Utility of Routine Post Kidney Transplant Anti-HLA Antibody Screening

Abstract

IntroductionDe novo DSA (dnDSA) is a strong biomarker associated with the development of antibody mediated rejection and graft loss after kidney transplantation. Although this procedure is expensive, systematic annual screening was recommended by some national organ transplant agencies or societies though its clinical utility was not clearly established. MethodsTo address this question, we retrospectively assessed the incidence of dnDSA according to the test justification (clinically indicated or systematic) in a cohort of low-immunological risk patients, defined by being non-HLA sensitized and having no prior kidney transplants. ResultsA total of 1072 patients, for whom 4611 anti-HLA tests were performed, were included in the study. During follow-up period of 8 IQR (5 ; 11) years, seventy-seven recipients developed dnDSA (prevalence of 7.2%) . Thirty-five (45.5%) of these dnDSA were detected during the first year posttransplantation. In 95% of patients with dnDSA, an immunizing event was identified in their medical records. De novo DSA was detected in 46 out of 4267 systematic screening tests performed (1.08%). Active and chronic antibody mediated rejection were frequently observed in biopsies performed after systematic DSA testing (17.9% and 15.4% respectively). ConclusionOur results suggest that the detection by systematic screening of dnDSA in low immunological risk kidney transplant patients without sensitizing events is a rare event, especially after one year. Moreover, in real life, systematic annual screening for dnDSA, seems having a limited impact to detect AMR at an earlier stage compared to patients in whom dnDSA was detected after a clinically indicated test.