ORIGINAL ARTICLE Korean J Obstet Gynecol 2012;55(7):485-492 http://dx.doi.org/10.5468/kjog.2012.55.7.485 pissn 2233-5188 eissn 2233-5196 RESISTANCE OF UTERINE RADIAL ARTERY BLOOD FLOW IS POSITIVELY CORRELATED WITH PERIPHERAL BLOOD NK CELL FRACTION IN PATIENTS WITH UNEXPLAINED RECURRENT SPONTANEOUS ABORTION Hwa Seon Koo, MD, Hyun Jeong Yi, MD, Min Young Lee, MD, Hyun Suk Ahn, MD, Min Hye Choi, MD, Na Young Sung, MD, Yu Im Hwang, MD, In Ok Song, MD, Mi Kyoung Koong, MD, Inn Soo Kang, MD, Kwang-Moon Yang, MD Department of Obstetrics and Gynecology, Cheil General Hospital and Women s Healthcare Center, Kwandong University College of Medicine, Seoul, Korea Objective To evaluate whether increased peripheral blood inflammatory immune cell can induce decrease of uterine blood flow in patients with unexplained recurrent spontaneous abortion (RSA). Methods This study designed prospectively 33 pregnant women between 5 to 7 gestational weeks with a history of unexplained RSA included in this study. 47 normal pregnant women between 5 to 7 gestational weeks without history of infertility and/or RSA included as a control. Peripheral blood natural killer (pbnk) (CD3 - /56 + ) fractions among peripheral blood monocyte (PBMC) were checked by flow cytometry. Uterine color-pulsed Doppler trans-vaginal ultrasound for evaluation of uterine radial artery RI was checked. Uterine radial artery resistance index (RI) compared between study and control group. After then, uterine radial artery RI was compared between high pbnk cell fraction above 12.1% among PBMC and normal pbnk cells fraction below 12.1%. Correlation between pbnk cell fraction to uterine radial artery RI was also evaluated. Results Uterine radial artery RI in early pregnancy was significantly higher in patients with RSA than that of normal control (0.60 ± 0.14 vs. 0.54 ± 0.12, P = 0.039). Especially, the mean value of uterine radial artery RI in RSA patients with elevated pbnk cells was significantly increased than that of normal control (0.62 ± 0.13 vs. 0.54 ± 0.12, P=0.029). Otherwise, pbnk cell fractions among PBMC displayed strong positive correlation to uterine radial artery RI (Pearson s correlation coefficient P=0.001, r = 0.667). Conclusion Increased pbnk cells can evoke decreased uterine blood flow by their pro-inflammatory action on micro vascular structure such as uterine radial artery. This can be a one causative mechanism of inducing spontaneous abortion by increased NK cells. But, larger scaled study is needed for clarify our results. Keywords: Recurrent spontaneous abortion; Natural killer cell; Uterine radial artery resistance index 일반적으로습관성유산 (recurrent spontaneous abortion, RSA) 은임신 20주이전 3번이상의자연유산으로정의되며, 300임신당하나의빈도로발생하는것으로알려져있다. 하지만 1) 태아의심장박동이있은후유산되었을경우, 2) 35세이상의고령산모에서유산되었을경우, 그리고 3) 불임환자등과같이임신이성공하기까지의과정이어려운경우등은 2회의연속유산시적절한진단과치료가요구된다고알려져있다 [1]. 습관성유산은전체가임여성의 0.5%-3% 에서발생한다고보고되고있으며그원인은유전적원인, 해부학적원인, 감염및자가항체등의원인으로분류될수있지만 30%-40% 의습관성유산환자에서는 Received: 2012.3.6. Revised: 2012.5.8. Accepted: 2012.5.21. Corresponding author: Kwang-Moon Yang, MD, PhD Department of Obstetrics and Gynecology, Cheil General Hospital and Women s Healthcare Center, Kwandong University College of Medicine, 17 Seoae-ro 1-gil, Jung-gu, Seoul 100-380, Korea Tel: +82-2-2000-7545 Fax: +82-2-2000-7790 E-mail: km1yang@naver.com This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright 2012. Korean Society of Obstetrics and Gynecology WWW.KJOG.ORG 485
KJOG Vol. 55, No. 7, 2012 기존의검사로그원인이밝혀지지않은원인불명 (unexplained cause) 으로분류되어왔다 [2,3]. 하지만비교적최근원인불명의습관성유산환자의진단을위해동종면역기전에의한원인이생식면역학자들을중심으로연구되고있으며습관성유산의면역학적원인에대한성공적인치료성과가보고되고있다. 여러연구결과에의하여습관성유산환자에서말초혈액의자연살해세포의비율이그대조군에비해현저하게증가되어있음이밝혀졌고, 이러한자연살해세포를감소시키는치료가임신의유지에도움이된다는것또한보고되어왔다 [4,5]. 국내의한연구결과에의하면습관성유산환자에서임신전측정한말초혈액의자연살해세포비율은대조군에비하여현저하게증가되어있었으며그절단값 (cut-off value) 을 12.1% 로정하였을때말초혈액자연살해세포비율이그이상증가된환자에서정상군에비해습관성유산의위험도는약 8.4배증가함을보고한바있다 [6]. 하지만증가된자연살해세포가습관성유산을유발하는원인기전은아직명확하지않다. 한기전으로자연살해세포가융모세포 (trophoblastic cell) 의림포카인활성효소 (lymphokine activated kinase) 에직접적으로작용하여융모세포의세포자멸사 (apoptosis) 를유발하여유산을일으킨다고설명하고있으며 [7], 또다른기전으로 tumor necrosis factor-alpha, interferon-gamma 와같은향염증성 (pro-inflammatory) 싸이토카인을분비하여태반기저부의모체- 태아간극 (inter-space in placental bed) 에무균성염증반응 (sterile inflammation) 을유발하며, 그결과미세혈관의혈전 (micro-vascular thrombosis) 이생기고이것이 RSA을일으킨다고설명하고있다 [8]. 한편다른연구에서는습관성유산환자에서임신전에자연살해세포의독성이정상대조군에비해현저하게증가되어자연살해세포의수적증가뿐아니라세포용해능의증가또한습관성유산의원인이됨을보고하고있다 [6]. 한편여러보고자에의해습관성유산환자에서자궁동맥혈관저항이증가되어있는것이관찰되었으며그것은자궁동맥에의한혈류공급이자궁내막의수용성 (receptivity) 을조절하며따라서자궁의저하된관류 (perfusion) 가습관성유산의원인으로작용할수있다고설명하고 있다 [2,3]. 또한자궁으로의혈류 (uterine blood flow) 를측정하는것이불임및 유산의위험성을진단하는유용한방법이라는연구결과가있으며 그중습관성유산환자에서는그대조군에비하여자궁동맥 (uterine artery) 의저항지수 (resistance index, RI) 가현저하게증가되어있다는 보고와자궁동맥의 pulsed doppler 가자궁혈류 (uterine circulation) 의 장애에의한원인불명의습관성유산환자를진단하는데유용한방법 이된다는보고가있었다 [9]. 하지만습관성유산환자에서자궁내혈 관의혈역학적또는혈류변화에관한연구는아직까지연구가많이이 루어지지않고있는실정이다 [10]. 최근의연구에의하면정상임신군에서임신초기부터임신중기까지 자궁동맥의저항지수는변화가없는반면자궁방사동맥 (uterine radial artery) 의저항지수는현저하게줄어드는변화를보였다. 이러한결과 는자궁내혈류를공급하는혈관중그저항이측정가능한최말단분 지인자궁방사동맥의혈류측정이임신초기에태아에게공급되는혈액 정도를자궁동맥에비해더잘반영한다고할수있겠다 [11]. 본연구에서저자들은습관성유산환자에서말초혈액의자연살해세 포비율변화가유산을일으키는기전으로자궁내혈관에무균성염증 반응을유발하며그결과자궁혈류변화에영향을줄수있을것이라는 가정하에원인불명의습관성유산환자에서비정상적으로증가된말초 혈액자연살해세포비율이자궁방사동맥의혈류를감소시키는지에대 해알아보고자하였다. 연구대상및방법 1. 연구대상군본연구는 2011 년 2 월부터 2011 년 6 월까지본원불임클리닉을내 원한습관성유산기왕력이있는환자를대상으로진행되었다. 자연 유산기왕력이 2 번이상있는임신 5-7 주여성 33 명을실험군 (RSA group) 으로설정하였다. 이들중습관성유산의원인이될수있는자 궁기형, 염색체이상, 항인지질항체증후군, 항갑상선글로불린항체및 Pregnant women at gestational age 5-7 wk (n = 80) Recurrent spontaneous abortion at gestational age 5-7 wk (n = 33) Fertile control at gestational age 5-7 wk (n = 47) Normal pbnk (pbnk cell <12.1%) (n = 13) Elevated pbnk (pbnk cell 12.1%) (n = 20) Fig. 1. Diagram of study subjects. pbnk, peripheral blood natural killer. 486 WWW.KJOG.ORG
Hwa Seon Koo, et al. Uterine artery Doppler in RSA 감염등이있는경우를제외하였다. 그리고습관성유산의기왕력이없 는임신초기의산모 47 명을대조군 (fertile control group) 으로선정하였 다 (Fig. 1). 2. CD3 - /CD56 + /CD16 + Peripheral blood natural killer (pbnk) cell 분획 (fraction) 측정각각의환자로부터말초혈액 10 ml 을채취하여그중 100 μl 의전 혈을사용하였다. CD3, CD56 및 CD16 세포표면항원을혈액세포에 단클론항체 (monoclonal antibody) 를이용하여간접형광염색하여유 세포분석기 (FACS Calibur, Becton-Dickinson Co, San Jose, CA, USA) 를사용하여분석하였다. 단클론항체는 CD3 - FITC/CD56 + CD16 + PE 를사용하였다. 간접형광염색법에서는모두 FITC-IgG1/PE- IgG2 를 음성대조형광물질로사용하였다. 헤파린이처리된진공시험관에채 A R1 (lymphocyte) gating CD3 - /CD16 + /CD56 + (upper right) part reading 취한전혈 100 μl 에형광색소가부착된각각의항체 10 μl 를넣어준 후, 잘혼합하여 4 o C 에서 20 분간반응시킨다. 적혈구용혈용액 1 ml 을넣고잘혼합하고실온암소에서 10 분간반응시켰다. 5 분간원심분 리 (1,600 rpm) 하여상층액을버리고 phosphate buffered saline 으로 2 회세척한후 1% paraformaldehyde 용액을넣고잘섞어준후분석하 였다. 결과분석은 Cell Quest pro software (FACS Calibur) 를이용하여 림프구만을 gating (R1) 한후, 선별된림프구들중에서 CD3 - /CD56 + / CD16 + 부분만을백분율 (CD3 - /CD56 + /CD16 + number/lymphocyte number 100) 로구하였다 (Fig. 2). 3. pbnk cell 의세포용해활성도측정각각의환자로부터말초혈액 10 ml 을채취하여 Ficoll-hypaque gradient solution 을이용하여림프구와단핵세포층 (peripheral blood monocytes, PBMCs) 을분리하여세척하였다. 수획한 PBMCs 와 PKH2 로염색한 K562 세포를함께배양하였으며, 용혈된표적세포 는 propidum iodide dye (PI) 를이용하여핵을염색하여유세포분석 기를사용하여분석하였다. 헤파린이처리된진공시험관에채취한말 초혈액 10 ml 에서 PBMCs 를분리하고, 세포수를측정하였다. K562 는배양액으로세척한후, PKH2 염색약 1 μl 를넣고잘섞어 1 분간반 응시킨후, 세포용해활성도분석용 K562 세포를준비하였다. 세포용 해활성도는 effector cell:target cell (E:T) 의비율을 50:1, 25:1, 그리 고 12.5:1 로 2 시간동안 PBMC 와 K562 cell 을함께반응시킨후, PI 로 1-5 분간염색한후분석하였다. 결과분석은 Cell Quest Pro Software 를이용하여각각의 E:T 비율에서의세포용해활성도 (K562 dead cell number/k562 whole cell number 100) 를계산하였다 (Fig. 2). 33 명의습관성유산기왕력이있는산모에서, 임신 5 에서 7 주사이 에혈액검사를위해혈액을채취한후유세포분석기를이용하여말초 혈액자연살해세포의비율및자연살해세포독성을측정하였다. 이전 연구결과를바탕으로습관성유산환자 33 명을자연살해세포비율 12.1% 를기준으로그이상인산모를증가 NK 군 (elevated NK, n = 20), 12.1% 미만인산모를정상 NK 군 (normal NK, n = 13) 로분류하였다 (Fig. 1). B Fig. 2. Analysis of peripheral blood natural killer (pbnk) cell fraction and NK cell cytolytic activities (NKA) by using flow cytometry at gestational age 5 to 7 weeks (A) analysis of pbnk by using flowcytometry. Circled area in left figure indicated lymphocyte population among peripheral blood monocyte (PBMC). Circled area in right figure indicated NK cell (CD3-56 + ) cell population among lymphocyte. (B) Analysis of NKA by using flow cytometry. NKA was checked by % dead target cell (K562 cell) after 2 hour incubation of PBMC in three different effector to target (E:T) ratio. 4. 자궁의혈류측정자궁혈류의측정은자궁으로혈류를공급하는말단혈관인자궁방사 동맥의저항지수를측정하는방법을사용하였다. 질식도플러초음파를 이용하여자궁의내막 (endometrium) 과근층 (myometrium) 의접합부 분에서자궁방사동맥을숙지한후그저항지수를측정하였으며저항 지수는최고수축기혈류속도에서이완기말혈류속도를뺀값을최고 수축기혈류속도로나눈값즉, [ 최고수축기혈류속도 (peak systolic velocity)- 이완기말혈류속도 (end diastolic velocity)] 최고수축기혈 류속도 (peak systolic velocity) 의공식을이용하여계산하였다 [12]. 이러한방법을이용하여임신 5-7 주산모의자궁방사동맥저항지수 를측정하였고오차를줄이기위해자궁내막의서로다른 3 곳에서자 궁방사동맥저항지수를측정한후그의평균값을이용하여본연구에 WWW.KJOG.ORG 487
KJOG Vol. 55, No. 7, 2012 Fig. 3. Measurement of uterine blood flow by Doppler ultrasonogram. Resistance index (RI)=(peak systolic velocity-end diastolic velocity)/peak systolic velocity; Z1, zone for the 1st time measured resistance index; Z2, zone for the 2nd time measured resistance index; Z3, zone for the 3rd time measured resistance index. Table 1. Clinical characteristic of study groups Characteristic Control RSA (n = 47) Normal pbnk (n = 13) Elevated pbnk (n = 20) Age (yr) 34.2 ± 3.8 35.0 ± 4.2 34.0 ± 3.0 NS P-value Gravity 1.4 ± 1.6 2.9 ± 1.9 2.6 ± 1.2 0.000/0.002 a Parity 0.4 ± 0.6 0.4 ± 0.6 0.4 ± 0.6 NS Live birth 0.3 ± 0.6 0.3 ± 0.6 0.4 ± 0.6 NS No. of SA - 2.7 ± 0.3 2.5 ± 0.2 NS NKA (%) 50:01:00-25.9 ± 12.3 32.9 ± 22.1 NS 25:01:00-17.7 ± 9.3 24.3 ± 18.7 NS 12.5:1-10.6 ± 6.7 15.9 ± 13.6 NS Values are presented as mean ± standard deviation. pbnk, peripheral blood natural killer cell; SA, spontaneous abortion; NKA, NK cell cytolytic acivity; NS, not significant. a Statistically significant different between control and normal pbnk/control and elevated pbnk. 이용하였다 (Fig. 3). 또한자궁방사동맥저항지수의측정은산모의기왕 력을모르는한연구자에의해측정되었다. 였다. 5. 결과의분석각군별로자궁방사동맥의저항지수를비교하였고, 습관성유산환 자에서말초혈액자연살해세포의비율과자궁방사동맥저항지수간의 상관관계를알아보았다. 연구결과는 SPSS ver. 12.0 (SPSS Inc. Chicago, IL, USA) 통계프 로그램을사용하여분석하였다. 각군간의비교를위해연속변수의 비교는 one way analysis of variance 와 Student s t-test 를이용하였 고, 상관관계분석을위해서는 Pearson s correlation 을사용하였으며 통계분석후 P 값이 0.05 이하인경우통계적으로유의하다고정의하 결과 1. 대상환자의특성각군의나이및환자의분만력, 출산력은통계학적으로유의한차이 를보이지않았다. 다만자연유산의경험횟수는습관성유산환자에서 평균 2.6 ± 0.2 회였고습관성유산환자중말초혈액자연살해세포비 율이 12.1% 미만인습관성유산환자그룹 (normal NK) 에서는 2.7 ± 0.3, NK 가 12.1% 이상증가된습관성유산환자그룹 (elevated NK) 에서는 2.5 ± 0.2 이었으며이는통계학적으로유의한차이를보이지않았다. 488 WWW.KJOG.ORG
Hwa Seon Koo, et al. Uterine artery Doppler in RSA Table 2. Comparison of mean uterine radial artery resistance index between groups Control (n = 47) RSA total (n = 33) Normal pbnk (n = 13) Elevated pbnk (n = 20) Mean resistance index 0.54 ± 0.12 a,b 0.60 ± 0.14 a 0.58 ± 0.16 0.62 ± 0.13 b RSA, recurrent spontaneous abortion; normal pbnk, peripheral blood natural killer cell fraction among lymphocyte showed below 12.1%; elevated pbnk, peripheral blood NK cell fraction among lymphocyte showed above 12.1%. a P=0.039, Student s t-test, b P=0.029, one-way analysis of variance. RSA a P=0.029 RSA (n = 33) 1.00 P= 0.013 r = 0.429 Mean RI RI1 0.80 0.60 Fertile control Normal pbnk Elevated pbnk Recurrent spontaneous abortion Fig. 4. Comparison of mean uterine radial artery resistance index. RI, resistance index; pbnk, peripheral blood natural killer. 또한말초혈액자연살해세포독성도 normal NK 군과 elevated NK 군간 통계학적으로유의한차이를보이지는않았다 (Table 1). 2. 각군간의자궁방사동맥저항지수비교자궁방사동맥의평균저항지수는대조군에비하여습관성유산환 자군에서통계학적으로의미있게높은결과를보였다 (0.60 ± 0.14 vs. 0.54 ± 0.12, P = 0.039). 자궁방사동맥의평균저항지수를말초혈액의 NK cell 의증감에따라각군을비교한결과말초혈액 NK 세포의분 획이 12.1% 이상증가된 elevated NK 군에서정상대조군에비해통 계학적으로유의하게높게나타난결과를보인반면 (normal fertile vs. elevated NK, 0.54 ± 0.12 vs. 0.62 ± 0.13; P = 0.029), 정상말초혈액분 획군 (normal NK group) 의자궁방사동맥저항지수의평균은대조군과 비교하여통계학적으로유의한차이를보이지는않았다 (normal fertile vs. normal NK, 0.54 ± 0.12 vs. 0.58 ± 0.16; P>0.05) (Table 2, Fig. 4). 3. 말초혈액자연살해세포비율과자궁방사동맥저항지수와의상관관계습관성유산환자에서말초혈액자연살해세포의비율과자궁방사동 맥저항지수의상관관계를보았을때전체습관성유산환자에서말 초혈액자연살해세포의비율과자궁방사동맥저항지수사이에는양 의상관관계가나타났고 (P = 0.013, r = 0.429), 특히습관성유산환자 중증가 NK (elevated NK) 군에서는더욱강한양의상관관계를보였다 0.40 (P = 0.001, r = 0.667) (Fig. 5). 하지만습관성유산환자중 normal NK 군에는말초혈액자연살해세 포비율과자궁방사동맥저항지수와는통계학적으로유의한상관관계 를보이지않았다 (P = 0.996, r = -0.002) (Fig. 6). 고찰 CD3nCD45pPER R Sq Linear = 0.184 5.00 10.00 15.00 20.00 25.00 30.00 35.00 Fig. 5. Correration of uterine radial artery resistnace index and pbnk cell fraction in RSA group. RI, resistance index; RSA, recurrent spontaneous abortion. 임신중자궁내혈관의혈류공급및관류는응고 - 항응고 (coagulation vs. anticoagulation) 및섬유소용해 - 반섬유소용해 (fibrinolysis vs. anti-frinolysis) 활동의적절한조절에의해적당한상태를유지하는것 이태아의생존및성장에불가피한요소이다 [13]. 또한자궁으로의혈 류공급및원활한관류는수정란의착상및임신의유지에매우중 요한역할을하며비정상적인자궁으로의혈류공급및관류는원인이 밝혀지지않은불임의원인이될수있다고많은연구에서밝혀졌다 [14,15]. 또한습관성유산환자에서는그대조군에비하여자궁동맥의 저항지수가현저하게증가되어있다는보고가있지만 [9], 자궁혈류이 상과습관성유산의상관관계에대한연구는아직미미한실정이며현 WWW.KJOG.ORG 489
KJOG Vol. 55, No. 7, 2012 Normal pbnk (n =13) Elevated pbnk (n = 20) pbnk cell fraction pbnk cell fraction Fig. 6. Correlation between uterine RA-RI and pbnk cell fraction in normal and elevated NK groups. RA-RI, radial artery-resistance index; pbnk, peripheral blood natural killer. 재까지자궁혈류이상과말초혈액자연살해세포의연관성에관한연구는이루어지지않고있는실정이다. 본연구에서저자들은원인불명의습관성유산환자에서자궁동맥보다자궁으로의혈류공급을더욱정확하게반영하는것으로보고되는자궁방사동맥저항의측정을통해자궁혈류의변화와습관성유산의상관관계에대해규명하고자하였다. 그결과습관성유산환자의자궁방사동맥저항지수는정상군에서의자궁방사동맥의저항지수와비교해보았을때통계학적으로유의하게높은결과를보여임신초기자궁으로의혈류공급저하가습관성유산의원인이될수있음을제시하였다. 한편, 말초혈액자연살해세포가증가되어있는습관성유산환자에서, 자궁방사동맥의저항지수는정상군에비하여현저하게증가되어있는반면, 말초혈액자연살해세포가정상인습관성유산환자에서자궁방사동맥의저항지수는정상을보이며, 습관성유산환자를대상으로분석한결과자궁방사동맥의저항지수가말초혈액자연살해세포의비율과양의상관관계를보이고그정도는말초혈액자연살해세포의비율이증가되어있는경우에는더욱강한결과를보여, 말초혈액에서증가된자연살해세포가유산을유발하는병인적기전이임신초기자궁내혈류공급과연관될수있음을제안할수있었다. 기존문헌에의하면말초혈액자연살해세포의습관성유산에대한병인적설명으로자연살해세포가다른면역세포를자극하여 pro-inflammatory 싸이토카인의분비를증가시키고증가된 proinflammatory 싸이토카인들이탈락막의미세혈관에서무균성염증반 응 (sterile inflammation) 과혈전형성을촉진시켜자궁으로의혈류를감소시킨다고설명하고있지만 [16] 명확한기전적설명을위해서는더욱많은연구가요구된다. 저자들은본연구의결과에의해말초혈액자연살해세포비율측정및질식초음파및 Doppler 를이용한자궁으로의혈류공급및관류의평가는습관성유산환자에서임신초기해당임신의반복유산의위험도를예측하는유용한방법이될수있으며유산의재발방지를위한면역억제치료및자궁혈액관류를증가시킬수있는항응고제사용과해당약물투여의치료효과를측정하고궁극적으로임신의산과적예후를양호하게하는객관적인진단표식자로의이용이가능할수있음을제안하고자한다. 하지만본연구는대상군의수가적다는점과자연살해세포및사이토카인에대한분자생물학적기전및특성을밝히지못한점및말초혈액자연살해세포비율이증가되어있지않은환자에서의습관성유산의원인에대한연구가이루어지지못한한계점이있다. 이러한한계를극복하기위해더많은대상군및임신의산과적예후 (obstetric outcomes) 까지포함한연구가필요할것으로생각되며저자들은해당연구를진행중에있다. References 1. Berek JS, Novak E. Berek & Novak s gynecology. 15th ed. Phi- 490 WWW.KJOG.ORG
Hwa Seon Koo, et al. Uterine artery Doppler in RSA adelphia (PA): Linppincott williams & Wilkins; 2007. 2. El-mashad AI, Mohamed MA, Farag MA, Ahmad MK, Ismail Y. Role of uterine artery Doppler velocimetry indices and plasma adrenomedullin level in women with unexplained recurrent pregnancy loss. J Obstet Gynaecol Res 2011;37:51-7. 3. Ferreira AM, Pires CR, Moron AF, Araujo Júnior E, Traina E, Mattar R. Doppler assessment of uterine blood flow in recurrent pregnancy loss. Int J Gynaecol Obstet 2007;98:115-9. 4. Beer AE, Kwak JY, Ruiz JE. Immunophenotypic profiles of peripheral blood lymphocytes in women with recurrent pregnancy losses and in infertile women with multiple failed in vitro fertilization cycles. Am J Reprod Immunol 1996;35:376-82. 5. Perricone C, De Carolis C, Giacomelli R, Zaccari G, Cipriani P, Bizzi E, et al. High levels of NK cells in the peripheral blood of patients affected with anti-phospholipid syndrome and recurrent spontaneous abortion: a potential new hypothesis. Rheumatology (Oxford) 2007;46:1574-8. 6. Choi JY, Hwang SJ, Han AR, Yoo JH, Park DW, Park CW, et al. Increased peripheral NK cell fraction and their cytolytic activity in patients with history of recurrent spontaneous abortion. Korean J Reprod Med 2010;37:115-24. 7. Avril T, Jarousseau AC, Watier H, Boucraut J, Le Bouteiller P, Bardos P, et al. Trophoblast cell line resistance to NK lysis mainly involves an HLA class I-independent mechanism. J Immunol 1999;162:5902-9. 8. Kwak-Kim J, Park JC, Ahn HK, Kim JW, Gilman-Sachs A. Immunological modes of pregnancy loss. Am J Reprod Immunol 2010;63:611-23. 9. Habara T, Nakatsuka M, Konishi H, Asagiri K, Noguchi S, Kudo T. Elevated blood flow resistance in uterine arteries of women with unexplained recurrent pregnancy loss. Hum Reprod 2002;17:190-4. 10. Ghosh A, Ghosh M, Bhattacharya SM. Anti-phospholipid antibodies as a cause of recurrent pregnancy loss: a study in Calcutta, India. J Obstet Gynaecol 2006;26:407-10. 11. Tamura H, Miwa I, Taniguchi K, Maekawa R, Asada H, Taketani T, et al. Different changes in resistance index between uterine artery and uterine radial artery during early pregnancy. Hum Reprod 2008;23:285-9. 12. Keats TE, Sistrom C. Atlas de medidas radiológicas. Madrid, España: Elservier Science; 2002. 13. Hui C, Lili M, Libin C, Rui Z, Fang G, Ling G, et al. Changes in coagulation and hemodynamics during pregnancy: a prospective longitudinal study of 58 cases. Arch Gynecol Obstet 2012;285:1231-6. 14. Steer CV, Tan SL, Mason BA, Campbell S. Midluteal-phase vaginal color Doppler assessment of uterine artery impedance in a subfertile population. Fertil Steril 1994;61:53-8. 15. Goswamy RK, Williams G, Steptoe PC. Decreased uterine perfusion: a cause of infertility. Hum Reprod 1988;3:955-9. 16. De Carolis C, Perricone C, Perricone R. NK cells, autoantibodies, and immunologic infertility: a complex interplay. Clin Rev Allergy Immunol 2010;39:166-75. WWW.KJOG.ORG 491
KJOG Vol. 55, No. 7, 2012 원인불명의습관성유산환자에서말초혈액자연살해세포의증가가임신초기자궁혈류의변화에미치는영향 관동대학교의과대학제일병원산부인과구화선, 이현정, 이민영, 안현숙, 최민혜, 성나영, 황유임, 송인옥, 궁미경, 강인수, 양광문 목적원인불명의습관성유산환자에서말초혈액중비정상적비율로증가된자연살해세포가자궁으로의혈류를감소시키는지에대해알아보고자하였다. 연구방법본연구는전향적연구로, 습관성유산의기왕력을갖는임신 5-7주사이의환자 33명을대상으로하였으며습관성유산의기왕력이없는정상임신 5-7주 47명을대조군으로하였고, 습관성유산군은말초혈액자연살해세포비율 12.1% 를기준으로정상 (normal) natural killer (NK) group 과증가 (elevated) NK group 으로나누어연구를진행하였다. 임신 5-7주사이에측정한말초혈액에서유세포분석기를이용하여말초혈액자연살해세포분획및세포용해활성도를측정후그결과를비교분석하였고질식초음파의 Doppler 를이용하여자궁방사동맥의저항을측정후각군에서비교하였다. 또한말초혈액자연살해세포분획과자궁방사동맥저항지수간의연관성을알아보았다. 결과자궁방사동맥의평균저항지수는대조군에비교하여습관성유산환자군에서통계학적으로의미있게높았고 (0.60 ± 0.14 vs. 0.54 ± 0.12, P = 0.039), 말초혈액자연살해세포의분획이 12.1% 이상증가 (elevated NK) 군에서도정상대조군에비해통계학적으로유의하게높게나타났다 (0.62 ± 0.13 vs. 0.54 ± 0.12, P = 0.029). 또한전체습관성유산환자에서말초혈액자연살해세포의비율과자궁방사동맥저항지수사이에는양의상관관계가나타났고 (P = 0.013, r = 0.429), 특히습관성유산환자중증가 (elevated) NK군에서는더욱강한양의상관관계를보였다 (P = 0.001, r=0.667). 결론증가된말초혈액의자연살해세포는자궁방사동맥과같은미세혈관에향염증반응을일으켜자궁으로의혈류를감소시켜습관성유산을야기한다고설명할수있겠다. 하지만본연구의결론을확인하기위해서는더큰규모의연구뿐아니라분자생물학적기전에대한연구도필요할것으로생각된다. 중심단어 : 습관성유산, 자연살해세포, 자궁방사동맥저항지수 492 WWW.KJOG.ORG