CCL18 -- potential biomarker of fibroinflammatory activity in chronic periaortitis.

OBJECTIVE: Promising therapeutic approaches have emerged in chronic periaortitis, whereas peripheral blood biomarkers are lacking. CC-chemokine ligand 18 (CCL18) is known as a marker of fibrotic activity and prognosis in pulmonary fibrosis. We investigated whether CCL18 levels are increased in patients with chronic periaortitis and are associated with clinical, laboratory, and imaging findings.
METHODS: In this retrospective study, serum concentrations of CCL18 were assessed in 30 patients with chronic periaortitis and related to clinical data, laboratory variables, and imaging studies. Serum levels were compared to 15 apparently healthy volunteers and 15 controls with aortic sclerosis.
RESULTS: Serum concentrations of CCL18 were increased in patients with chronic periaortitis (median 197.6 ng/ml, range 73.7-301.0) compared to healthy volunteers (median 34.6 ng/ml, range 22.6-70.4; p < 0.0001) and controls with aortic sclerosis (median 50.4 ng/ml, range 24.5-141.2; p < 0.0001). CCL18 levels correlated with (n = 30; r = 0.461, p = 0.01) and increased with the transversal diameter of the periaortic mantle < 5, 5-10, and ≥ 10 mm (p = 0.008). Contrast enhancement (p = 0.044), treatment naivety (p = 0.042), and the occurrence of systemic symptoms (p = 0.007) were associated with higher CCL18 levels. During followup, changes of CCL18 correlated with changes of the transverse diameter of the periaortic mantle (n = 17; r = 0.512, p = 0.033).
CONCLUSION: Serum concentration of CCL18 reflects fibroinflammatory activity and extent of disease in patients with chronic periaortitis.