<qa>  How many patients will be enrolled from all study sites?The accrual ceiling will be unlimited. Approximately 700 patients will be enrolled from all study sites. Approximately 150 patients will be recruited at the NIH. Other sites participating in this study are Cedars-Sinai Medical Center, Los Angeles, CA; the University of California-San Francisco and University of Texas-Houston Health Sciences Center. To ensure a sufficient sample of patients with active inflammation, enrollment in the study will be monitored so that at least 80 patients will be included who have an ESR of 40 mmhr or higher at the screening visit or visit 1, or who have an elevated serum C-reactive protein level at visit 1. 