DYNAMICS AND CLINICAL SIGNIFICANCE OF ANTI-HLA ALLOANTIBODIES IN SOLID ORGAN TRANSPLANTATION

Abstract

P6 The aim of this prospective study was to describe the level and dynamics of de novo and donor-specific anti-HLA alloantibodies (HLA-Ab) developed after transplantation, and their clinical significance. Methods: 284 patients were tested by ELISA for HLA-Ab (1820 serum samples). The cohort consisted of 89 lung, 51 heart, 112 kidney/kidney-pancreas, and 32 intestine transplanted patients. The mean follow-up was 2.9 years, range 1 – 5 years. Results: The prevalence of HLA-Ab producers at one year post-transplantation was 30 ± 5% on average, and reached 50% at five years. De novo sensitization at one year after transplantation was 17% in lung, 15% in heart, 15% in kidney, 18% in pancreas, and 20% in intestine transplanted patients; 50% of de novo HLA-Ab appeared in the first 3 months. After one year, de novo sensitization increased with 5% per year. It was a higher incidence of Class I HLA-Ab in the first 3 months, and Class II after 9 months (p<0.0001). HLA-Ab were associated with increased prevalence of biopsy-proven high grade acute rejection in lung, heart and kidney groups. Conclusions: The level and dynamics of de novo HLA-Ab were similar in all types of solid-organ transplants. In the first year after transplantation, 15% of patients developed de novo HLA-Ab, while a steady increase of 5% per year was noted thereafter. Anti Class I de novo HLA-Ab were more frequent in the first 3 months, and de novo Class II after 9 months. A combination of a sensitive screening method with a good sampling frequency, allowed the detection of clinically relevant de novo and donor-specific HLA-Ab.