Naziruddin B, Durriya S, Phelan D, Duffy B F, Olack B, Smith D, Howard T, Mohanakumar T
Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Transplantation. 1998 Oct 27;66(8):1074-80. doi: 10.1097/00007890-199810270-00018.
To determine whether preformed HLA alloantibodies present in the sera of patients awaiting kidney transplantation will be detrimental to a potential porcine xenograft, we tested their cross-reactivity to swine leukocyte antigens (SLA).
Sera obtained from patients with varying levels of HLA sensitization (high panel-reactive antibodies > 70%, n= 7; moderate panel-reactive antibodies 30-40%, n=2) were analyzed. Pooled normal human AB sera and sera from nonsensitized patients (n=3) served as negative control. IgG was purified by protein-G chromatography, and xenoreactive natural antibodies (XNA) were depleted by passing the IgG through a series of melibiose and thyroglobulin-agarose columns. The elimination of XNA from HLA IgG preparations was confirmed by GS-IB4 lectin blocking assay and by an ELISA.
IgG isolated from normal AB serum and three nonsensitized patients, which was depleted of XNA (HLA-IgG), did not react to human or porcine lymphocytes (peripheral blood mononuclear cells; PBMC) either by flow cytometry or by complement-dependent microcytotoxicity assays. However, HLA-IgG isolated from nine sensitized patients were reactive to a panel of porcine peripheral blood lymphocytes (n=6) by flow cytometry (>50 mean channel shift) and in complement-dependent microcytotoxicity assays in addition to their reactivity to human PBMC. The binding of HLA-IgG to porcine PBMC was significantly reduced by preabsorption with pooled human platelet concentrate. Further, the HLA IgG showed recognition of 45-kDa affinity-purified SLA class I on Western blots.
This study demonstrates that HLA antibodies present in the sera of sensitized individuals can cross-react with SLA. Thus, xenotransplantation of porcine organs into HLA-sensitized patients has the potential to be rejected by humoral mechanisms. Testing to avoid such cross-reactive antibodies should be considered.
为了确定等待肾移植患者血清中预先形成的HLA同种抗体是否会对潜在的猪异种移植物产生不利影响，我们检测了它们与猪白细胞抗原（SLA）的交叉反应性。
分析了从具有不同水平HLA致敏的患者（高群体反应性抗体>70%，n = 7；中等群体反应性抗体30 - 40%，n = 2）获得的血清。混合的正常人AB血清和未致敏患者的血清（n = 3）作为阴性对照。通过蛋白G层析纯化IgG，并通过使IgG通过一系列蜜二糖和甲状腺球蛋白 - 琼脂糖柱来去除异种反应性天然抗体（XNA）。通过GS - IB4凝集素阻断试验和ELISA确认从HLA IgG制剂中去除了XNA。
从正常AB血清和三名未致敏患者中分离的IgG，去除了XNA（HLA - IgG）后，通过流式细胞术或补体依赖性微细胞毒性试验对人或猪淋巴细胞（外周血单个核细胞；PBMC）均无反应。然而，从九名致敏患者中分离的HLA - IgG通过流式细胞术（平均通道偏移>50）和补体依赖性微细胞毒性试验，除了对人PBMC有反应外，还对一组猪外周血淋巴细胞（n = 6）有反应。用混合人血小板浓缩物预吸收后，HLA - IgG与猪PBMC的结合显著降低。此外，HLA IgG在蛋白质印迹上显示出对45 kDa亲和纯化的SLA I类的识别。
本研究表明，致敏个体血清中存在的HLA抗体可与SLA发生交叉反应。因此，将猪器官异种移植到HLA致敏患者中有可能被体液机制排斥。应考虑进行检测以避免此类交叉反应性抗体。
