BTLA and systemic lupus erythematosus: Similarly, German SLE patients treated with immunosuppressive agents (prednisone, hydroxychloroquine, azathioprine, mycophenolate mofetil, belimumab) with active disease activity reported a higher expression of B- and T-lymphocyte attenuator (BTLA) in CD3+CD8-CD69+IFNγ+ cells than that in inactive SLE patients and healthy controls (7).