Complement Factor C5a Is Increased in Blood of Patients with Abdominal Aortic Aneurysm and Has Prognostic Potential for Aneurysm Growth

• Published in: Journal of cardiovascular translational research Vol. 14; no. 4; pp. 761 - 769
• Main Authors: Zagrapan, Branislav, Eilenberg, Wolf, Scheuba, Andreas, Klopf, Johannes, Brandau, Annika, Story, Julia, Dosch, Katharina, Hayden, Hubert, Domenig, Christoph M., Fuchs, Lukas, Schernthaner, Rüdiger, Ristl, Robin, Huk, Ihor, Neumayer, Christoph, Brostjan, Christine
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2021
• Subjects: Aged; Aged, 80 and over; Aortic Aneurysm, Abdominal - blood; Aortic Aneurysm, Abdominal - diagnostic imaging; Aortography; Biomarkers - blood; Biomedical Engineering and Bioengineering; Biomedicine; Cardiology; Case-Control Studies; Complement C5a - analysis; Computed Tomography Angiography; Disease Progression; Enzyme-Linked Immunosorbent Assay; Female; Human Genetics; Humans; Male; Medicine; Medicine & Public Health; Middle Aged; Original; Original Article; Predictive Value of Tests; Prognosis; Time Factors; Up-Regulation; C3a; Prognosis; Diagnosis; Leukotriene B4; C5a; Abdominal aortic aneurysm
• ISSN: 1937-5387; 1937-5395
• DOI: 10.1007/s12265-020-10086-5

In this observational case-control study, circulating levels of complement factors C3a and C5a and leukotriene B4 (LTB4) were analysed in abdominal aortic aneurysm (AAA) patients regarding their association with diagnosis and prognosis. Serum C5a was significantly raised in AAA patients compared to healthy controls—median 84.5 ng/ml (IQR = 37.5 ng/ml) vs. 67.7 ng/ml (IQR = 26.2 ng/ml), p  = 0.007—but was not elevated in patients with athero-occlusive disease. Serum C5a levels correlated significantly with the increase in maximum AAA diameter over the following 6 months ( r  = 0.319, p  = 0.021). The median growth in the lowest quartile of C5a (< 70 ng/ml) was 50% less compared to the highest C5a quartile (> 101 ng/ml): 1.0 mm/6 months (IQR = 0.8 mm) vs. 2.0 mm/6 months (IQR = 1.5 mm), p  = 0.014. A log-linear mixed model predicted AAA expansion based on current diameter and C5a level. To our knowledge, this is the first study linking complement activation, in particular C5a serum level, with AAA progression. Graphical Abstract