P123

• Published in: Human immunology 2014-10, Vol.75, p.135-135
• Main Authors: Lemp, Nathan A, Cicciarelli, James C, Kasahara, Noriyuki, Koss, Michael, Vu, Don, Naraghi, Robert, Shah, Tariq
• Format: Article
• Language: English
• Subjects: Allergy and Immunology
• ISSN: 0198-8859
• DOI: 10.1016/j.humimm.2014.08.185

Among prospective kidney transplant recipients, antibodies to HLA-DP are most frequently identified in re-transplant candidates. The significance of these antibodies and their ability to cause rejection is subject to an ongoing debate. The following is a case study of a kidney re-transplant recipient with many HLA-DP antibodies. The patient is a 27 year-old female who had received one prior transplant. Anti-HLA antibodies were determined by Luminex® single antigen beads. Crossmatching was performed by complement-dependent cytotoxicity (CDC) with and without Dithiothreitol (DTT), and flow cytometry (FXM) with and without Pronase®. The patient exhibited only Class II antibodies, including 16 HLA-DP specificities with MFI >10,000. The recipient had a single donor-specific antibody to HLA-DP11 (21,000 MFI) to the potential living donor. The preliminary crossmatch was negative by both CDC and FXM and was reconfirmed with subsequent crossmatches. Post-transplant, the recipient demonstrated good kidney function and a steady decrease in serum creatinine (sCr) to 1.1 mg/dL until developing pyelonephritis two weeks later. The infection was resolved with antibiotics, but the patient’s sCr increased a week later to 3.1 mg/dL, and a kidney biopsy was performed. The biopsy was positive for vasculitis and cellular rejection, with equivocal C4d staining. Following treatment with steroids, IVIG, and thymoglobulin, the patient stabilized with a sCr of 1.6 mg/dL, and the single HLA-DP11 donor-specific antibody persists. Crossmatches performed with current serum and freshly drawn cells from the living donor remained negative. In the presence of negative crossmatches, the recipient experienced cellular and antibody-mediated rejection associated with a donor specific antibody against HLA-DP. The findings suggest that donor-specific HLA-DP antibodies present a risk to kidney transplantation.