HLA-DR matching improves survival after heart transplantation: is it time to change allocation policies?

HLA matching has improved outcome in kidney transplantation but is not considered in current allocation policies in heart transplantation. The aim of this single-center study was to assess the impact of HLA matching on long- term outcome after heart transplantation.

The records of 240 consecutive heart transplant recipients (time period 1995 to 2002; mean age 51.8 +/- 11.7 years; mean follow-up 5.9 +/- 1.8 years) were analyzed retrospectively. According to the renal allocation policy, HLA mismatches (MM) on the major antigen loci HLA-A, HLA-B and HLA-DR were calculated, demonstrating 0 to 6 MM. Patients with primary graft failure were excluded from statistical analysis.

Survival analysis revealed a statistically significant impact of HLA-DR MM on survival. Five-year survival was 90% in patients without HLA-DR MM (n = 10), 79% in patients with 1 HLA-DR MM (n = 113), and 68.1% in patients with 2 HLA-DR MM (n = 117) (1 MM vs 2 MM: p < 0.05). Freedom from cardiac allograft vasculopathy after 5 years was 89% in HLA-DR-identical recipients (n = 10), 61% in patients with 1 HLA-DR MM (n = 102), 54% in patients with 2 HLA-DR MM (n = 104). Conventional matching with 6 mismatches over the three major HLA antigen loci revealed a trend toward a higher relative risk for adverse outcome in patients with increased MM.

HLA-DR matching had a significant impact on survival after heart transplantation (HTx) at our center. In the effort to achieve the best comparative use of scarce donor organs the inclusion of HLA-DR matching into allocation policies might improve long-term outcome after HTx.