The analysis of the initial validation of SLEDAI-2KG will be conducted on the selected patients from the TLC. Improved patients (responders) will be identified based on SLEDAI-2K definition of improvement and further will be studied by calculating the SLEDAI-2KG using the above described models. The mean change of SLEDAI-2K scores and the mean change of SLEDAI-2KG scores in the responders will be studied. Using the SLEDAI-2K responders as "Gold Standard", it will be determined if SLEDAI-2KG responders are true responders and not false responders.