Effectiveness of Mycophenolate Mofetil Combined With Tacrolimus for Steroid Tapering in Systemic Lupus Erythematosus

Inclusion Criteria: * Systemic lupus erythematosus participants diagnosed with 2019 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria, fulfilled with American College of Rheumatology (ACR) lupus nephritis definition, and have reached treatment target (accord with lupus nephritis clinical remission and DORIS) for at least 6 months. The target is defined as: (1)24h urine protein ≤0.5g/d；(2)stable of improved renal function (baseline creatinine ±10% or decrease 15%)；(3)clinical SLE Disease Activity Index (cSLEDAI) =0 (all scores are required zero, except hypocomplementemia and anti-dsDNA antibody positivity)；(4)PGA score (Physician Global Assessment)\<0.5; (5)prednisone or equivalent steroid dose≤5mg/d；(6)stable use of immunosuppressants and antimalarial drugs; (7)no use of biological agents. * According to the physician, the participant can accept this treatment. * The participant is willing to join this clinical trial, has good compliance, and could understand and sign the informed consent before the study begins. Exclusion Criteria: * SLE complicated with important organ dysfunction, including consciousness disorder, cognitive disorder, renal dysfunction, heart dysfunction (NYHA class 3, 4), pulmonary arterial hypertension, and interstitial lung disease. * SLE with active vital organ disease (not satisfied with DORIS), including but not limited to active neuropsychiatric systemic lupus erythematosus, lupus nephritis, thrombocytopenia, hemolytic anemia, myocardial involvement, gastrointestinal involvement, etc. * Participants who are allergic to or intolerant with mycophenolate mofetil or tacrolimus. * Participants with acute and chronic infections requiring anti-infective treatment, including but not limited to tuberculosis infection, Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) infection, Human Immunodeficiency Virus (HIV) infection, and Cytomegalovirus (CMV) infection. * Participants who are pregnant or planning to become pregnant. * Participants who have used biological agents within 6 months before enrollment. * The researcher considers any condition that may cause the participant to be unable to complete the study or bring an obvious risk to the participant.