The risk of heart transplant rejection can be reduced by desensitising patient antibodies, according to research presented at Heart Failure 2017 and the 4th World Congress on Acute Heart Failure.
The European Society of Cardiology announced that this breakthrough comes on the 50th anniversary of heart transplantation.
Before heart transplantation the serum of heart transplant candidates is tested for levels of anti-human leukocyte antigen (HLA) which could bind to donor HLA antigens and cause rejection of the organ. At the time of transplantation, a virtual crossmatch is conducted to determine if the patient’s anti-HLA antibodies are directed against the donor’s specific HLA antigen – if yes, they are called “donor specific anti-HLA antibody” (DSA).
“Most centres do not perform heart transplantation in patients with a high DSA level since the risk of antibody-mediated rejection is high, particularly hyper-acute rejection,” said lead author Dr Guillaume Coutance, a cardiologist at Pitié-Salpêtrière Hospital in Paris, France. “Patients then have to wait for a donor with different HLA antigens.”
To reduce the chance of rejection in these patients at high immunological risk, in 2009 Pitié-Salpêtrière Hospital began a desensitisation programme. The current study analysed the impact of the programme on survival after heart transplantations performed during 2009 to 2015.
The type of desensitisation patients receive depends on their DSA level, which is measured by mean fluorescence intensity (MFI). An MFI between 500 and 1000 is considered “low DSA” and an MFI above 1000 is considered “high DSA”. All patients receive anti-thymocyte globulins and conventional immunosuppressive therapy (calcineurin inhibitors, mycophenolate mofetil, and corticosteroids).
On top of this, patients with low DSA levels receive intravenous immunoglobulins. Patients with high DSA levels are treated with plasmapheresis before and after transplantation, followed by intravenous immunoglobulins after the complete cycle of plasmapheresis.
The study included 523 patients who were 50 years old on average and 77% were men. Nearly half (46%) of patients had no DSA, 17% had low DSA, and 37% had high DSA levels. Patients were followed-up for an average of 3.7 years and survival was compared between the three groups.