Lupus is a representative autoimmune disease that affects the whole body. It is occurred by generation of autoantibody and immune complex due to abnormal activation of the immune cells on the basis of abnormal immune responses.~Although about 50% of lupus patients have lupus nephritis, there is no therapeutic product targeting for the lupus nephritis so far.~The investigator has performed the pre-clinical and clinical studies using allogenic bone marrow derived mesenchymal stem cells in SLE.~CS20AT04 has anti-inflammatory effects, controls activity of immune cells and reduces generation of autoantibodies. So, it is expected to have therapeutic effects on lupus nephritis.~Phase 1 clinical trial was conducted as a single center, open-label.~The main component of CS20AT04 is bone marrow-derived mesenchymal stem cells. And the risk of tumor formation is low. Through the repeated administration and long-term observation with mouse model, it was confirmed that there was no oncogenicity. In addition, it was confirmed through the cell residual tracking test of the animal model that the in vivo residual period was shorter than 14 days.~However, since long-term safety has not been evaluated after administering CS20AT04 to humans, the investigator will confirm the safety of stem cells for up to 5 years according to the risk management plan for stem cell products of the Ministry of Food and Drug Safety and already approved phase 1 clinical trial.~Also In the phase 1 clinical trial that only confirmed safety and tolerability for 28 days after administration of CS20AT04, it is difficult to confirm the continuous change of the indicator for evaluating efficacy.~So, it is necessary to check the efficacy in this observation study.
This observation study is planned to evaluate the safety and efficacy of the subjects who received CS20AT04 in the phase 1 clinical trial.~If the subjects who participated in the phase 1 clinical trial voluntarily agree to participate in this observation study, visit 1 and visit 2 will be conducted every 3 months according to the clinical trial protocol until 6 months after administration of CS20AT04 in the phase 1 clinical trial. And Visit 3 after 6 months, Visit 4~Visit 7 will be conducted every 12 months. During each visit, subjects are assessed for the efficacy and occurrence of adverse events.