대한진단검사의학회지제 26 권제 6 호 2006 Korean J Lab Med 2006;26:424-30 원저 진단면역학 실시간정량적중합효소연쇄반응을이용한혈청 B 형간염바이러스 DNA 검사 허정 1 고원욱 1 김광하 1 강대환 1 송근암 1 조몽 1 김형회 2,3 이은엽 2 부산대학교의학전문대학원내과학교실 1, 진단검사의학교실 2, 생명의료정보실 3 HBV DNA Quantitation Using Real-time PCR Jeong Heo, M.D. 1, Won Ook Go, M.D. 1, Gwang Ha Kim, M.D. 1, Dae Hwan Kang, M.D. 1, Geun Am Song, M.D. 1, Mong Cho, M.D., Hyung Hoi Kim, M.D. 2,3, and Eeu Yup Lee, M.D. 2 Departments of Internal Medicine 1 and Laboratory Medicine 2, Unit of Biomedical Informatics 3, Pusan National University, School of Medicine, Busan, Korea Background : Accurate measurement of the concentration of hepatitis B virus (HBV) DNA in clinical samples is important for the appropriate treatment of patients and evaluation of their therapeutic responses. In addition, the concentration of HBV DNA in the serum of patients with chronic HBV infection has a very broad range. Real-time PCR is very sensitive and useful to detect HBV DNA in a wide range of concentrations. We designed new primers and probes for real-time PCR to detect HBV DNA. Methods : Primers and probes specific for HBV were designed. EUROHEP HBV DNA standards (NIBSC, Hertfordshire, UK) with the HBV DNA concentration of 7.0 10 4 copies/ml was used to determine the calibration curve and efficacy for the real-time PCR assay. Sensitivity, dynamic range, and precision were evaluated. The correlation between the real-time PCR and Cobas Amplicor HBV Monitor TM assay in the measurement of serum HBV DNA concentrations in 52 patients with chronic HBV infection was evaluated. Results : The sensitivity of the assay was approximately 6.08 10 2 copies/ml for HBV, and the quantitation was accurate and reproducible over a wide dynamic range from 6.1 0 2 to 6.5 10 9 copies/ml without any dilution of specimens. The assay showed low coefficients of variation of repeatability (3.7-24.9%) and reproducibility (7.8-24.7%). The results were found to correlate well with those obtained by Cobas Amplicor HBV Monitor TM kit. Conclusions : We provide a new in-house method for the measurement of serum HBV DNA using real-time PCR, which enables us to detect HBV DNA rapidly, sensitively, and accurately. (Korean J Lab Med 2006;26:424-30) Key Words : HBV DNA quantitation, Real time PCR, Cobas amplicor 서 B형간염바이러스 (Hepatitis B virus, HBV) 감염환자를평가하기위한검사법은혈청학적진단법에서분자생물학적진단법 접수 : 2006 년 3 월 13 일접수번호 : KJLM1935 수정본접수 : 2006 년 10 월 31 일게재승인일 : 2006 년 11 월 12 일교신저자 : 김형회우 602-739 부산광역시서구아미동 1-10 부산대학교의과대학진단검사의학교실전화 : 051-240-7414, Fax: 051-247-6560 E-mail: hhkim@pusan.ac.kr 론 으로발전하고있다. 바이러스의증식능을검출하는검사는 HBe- Ag 검사, DNA polymerase 활성측정법, 그리고바이러스농도측정법 (viral load test) 등이다. 자연적인혹은치료에의한 HBe- Ag의혈청전환은만성 B형간염바이러스감염의자연경과에서중요한전환기가되며임상병기를판단하는데필수적인요소로서인터페론혹은라미부딘치료후효과판정의기준이된다. 그러나 HBeAg 음성만성 B형간염 (HBeAg negative Chronic Hepatitis B; HBeAg negative CHB) 은 HBeAg은음성이나 HBV가활발하게증식하면서간손상을지속적으로야기하여간경변증과간암발생위험이증가한다 [1, 2]. HBeAg 음성인상태 424
실시간정량적중합효소연쇄반응을이용한혈청 B 형간염바이러스 DNA 검사 425 는 HBeAg 음성만성 B형간염과비활동성 HBsAg 보유상태 (inactive HBsAg carrier; inactive carrier) 가포함되어있는이질적요소로구성되어있다. 대부분의 HBeAg 음성만성 B형간염환자는간효소치의지속적인상승이나잦은변동이관찰될수있으나, 일부환자는일정기간정상간기능을보일수있어비활동성 (non-replication) 혹은저활동성 (low-replication) B형간염바이러스보유자와임상적으로구분하기어려운경우가많다 [3]. 따라서만성 B형간염환자에대한진단과치료에더민감한검사법의필요성이대두되었다. 혈청 HBV DNA의직접적인검출은 HBV 감염을진단하고항바이러스제제치료반응평가에가장신뢰할검사법이다. 나아가, 혈청 HBV DNA 정량검사는 HBV 복제수준에대한정보를제공하고, 예후평가나항바이러스제제에대한반응지침으로이용될수있다 [4-9]. 최근혈청 HBV DNA의정량적측정을위한표준화되고상업화된예민한 PCR 방법들이개발되어상호보완적으로사용되고있다 [10]. PCR을이용한 HBV DNA 정량법중 Cobas Amplicor HBV Monitor test TM (Roche Diagnostics Systems, Meylan, France) 는높은민감도를가지고있으나검사법의측정가능범위가 2.0 10 2-2.0 10 5 copies/ml로좁아정확한정량이가능한직선범위내에서측정하기위해검체희석을필요로하는단점이있어이를극복하기위해측정가능범위가넓은실시간정량적중합효소연쇄반응법 (real-time PCR) 들이개발되었다. 본연구에서저자들이고안한 real-time PCR법으로우리나라만성 HBV 감염환자의혈청 HBV DNA치를측정하고, 기존사용되고있는 Cobas Amplicor HBV Monitor TM 검사법과비교함으로써그적절성을평가하고자하였다. 대상및방법 1. 대상 로진단된환자중 HBV DNA가 Cobas Amplicor HBV Monitor test TM (Roche Diagnostics Systems) 으로 10 3 copies/ml 이상인 52명의혈청을무작위로추출하여대상으로하였고, 혈청은측정하기전까지 -70 에서보관되었다 (Table 1). 2. Real-time PCR 법에의한정량 1) HBV DNA standards의준비 7.0 10 4 copies/ml 농도의 EUROHEP standard (NIBSC, Hertfordshire, UK) 를연속희석 (serial dilution) 하여 real-time PCR을이용한 HBV DNA 정량의교정곡선 (calibration curve) 과유효성 (validation) 평가에사용하였다. 2) Calibrators 제조를위한 HBV DNA standard plasmid의준비환자혈청에서분리한 HBV의전체유전자를시발체 (primers) P1-Eco와 P2-Pst를사용하여 PCR 증폭하였다 (Table 2). 증폭된결과물은 pgem-t Easy (Promega, Mandison, WI) 에클로닝하였으며이렇게만들어진 plasmid DNA는 plasmid mini kit (QIAGEN GmbH, Hilden, Germany) 로추출하였다. Standard plasmid는공식인정정량되어진 EUROHEP standard를기준으로 HBV DNA를정량한다음, 5.0 10 9, 5.0 10 7, 5.0 10 5, 5.0 10 3 copies/ml의네가지 HBV DNA 농도를 real-time PCR 를이용한 HBV DNA 정량측정을위한 calibrators로제조하였다. 3) 혈청으로부터 HBV DNA 추출 HBV 감염환자의혈청 200 L를 QiAamp DNA blood kit (QIAGEN GmbH, Hilden, Germany) 를사용하여최종적으로 50 L 용리완충액 (elution buffer) 으로추출하여 QIAamp spin column (QIAGEN GmbH, Hilden, Germany) 으로부터 real-time PCR의주형 (template) 으로실험에사용하기전까지 -20 에보관하였다. 부산대학교병원에서 2005 년 1 월부터 6 월까지만성 B 형간염으 Table 1. Clinical and laboratory features of patients Number of patients 52 Mean age (range), yr 43 (10-75) Sex, male/female, n 34/18 Log10 [Serum HBV DNA], mean±s.d, copies/ml 6.0±1.0 HBeAg positive/negative, n (%) 33/19 (63.5/36.5%) Chronic hepatitis/liver cirrhosis, n 27/25 Table 2. Primers of PCR amplication for standard plasmid Primer P1-Eco, forward, 5 -GAGAGAATTCTTTTTCACCTCTGCCTAATCA-3 P2-Pst, reverse, 5 -GAGACTGCAGAAAAAGTTGCATGGTGCTGG-3 4) Real-time PCR을위한 oligonucleotide primers와 probe 제작 Real-time PCR을위한시발체와탐촉자 (probes) 에대한제작은 TibMol사 (Berlin, Germany) 에의뢰하여제작하였다. 시발체는잘보존되는 HBV core 말단영역 (HBV Forward, HBV 508 Table 3. Primers and probes of real-time PCR for HBV DNA quantitation Primer HBV Forward, 5 -GAC CAC CAA ATG CCC CTA T-3 HBV 508 Reverse, 5 - AAG CGC TGC GTG TAG TTT CT-3 Probe HBV FL, 5 -GAV GCA GGW CCC CTA GAA GAA GAA-fluorescein-3 HBV LC, 5 -LCRde-TCC CTC GCC TCG CAG ACG AAG TRC TSphosphate-3
426 허정 고원욱 김광하외 5 인 2.4 kb 2.1 kb pre S1 pre S2 s P HBV FL HBV IC HBV F HBV R 2349 2444 C strand DR1 DR2 5 5 pre-c X 0.7 kb 3.5 kb Fig. 1. The genomic site (dotted box) of HBV DNA for primers and probes. Reverse) 을증폭하며최종산물은약 500 bp 의크기를가진다. 탐촉자는 PCR 산물에직접적으로결합하는서열을제작하여 donor fluorescein 탐촉자 (HBV FL) 와 acceptor LightCycler-Red 640 (LCRed) 탐촉자 (HBV LC) 를합성하여사용하였다 (Table 3). 시발체 HBV Forward는 2,297-2,316 bp, 시발체 HBV 508 Reverse는 2,416-2,436 bp를대상으로하였고, 탐촉자 HBV FL은 2,355-2,379 bp, 탐촉자 HBV LC는 2,381-2,406 bp를대상으로하였다 (Fig. 1). 5) Real-time PCR에의한 HBV DNA 정량 Real-time PCR은 Roche Diagnostics LightCycler, version 1.0 (Roche Diagnostics, Mannheim, Germany) 을사용하여수행하였다. 30 L의반응혼합액은주형 10 L, 10 LightCycler FastStart DNA 주교잡 (Master hybridization) 탐촉자 (Roche Molecular Systems, California, USA) 3 L, HBV Forward 시발체 0.5 M, HBV Reverse 시발체 0.5 M, HBV FL donor 탐촉자 0.2 M, HBV LC acceptor 탐촉자 0.2 M와 MgCl 2 4 mm을포함하였다. Real-time PCR의반응조건은 95 에서먼저 10분간반응을하여 FastStart Taq DNA polymerase를활성화시켰으며총 50 주기를진행하는동안 95 에서 10초간 denaturation, 55 에서 5초간 annealing, 72 에서 17초간 extension을하였다. 반응이종결된후각각의 HBV DNA 시료는 Roche Diagnostics Light- Cycler 소프트웨어 (3.5.3판) 로분석, 정량하였다. 3. Amplicor HBV Monitor TM 법에의한정량 첨부된설명서에따라 Cobas Amplicor HBV Monitor test TM (Roche Diagnostics Systems, Meylan, France) 를사용하여제조사의사용설명서에따라다음과같이혈청 HBV DNA를정량하였다 [11, 12]. 4. 정밀도평가 5.0 10 8 copies/ml 농도의 HBV standard plasmid를단계희석하여사용하였다. 각농도별로매일연속 5번 5일간반복측정하였다. 이결과를이용하여검사중변이계수 (within-run coefficient of variation), 일간변이계수 (between-day coefficient of variation) 를구하여평가하였다. 5. 특이도평가본원에건강검진목적으로내원한건강한성인중 Architect HBsAg (Abbott Laboratories, IL, USA) 검사에서음성인 50 검체를이용하여 Real-time PCR를시행하였다. 6. 직선성평가 HBV standard plasmid를순차적으로 10 2 copies/ml에서 10 10 copes/ml 범위에서 10배수연속희석한농도에대해각농도마다 5회반복측정하여직선성을평가하였다. 7. 상관성비교본원내과에서만성B형간염으로진단된환자중다양한범위의농도를가진 52명의혈청을이용하여 Cobas Amplicor HBV Monitor TM (Roche Diagnostics Systems) 와비교하였으며 Cobas Amplicor HBV Monitor TM 법에서는 2.0 10 5 copies/ml 이상인검체는희석하여정량하였다. 선형회귀모델을이용하여검사간상관성을평가하였다. 8. 통계처리 Excel statistics package (Microsoft Corporation, New York,
실시간정량적중합효소연쇄반응을이용한혈청 B 형간염바이러스 DNA 검사 427 USA) 를이용하여정밀도평가를위해서는변이계수를구하였으며, 직선성평가에서는일반선형모델로희귀분석을실시하였고검사간상관성분석은선형회귀분석을이용하였다. P<0.05 일때통계적으로유의한것으로판정하였다. 결 과 1. Real-time PCR 법에의한 HBV DNA 검사의정밀도평가 Real-time PCR 검사의검사중변이계수 (within-run coefficient of variation) 는 3.7-24.9% 범위이고일간변이계수 (betweenday coefficient of variation) 는 7.8-24.7% 를보였다 (Table 4). 2. 특이도 Real-time PCR 검사로 HBsAg 음성인혈청전부에서 HBV DNA는증폭되지않아서진단특이도는 100% 이었다. Table 4. Precision of real-time PCR on serial dilution of standard plasmid (5.0 10 8 copies/ml) 0.028 0.024 0.022 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 B C D E 0.004 0.002 A 0.000-0.002 0 2 4 6 8 101214161820222426283032343638404244464850 Fluorescence (F2/F1) Precision Log10 dilution Abbreviation: CV, Coefficient of variation. Observed (copies/ml) Mean SD Cycle Number CV (%) Within-run 0 4.8 10 8 5.6 10 7 11.6-2 7.2 10 6 2.6 10 5 3.7-4 5.1 10 4 3.8 10 3 7.5-6 4.5 10 2 1.1 10 2 24.9 Between-day 0 4.7 10 8 3.7 10 7 7.8-2 5.9 10 6 1.1 10 5 18.6-4 5.5 10 4 7.4 10 3 13.6-6 5.4 10 2 1.3 10 2 24.7 Fig. 2. Sigmoid fluorescence curves obtained with serial dilutions of standard plasmid. A, distilled water; B, 5.0 10 9 copies/ml; C, 5.0 10 7 copies/ml; D, 5.0 10 5 copies/ml; and E, 5.0 10 3 copies/ml. 3. Real-time PCR 법에의한 HBV DNA 검사의직선성평가 Real-time PCR의측정가능범위를확인하기위해 EURO- HEP standard로정량된 standard plasmid를증류수를사용하여순차적으로희석하였다. 각검사마다 5회반복하여시행한결과전형적인 S자형형광곡선 (sigmoid fluorescence curves) (Fig. 2) 를보여주었다. EUROHEP standard의해정량된 standard plasmid를순차적으로희석하여확인된측정가능한농도범위는 6.1 10 2 copies/ ml에서 6.5 10 9 copies/ml 내에서결정계수 (R 2 ) 가 0.9988으로매우우수한직선성을보였다 (Fig. 3). Observed real-time PCR HBV titer (Log10 HBV copies/ml) Real-time PCR HBV titer (Log10 HBV copies/ml) 4. 혈청에서 HBV DNA 정량과 Cobas Amplicor HBV Monitor TM 와의연관성 대상환자모두에서본 real time PCR 법으로 HBV DNA 가 10 8 6 4 2 0 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 1.E+09 Serial dilutions of standard plasmid 10 8 6 4 2 y=0.9904x+1.7525 R 2 =0.9988 Fig. 3. The dilutional linearity of HBV DNA quantitation using realtime PCR. The standard curve was obtained with serial dilutions of standard plasmid (, mean of 5 experiments). y=1.0025x-0.0299 R 2 =0.7553 0 0 2 4 6 8 10 Cobas Amplicor HBV Monitor test (Log10 HBV copies/ml) Fig. 4. Correlation between real-time PCR HBV DNA quantitation and the Cobas Amplicor HBV Monitor TM test (P<0.001). Regression analysis of 52 sera of chronic hepatitis B patients analysed by both test methods. The real-time PCR HBV DNA quantitation test was duplicated. All specimens had titers above 1,000 copies/ ml. Samples above 2.0 10 5 copies/ml in the the Cobas Amplicor HBV Monitor TM test were diluted.
428 허정 고원욱 김광하외 5 인 검출되었다. 모든검체의 HBV DNA치는 10 3 copies/ml 이상이었으며, 두검사법간의 HBV DNA치는기울기 =1.0025, R 2 = 0.7553로유의한상관성이있었고 (P<0.001), 두검사치차이의평균과표준편차는각각 0.69 log 10, 0.60 log 10 이었다 (Fig. 4). 고찰 1980년대초반에는분자생물학적진단법의발전으로 HBV DNA 교잡법 (hybridization) 의정성한계가 10 6-10 7 copies/ml이었으나, 1980년대후반부터는 PCR의도입으로 HBV DNA 정성한계가 10 2-10 3 copies/ml로낮아졌다. 따라서 HBV DNA 검사법의발전으로 HBV 감염의병인, 자연사를더잘이해할수있게되었고치료반응에대한평가도용이해졌다. 이전에는 HBV DNA 교잡법으로혈청에서 HBV DNA가검출되지않는환자는비활동성감염으로간주되었다. 이런환자는다른원인의간질환이없다면, 치료를요하지않고간내염증도없는것으로여겨졌다. 급성 B형간염에서회복된환자에서교잡법으로는 HBV DNA 가검출되지않지만더민감한 PCR 검사법에서는 10 3 copies/ml 이하의낮은 HBV DNA치로검출되었고 [13, 14], 급성감염회복후에도 HBV DNA는수년간지속된다 [15]. HBeAg음성, anti-hbeab양성인만성 HBV 감염환자대부분이 PCR을이용한 HBV DNA 검사에서양성이다 [13, 14]. 이런임상소견은몇가지임상적으로중요한의문을제기한다. 첫째, 어느정도의혈청 HBV DNA치가진행성간질환과관련이있는가? 둘째, 어느정도의 HBV DNA치가치료적응이되는가? 셋째, 치료중지속적인바이러스억제, HBeAg 혈청전환과간염완치를위해어느정도까지혈청 HBV DNA치를낮추어야하는가? 이러한의문들에대한답을제시하고자미국국립보건원 (National Institute of Health, NIH) 워크숍에서임의로혈청 HBV DNA 10 5 copies/ ml를비활동성보유자와만성 B형간염을구분하는기준으로제안하였다 [16]. 이 HBV DNA치는 PCR을이용하지않는상업적인키트를이용하는 HBV DNA 검사의대략적인검출한계이다. PCR법이개발되기전인 1980년대와 1990년대초반에이루어진연구에서자연적으로혹은치료후 HBeAg 혈청전환이생긴환자에서정상 alanine aminotransferase (ALT) 치, 간조직활성도감소, 간기능부전위험감소와생존기간증가를보였고당시의교잡법으로는 HBV DNA가검출되지않았다. 만약 PCR 법으로검사되었다면대부분의이들환자에서양성소견을보였을것이나 HBV DNA치가낮아치료의대상이되지는않았을것이다. 그러나 HBeAg 양성혹은음성만성 B형간염과비활성보유자의기준점으로혈청 HBV DNA 10 5 copies/ml는확실하지않다 [17-19]. 만성 B형간염환자에서주기적인 HBV DNA 정량검사는감염기전연구, 진단, 치료방향결정, 치료효과판정과항바이러스제제투여로인한내성발생에대한체계적인관리지침을 제공하며, 이를위해폭넓은검출범위를요한다. PCR에기초한 HBV DNA 정량법들은항바이러스치료동안이나비증식 HBs- Ag 보유자같은낮은수준의 HBV DNA 정량에유리하나측정가능범위는한계가있다. Cobas Amplicor HBV Monitor TM 법은상한직선범위가 2.0 10 5 copies/ml로대부분의 HBe항원양성인치료전만성 B형간염환자, 치료중내성발현이의심되는검체는희석해야한다. 이러한점들을개선하고자 HBV 감염환자의혈청 HBV DNA 치를대상으로저자들이고안한 real-time PCR을이용한정량법의타당성을평가하고기존사용되고있는 Cobas Amplicor HBV Monitor TM 검사법과상관성을평가하였다. 저자들이고안한 realtime PCR을이용한 HBV DNA 정량법은 6.1 10 2 copies/ml 에서 6.5 10 9 copies/ml까지직선성을보이므로허등 [18] 이보고한우리나라의만성 B형간염바이러스보유자에서항바이러스약제투여전. 후와 HBe항원의유. 무와관계없이정확한정량이가능하다. 다른 real-time PCR법에의한검사범위와유사하다 [13, 20-24]. 본연구의 HBV DNA 검사치가검출범위내에서반복성과재현성이 CV가 25% 이하로 PCR을이용한상업용 HBV DNA 정량검사법들과유사하였다 [25]. 이미 real-time PCR을이용한 Cobas TaqMan TM (Roche Diagnostics, Mannheim, Germany) HBV DNA 정량법이상용화되어있으며유효검출범위는 1.7 10 2 copies/ml에서 8.5 10 8 copies/ml이다. Cobas TaqMan TM 법은 Cobas Amplicor HBV Monitor TM 법에비해검사범위가넓어검체희석을요하지않으나상대적으로검사비용이고가인것이단점이다. 본연구에서고안된시발체와탐촉자를사용한 real-time PCR에기초한 HBV DNA 정량법은 Cobas Amplicor HBV Monitor TM 법에비해서도검사비용이저렴하며검사범위가 Cobas TaqMan TM 법과거의동일하다. 검출범위의하한은 6.1 10 2 copies/ml로 Cobas Amplicor HBV Monitor TM 법의 2.0 10 2 copies/ml와 Cobas TaqMan TM 법의 1.7 10 2 copies/ml에비해다소높으나, 이는저자가사용한 Roche Diagnostics LightCycler, version 1.0의모세관크기가 30 L의반응혼합액만을수용할수밖에없어반응액을제외하고 10 L의분리된혈청검체만을투입할수있는데비해 Cobas TaqMan TM 법은모세관의용적이커서 100 L의반응액중 50 L의분리된혈청검체를측정하는데기인할것으로생각된다 [24]. 개선된 LightCycler version 2.0은모세관의용적이 50 L 로증가되어더많은분리된혈청검체를투입할경우더높은민감도를기대할수있다. 높은 HBV DNA치가의심되는검체인경우희석해야하는 Cobas Amplicor HBV Monitor TM 법과의비교에서도유의한상관성을보였으며두검사법간의측정된범위에서농도차이가 0.69 log 10 로상업적으로사용중인다른검사법에비해차이가없었다 [25]. 본연구에사용된시발체와탐촉자는유전형에관계없이잘
실시간정량적중합효소연쇄반응을이용한혈청 B 형간염바이러스 DNA 검사 429 보존되어있는 core부위를대상으로하여 HBV의유전형에관계없이정확한정량이될것으로여겨지나이를검정하기위한추가적인연구가필요한것으로생각되고 Cobas TaqMan TM 법과동일하게혈청에서 HBV DNA 추출, 증폭및분석이 4시간이내로검사시간이짧아다른검사법에비해신속하였다. 결론적으로 real-time PCR을이용한 HBV DNA 정량법은신속하고민감하게넓은검출범위로정량측정이가능한것으로생각된다. 요약배경및목적 : 정확한 HBV DNA의측정은치료대상선정, 치료반응평가등에매우중요하다. 중합효소연쇄반응법 (PCR) 을이용한 HBV DNA 정량법은검사법의직선성 (linearity) 을나타내는농도범위가좁은반면, 실시간정량적중합효소연쇄반응법 (real-time PCR) 은검사범위가넓은장점이있다. 저자들은 real-time PCR로 HBV DNA 정량을위한새로운시발체와탐촉자를고안하고, 혈청 HBV DNA치를측정하여검출범위, 반복성및재현성을평가하고 Cobas Amplicor HBV Monitor TM 법과비교하고자하였다. 대상및방법 : HBV DNA에특이적인시발체와탐촉자를고안하여, 7.0 10 4 copies/ml 농도의 EUROHEP standard HBV DNA (NIBSC) 를 real-time PCR 정량법의교정곡선 (calibration curve) 과유효성평가를위해연속희석하여사용하였고, 무작위로추출한만성 B형간염환자 52명의혈청 HBV DNA치를정량하였다. 정량결과를이용하여검출범위, 반복성을평가하고 Cobas Amplicor HBV Monitor TM 법에의한 HBV DNA치와상관성을평가하였다. 결과 : 본연구에서고안한 real-time PCR을이용한 HBV DNA 정량법의검출범위는 6.1 10 2 copies/ml부터 6.5 10 9 copies/ml까지였다. 반복성과재현성은 CV (coefficient of variation) 가각각 3.7-24.9%, 7.8-24.7% 였다. 희석하지않은본검사법에의한정량결과와 Cobas Amplicor HBV Monitor TM 법에의한 HBV DNA치비교에서상관계수 0.8691로높은상관성을보였다. 결론 : 본연구를통해개발한 HBV DNA Real-time PCR은민감하게넓은검출범위로정확한정량측정이가능하였고현재시판되는상업키트와비교하여동등한수준의성능을가진것으로사료된다. 참고문헌 1. Hoofnagle JH, Shafritz DA, Popper H. Chronic type B hepatitis and the healthy HBsAg carrier state. Hepatology 1987;7:758-63. 2. Kaneko S, Miller RH, Di Bisceglie AM, Feinstone SM, Hoofnagle JH, Purcell RH. Detection of hepatitis B virus DNA in serum by polymerase chain reaction. Application for clinical diagnosis. Gastroenterology 1990;99:799-804. 3. Hadziyannis SJ and Vassilopoulos D. Hepatitis B e antigen-negative chronic hepatitis B. Hepatology 2001;34:617-24. 4. Pawlotsky JM. Molecular diagnosis of viral hepatitis. Gastroenterology 2002;122:1554-68. 5. Saldanha J, Gerlich W, Lelie N, Dawson P, Heermann K, Heath A, et al. An international collaborative study to establish a World Health Organization international standard for hepatitis B virus DNA nucleic acid amplification techniques. Vox Sang 2001;80:63-71. 6. Aspinall S, Steele AD, Peenze I, Mphahlele MJ. Detection and quantitation of hepatitis B virus DNA: comparison of two commercial hybridization assays with polymerase chain reaction. J Viral Hepat 1995;2:107-11. 7. Barlet V, Cohard M, Thelu MA, Chaix MJ, Baccard C, Zarski JP, et al. Quantitative detection of hepatitis B virus DNA in serum using chemiluminescence: comparison with radioactive solution hybridization assay. J Virol Methods 1994;49:141-51. 8. Krajden M, Minor J, Cork L, Comanor L. Multi-measurement method comparison of three commercial hepatitis B virus DNA quantification assays. J Viral Hepat 1998;5:415-22. 9. Chan HL, Leung NW, Lau TC, Wong ML, Sung JJ. Comparison of three different sensitive assays for hepatitis B virus DNA in monitoring of responses to antiviral therapy. J Clin Microbiol 2000;38: 3205-8. 10. Hendricks DA, Stowe BJ, Hoo BS, Kolberg J, Irvine BD, Neuwald PD, et al. Quantitation of HBV DNA in human serum using a branched DNA (bdna) signal amplification assay. Am J Clin Pathol 1995;104:537-46. 11. Ho SK, Chan TM, Cheng IK, Lai KN. Comparison of the second-generation digene hybrid capture assay with the branched-dna assay for measurement of hepatitis B virus DNA in serum. J Clin Microbiol 1999;37:2461-5. 12. Niesters HG, Krajden M, Cork L, de Medina M, Hill M, Fries E, et al. A multicenter study evaluation of the digene hybrid capture II signal amplification technique for detection of hepatitis B virus DNA in serum samples and testing of EUROHEP standards. J Clin Microbiol 2000;38:2150-5. 13. Loeb KR, Jerome KR, Goddard J, Huang M, Cent A, Corey L. Highthroughput quantitative analysis of hepatitis B virus DNA in serum using the TaqMan fluorogenic detection system. Hepatology 2000;32: 626-9. 14. Noborg U, Gusdal A, Horal P, Lindh M. Levels of viraemia in sub-
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