Knowledge Gaps and Future Research Most studies for primary or secondary stroke preven- tion in SCD were conducted in the pediatric popu- lation. Therefore, there is a gap in understanding whether transfusion or hydroxyurea recommendations in the pediatric population hold true in the adult patient with SCD with symptomatic or asymptomatic stroke, elevated TCD velocities, or vessel imaging notable for vasculopathy. 5.13.1. Autoimmune Vasculitis Recommendations for Autoimmune Vasculitis Referenced studies that support recommendations are summarized in online Data Supplement 50. COR LOE Recommendations In patients with ischemic stroke or TIA and symptoms attributed to giant cell arteri- tis, immediate initiation of oral high-dose glucocorticoids is recommended to reduce recurrent stroke risk.672 681 In patients with ischemic stroke or TIA and diagnosis of giant cell arteritis, methotrexate or tocilizumab therapy adjunctive to steroids is reasonable to lower the risk of recurrent In patients with ischemic stroke or TIA and diagnosis of primary CNS angiitis, induc- tion therapy with glucocorticoids and/or immunosuppressants followed by long-term maintenance therapy with steroid-sparing immunosuppressants is reasonable to lower the risk of stroke recurrence.691 696 3: Harm B-R In patients with ischemic stroke or TIA and confirmed diagnosis of giant cell arteritis, infliximab is associated with recurrent ocular symptoms and markers of disease activity and should not be administered.697 704 Synopsis Autoimmune vasculitis is a subset of disease that may cause stroke. The overall prevalence of autoim- mune vasculitis in stroke population is very low but age dependent. In cohorts of younger patients (eg, age <45 years), vasculitis may account for 0% to 20% of stroke cases, depending on the depth of workup.705 In older population, the proportion of strokes caused by vas- culitis is smaller because of the increasing burden of aging-related risk factors. 