Place de la tomographie par émission de positrons (TEP) au [18F]FDG dans l’exploration et la surveillance des vascularites

[18F]fluorodeoxyglucose positron emission tomography (PET) is a noninvasive metabolic imaging modality that is well-suited to the assessment of activity and extent of large vessel vasculitis. PET imaging has demonstrated its usefulness in diagnosing giant cell arteritis (notably in its silent form), Takayasu's arteritis, and unclassified aortitis. PET imaging could be more effective than magnetic resonance imaging in detecting the earliest stages of vascular wall inflammation. The visual grading of vascular [18F]FDG uptake makes it possible to discriminate arteritis from active atherosclerosis, providing therefore high specificity. High sensitivity can also be achieved provided scanning is performed during active inflammatory phase, preferably before starting corticosteroid treatment. Prospective studies are needed to determine the exact value of PET imaging in assessing other vasculitis subsets, infectious aortitis, and large vessel vasculitis outcome and response to immunosuppressive treatment.     

Fibrose(s) rétropéritonéale(s) : stratégie diagnostique,pathologies associées et suivi à long terme d’une cohorte française

Purpose

Retroperitoneal fibrosis (RPF) is a rare disease with an expanding etiologic spectrum. We aimed to analyze non-invasive diagnosis strategy, associated disorders, monitoring, treatment and prognosis.

Methods

Retrospective cohort study in a single tertiary center.

Results

Eighteen RPF cases (11 males) followed between 1996 and 2009 were reviewed. Blood CRP level was high in all cases before treatment. CT scan, associated or not with MRI or 18-FDG PET-scan, confirmed the diagnosis in 15 patients. Histological analysis of a surgical biopsy specimen was performed in only three cases. Ten patients suffered retroperitoneal fibrosis secondary to systemic vasculitis (granulomatosis with polyangeitis, n = 1, Takayasu aortitis, n = 2), systemic fibrosis with Riedel thyroiditis (n = 1) and atheromatous periaortitis (n = 6). Fifteen patients were treated with corticosteroids with a mean treatment duration of 60 months (12–228). Dependency to corticosteroids was recorded in ten patients. Patients with fibrosis related to vasculitis were younger, had a higher CRP level, more frequent corticosteroid dependency and a higher relapse rate. Relapses were successfully treated with steroids. Immunosuppressive treatment was only prescribed in the setting of systemic vasculitis. No patient died, after a 6 ± 2 years follow-up. Late relapses could occur, sometimes years after steroid therapy cessation.

Conclusion

In our study, RPF occurred as a secondary disorder in 60% of the cases. Disease extension, relapse rate and treatment response varied according to the underlying cause of RPF, pleading for an extensive and systematic initial assessment. Since no death or end-stage renal insufficiency was observed, RPF might be considered as a steroid-sensitive and benign disorder.     

Efficacité et tolérance du tocilizumab en traitement d’épargne cortisonique dans l’artérite à cellules géantes et les aortites : expérience du centre hospitalier de Nîmes à propos de onze patients

Introduction

Giant cell arteritis is a large-vessels vasculitis, which treatment consists in a slowly-tappered steroid-therapy. Immunosuppressive agents are sometimes used in case of steroid-dependance. We have conducted an observationnal retrospective study including patients treated with tocilizumab for a giant cell arteritis or an aortitis in the internal medicine department at the Nîmes University Hospital.

Aortite et complications aortiques de l’artérite à cellules géantes (maladie de Horton)

Aortitis is a serious complication of giant cell arteritis (GCA), because of the risk of aortic aneurism, rupture, or dissection. Aortitis is present either at presentation or, more frequently, occurs as a delayed complication, typically as an aortic aneurism of the ascending part of the aorta. An aortic aneurism may occur in up to 10% of patients. Aortitis is sometimes associated to arteritis of the supra-aortic vessels. Risk factors for aortitis remain unknown. Recent clinical studies indicate that prevalence of aortitis was initially under-estimated. Imaging studies show signs of infra-clinical aortitis in 20 to 65% of cases at diagnosis. Using ultrasonography, thickening of the vascular wall with an hypoechoic halo around the abdominal aorta is suggestive of abdominal aortitis. Positron emission tomography shows a metabolic hypersignal of the aorta in about 50% of patients with giant cell arteritis. Aortic computed tomographic (CT) scan visualizes aneurysmal dilatations, ectasia or focal or concentric parietal thickenings. When present at the time of diagnosis of GCA, these findings seem to be associated with frequent relapses and perhaps with a higher long-term vascular mortality rate. Therefore, we recommend the screening of aortitis lesions at GCA diagnosis by an aortic CT-scan and follow-up. Therapeutic trials should be conducted to try to improve the treatment of aortitis in GCA.