Comparative analysis of two methods to detect donor-specific anti-HLA antibodies after kidney transplant

• Published in: Transplant immunology 2018-08, Vol.49, p.7-11
• Main Authors: Gil, Beatriz Chamun, Kulzer, Adriane Stefani Silva, de Moraes, Priscila, Toresan, Realdete, da Rosa Vicari, Alessandra, dos Santos Fagundes, Iara, Merzoni, Jóice, Ewald, Gisele Menezes, Cardone, Jacqueline Moraes, Silva, Fernanda Gamio, Manfro, Roberto Ceratti, Jobim, Luiz Fernando
• Format: Article
• Language: English
• Subjects: Adult; Anti-HLA antibodies; Cross-Sectional Studies; DSA; Female; Graft Rejection - diagnosis; Graft Rejection - mortality; Histocompatibility Testing - methods; HLA Antigens - immunology; Humans; Isoantibodies - blood; Isoantigens - immunology; Kidney Diseases - mortality; Kidney Diseases - therapy; Kidney transplant; Kidney Transplantation; Male; Middle Aged; Monitoring, Physiologic; Serologic Tests; Single antigen assay; Survival Analysis; Tissue Donors; Transplantation, Homologous; Xm-DSA assay
• ISSN: 0966-3274; 1878-5492
• DOI: 10.1016/j.trim.2018.03.006

Preformed anti-human leukocyte antigen (HLA) antibodies may be present in the blood of kidney transplant candidates. The production of these antibodies may occur in the post-transplant period, with the possible development of donor-specific antibodies (DSA). Luminex-based tests, such as the single antigen (SA) assay and the Luminex crossmatch (Xm-DSA) assay are the most commonly used tools to detect anti-HLA antibodies, due to their high sensitivity and specificity. This cross-sectional study aimed to compare the findings of two methods for the detection of DSAs after kidney transplant: SA and Xm-DSA. A total of 122 patients who underwent deceased donor kidney transplant at Hospital de Clínicas de Porto Alegre were included. The SA assay detected anti-class I HLA DSAs in 17 patients (13.9%) and anti-class II HLA DSAs in 22 patients (19.6%), whereas the Xm-DSA detected DSAs in 18 patients (14.8%) both against class I and class II antigens. There was agreement between the two methods for class I (kappa = 0.66, p = 0.001) and class II (kappa = 0.54, p = 0.025) antigens. The incidence of DSAs as obtained by the SA assay was 15.57%, and the most prevalent DSAs were those against HLA-DR antigens. Patient survival at 3 years was 92%. The two techniques assessed in this study provide important information on the presence of DSAs and may help in the post-transplant patient monitoring and in immunosuppressive strategy. •DSA prevalence in the 6th month after transplant was 26.2% (SA) and 22.1% (Xm-DSA).•Comparing SA and xm-DSA in DSA detection (kappa): class I (0.6) and class II (0.4)•Patient survival at 3 years was 95% without DSA and 63% with DSA class I and II.•Xm-DSA showed a higher correlation with CDC crossmatch and FCXM than those of SA.