Circulating fibrillin fragment concentrations in patients with and without aortic pathology

Fragments of fibrillin-1 and fibrillin-2 will be detectable in the plasma of patients with aortic dissections and aneurysms. We sought to determine whether the plasma fibrillin fragment levels (PFFLs) differ between patients with thoracic aortic pathology and those presenting with nonaortic chest pain.

PFFLs were measured in patients with thoracic aortic aneurysm (n = 27) or dissection (n = 28). For comparison, patients without aortic pathology who had presented to the emergency department with acute chest pain (n = 281) were categorized into three groups according to the cause of the chest pain: ischemic cardiac chest pain; nonischemic cardiac chest pain; and noncardiac chest pain. The PFFLs were measured using a sandwich enzyme-linked immunosorbent assay.

Fibrillin-1 fragments were detectable in all patients and were lowest in the ischemic cardiac chest pain group. Age, sex, and the presence of hypertension were associated with differences in fibrillin-1 fragment levels. Fibrillin-2 fragments were detected more often in the thoracic aneurysm and dissection groups than in the emergency department chest pain group (P < .0001). Patients with aortic dissection demonstrated a trend toward increased detectability (P = .051) and concentrations (P = .06) of fibrillin-2 fragments compared with patients with aortic aneurysms. Analysis of specific antibody pairs identified fibrillin-1 B15-HRP26 and fibrillin-2 B205-HRP143 as the most informative in distinguishing between the emergency department and aortic pathology groups.

Patients with thoracic aortic dissections demonstrated elevated plasma fibrillin-2 fragment levels (B205-HRP143) compared with patients presenting with ischemic or nonischemic cardiac chest pain and increased fibrillin-1 levels (B15-HRP26) compared with patients with ischemic cardiac chest pain. Investigation of fibrillin-1 and fibrillin-2 fragment generation might lead to diagnostic, therapeutic, and prognostic advances for patients with thoracic aortic dissection.