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

Objectives: HLA matching has improved outcome in kidney transplantation but is not considered in current allocation policies in heart transplantation. This study analyses the impact of HLA matching on long-term outcome after heart transplantation.

Material and Methods: The records of 240 consecutive heart transplant recipients (1995–2003, 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 loci HLA-A, HLA-B and HLA-DR were calculated, resulting in 0 to 6 MM. Patients with primary graft failure were excluded from statistical analysis.

Results: Survival analysis revealed a statistically significant impact of HLA-DR MM on survival. 5-year survival in patients without HLA-DR MM (n=9) was 100%, in patients with one HLA-DR MM (n=102) 82% and 75% in patients with two HLA-DR MM (n=104; log rank 1MM vs. 2MM: p=0.05). Freedom from cardiac allograft vasculopathy after 5 years was 89% in HLA-DR identical recipients (n=9), 61% in patients with one HLA-DR MM (n=93) and 54% in patients with two HLA-DR MM (n=92; log rank 1MM vs. 2MM: p=0.09). Conventional matching with 6 missmatches over the 3 major HLA loci revealed that the relative risk for adverse outcome increases with the numbers of MM.

Conclusions: HLA-DR matching had a significant impact on survival after HTx in our centre. In our efforts 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.