Koster, Matthew J.

Abstract Erdheim-Chester disease (ECD) is a rare histiocytosis of the “L” (Langerhans) group with multisystem involvement that can affect the large and medium-sized arteries mimicking vasculitis. Aortic involvement is common but the frequency and outcome of aortic branch vessel abnormalities are less well described. Patients with ECD were retrospectively identified. Images containing information of arterial involvement within 6 months of diagnosis were considered baseline and compared to last follow-up studies. Two physicians independently reviewed the studies to evaluate for presence of abnormalities attributable to ECD. Age and sex-adjusted logistic regression models were used to examine associations between patient characteristics and vessel involvement at baseline. Among a cohort of 64 patients with ECD, 63 had baseline imaging of vascular structures. ECD involvement of at least 1 segment of the aorta was observed in 56%. Abnormalities were also observed in aortic arch branches (26%), visceral branch arteries (40%), iliofemoral arteries (31%), coronary (5%), and pulmonary (3%) arteries. Perinephric fibrosis was strongly associated with the identification of abnormalities in the thoracic aorta (OR 4.92 [1.54, 15.75]; P = .007), abdominal aorta (OR 7.57 [2.28, 25.07]; P = .001) and visceral branch arteries (OR 6.05 [1.52, 24.03]; P = .01) but not pelvic/lower extremity arteries. Complete normalization of arterial abnormalities at follow-up was only observed in 9% or less of arterial segments involved at baseline. Aortic and aortic branch vessel abnormalities are frequently observed in patients with ECD and are often asymptomatic. Partial and/or complete resolution of arterial findings is uncommon.

ObjectiveTo compare patients with large‐vessel giant cell arteritis (LV‐GCA) characterized by wall thickening, stenosis, and/or occlusion of subclavian arteries to those with subclavian dilatation.MethodsFor the purposes of the present retrospective study, 2 different subsets of LV‐GCA were identified and compared from an established cohort of patients with radiographic evidence of subclavian artery vasculitis secondary to GCA: LV‐GCA with wall thickening, stenosis, and/or occlusion of subclavian arteries (Group 1), and LV‐GCA with dilatation of subclavian arteries without wall thickening or stenotic changes (Group 2).ResultsThe study included 109 patients in Group 1 and 11 in Group 2. Large‐vessel involvement secondary to GCA was diagnosed significantly later in patients from Group 2 compared to those from Group 1 (median 15.3 versus 0.0 months; P = 0.010). Compared to patients from Group 1, those from Group 2 were more frequently male (17% versus 45%; P = 0.027), ever smokers (42% versus 73%; P = 0.048), and more frequently had a history of coronary artery disease (11% versus 36%; P = 0.018). At LV‐GCA diagnosis, 10 of the 11 patients (91%) from Group 2 had aortic dilatation compared to 13 of 109 patients (12%) from Group 1 (P < 0.001). During the followup period, the prevalence of aortic aneurysm was significantly higher in patients from Group 2 compared with those from Group 1 (64% versus 7% at 5 years; P < 0.001).ConclusionTwo different subsets of LV‐GCA were identified. Given the strong association between subclavian artery dilatation and aortic aneurysm, such patients should be evaluated and monitored carefully for aortic dilatation.

Key Clinical Message Erdheim‐Chester Disease is a multi‐systemic condition characterized by non‐Langerhans histiocytic infiltration. Cardiovascular involvement with pseudotumoral infiltration of the right atrium is present in approximately one‐third of patients and may be asymptomatic. Although retroperitoneal fibrosis is common, perinephric dystrophic calcification has not been previously described.

ObjectivePolyarteritis nodosa (PAN) is a systemic necrotizing vasculitis of medium‐sized visceral vessels. However, cutaneous arteritis (CA) and gastrointestinal (GI) vasculitis are forms of single‐organ vasculitis having indistinguishable histopathologic findings from PAN. The aim of this study was to evaluate and compare the clinical characteristics, treatment, and outcomes of patients with systemic PAN, CA, and GI vasculitis.MethodsRetrospective cohorts were assembled, consisting of patients with PAN, CA, and GI vasculitis between 1980 and 2014. The demographics, clinical characteristics, treatment, and outcomes of patients were abstracted from medical records.ResultsWe included 48 patients with PAN, 41 patients with CA, and 19 patients with GI vasculitis. The disease of 1 patient evolved from CA to systemic PAN during the disease course. At diagnosis, 94% of patients with PAN, 93% of patients with CA, and 67% of patients with GI vasculitis were treated with glucocorticoids. Additional immunosuppressive agents were used in 67% of PAN, 37% of GI vasculitis, and 32% of CA cases. The 5‐year cumulative relapse rate was 45.2% in CA, and only 9.6% in PAN during a followup of approximately 6 years. No deaths were observed in the CA group. The survival rate at 10 years was 66% in the PAN group and 61% in the GI vasculitis group.ConclusionSystemic PAN, CA, and GI vasculitis take different clinical courses and therefore may be different diseases, rather than existing on a spectrum of the same disease. Progression of CA to systemic PAN is very rare. Relapse risk is low during followup in PAN. Patients with CA have a higher relapse rate than those with systemic PAN, possibly due to less use of immunosuppressive therapy in CA.