Biomarkers of Idiopathic Retroperitoneal Fibrosis and Other Fibrotic Disease in Rheumatology

The prognosis of some rheumatic diseases is mainly determined by fibrosis of the affected organs. In addition to the at least partially invasive and costly examinations for follow-up, there is a need for serum-derived biomarkers, which allow an examination of the presence, activity and follow-up of fibrotic manifestations. In particular for systemic sclerosis there are several new studies supporting a potential role of the serum CCL18 and osteopontin levels as well as circulating fibrocytes in the peripheral blood. Also for the idiopathic retroperitoneal fibrosis (IRF, Ormond's disease), a fibro-inflammatory disease involving the retroperitoneum, there is recent evidence for potential serological biomarkers, which reflect disease activity and treatment response. In this article we review new candidates and discuss the evidence of their use for IRF and other fibrotic disease in rheumatology.