Detection of MICA Antibodies in Kidney Transplant Candidates on the Deceased Donor Waiting List in Panama.

Abstract

AIM: The Contribution of HLA and MICA antibodies to AMR and poor transplant outcomes have been described by multiple reports. We tested patients that were positive for the presence of HLA Class I and/or Class II and for the presence of MICA antibodies to assess the prevalence of such antibodies. METHODS: A total of 138 patients were tested for the presence of Class I and Class II HLA and MICA antibodies using Screen De Luxe Life Codes. The patients that tested positive or negative for HLA antibodies Class I and/or Class II were tested for the presence of MICA antibodies using LifeCodes LSA-MIC. Presence of HLA class I and II HLA antibodies and Clinical data pertinent to common risk factors of allosensitization (pregnancy, transfusion and prior transplants) were collected and correlated to the presence of MICA antibodies. RESULTS: The study included 53 women, 28 had prior pregnancies. Of all 138 patients 45 had prior transfusion and 7 had prior transplants. 18/138 patients were positive for MICA antibodies (13%) and several had multiple antibodies (8/18). Of those 6 were negative for both class I and class II HLA antibodies (33%) and 12 were positive HLA Antibodies (2 for class I only, 11%; 2 for class II only, 11%; 8 for both class I and class II, 45%). Of the 120 patients negative for MICA antibodies 52 were negative for both class I and class II HLA antibodies as well (43%). In this cohort there was no evidence of association between MICA antibodies and presence of Class I HLA antibodies, female gender, pregnancy, transfusion or prior transplants. There was a tendency for association between presence of MICA antibodies and HLA class II antibodies (p= 0.06).CONCLUSION: Our results indicate that MICA antibodies are present in a significant proportion of patients on the deceased donor kidney waiting list. Our results suggest that risk factors for MICA allosensitization may not be the same for HLA allosensitization and imply the relevance of MICA.