1 Korean J Clin Lab Sci. 2011, 43(1) : 1-5 ISSN A Comparative Evaluation of Three Rapid Tests of Syphilis and ARCHITECT Syphilis TP Won-Shik

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1 1 ISSN A Comparative Evaluation of Three Rapid Tests of Syphilis and ARCHITECT Syphilis TP Won-Shik Kim Department of Labaratory Medicine, Chungbuk National University Hospital, Cheongju , Korea The infection rate of syphilis is still increasing in the world especially in developing countries and the infection is often seen in large amounts of clinical specimens. For the diagnosis of this disease, Rapid Plasma Reagin (RPR)/ Venereal Disease Research Laboratory (VDRL) has still been used as one of major primary methods to diagnose syphilis even though the test readings are somewhat subjective with high false positive rates. Recently, the automatic ARCHITECT Syphilis TP, which is based on the detection of the TP-specific antibodies, has been introduced in many laboratories. Therefore, the clinical assessment of the method is needed to provide primary diagnosis of syphilis at the moment. We evaluated 3 different manual rapid kits and ARCHITECT Syphilis TP comparing with RPR/FTA-ABS and analysed their diagnostic properties. From February 2006 to April 2008, 203 positive and 250 negative specimens, obtained from Chungbuk National University Hospital were used for the evaluation. In the evaluation between manual rapid kits, their specificities were as high as 99.2 ~ 99.6% while their sensitivities were observed with little differences; 98.0% (199/203) for Kit A, 96.6% (196/203) for Kit B, and 97.4% (197/203) for Kit S. In the case of ARCHITECT Syphilis TP test, it showed 100% specificity (250/250) and 98.5% sensitivity (249/250). Kappa values comparing with RPR/FTA-ABS were for Kit A, for Kit B and Kit S, and for ARCHITECT Syphilis TP. From our evaluation, we found out that manual rapid tests and ARCHITECT Syphilis TP have very good clinical accuracies and high kappa agreements with RPR/FTA-ABS. Due to its automation and quick simultaneous diagnosis with another serological markers, we suggest that the ARCHITECT Syphilis TP is one of best suitable method for the primary diagnosis of syphilis and that it might be able to replace RPR method in the laboratories. Key Words : Syphilis, Rapid test, ARCHITECT Syphilis TP 서론 매독은성 ( 性 ) 접촉에의한 Treponema pallidum 의감염 으로발생하는질환이다 (Willcox, 1972). 감염후 10~90 일 내에발생하는매독을초기매독이라하며, 그질환은 1~3 주 Corresponding author: Kim, Won-Shik. Department of Labaratory Medicine, Chungbuk National University Hospital, Cheongju , Korea. Tel: , wshik7025@hanmail.net Received : 29 January 2011 Return for modification : 13 March 2011 Accepted : 24 March 2011 일간존속하다자연적으로혹은치료를받음으로써치유된다. 초기매독증상, 즉일차하감 (primary chancre) 이없어진 2~10주후전신적으로피부발작이나타나는데, 이시기를이차매독이라한다. 초기매독의약 30% 는치료하지않고도완전히치유되며, 약 30% 는성접촉에의해서전염될수있는잠복매독이되고, 약 40% 만이현증감염으로서 3차매독으로진행된다 ( 오와이, 1991) 년 Wassermann 등이처음으로매독진단에있어서혈청학적검사법을발전시킨이래로현재사용되고있는매독의혈청학적검사방법을널리사용되고있으며선별검사로잘알려진 VDRL (venereal disease research laboratory)/ RPR (rapid plasma reagin) 는매독환자의혈청또는혈장내에생성된항체와비슷한물질인리아긴 (reagin) 과반응 1

2 시키는비특이적인검사법으로매독감염이외의말라리아감염, 백신접종, 자가면역질환, 결핵이나폐렴등세균및바이러스감염과노인등에서도증가하여 20~30% 로매우높은위양성률을나타낸다 (Catterall, 1961; Harris 등, 1962; Grossman과 Peery, 1969; Kaufman 등, 1974) 년 Mahoney 등이매독치료에 penicillin을사용하였으며 (Lucas, 1972; Willcox, 1972), 최근 Zeltser와 Kurban(2004) 의보고에의하면감염률이점차증가하고있는추세이다. 우리나라에서도 2002년부터 HIV 양성환자를중심으로 1기, 2기매독의양성률이증가한다는보고가있다 ( 정등, 2004). 우리나라질병관리본부감염병웹통계시스템자료 ( 에의하면매독은 2003 년도 586건에서이후점차적으로증가하여 2006년도에는 1188건, 2008년에는 1561건으로약 3배가량증가한것으로나타났다. 이와같이매독은점차증가추세로다량의검체를신속정확한검사가요구되고있으나, 아직도 RPR/ VDRL 검사가전세계적으로매독진단의선별검사로이용되고있다. 또한, 매독환자의확진을위해서는수기법으로 Treponema pallidum 에대한특이항체확인을위해 TPHA (Treponema pallidum hemagglutination assay) 또는 FTA- ABS (fluorescent treponemal antibody absorption) 법으로확인검사를해왔다. RPR/VDRL 검사는수기법이므로다량의검체를신속히처리하는데시간이많이걸리고결과판독에있어서도다소주관적이며생물학적위양성률을보이는단점이있다. 이러한단점을보완하기위해 1980년대에들어효소면역검사법에의한매독검사가처음소개되었으며 (Müller와 Moskophildis, 1984; Young 등, 1992), 최근국내에서도개발되어보고되었다 ( 최등, 1999). 효소면역검사법에사용되는항원은매독항원그자체이거나혹은재조합기술에의한항원이다 (Young, 1998; Zrein 등, 1995; Young 등, 1998). RPR은알려진바와같이매우높은위양성률을보여일선검사실에서매독의선별검사로서한계가있어, 이를 Syphilis IgG EIA법으로대체될것이라는보고가있다 (Pope, 2004). 이들면역검사법의경우, 민감도는 RPR과동등하며특이도는보다뛰어나기때문에대부분의검사에이방법이사용되고, RPR은매독의치료효과를모니터링하고재감염여부를확인하는데에사용될것이라는보고도있다 (Jurado 와 Rafael, 1996). 이에본연구자들은 FTA-ABS 검사에서양성인검체와음성을보인대조군검체를이용해, 최근알려진매독항원을이용한특이항체검출의신속검사법과 rapid test의자동화법인 ARCHITECT Syphilis TP 방법을비교조사하였으며, 이때진단의정확도는 FTA-ABS 검사결과를기준으로평가하였다. 재료및방법 1. 재료 2006년 2월부터 2008년 4월까지충북대학교병원진단검사의학과에매독혈청검사로의뢰된환자의검체중에서 FTA-ABS 검사에서양성의결과를보인 203 예와음성의결과를보인 250 예를대상으로조사하였다. 이때사용된검체들은 RPR 검사와 FTA-ABS 검사의결과가동일하였다. 2. 방법 1) RPR 시험과 FTA-ABS RPR 시험은 RPR Card (Asan Pharm, Inc., Korea) 를사용하였으며 FTA-ABS 는 FTA-ABS IFA System (ZEUS Scientific, Inc., USA) 을사용하였다. 시험방법은각제조사의설명서를따라수행하였다. 2) ARCHITECT Syphilis TP 매독혈청검사를위한자동화장비는 ARCHITECT i2000 SR (Abott Inc., USA) 를사용하였다. 또한, 시약은 ARCHITECT Syphilis TP Reagent Kit을사용하였으며, 시험방법은제조사의설명서를따라수행하였다. 3) 신속검사국내에서많이사용되고있는 3 종류의신속검사키트, 즉, EasyTest Syphilis (Asan Pharm, Inc., Korea; 키트 A), Nanosign Syphilis (Bioland, Co., Korea; 키트 B), 그리고 2 A Comparative Evaluation of Three Rapid Tests of Syphilis and ARCHITECT Syphilis TP

3 Bioline Syphilis (SD., Korea; 키트 S) 을평가시험에이용 하였다. 이들키트사용은각제조사의설명서에따라서수 행하였다. 4) 진단적정확도계산 진단적정확도, 즉민감도, 특이도, 양성예측치, 그리 고, 음성예측치등은 Jacobson 방법을따라계산하였으며 (Jacobson, 1998), 카파일치율 (kappa agreement) 는 Cohen 의방법을이용하여계산하였다 (Cohen, 1960). 여기서, 진단적정확도는양성및음성표준치에대해각 키트들의시험치비율을구한다음이를백분율로환산한 것이다. 표준방법 양성 (+) 음성 (-) 합계 키트결과양성 (+) a b a+b 음성 (-) c d c+d 합계 a+c b+d a+b+c+d 민감도 = a/(a+c), 특이도 = d/(b+d), 양성예측치 = a/(a+b), 음성예측치 = d/(c+d) 1. 진단적정확도 결과 203 건의양성검체들에대해서키트 A 는 199 건, 키트 B 는 196 건, 키트 S 는 197 건, 그리고 ARCHITECT Syphilis TP 는 200 건의양성결과를보였으며이들의민감도는 98.0%, 96.6%, 97.4%, 그리고 98.5% 로각각나타났다 (Table 1; p <0.05). 250건의음성검체를이용한시험에서는키트 A 와키트 B는 249건, 키트 S는248건, 그리고 ARCHITECT Syphilis TP는 250건의음성의결과를보여이들의특이도가 99.6%, 99.6%, 99.2%, 그리고 100% 로나타났다 (Table 1; p <0.05). 한편, 위양성결과를나타낸검체 1건은신속검사키트에서모두공통적으로나타냈다. Table 2는이들신속검사키트들과 ARCHITECT Syphilis TP에대한민감도, 특이도, 양성예측도, 그리고음성예측도를나타냈다.. 2. 검사법간비교 RPR/FTA-ABS 의결과에대한 ARCHITECT Syphilis TP 와신속검사키트들간의일치도를확인하기위해서 Cohen 의카파값 (κ) 을구하였다. 카파일치율을구하는시험에서는 ARCHITECT Syphilis TP는 0.987(p <0.0003), 키트 A에대해서는 0.978(p <0.0005), 그리고키트 B와 S에대해서는 0.964(p <0.0002) 로나타났다 (Table 2). 따라서, RPR/FTA- ABS와의비교시험에있어 ARCHITECT Syphilis TP이가장높은일치도를보여주었다. 신속검사키트중에서는키트 A 가가장높게나타났다. 한편, ARCHITECT Syphilis TP와신속검사키트들의비교시험에있어서는키트 A와는 4 건이, 그리고, 키트 B와 S와는 7 건이불일치한결과를나타냈다. 여기서, ARCHITECT Syphilis TP의검체간일치율은키트 A 에대해서는 99.1%(449/453), 그리고키트 B와 S에대해서는 98.5%(446/453) 로나타났다. Table 1. Clinical evaluation of three rapid tests and ARCHITECT Syphilis TP Rapid test Kit A* Kit B* Kit S* ARCHITECT Syphilis TP* RPR/FTA-ABS* Sum * +, Positive; -, Negative. p<0.05 A Comparative Evaluation of Three Rapid Tests of Syphilis and ARCHITECT Syphilis TP 3

4 Table 2. Clinical characteristics of three rapid tests and ARCHITECT Syphilis TP Sensitivity (%) Specificity (%) PPV* (%) NPV (%) Kappa value Kit A (p <0.0005) Kit B (p <0.0002) Kit S (p <0.0002) ARCHITECT Syphilis TP (p <0.0003) * PPV, positive predictive value NPV, negative predictive value. Kappa agreement of each kit was compared and calculated with RPR/FTA-ABS test. PPV and NPV were calculated by Jacobson s method and kappa values were by Cohen s method. 고찰 매독의검사법은 Wassermann 등에의해보체결합검사로처음으로소개된이후 cardiolipin-lecithin-cholesterol 복합체를항원으로사용하는 VDRL 법과매독항체를직접검출하는검사법으로발전하였고, 이는지난보고와같이크게변하지않았다 (Wicher 등, 1999). 매독은염색이나배양으로진단하기어렵기때문에혈청학적검사에의존하고있는데전통적으로이중검사원칙을현재까지고수하고있다. 즉, 첫번째로 VDRL/RPR 선별검사를시행하고, 두번째단계로매독특이항원을이용하여이에대한항체를검사하는TPHA또는FTA-ABS 로확인검사를수행하고있다 (Hook와 Marra, 1992; Backhouse 와 Hudson, 1995; Reisner, 1997). 여기서 VDRL/RPR 선별검사는자동화가불가능하여검사시간과노동력이많이요구되며, 20-30% 정도의위양성률을가진다는보고 (Catterall, 1961; Harris 등, 1962; Grossman 와 Peery, 1969; Kaufman, 1974) 뿐만아니라, 결과판독이다소주관적인단점을가지고있다. 이에반해최근다량의검체를빠르고신속하게처리할수있는자동화검사법 (ARCHITECT Syphilis TP) 이각검사실에소개되고있다. 이를선별검사법으로사용하게되면 VDRL/ RPR 법의단점을극복할수있을것으로예상이되지만, 이에앞서충분한진단적정확성과선별검사로서의적합성을 확인하는것이선행되어야한다. ARCHITECT Syphilis TP는자동화된일종의효소면역측정법으로써매독에특이적인항원을이용하여매독항체를검사하는방법이다. 이는현재검사실에도입되어있는신속검사키트와그원리가비슷하나검사단계중에세정단계가있어보다정확한결과 ( 특히, 낮은위양성 ) 를도출할수있다고일반적으로알려져있다. 본평가시험에있어서도 250 건의음성검체에대해서 100% 의특이도를보여세정단계가없는신속검사키트들보다우수한결과를나타내었다. RPR과 FTA-ABS 법과의민감도비교시험에서도 ARCHITECT Syphilis TP는 100% 의양성예측률을보였으며, 카파값 (κ) 도 0.987로서 FTA-ABS 결과와매우높은일치도를보여주고있어, 이방법이정확도가높은매독검사임을알수있었다. 매독의선별검사를위해서는대량검체처리가용이해야하고, 자동화가가능하며, 결과판독이객관적이며, 수혈전검사항목의하나로써 HBsAg, anti-hbs, anti-hbc 및 anti HIV등과함께일괄검사로신속하게처리할수있는방법이가장이상적이다. 기존의 RPR/VDRL 법은이미언급한대로선별검사로서의단점이있다. 신속검사키트들은정확도가비교적높고사용법이간단하고신속하다는장점은있지만, 다량의검체를자동화로처리하기에는불가능하고간혹판독에있어혼선을주는단점을갖고있다. 이 4 A Comparative Evaluation of Three Rapid Tests of Syphilis and ARCHITECT Syphilis TP

5 와같은단점들을충족시키며선별검사용으로사용하기에 는 ARCHITECT Syphilis TP 법이적합한방법으로추천될 수있다고사료된다. 참고문헌 1. Backhouse JL, Hudson BJ. Evaluation of immunoglobulin G enzyme immunoassay for serodiagnosis of yaws. J Clin Microbiol. 1995, 33(5): Catterall RD. Collagen disease and the chronic biological false positive phenomenon. Q J Med. 1961, 30: Cohen JA. A coefficient of agreement for nominal scales. Educ Psychol Meas. 1960, 20: Grossman LJ, Peery TM. Biologically false-positive serologic tests for syphilis due to smallpox vaccination. Am J Clin Pathol. 1969, 51(3): Harris A, Brown L, Portnoy J, Price EV. Narcotic addiction and BFP reactions in tests for syphilis. Public Health Rep. 1962, 77: Hook EW 3rd, Marra CM. Acquired syphilis in adults. N Engl J Med. 1992, 326(16): Jurado, Rafael. Syphilis serology: a practical approach. Infect Dis Clin Pract. 1996, 5(6): Jacobson RH. Validation of serological assays for diagnosis of infectious diseases. Rev Sci Tech. 1998, 17(2): Kaufman RE, Weiss S, Moore JD, Falcone V, Wiesner PJ. Biological false positive serological tests for syphilis among drug addicts. Br J Vener Dis. 1974, 50(5): Lucas JB. The national venereal disease problem. Med Clin North Am. 1972, 56: Müller F, Moskophidis M. Evaluation of an enzyme immunoassay for IgM antibodies to Treponema pallidum in syphilis in man. Br J Vener Dis. 1984, 60(5): Pope V. Use of Treponemal tests to screen for syphilis. Infect Med. 2004, 21: Reisner BS, Mann LM, Tholcken CA, Waite RT, Woods GL. Use of the Treponema pallidum-specific captia syphilis IgG assay in conjunction with the rapid plasma reagin to test for syphilis. J Clin Microbiol. 1997, 35(5): Wicher K, Horowitz HW, Wicher V. Laboratory methods of diagnosis of syphilis for the beginning of the third millennium. Microbes Infect. 1999, 1(12): Willcox RR. A world-wide view of venereal disease. Br J Vener Dis. 1972, 48(3): Young H. Syphilis. Serology. Dermatol Clin. 1998, 16(4): Young H, Moyes A, McMillan A, Patterson J. Enzyme immunoassay for anti-treponemal IgG: screening or confirmatory test? J Clin Pathol. 1992, 45(1): Young H, Moyes A, Seagar L, McMillan A. Novel recombinantantigen enzyme immunoassay for serological diagnosis of syphilis. J Clin Microbiol. 1998, 36(4): Zeltser R, Kurban AK. Syphilis. Clin Dermatol. 2004, 22(6): Zrein M, Maure I, Boursier F, Soufflet L. Recombinant antigenbased enzyme immunoassay for screening of Treponema pallidum antibodies in blood bank routine. J Clin Microbiol. 1995, 33(3): 오재세, 이건섭. 면역혈청학. 제 3 판,1999, p , 신광출판사, 서울. 22. 정희창, 조재현, 박완범, 이기덕, 이창섭, 김홍빈, 오명돈, 최강원. 인간면역부전바이러스 (HIV) 감염자사이에서의 1 기및 2 기매독의유행. 감염과화학요법. 2004, 36(6): 최수진, 오흥범, 오선영, 황유성, 이정환. 매독항체효소면역검사시약 동아시필리스 의평가. 대한수혈학회지. 1999, 10(2): A Comparative Evaluation of Three Rapid Tests of Syphilis and ARCHITECT Syphilis TP 5

대한진단검사의학회지제 27 권제 5 호 2007 Korean J Lab Med 2007;27:324-9 DOI /kjlm 원저 임상화학 자동화매독검사인 Mediace Rapid Plasma Reagin과 Treponema palli

대한진단검사의학회지제 27 권제 5 호 2007 Korean J Lab Med 2007;27:324-9 DOI 10.3343/kjlm.2007.27.5.324 원저 임상화학 자동화매독검사인 Mediace Rapid Plasma Reagin과 Treponema pallidum Latex Agglutination 양성결과분석 허희진 1 이교관 1 김의석 2 채석래