CTLA4 and infection: During the follow-up period of 12 months, 7 RA patients (20.6% of the general cohort) withdrew from the study, of whom 6 RA patients interrupted the study because of treatment failure (2 after 3 months and 4 after 6 months of CTLA4-Ig treatment) and 1 due to severe infection (testicular abscess) at 6 months of CTLA4-Ig treatment along with persistent RA disease activity.