Prognosis and progress in immunotherapies for organ involvements in systemic autoimmune diseases

Treatment of organ involvements accompanied by systemic autoimmune diseases is still challenging for clinicians, reminding the existence of unmet needs. Among them, lupus nephritis (LN), neuropsychiatric lupus, interstitial lung diseases (ILD) complicated with polymyositis/dermatomyositis (PM/DM) or systemic sclerosis (SSc) are the most severe conditions with poor prognosis. Because of the rarity and severity of the disease status, and of variety in evaluation methods, randomized clinical trials tend to be difficult in recruiting patients, in designing protocols, and in meeting primary endpoints. In such tough conditions, superiority of IVCY over corticosteroids alone for LN has been established, which is now going to be replaced by mycophenolate mofetil (MMF). Moreover, non-inferiority of tacrolimus to MMF is reported and efficacy of biologics such as Rituximab and Abatacept for LN is under investigation. In contrast, PM/DM-ILD is not suitable for randomized controlled trial because of the severity/acute progression in some patients. Intensive immunosuppressive regimen is recommended for those with poor prognostic factor(s). Cyclophosphamide has limited efficacy in SSc-ILD. Hematopoietic stem cell transplantation elongated patient survival and improved ILD, but with high treatment-related mortality rate. Efficacy of rituximab and MMF has been reported in small-sized trials. In this review, previously established treatment as well as emerging immunotherapies for organ involvements will be discussed. Our experiences in autoimmune settings also will be introduced.