Serum Levels of PCSK9 Are Increased in Patients With Active Ulcerative Colitis Representing a Potential Biomarker of Disease Activity: A Cross-sectional Study

Ulcerative colitis (UC) is characterized by chronic inflammation and progressive course, with potential extraintestinal complications including cardiovascular mortality. Serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels have been recently recognized as biomarkers of low-grade inflammation and cardiovascular disease. The aim of our study was to evaluate PCSK9 levels in patients with UC and different degrees of disease activity. METHODS: We prospectively recruited consecutive patients with UC attending our center at the University Hospital of Padua. Demographics, clinical characteristics, and biochemical data, including PCSK9, high sensitivity C-reactive protein, and fecal calprotectin, were recorded. Moreover, endoscopic procedures were performed in all subjects. RESULTS: We included 112 patients with UC (mean age=52.62±12.84 y; 52.62% males). Patients with UC and abnormal fecal calprotectin (≥250 µg/g) and/or C-reactive protein (≥3 mg/L) had greater levels of PCSK9 compared with UC patients with normal fecal calprotectin and high sensitivity C-reactive protein (P=0.03 and 0.005, respectively). Higher endoscopic scores in UC were characterized by greater levels of PCSK9 (P=0.03). Furthermore, we found a positive correlation between PCSK9 levels and fecal calprotectin (r=0.18, P=0.04), endoscopic Mayo Score (r=0.25, P=0.007), and UC-Riley Index (r=0.22, P=0.01). We also found a positive correlation between PCSK9 levels and both total and low-density lipoprotein cholesterol values (P<0.05). CONCLUSIONS: Serum PCSK9 levels are increased in patients with biochemical and endoscopic evidence of active disease in UC. Further longitudinal studies are necessary to evaluate the role of PCSK9 as a potential biomarker of disease activity and cardiovascular risk in UC.