Is All Inflammation within Temporal Artery Biopsies Temporal Arteritis?

• Published in: Human pathology 2016-11, Vol.57, p.17-21
• Main Authors: Jia, Liwei, MD PhD, Couce, Marta, MD, PhD, Barnholtz-Sloan, Jill S, Cohen, Mark L., MD
• Format: Article
• Language: English
• Subjects: Adrenal Cortex Hormones - adverse effects; Adventitia - pathology; Age; Aged; Aged, 80 and over; Biopsy; Case-Control Studies; False Positive Reactions; Female; Giant cell arteritis; Giant Cell Arteritis - drug therapy; Giant Cell Arteritis - pathology; Humans; Inflammation; Inflammation - drug therapy; Inflammation - pathology; Male; Middle Aged; Older people; Pathology; Predictive Value of Tests; Prognosis; Risk Factors; Small vessel vasculitis; Temporal Arteries - drug effects; Temporal Arteries - pathology; Temporal arteritis; Temporal artery biopsy; Time Factors; Vasa vasorum vasculitis; Veins & arteries
• ISSN: 0046-8177; 1532-8392
• DOI: 10.1016/j.humpath.2016.07.004

Temporal arteritis peaks during the 8th decade, affecting patients with frequent comorbidities who are especially prone to adverse effects of corticosteroid therapy. Perivascular inflammation involving small periadventitial vessels is not uncommon in otherwise normal temporal artery biopsies (TAB). As ischemic events occur in patients with non-temporal artery based inflammation, it has been recommended any vascular inflammation within temporal artery biopsies be treated with corticosteroids. We sought to determine whether such patients are at increased risk for temporal arteritis-like adverse events compared with age-matched controls devoid of inflammatory infiltrates. TABs without transmural temporal arteritic damage accessioned between 2002 and 2012 were reviewed for inflammation (>15 perivascular lymphocytes) involving small blood vessels and/or temporal artery adventitia. 278/343 (81%) of TABs were negative for transmural arteritis. Inflammation involving small vessels and/or temporal artery adventitia was present in 56 cases (20%). Age-matched controls were available for 39 cases. With a mean follow up of 5 years (range 1-11 years), 6/39 (15%) of patients developed stroke, cardiovascular events or died, compared with 7/39 (18%) of age matched controls. None of the patients with study-positive TAB had documented steroid therapy prior to, or after, temporal artery biopsy. Our results demonstrate that patients with inflammation involving only small vessels or temporal artery adventitia are not at increased risk for temporal arteritis- like adverse events, and suggest that the risks of protracted corticosteroid therapy in this elderly population likely exceed any potential benefits. We advise against diagnosing vasculitis in the absence of temporal arteritic damage.