This is a multi-country, multi-site retrospective chart review study that will use data extracted from the medical charts of SLE patients who participated in the anifrolumab EAPs AMANA or ATUc in France, Germany, Greece, Israel, Italy, Portugal, Spain, and the UK. Patient level data will be captured longitudinally for each patient over a 12- to 18-month period. The study period will include retrospective data collection covering a minimum 6- month baseline period prior to the index date and retrospective data collection covering a minimum 6-month FU period from the first Anifrolumab infusion. The index date is defined as the date of first anifrolumab infusion during the indexing period. The indexing period is between the earliest date of patient enrolment into the EAP and the date of last new patient enrolment into EAP. The EAPs have closed by end of February 2023 in all countries included in the ERYTHRO study. One data extraction will be performed per patient.