Distribution of arterial lesions in Takayasu's arteritis and giant cell arteritis.
OBJECTIVE
To compare patterns of arteriographic lesions of the aorta and primary branches in patients with Takayasu's arteritis (TAK) and giant cell arteritis (GCA).


METHODS
Patients were selected from two North American cohorts of TAK and GCA. The frequency of arteriographic lesions was calculated for 15 large arteries. Cluster analysis was used to derive patterns of arterial disease in TAK versus GCA and in patients categorised by age at disease onset. Using latent class analysis, computer derived classification models based upon patterns of arterial disease were compared with traditional classification.


RESULTS
Arteriographic lesions were identified in 145 patients with TAK and 62 patients with GCA. Cluster analysis demonstrated that arterial involvement was contiguous in the aorta and usually symmetric in paired branch vessels for TAK and GCA. There was significantly more left carotid (p=0.03) and mesenteric (p=0.02) artery disease in TAK and more left and right axillary (p<0.01) artery disease in GCA. Subclavian disease clustered asymmetrically in TAK and in patients ≤55 years at disease onset and clustered symmetrically in GCA and patients >55 years at disease onset. Computer derived classification models distinguished TAK from GCA in two subgroups, defining 26% and 18% of the study sample; however, 56% of patients were classified into a subgroup that did not strongly differentiate between TAK and GCA.


CONCLUSIONS
Strong similarities and subtle differences in the distribution of arterial disease were observed between TAK and GCA. These findings suggest that TAK and GCA may exist on a spectrum within the same disease.
The Vasculitis Center, Section of Rheumatology, and the Clinical Epidemiology Unit, Boston University School of Medicine, Boston, Massachusetts, USA.
Peter C
PC
Grayson
Kathleen
K
Maksimowicz-McKinnon
Tiffany M
TM
Clark
Gunnar
G
Tomasson
David
D
Cuthbertson
Simon
S
Carette
Nader A
NA
Khalidi
Carol A
CA
Langford
Paul A
PA
Monach
Philip
P
Seo
Kenneth J
KJ
Warrington
Steven R
SR
Ytterberg
Gary S
GS
Hoffman
Peter A
PA
Merkel
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000473:pathology*; D001366:Axillary Artery / Q000473:pathology; D002170:Canada / Q000453:epidemiology; D002339:Carotid Arteries / Q000473:pathology; D002648:Child; D016000:Cluster Analysis; D015897:Comorbidity; D005260:Female; D013700:Giant Cell Arteritis / Q000453:epidemiology / Q000473:pathology*; D006801:Humans; D008297:Male; D008638:Mesenteric Arteries / Q000473:pathology; D008875:Middle Aged; D013625:Takayasu Arteritis / Q000453:epidemiology / Q000473:pathology*; D014481:United States / Q000453:epidemiology; D055815:Young Adult