis. (Korean J Lab Med 2010;30:38-44)

t(9;21)(q13;21) 균형전좌 아버지로부터 출생한 9번 염색체 단완 및장완의 부분세염색체증후군

우광숙,김경은,권은영,김중표,한진영 대한진단검사의학회 2008 Annals of Laboratory Medicine Vol.28 No.2

Trisomy 9p is one of the most frequent autosomal anomalies compatible with a long survival rate. Clinical characteristics are craniofacial dysmorphisms including hypertelorism, prominent nose, deepset eyes, and down-slanting palpebral fissures. The degree of clinical severity in trisomy 9 roughly correlates with the extent of trisomic chromosomal material. If the trisomic segments include the long arm of chromosome 9, clinical findings may not fit into the trisomy 9p but rather resemble trisomy 9 mosaic syndrome and are associated with muscular and cardiac anomalies. Therefore, breakpoints as well as clinical findings need to be precisely defined for differential diagnosis. Cases with trisomy 9p, especially involving proximal 9q, are very rare in Korea. The patient was a 1,920 g male infant born at 36 weeks 3 days of gestation to a 27-yr-old mother and 32-yr-old father after Cesarian section. The patient showed specific craniofacial anomalies, cardiac defects, and hand anomalies. Routine cytogenetic analysis, performed on peripheral blood using GTG banding, showed 46,XY,+der(9)t (9;21)(q13;q21),-21pat. Furthermore, FISH (Vysis Inc., USA) analysis with whole chromosome painting probes confirmed the derivative chromosome 9. (Korean J Lab Med 2008;28:155-9)

Interferon-gamma Release Assay의 임상적 이용

우광숙,김경희 대한진단검사의학회 2016 Laboratory Medicine Online Vol.6 No.1

Mycobacterium tuberculosis infection remains an important problem in Korea and globally. Interferon-gamma release assays (IGRAs) are blood-based tests that measure the amount of interferon-gamma released by T lymphocytes after stimulation by antigens specific for M. tuberculosis. IGRAs are not recommended for diagnosis of active pulmonary tuberculosis because they cannot distinguish between latent tuberculosis infection (LTBI) and the active disease. For extrapulmonary tuberculosis, IGRAs are considered adjuvant diagnostic tools. The diagnostic performance of IGRAs differs according to infection site. The sensitivity of IGRAs in children is suboptimal in low- and middle-income countries. In Korea, for children who have received a M. bovis bacille Calmette-Guérin (BCG) vaccine after 1 yr of age or have been inoculated with the BCG vaccine twice or more, IGRA is recommended instead of the tuberculin skin test (TST). Diagnosis and treatment of LTBI before the initiation of anti-tumor necrosis factor (TNF) agents are recommended in patients with immune-mediated inflammatory diseases because anti-TNF therapy is associated with an increased risk of developing tuberculosis. A strategy using both TST and IGRA is used for immunocompromised adults in Korea; positive results obtained by either test confirm a diagnosis of LTBI. Negative results of only TST are not considered conclusively negative for LTBI. In addition to interferon-gamma, a biomarker to discriminate between active and latent tuberculosis is required, and IP-10 and IL-2 are currently being investigated in this regard. The use of IGRA would improve the diagnosis of extrapulmonary tuberculosis and LTBI. Mycobacterium tuberculosis 감염은 국내와 전세계적으로 여전히 중요한 문제이다. Interferon-gamma release assay (IGRA)는 M. tuberculosis 특이항원으로 말초혈액 내의 T 림프구를 자극한 후에 유리된 interferon-gamma의 양을 측정하여 결핵균에 감염되었는지를 검출하는 검사이다. IGRA는 잠복결핵감염과 활동성 결핵을 감별할 수 없기 때문에 활동성 폐결핵의 진단에는 추천되지 않지만 폐외결핵의 진단에 보조적인 진단 방법으로 이용될 수 있다. 폐외결핵에서의 IGRA 진단적 성능은 감염 부위에 따라 다르다. 소아에서의 IGRA 민감도는 소득수준이 낮거나 중간 정도인 국가에서는 기대에 미치지 못하는 것으로 보고되고 있다. 국내에서는 BCG 백신을 1세 이후에 맞았거나, 2회 이상 접종 받은 경우에는 투베르쿨린 검사 대신에 IGRA로만 결핵 감염 여부를 확인하도록 권장하고 있다. Tumor necrosis factor (TNF) 길항제 치료는 결핵 발생의 위험을 증가시키기 때문에 TNF 길항제 치료 예정자인 경우에는 잠복 결핵 감염을 진단, 치료하도록 해야 한다. 국내에서는 성인 면역저하자인 경우 IGRA 단독 혹은 IGRA와 투베르쿨린 검사 병합법을 사용할 수 있으며, 투베르쿨린 검사 단독으로 잠복 결핵 감염 음성으로 진단하는 것은 권고하지 않는다. interferon-gamma 외에도 IP-10과 IL-2가 활동성 결핵과 잠복결핵감염을 구별할 수 있는 표지자로 연구가 진행되고 있다. 요약하면 IGRA의 사용은 잠복결핵감염과 폐외결핵의 진단에 도움이 되고 있다.

새로운 ARCHITECT AFP Assay의 분석능 평가

우광숙,안규대,임현호,한진영 대한진단검사의학회 2018 Laboratory Medicine Online Vol.8 No.2

Alpha-fetoprotein (AFP) is frequently used for hepatocellular carcinoma (HCC) diagnosis and surveillance. Although the current ARCHITECT AFP (List number 7K67) assay range is 0–350 ng/mL, all samples with test results between 200 and 350 ng/mL must be diluted and retested until their levels are <200 ng/mL. A new ARCHITECT AFP (8100/3P36) assay with a dynamic range of up to 2000 ng/mL has been introduced. The aim of this study was to perform a method comparison between the current ARCHITECT AFP assay and the new assay. The precision study showed excellent results for both high and low controls. There was a positive correlation between the two assay systems and clinical samples. The new ARCHITECT AFP assay with a wide assay range demonstrated good analytical performance. Therefore, the current ARCHITECT AFP assay could be replaced by the new assay, which is more convenient and minimizes manual labor. 알파태아단백(AFP)은 간세포암의 진단과 감시에 흔히 사용된다. 이전에 사용하던 ARCHITECT AFP (List number 7K67) 시약은 그측정 범위가 0–350 ng/mL여서 200–350 ng/mL 사이의 검체는 희석이 필요하다. 새로운 ARCHITECT AFP (8100/3P36) 시약은 그측정 범위가 2,000 ng/mL로 확대되었다. 이 연구의 목적은 이전의시약과 새로운 시약의 비교평가이며 새로운 시약의 분석능 또한평가하였다. 비교평가 결과 우수한 상관성을 보였으며 정밀도 검사에서도 우수한 결과를 보였다. 새로운 ARCHITECT AFP 시약은그 측정 범위가 넓어 희석에 필요한 수고를 줄일 수 있으며 우수한분석능을 가지고 있으므로 이전의 시약을 대체하기에 충분한 것으로 사료된다.