[Lupus Foundation of America LUPUS 21ST CENTURY 2018 CONFERENCE, Abstracts of the Fourth Biannual Scientific Meeting of the North and South American and Caribbean Lupus Community, Armonk, New York, USA, September 13 – 15, 2018 - ()] Clinical Trials - CT-04 Safety and efficacy of allogeneic umbilical cord-derived mesenchymal stem cells (MSCs) in patients with systemic lupus erythematosus: results of an open-label phase I study