OR31: CASE STUDY: DOA: DONOR ORIGINATING ANTIBODY; A CASE OF PASSIVE ANTIBODY TRANSFER

Abstract

Aim To investigate the unexplained HLA antibody specificity observed in a post-transplant serum specimen from a lung transplant recipient. Methods Antibody (Ab) evaluation was performed using phenotype and single antigen panels tested on the Luminex ® platform (Lifecodes, One Lambda). Results Patient JD is a 47 year old female with a history of cystic fibrosis. The patient received a bilateral lung transplant on October 3, 2013 from a deceased donor at Johns Hopkins Hospital. A serum specimen drawn immediately prior to transplant was negative for IgG, HLA class I-specific antibody and demonstrated very weak reactivity for IgG, class II-specific antibody. At day T + 4, a post-transplant serum specimen exhibited a substantial antibody increase. Although the timing of antibody appearance indicated an anamnestic response, the specificity was inconsistent with the patient’s historical HLA-specific antibody and appeared to be specific for non-donor antigens. Repeated testing and testing with additional assays confirmed the initial results. Transplanted lungs can be accompanied by substantial donor lymphoid tissue. We therefore tested donor serum for HLA specific antibody. Tests of the deceased donor serum revealed strong HLA-specific antibody nearly identical to the pattern observed with the recipient’s Day T + 4 post-transplant serum. Upon further investigation, we found that, in fact, the donor has been the recipient of a kidney transplant. The deceased donor’s previous transplant information was obtained. The antibody detected in the donor serum was specific for multiple mismatched antigens present in the HLA phenotype of the deceased donor’s kidney transplant. Tests of sera obtained monthly from the lung recipient have shown a steady reduction in antibody strength and breadth. The pattern and the course of the antibody over time suggest that the antibody was of donor origin. Conclusion In this case, having access to the deceased donor’s serum allowed us to investigate the anomalous HLA-specific antibody testing results. Retrieving the deceased donor’s past medical history listed in UNET provided evidence of the transfer of donor antibody-producing cell to the patient JD.