Rationale: The role of circulating antibodies in addition to traditional cardiovascular risk factors in the development of accelerated arteriosclerosis and their long-term clinical consequences have not been demonstrated.
Objective: We investigated the role of circulating antibodies in accelerated arteriosclerosis and the role of immune-associated arteriosclerosis in graft and patient survival and the occurrence of major adverse cardiovascular events.
Methods and Results: This was an observational prospective cohort study that included 1065 kidney transplant patients (principal cohort, n=744; validation cohort, n=321) between 2004 and 2010. Participants were assessed for traditional cardiovascular risk factors and circulating anti–human leukocyte antigen (HLA) antibodies. All patients underwent allograft biopsies to assess arteriosclerotic lesions and endothelial activation, endarteritis, and complement deposition. In the principal cohort, 250 (33.6%) patients had severe arteriosclerosis (luminal narrowing >25% via fibrointimal arterial thickening). Circulating donor-specific anti-HLA antibodies were significantly associated with severe allograft arteriosclerosis (hazard ratio, 2.9; P<0.0001), independently of traditional risk factors. Patients with severe arteriosclerosis and anti-HLA antibodies (n=91, 12.2%) demonstrated allograft endothelial activation, endarteritis, and complement deposition. High levels of anti-HLA antibodies and their complement binding capacity were associated with increased severity of arteriosclerosis. Patients with antibody-associated severe arteriosclerosis had decreased allograft survival and increased mortality (P<0.0001); they exhibited a 2.5- and 4.1-fold increased risk of major adverse cardiovascular events compared with patients who had severe arteriosclerosis without antibodies and patients with minimal arteriosclerosis, respectively (P<0.0005). Circulating donor-specific anti-HLA antibodies were significantly associated with occurrence of major adverse cardiovascular events (hazard ratio, 2.4; P=0.0004), independently of traditional risk factors.
Conclusions: Circulating antibodies are major determinants of severe arteriosclerosis and major adverse cardiovascular events, independent of traditional cardiovascular risk factors.