2429 例尿毒症患者致敏因素的分析

目的 分析尿毒症患者肾移植前存在的致敏因素. 方法 自2002年4月至2008年12月,共对2429例准备进行肾移植的尿毒症患者进行了群体反应性抗体(PRA)的检测.在检测PRA之前,根据患者的临床资料不同,分为5组.(1)无既往病史组(1097例):患者既往无输血、妊娠和移植史;(2)单纯输血组(361例):患者曾输血200ml以上;(3)单纯妊娠组(481例):患者曾有妊娠史;(4)输血+妊娠组(294例):患者既有输血史又有妊娠史;(5)再次移植组(196例):患者曾进行过肾移植,但移植肾功能丧失,准备再次进行肾移植. 结果 无既往病史组的男性患者PRA均阴性,仅3例女性患者呈现抗HLAⅡ类抗体弱阳性;单纯输血组共有55例患者PRA阳性,阳性率为15.24%(55/361);单纯妊娠组共有39例患者PRA阳性,阳性率为8.11%(39/481);输血+妊娠组共有90例患者PRA阳性,阳性率为30.61%(90/294);再次移植组共有139例患者PRA阳性,阳性率为70.92%(139/196),且PRA强度＞60%以上的患者有72例. 结论 单纯输血和单纯妊娠可产生PRA,但产生的几率均较低;既输血又妊娠产生PRA的几率大于单纯输血和单纯妊娠的患者;器官移植物刺激产生的抗HLA抗体,无论是在强度上还是在类型上均远远超过了其他抗原的刺激.     

等候肾移植者群体反应性抗体的变化及HLA致敏途径对其的影响

目的 探讨等候肾移植者群体反应性抗体(PRA)阳性率的变化及HLA致敏途径对其的影响.方法 对1991年1月至2010年12月间来自51个肾移植中心的8926例等候肾移植者10 555例次血液样本PRA检测的结果进行分析.1991～1998年组采用补体依赖的细胞毒性试验技术检测PRA; 1999～2010年组采用酶联免疫吸附试验技术检测PRA.搜集患者的临床资料,分析输血、妊娠和移植对PRA阳性率的影响.结果 8926例中PRA阳性者为1324例(14.83％),其中1991-1998年的PRA平均阳性率为18.17％ (513/2823),1999 2010年的结果为13.29％(811/6103),差异有统计学意义(P＜0.01).1324例PRA阳性者中,PRA为1％～30％者占71.83％;PRA≥30％者占28.17％.既往有血液成分输血史者的PRA阳性率为31.77％,无输血史者的PRA阳性率为1.21％,差异有统计学意义(P＜0.01).女性患者中,有妊娠史者的PRA阳性率为24.64％;无妊娠史者的PRA阳性率为7.19％,差异有统计学意义(P＜0.01).初次移植者的PRA阳性率为13.35％,既往有肾移植经历的受者的PRA阳性率为40.62％,差异有统计学意义(P＜0.01).结论 近20年大多数PRA阳性者其PRA＜30％.输血和肾移植史是导致PRA阳性的重要影响因素;妊娠史是PRA阳性的关联因素.     

人类白细胞抗原配型对移植肾失功患者群体反应性抗体产生的影响

目的 探讨人类白细胞抗原(HLA)配型对移植肾失功患者群体反应性抗体(PRA)产生的影响. 方法对24例术前PRA阴性的初次肾移植病例行供受者HLA分型,移植.肾失功后检测受者PRA并确定抗体特异性.PRA定性、定量及确定抗体特异性用莱姆德混合抗原板(LATM)及莱姆德抗原板1240(LAT1240)检测.HLAI类及Ⅱ类抗原分型用顺序特异引物聚合酶链反应(PCR-SSP)技术.观察PRA产生情况,比较致敏与非致敏病例的HLA配型情况,并分析HLA错配与PRA产生的关系.结果 24例中PRA阳性17例,阴性7例.17例致敏患者中Ⅰ类抗体阳性8例,Ⅱ类抗体阳性15例,Ⅰ类及Ⅱ类抗体同时阳性6例.A1(3例)、A24(2例)、DR7(6例)、DR9(4例)、DRl2(3例)及DRl3(4例)抗体多见,供者特异性抗体(DSA)中A1(2例)、DR7(4例)及DR9(3例)多见.按6抗原配型标准比较Ⅰ类抗原错配数,Ⅰ类抗体阳性组(8例)与阴性组(16例)问比较差异无统计学意义(P＞0.05),按交叉反应组(CREG)配型标准阳性组错配数多于阴性组(P＜0.01);比较Ⅱ类抗原错配数,Ⅱ类抗体阳性组(15例)错配数多于阴性组(9例)(按6抗原配型标准P＜0.05,按CREG配型标准P＜0.01).供者HLA频率及错配频率最高的A2及A30未发现相应抗体产生,供者A1-受者A2、DR7及DR9错配易导致DSA产生.结论 HLA错配是移植肾失功患者致敏的重要原因.供者抗原出现频率及错配频率与PRA及DSA出现频率不完全一致,某些抗原错配更易导致PRA及DSA产生.初次肾移植良好的HLA配型可减少等待再次肾移植患者的致敏发生率.     

早期移植肾丢失引起HLA体液致敏的机制 (附3例报告)

目的探讨早期移植肾丢失引起HLA体液致敏的机制.方法采用LAT-ELISA法分别检测3例首次尸肾移植丢失的受者术前1周、术后1个月群体反应性抗体(PRA)IgG类HLA抗体水平,并分析其性质.结果1例女性受者术前1周PRA水平Ⅰ类为17.9%,其抗体特异性为B60,Ⅱ类为阴性;术后1个月PRA水平Ⅰ类为39.3%,其抗体特异性为B17,Ⅱ类为阴性.2例男性受者术前1周Ⅰ、Ⅱ类PRA为阴性(PRA＜10%).术后1个月Ⅰ类PRA水平分别为46.4%和41.7%,其抗体特异性分别为B63、B22;Ⅱ类PRA水平分别为25.0%、23.1%,其抗体特异性均为DR53.结论移植肾丢失患者术后产生抗供者特异性抗体(Ds-Ab),表明移植物是机体HLA体液致敏的重要危险因素之一.     

肾移植患者术前输血与再次移植致抗体生成的比较

目的 研究肾移植患者术前输血与再次移植导致抗体生成的机率.方法 自2002年4月～2006年12月共检测了肾移植前1810例患者群体反应性抗体,其中输血200 mL以上患者509人,男性185人,女性324人;再移植患者136人,男性93人,女性43人.PRA检测采用美国One lanmbda公司和美国GTI公司提供的ELISA筛选人类白细胞抗原(human leucocyte antigen,HLA-Ⅰ),类、HLA-Ⅱ类混合抗原板.鉴定抗体类型采用采用美国One lanmbda公司鉴定抗原板(LAT-1240).结果 移植前输血患者509例,88例PRA阳性,占输血人数的17.28%,其中男性患者占4.32%,女性患者占12.97%.再次移植前患者136例,97例PRA阳性,占71.32%;其中男性患者占50%,女性患者占21.32%.肾移植术前输血患者PRA出现机率较高的抗HLA-Ⅰ类抗体有抗HLA-A1、A2、A3、A11和A24抗体;抗HLA-B13、1327、B60、B22、B51和B17.抗HLAII类抗体在输血患者中未能检测出较高反应抗体.再次移植前患者PRA出现机率较高的抗HLA-Ⅰ类抗体有抗HLA-A2、A11和A24抗体;抗HLA-B13、B5和B40.抗HLA-Ⅱ类抗体出现机率较高有抗HLA-DR1、4、7、8、15抗体.结论 再次移植前患者产生抗HLA-抗体的机率高于肾移植术前输血患者,而且产生的抗HLA强度和类型比输血患者更复杂,因此再次移植患者术后更易发生排斥反应.     

高致敏肾移植供受者的HLA配型研究

目的　探讨人类白细胞抗原 (HLA)配型在高致敏受者肾脏移植中的临床意义。　方法　对 18例高致敏受者采用酶联免疫吸附法 (ELISA)检测体内预存的群体反应性抗体 (PRA IgG)水平及其特异性 ;采用补体依赖性细胞毒试验 (CDC)和微量序列特异性引物聚合酶链反应 (Micro PCR SSP)技术进行HLA I类和II类分型。　结果　 18例高度致敏受者的PRA IgG水平为 40 %～ 96 % ,平均 5 6 % ;供受者之间按传统的HLA A、B、DR抗原错配 (MM )原则 ,0～ 1MM者 5例 (2 8% ) ,2～3MM者 13例 (72 % ) ,而按交叉反应组 (CREGs)错配原则 ,0～ 1MM者 11例 (6 1% ) ,增加了 33 % ,而2～ 3MM者仅 7例 (39% ) ;肾移植术后仅 4例发生急性排斥反应 ,排斥发生率为 2 2 % ,经OKT3 治疗后逆转。　结论　CREGs配型可显著提高供受者的HLA配合率 ,良好的HLA配型对减少高致敏受者肾移植的排斥反应、提高移植物存活率具有重要临床意义     

致敏受者移植肾存活率和抗HLA抗体的临床观察

目的观察致敏受者与非致敏受者移植肾存活率的差别,以及移植肾功能与抗HLA抗体变化的关系。方法纳入中山大学附属第一医院器官移植中心2000年4月至2008年12月间行肾移植后资料完整受者1309例。根据受者术前ELISA检测群体反应性抗体（PRA）的结果将受者分为50%≤PRA≤100%组（n=35）、10%≤PRA〈50%组（n=47）和PRA〈10%组（n=1227）。所有供受者采用PCR序列特异性引物进行HLA分型。运用标准HLA配型和氨基酸残基配型。采用Kaplan-Meier法对3组受者术后存活率进行组间生存分析。分析肾移植后抗HLA抗体的变化及其与移植肾功能和HLA错配的关系。结果随着随访时间增加,3组移植肾累积存活率均有下降。在术后3年内3组移植肾存活率差异较小（P〉0.05）,3年后3组移植肾存活率差异有统计学意义（P〈0.05）。10%≤PRA≤100%受者移植肾累积存活率显著低于PRA〈10%受者（P〈0.05）,50%≤PRA≤100%受者移植肾累积存活率也显著低于10%≤PRA〈50%受者（P〈0.05）。12例移植肾失功的受者中7例（58.3%）出现抗体增强,62例移植肾功能正常的受者中仅8例（12.9%）出现抗体增强,两者差异有统计学意义（P〈0.05）。出现新生抗体的受者抗体谱中,大多数包含有针对错配抗原的抗HLA抗体。结论无论是供者特异性还是非供者特异性抗体,抗HLA抗体的存在及其效价都会影响移植肾的存活。术后抗HLA抗体的变化与移植肾功能有关。     

异体手移植的组织配型探讨

目的：研究组织配型在异体肢体移植中的基础作用和意义。方法：对患者和供者进行ABO血型和Rh血型，群体反应性抗体（PRA）检测及淋巴细胞毒性试验，测定人类白细胞抗原（HLA），结果：ABO血型（B－B）Rh血型相符，PRA和淋巴毒性交叉实验均为阴性，人类白细胞抗原（HLA）配型HLA－B，D，DR，DQ位点有4个抗原相合，手术后联合免疫抑制剂，移植双手成功，结论：理想的组织配型可避免异体手移植发生排斥反应，提高异体手移植成功率。     

肾移植受者抗HLA抗体监测的临床意义

目的探讨动态监测肾移植受者抗HLA抗体的临床意义。方法采用酶联免疫吸附试验(ELISA)对1517例肾移植受者进行手术前、后血清群体反应性抗体(panel reactive antibody,PRA)强度动态监测,对PRA阳性受体进一步行抗HLA抗体分型并进行随访,观察PRA水平对移植物长期存活和移植肾功能的影响。结果1517例中,术前PRA阴性者1336例,阳性者181例。术前PRA阳性受者和阴性受者的移植物功能延迟恢复(DGF)发生率分别为34.8%、11.9%,两组比较差异有统计学意义(P0.01)。术前PRA阳性受者的移植肾1、3、5、8年存活率分别为94%、85%、73%和63%,术前PRA阴性受者相应为96%、87%、72%和65%,两组比较差异均无统计学意义(P0.05)。移植前及移植6个月后PRA均为阴性的265例受者中,血清肌酐水平异常者仅占19.6%,而术后PRA转为阳性的57例受者中,血清肌酐异常者高达61%,两者比较差异有统计学意义(P0.01);移植前PRA阳性的53例受者中,有24例移植后PRA转为阴性,术后血清肌酐全部正常。结论术前筛查PRA可科学评估肾移植患者的体液致敏状态,为致敏患者选配合适供者;术后监测PRA可及时了解移植肾的免疫状态,有利于防治排斥反应。     

群体反应性抗体检测技术的新进展——免疫磁珠流式细胞仪技术

毋庸置疑，补体依赖的抗-HLA抗体是介导尸体器官移植后严重排斥（超急或加速排斥）反应的元凶。群体反应性抗体（panel—reactive antibody，PRA）是患者HLA抗原致敏的结果，临床上常因怀孕、输血或接受器官移植而产生，它与移植物排斥反应及存活率密切相关。PRA分析是反映移植受者体内抗-HLA抗体水平的实验方法，借助对受者预致敏状态的分析可识别受者不能接受的HLA基因。近年来的一些实验研究结果显示，这些PRA既有IgG抗体、Ign抗体和IgA抗体，也存在自身抗体，而自身抗体的存在不仅不会增加移植失败的危险，还会提高移植物存活率，所以真正对移植物存活和排斥反应有影响的抗体只有IgG。这就要求PRA检测技术既要有较高的灵敏度，又能够排除非IgG抗体的干扰。因此，对PRA检测技术的灵敏度、特异性等要求就相当高。     

同种异体肾移植的HLA配型效果观察

目的：探讨同种异体肾移植的HLA配型效果.方法：比较同种异体肾移植中采用传统HLA配型方法与CREG配型方法的移植状况;对比HLA配型组和未配型组1年移植效果的不同.结果：HLA抗原出现频率较高的有HLA-A2、A11、A24、B60（40）、B13、DR15、DR51、DR52、DR53、DR 4.根据HLA 6位点相配原则,0～6个位点错配（mismatch,MM）所占比例分别为0.78%、1.56%、5.06%、10.12%、27.63%、29.96%和24.9%;而采用交叉组间配型原则（CREGs）,0～6位点错配率分别为3.89%、6.23%、17.51%、33.85%、19.84%、13.23%、5.45%.结论：具有某些HLA位点的受者相对来说有更多的获得良好HLA配型的机会;CREGs配型原则明显提高了供、受者间的相配率,但移植效果仍有争议.     

肾移植受者群体反应性抗体监测的临床意义

目的 分析群体反应性抗体（PRA）监测对预测肾移植受者排斥反应发生的意义及探讨对高水平PRA受者的临床处理.方法 应用酶联免疫吸附分析法（ELISA法）动态监测肾移植受者的PRA水平,以PRA≥10%为阳性,10%≤PRA＜50%为低致敏、PRA≥50%为高致敏,并对37例术前高致敏患者行血浆置换.结果 1527例肾移植受者中,PRA阳性350例（22.9% ）,其中高致敏 94例（26.8% ）;PRA阳性组排斥反应发生率（21.1% ）高于PRA阴性组（3.8% , P〈0.01）, 术后PRA转为阳性组排斥反应发生率高于PRA无变化组（P〈0.01）,行血浆置换受者与未行血浆置换受者排斥反应发生率无差异（P〉0.05）,接受过移植、多次妊娠、多次输血受者易致敏,HLA-A、B、DR配型错配抗原〉3个受者急性排斥的发生率（16.9% ）明显高于错配抗原≤3个受者（1.7% , P〈0.01）.结论 动态监测PRA水平有助于预测排斥反应的发生.     

Posttransplant antidonor lymphocytotoxic antibody production in relation to graft outcome

Serial serum samples from 266 recipients of primary renal allografts were monitored posttransplant for the presence of panel reactive lymphocytotoxic antibodies (PRA). The minimum posttransplant follow-up period was 18 months. Patients were classified according to whether or not they produced PRA before and/or after transplantation. The groups were as follows: PRA negative before and after transplant, -/-, 171; PRA positive before and negative after transplant, +/-, 5; PRA positive before and positive after transplant, +/+, 27; PRA negative before and positive after transplant, -/+, 63. Actuarial graft survival at 1 year for each group was 81.3%, 100%, 70.4%, 47.6%, respectively. Fifty-five of the 63 -/+ recipients were retrospectively crossmatched with posttransplant sera against stored donor lymphocytes. Of these, 50 (91%) were posttransplant cross match positive, and 37 (67%) have lost their grafts. In 23 of the 26 cases where an anti-HLA specificity was defined, the antibody was directed against antigens present in the donor but not in the recipient. These results clearly indicate that the production of PRA in recipients of renal transplants is associated with antidonor reactivity and poor graft outcome. The fact that these PRA were often directed against donor HLA antigens emphasizes one of the hazards of mismatching for HLA at transplantation.     

良好的HLA配型可改善群体反应性抗体高的受者肾移植效果

目的 探讨ＨＬＡ配型在高致敏受者肾移植中的意义。方法 对１２例群体反应性抗体为３６％￣７６％物肾功能衰竭患者使用特异性单克隆抗体ＩＬ－Ⅰ、Ⅱ类抗体分型盘进行ＨＬＡ配型。结果 供、受诸 ＨＬＡ－Ａ、Ｂ、ＤＲ位点各有一个抗原相符合３例;ＨＬＡ－Ｂ位点２个原、ＤＲ位点１个抗原相符者１例;ＨＬＡ－Ａ位点１个抗原、Ｂ位点２个抗原、ＤＲ位点１个抗原相符者６例;ＨＬＡ－Ａ位点２个抗原、Ｂ位点１个抗原、ＤＲ位点２     

Successful DR-incompatible cadaver kidney transplantation. Combined effect of HLA A and B matching and blood transfusion

The purpose of this retrospective analysis of DR-incompatible cadaver renal transplantation was to evaluate the effect of HLA A and B matching and blood transfusion status on actual one-year graft survival. There were 31 2-DR, 111 1-DR, and 27 0-DR grafts at risk during the study period. First, a comparison was made between preoperative (PRE) and peroperative (PER) transfusions alone. Graft survivals were 70% vs. 92% (2 DR), 67% vs. 52% (1 DR) and 71% vs. 39% (0 DR) for the PRE and PER groups, respectively. Statistical significance was not found between the two values in each DR subgroup, although the difference approached significance in the O DR group (0.1 greater than P greater than 0.05). Matching for greater than or equal to 2 A and B antigens significantly improved graft survival in the 1 DR-matched group when compared with those matched for less than 2 antigens (76% vs. 44%, P less than 0.005). While marked differences between the greater than or equal to 2 and less than 2 A and B matched groups were observed for both the 2 DR (92% vs. 68%, P greater than 0.1) and O DR groups (59% vs. 40%, P greater than 0.3) these differences were not significant. Stratifying the data for transfusion status revealed that the positive influence of HLA A and B matching in the 1 DR group was dependent upon the presence of preoperative blood administration. Graft survival of 87% for the PRE transfused recipients of grafts matched for greater than or equal to 2 A and B antigens was significantly better (P less than 0.001) than the 42% survival observed in similarly transfused recipients of poorer matched organs. Conversely, A and B matching was not significantly beneficial in the 1 DR recipients transfused only at the time of transplant with graft survivals of 57% vs. 43% for those matched for greater than or equal to 2 or less than 2 A and B antigens, respectively (P greater than 0.3). This analysis suggests that a combined effect of both HLA A and B matching and preoperative blood transfusions may allow for highly successful first cadaver renal transplantation in the face of DR incompatibility.     

Chimerism in peripheral blood of sensitized patients waiting for renal transplantation: clinical implications

BACKGROUND: Potential renal transplant recipients with preformed antibodies to HLA resulting from previous transplants, pregnancy, and/or transfusions are unlikely to receive an allograft. The factors contributing to the long-term maintenance of antibody titers in these individuals are still unknown. In the present study, we sought to determine whether chimerism in the blood correlates with maintenance of HLA sensitization in highly sensitized patients. METHODS: Qualitative analysis of chimerism in blood of sensitized patients was assessed by polymerase chain reaction-sequence specific oligonucleotide probes (PCR-SSOP) to HLA-DR. PCR single-strand conformation polymorphism (PCR-SSCP) was used to confirm the extra HLA-DR antigens detected by PCR-SSOP. RESULTS: Fourteen of 36 patients (38.9%) were positive for more than two HLA-DR indicative of chimerism. The presence of extra HLA-DR was confirmed by PCR-SSCP. When patients were analyzed on the basis of their panel-reactive antibody (PRA) status, 10 of 15 (66.7%) were positive for chimerism in the sensitized group, compared with only two of eight (25%) in the unsensitized group. Of the five males in the sensitized group who had received a blood transfusion but not a transplant, three were positive for chimerism. An association was observed between chimerism and maintenance of sensitization. None of the eight normal subjects studied demonstrated chimerism. CONCLUSIONS: The results obtained with sensitized patients suggest an association between blood chimerism and maintenance of HLA sensitization. We speculate that chimerism may lead to long-term maintenance of anti-HLA antibody titers. This finding implies that abolition of chimerism could result in the eventual elimination of antigenic stimuli for antibody production against HLA antigens.     

Potential risk factors for hypersensitization reflected by panel-reactive antibodies in dialysis patients

INTRODUCTION: The panel-reactive antibody (PRA) test has been considered to be a routine index of sensitization to human leukocyte antigens (HLA) in kidney transplant candidates. This study investigated the effect of potential risk factors and the time of blood sampling on PRA tests. METHODS: A total of 98 patients at two dialysis centers in Tehran were tested for PRA levels before and after dialysis sessions. We evaluated their history of potential sensitizing events and patient interviews for their association with PRA levels. Also we compared PRA levels obtained before and after dialysis. RESULTS: The mean age of the patients was 58.33 +/- 15.85 years. Only age and kidney transplantation history were correlated with PRA levels (r = .246, P = .014 and P = .0001, respectively). Logistic regression analysis revealed an association between age and PRA level (P = .037). Transplantation history was weakly correlated with PRA level (P = .076). History of pregnancy and transfusion, dialysis duration, gender, donor relation, and kidney allograft duration were not associated with PRA. PRA before dialysis sessions was significantly lower than that after dialysis (P = .0003). However, no difference was seen when divided into groups of negative/positive (PRA < 10% as negative) and high/low (PRA < 60% as low). CONCLUSION: Many factors expose patients to HLA as sensitizing factors. However, it seems that PRA level is not always predictable by such conditions. Furthermore, dialysis as a confounding procedure impacts PRA results; thus, when to obtain a blood sample is a crucial question.     

群体反应性抗体在肾移植中的意义

目的 研究群体反应性抗体（ＰＲＡ０在肾移植中的意义。方法 对１７８例肾移植患者进行了术前、术后ＰＲＡ检测。结果 肾移植术前ＰＲＡ阳性患者有２３例,肾移植术后发生急性排斥反应的为２０例。术后ＰＲＡ阳性受者５８例,发生排斥反应的有３４例。移植前后ＰＲＡ阴性患者有１０８例,有８例发生排斥。在肾移植患者中所产生的抗ＨＬＡ抗体的频率和ＨＬＡ抗原的分布不同。结论 ＰＲＡ检测对预测移植肾排斥有重要意义。