Angiotensin II Type 1–Receptor Activating Antibodies in Renal-Allograft Rejection

Antibodies against HLA antigens cause refractory allograft rejection with vasculopathy in some, but not all, patients.

We studied 33 kidney-transplant recipients who had refractory vascular rejection. Thirteen had donor-specific anti-HLA antibodies, whereas 20 did not. Malignant hypertension was present in 16 of the patients without anti-HLA antibodies, 4 of whom had seizures. The remaining 17 patients had no malignant hypertension. We hypothesized that activating antibodies targeting the angiotensin II type 1 (AT1) receptor might be involved.