Descartes-08 for Children, Adolescents, and Young Adults With Autoimmune Disorders

Inclusion Criteria: * At least age 12 * definitive diagnosis of childhood-onset systemic lupus erythematous, juvenile Myasthenie gravis, juvenile dermatomyositis and AAV * Signs and symptoms of moderate disease * History of systemic treatment * Parent/Guardian/Patient must be able to give written informed consent Exclusion Criteria: * Major chronic illness that is not well managed at the time of study entry and in the opinion of the investigator may increase the risk to the patient; * Abnormal PT/INR or PTT increased \> 1.5-fold or patient is on anticoagulation therapy (except in cases of elevated PTT with documented lupus anticoagulant; or in patients who have been on stable doses of anticoagulation therapy for more than 6 months of VTE diagnosis; or in patients on stable doses of anticoagulation therapy for at least 8 weeks of atrial fibrillation diagnosis; these conditions will not be exclusionary unless, in the investigator's opinion, they make participation in the study unsafe); * ANC \< 1000 cells/microliter ; * Hemoglobin \< 8.0 g/dL ; * Platelets \< 50,000/mm3 (NOTE: platelet transfusions are permissible); * ALT and/or AST with GGT ≥ 3× upper limit of normal * Creatine Clearance less than 30mL/min /1.73 m2; * History of primary immunodeficiency, organ, or allogeneic bone marrow transplant; * Patients must be seronegative for hepatitis B surface antigen; * Patients must be seronegative for hepatitis C antibody. If hepatitis C antibody test is positive, then patients…