Aminoterminal propeptide of type III procollagen in the follow-up of patients with abdominal aortic aneurysms

Purpose: We evaluate here whether serial changes in the concentration of the aminoterminal propeptide of type III procollagen (PIIINP) in serum bear any relationship to the rate of abdominal aortic aneurysm (AAA) expansion and whether serum PIIINP has any predictive value with respect to the rupture event. Methods: One hundred thirty-nine patients with asymptomatic AAAs were followed-up at intervals of 6 to 12 months by means of a clinical examination, B-mode ultrasound scan, and serum markers of collagen metabolism. Similar laboratory samples were also obtained from 18 patients who had a rupture of the AAA as their primary symptom soon after onset. Results: The primary correlation between serum PIIINP and AAA diameter was 0.22 (p = 0.01), and that between serum PIIINP and the thickness of the thrombus was 0.49 (p 0.001). Toward the end of the follow-up, however, the correlation increased to 0.55 (p 0.002) for serum PIIINP and diameter, but remained at 0.42 (p = 0.02) for serum PIIINP and the thickness of the thrombus. Serum PIIINP values were very high among the 18 patients who had ruptured AAAs. Conclusions: Acceleration of AAA growth is reflected in serum PIIINP, and a marked elevation of serum PIIINP during follow-up of a patient with an AAA may predict an approaching rupture event.