Zielińska H, Moszkowska G, Zieliński M, Debska-Ślizień A, Rutkowski B, Trzonkowski P
Department of Clinical Immunology and Transplantology, Medical University of Gdańsk, Gdańsk, Poland.
Transplant Proc. 2011 Oct;43(8):2903-7. doi: 10.1016/j.transproceed.2011.08.025.
Programs for immunized transplant recipients are essential to achieve graft survivals comparable to those of non-immunized recipients. The threshold in Poland is a PRA by the complement-dependent cytotoxicity (CDC) method greater than 50%, which includes approximately 3.8% of the patients. At the same time the United Network for Organ Sharing there recipients represent approximately 16% of the waiting list in the United Network for Organ Sharing (UNOS). The underestimation of the immunized group in Poland may be due to differences in laboratory techniques to assess alloantibodies.
This study investigated 55 potential recipients with a PRA by CDC>50%. We used the following algorithm to assess their immunization: Luminex screening test for an HLA antibody; specificity assessed with Luminex Single Antigen, vPRA (evaluation of immunization of the patient); and analysis of acceptable HLA incompatibilities (HLAMatchmaker).
All recipients were positive class I anti-HLA antibodies and 94.5% were positive for class II. For the groups of subjects with PRA-CDC from 50% to 79% versus those greater than 80%, the average values of PRA-CDC were 62.2% and 89.5%, respectively. The virtual PRA results for these groups were 95.7% and 97.2%, respectively. In addition, anti-HLA-Cw, anti-DQ and anti-DP antibodies were detected in 77%, 84%, and 51% of recipients, respectively. Immunized recipients reported to the next transplant were characterized by the antibodies against mismatch only in 68%. For all potential recipients, additional acceptable non-compliance was determined with HLAMatchmaker: 152 specificity for locus A and 252 for locus B.
Evaluation of immunization status of recipient candidates should be routinely performed using tests to assess class and specificity as well as level of alloantibodies to enable determination of a safe potential donor. As a routine test, PRA-CDC underestimates the number of highly immunized patients. Exclusion from the list of patients with repeated non-compliance is a simplification, which reduces their chance for transplantation.
免疫移植受者项目对于实现与非免疫受者相当的移植物存活率至关重要。波兰的阈值是通过补体依赖细胞毒性（CDC）方法测定的群体反应性抗体（PRA）大于50%，这包括约3.8%的患者。同时，在美国器官共享联合网络（UNOS）中，此类受者约占等待名单的16%。波兰对免疫群体的低估可能是由于评估同种抗体的实验室技术存在差异。
本研究调查了55例通过CDC测定PRA>50%的潜在受者。我们使用以下算法评估他们的免疫状态：Luminex筛选试验检测HLA抗体；用Luminex单抗原评估特异性、虚拟PRA（评估患者的免疫状态）；以及分析可接受的HLA不相容性（HLAMatchmaker）。
所有受者I类抗HLA抗体均为阳性，94.5%的受者II类抗体为阳性。对于PRA-CDC为50%至79%的受试者组与大于80%的受试者组，PRA-CDC的平均值分别为62.2%和89.5%。这些组的虚拟PRA结果分别为95.7%和97.2%。此外，分别在77%、84%和51%的受者中检测到抗HLA-Cw、抗-DQ和抗-DP抗体。报告接受下一次移植的免疫受者中，仅68%的受者具有针对错配的抗体。对于所有潜在受者，使用HLAMatchmaker确定了额外可接受的不匹配情况：A位点152种特异性，B位点252种特异性。
应常规使用评估类别、特异性以及同种抗体水平的检测方法来评估候选受者的免疫状态，以便确定安全的潜在供体。作为常规检测，PRA-CDC低估了高免疫患者的数量。将反复出现不匹配的患者排除在名单之外是一种简化做法，这会降低他们的移植机会。
