46-OR

Abstract

In 2008, an international collaborative study of post-transplant monitoring was launched with 44 transplant centers from 17 countries. One aim of the project was to study the time course of antibody development, from time of transplant to months and years post-transplantation, to examine the incidence of antibodies, time to antibody appearance, and time to clinical events. We also investigated possible factors affecting antibody development across multiple centers. As of May 2012, antibody data for 5,057 serial sera from 470 kidney and 97 heart recipients were submitted. For each patient, 3 to 12 sera were collected at various intervals from 1 mo to 14 yrs post-transplantation. Antibody testing was done by luminex methodology. Patient data including age, ethnicity, HLA mismatches, immunosuppression, serum creatinine, and clinical events were collected. An Antibody Tracking Program was developed to analyze antibody profile. At the time of this report, analysis was done for 224 patients. Figure shows an example of antibody plot generated by the tracking program. Incidence of donor-specific antibodies (DSA) at first year was approx. 10%. Median time to antibody appearance was 34 mo. Factors increasing DSA development included deceased donors and level of HLA mismatches. We are continuing to receive data from centers, and further investigation of factors affecting DSA production is underway. In studying natural history of antibody development across multiple centers, we are now able to identify some of the common factors that are predictive of DSA production, and gain an insight as to the time course of antibody development and clinical outcome [Fig. 1]. Ozawa: One Lambda Inc.: Employee. Everly: One Lambda Inc.: Employee. Terasaki: One Lambda Inc.: Stockholder.