Neeraja Mamidi, Kesireddy Sreedhar, Kumar Neerudi Raj, Kumar Madasu Praveen, Pullaiah Potlapally, Chittampalli Raju
Department of Transplant Immunology, Apollo Hospitals, Jubilee Hills, Hyderabad, Telangana, India.
Indian J Nephrol. 2023 May-Jun;33(3):170-176. doi: 10.4103/ijn.IJN_462_20. Epub 2023 Mar 2.
Recipient sensitization against donor human leukocyte antigens (HLA) plays a key role in transplant rejection, and this risk is best minimized by efficient pre transplant antibody detection. Determination of antibody specificity with the highest sensitivity and degree of resolution to the allelic antigen level is achieved by using single-antigen bead (SAB) assay.
This study evaluated the correlation of Luminex cross match (LXM) with SAB assay for detection of donor-specific antibodies (DSA). A total of 2075 renal transplant patients were screened for the presence of DSA by LXM, complement-dependent cytotoxicity (CDC) cross match, and 125 patients for SAB from January 2018 to December 2019.
There was a male preponderance among recipients ( < 0.0001), and the most affected age group was 21-40 years. HLA typing was done in 550/2075 by DNA PCR-reverse sequence-specific oligonucleotide probes (SSOP) method. HLA DSA by LXM was detected in 16.3% of recipients (338/2075). Majority 180/338 (53.2%) of the patients were class II DSA positive, ( < 0.0001). Among the class II DSA positive patients, 20/180 (11.1%) samples gave false-positive results by LXM. SAB for class I and class II HLA IgG antibodies was done in 125/338 renal transplant recipients, which included 20 recipients with false-positive class II Luminex DSA, to check whether the DSA detected were really donor specific or not. The results showed that although 20/125 patients had some antibodies detected in their serum, they were not against the donor HLA antigens, as per the HLA typing reports of the donors. When compared to SAB assay, LXM showed more discrepant results, particularly to class II DSA.
In conclusion, LXM, if used in combination with SAB assay and HLA typing of donors if necessary for virtual cross match, will help in avoiding unnecessary exclusion of donors for renal transplant recipients and also for post transplant monitoring of recipients, especially in cadaveric donor transplants.
受者对供者人类白细胞抗原（HLA）致敏在移植排斥反应中起关键作用，通过高效的移植前抗体检测可最大程度降低这种风险。使用单抗原珠（SAB）检测法可实现对抗体特异性的最高灵敏度及等位基因抗原水平分辨率的测定。
本研究评估了Luminex交叉配型（LXM）与SAB检测法在检测供者特异性抗体（DSA）方面的相关性。2018年1月至2019年12月，共对2075例肾移植患者进行了LXM、补体依赖细胞毒性（CDC）交叉配型以筛查DSA的存在，对125例患者进行了SAB检测。
受者中男性居多（<0.0001），受影响最大的年龄组为21 - 40岁。550/2075例通过DNA聚合酶链反应 - 反向序列特异性寡核苷酸探针（SSOP）法进行了HLA分型。通过LXM检测到16.3%（338/2075）的受者存在HLA DSA。大多数患者180/338（53.2%）为II类DSA阳性（<0.0001）。在II类DSA阳性患者中，20/180（11.1%）的样本通过LXM得出假阳性结果。对125/338例肾移植受者进行了I类和II类HLA IgG抗体的SAB检测，其中包括20例Luminex II类DSA假阳性的受者，以检查检测到的DSA是否真的针对供者。结果显示，尽管20/125例患者血清中检测到一些抗体，但根据供者的HLA分型报告，这些抗体并非针对供者HLA抗原。与SAB检测法相比，LXM显示出更多不一致的结果，尤其是对于II类DSA。
总之，如果将LXM与SAB检测法联合使用，并在必要时对供者进行HLA分型以进行虚拟交叉配型，将有助于避免肾移植受者不必要地排除供者，也有助于受者移植后的监测，尤其是在尸体供者移植中。
