Large Vessel Involvement In Giant Cell Arteritis - Incidence, Distribution And Predictors

Background Over the years it has become increasingly clear that vascular involvement in giant cell arteritis (GCA) is widespread, that vasculitic changes may become evident many years after onset of the disease, and that these anomalies may not always be symptomatic. Objectives To investigate the cumulative incidence of large vessel involvement (LVI), defined as aneurysm/ectasia/stenosis of the aorta and its main branches, in patients with biopsy-proven GCA, and to describe the distribution of LVI. Furthermore, to identify predictive factors and to evaluate to what extent the presence of LVI is systematically investigated at the time of diagnosis and during follow-up. Methods Patients with biopsy-proven GCA in the region of Kristianstad, the County of Skane in southern Sweden, diagnosed between 1997 and 2010, were investigated. Patients were identified using the regional register of the Department of Pathology in Skane as previously described (1). A retrospective review of case records and histopathology reports of all the identified patients was performed. Results A total of 169 patients were identified, of whom 24 (14.2%) had LVI with the following distribution: aortic ectasia n=17 (ascendens n=10, descendens n=3, abdominal n=4), aortic aneurysm n=10 (ascendens n=3, descendens n=2, abdominal n=5), aortic arch branches (cervical and upper-extremities) n=3, visceral arteries (truncus coeliacus, mesenteric arteries, renal arteries) n=5, lower extremity arteries (iliac, femoral, crural) n=10, intracranial vessels n=1. Two patients had concomitant aortic aneurysm and aortic dissection, two had ectasia at several levels of aorta and four had concomitant aortic aneurysm and ectasia. Fourteen (58%) had isolated aortic involvement and six (25%) had concomitant affection of the aorta and its tributaries. There were no major differences between those with LVI and those without regarding sex (71% vs 76% females) or age at diagnosis (mean 76.5 vs 75.8 years). LVI manifestations were initially noted a median of 3.7 years [interquartile range (IQR) 0.7-7.5] after the diagnosis of GCA. Presence of giant cells in the biopsy was significantly less frequent among patients with LVI (23% vs 52%; p=0.01). There was also a trend towards lower levels of CRP [median 75 (IQR 46-111) vs 90 mg/L (IQR 50-146); p=0.31] and ESR [mean 66 (SD 27) vs 75 mm1h (SD 28); p=0.15] at diagnosis among those with LVI, although this did not reach statistical significance. In general, patients were not systematically investigated regarding the presence of LVI at the time of diagnosis or during the course of the disease. Conclusions LVI of a number of different arteries is seen in GCA. The lower proportion with giant cells in the biopsy and the lower initial inflammatory response suggest that this is a subset of GCA with particular characteristics and disease mechanisms. It is likely that the occurrence of LVI in GCA is severely underrated due to lack of physician awareness of such complications. References Mohammad A et al. Ann Rheum Dis 2014; doi:10.1136/annrheumdis-2013-204652. Epub Jan 17. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.2853