Activating autoantibodies against the AT1-receptor in vascular disease

Activating autoantibodies to the angiotensin II type I receptor (AT1-AA) have been described in different vascular diseases: preeclampsia, non HLA-mediated transplantat rejection and systemic sclerosis. All three diseases are characterised by severe obliterative, inflammatory vasculopathy with a prominent autoimmune background. AT1-AA were described 12 years ago in preeclampsia. Preeclampsia is a common, pregnancy- induced disorder, consisting of hypertension and proteinuria in the last trimester. The condition is one of the leading causes for maternal and perinatal morbidity and mortality. An observation of a patient with transplant rejection without HLA antibodies and a preeclampsia in her medical history, let to the discovery of AT1-AA in these patients. Until then we relied on a subjective, time consuming bioassay to detect AT1-AA. The establishment and validation of a cell-based ELISA facilitated research on AT1-AA immensely. Recently, AT1-AA were found in patients with systemic sclerosis.