Treat to target (T2T) strategies have proved to be useful in several chronic disorders, including Rheumatoid Arthritis. In systemic lupus erythematosus (SLE), T2T strategy has been proposed in order to control disease activity, improve health-related quality of life, and reduce morbidity and mortality. Remission would be the main target, but a low disease activity state (LDAS) could be an acceptable alternative. However, due to SLE protean manifestations, the operational definitions of both remission and LDAS are still in progress. This clinical trial would like to assess the clinical value of T2T strategy in the treatment of children with SLE, optimize the treatment of children with SLE, andimprove the prognosis.

This two-center study retrospectively analyzed the follow-up data of children with systemic lupus erythematosus (SLE) in our center (the Children's Hospital of Chongqing Medical University) and the Children's Hospital of Nanjing Medical University, grouping the patients into two observation groups-low disease activity status Group (LDAS group) and never reached low disease activity group (Never LDAS group). We would analyze the risk factors of SLE that patients cannot reach LDAS by comparing baseline data and treatment conditions of the two groups. Meanwhile, we would evaluate the SLE clinical indicators, SLE disease activity, organ damage, and disease remission state at the end of the follow-up of the LDAS group, in order to assess the clinical value of T2T strategy in the treatment of children with SLE, optimize the treatment of children with SLE, andimprove the prognosis.

Inclusion Criteria:

(1）Children with SLE diagnosed by the SLICC classification criteria for systemic lupus erythematosus (2012); (2) Since diagnosed of SLE to follow-up termination, inpatient and/or outpatient follow-up at the research centers shall be carried out at least twice a year, the interval of follow-up is ≤3-6 months, and the total follow-up time is ≥1 year; (3) All children or guardians signed an informed consent file before inclusion.

Exclusion Criteria:

1. the treatment plan is unknown;
2. Excluding deaths caused by other diseases
3. follow-up was interrupted;
4. Follow-up time is less than 1 year, or interval is more than 6 months.

Children with SLE were diagnosed in the Children's Hospital of Chongqing Medical University and the Children's Hospital of Nanjing Medical University from January 2012 to December 2019 that meet the SLICC classification criteria for systemic lupus erythematosus (2012)