Objectives: To study structural and functional alterations of arteries in patients with Erdheim-Chester disease, a rare acquired idiopathic histiocytosis characterized by a circumferential fibrosis of the aorta and its main branches.

Methods : Fifteen patients underwent peripheral arteries assessment with measurement of intima media thickness (EIM), carotid femoral pulse wave velocity (PWV) by Complior®, radial augmentation index (AI) by Sphygmocor® and OMRON HEM9001®, and ankle brachial index (ABI) by SCVL®. Blood pressure was assessed by 24h measurement.

Results: Our population consisted in 85% of men from 30 to 76 years old. There was 45% of treated and controlled hypertensive, 57% of formers smokers and 14% of diabetics. One third was under interferon, 30% under corticosteroids and the rest were untreated. IMTs were all normals but a periarterial carotidal fibrosis was noted in 28% who also had aortitis on PET scan. An augmentation of the global aortic stiffness (PWV) was present in 90% of the patients. According to the nomograms, the radial distensibility was altered in 30% of the patients, especially in the youngest and the carotidal distensibility was normal in 90% of the patients. The mean difference between central blood pressure and brachial blood pressure was −18 mmHg and −23.5mmHg for those with aortitis. All ABI were normal.

Conclusion: Arterial explorations of Erdheim-Chester patients unravel a periarterial fibrosis in 28% of the patients but an increased aortic stiffness in 90%. The absence of carotidal augmentation indexes abnormalities suggests that those alterations may not influence central blood pressure