Study to Assess Real-world Effectiveness of Belimumab for Treatment of Adults With LN

Inclusion Criteria:

* Participants to provide a signed informed consent at the time of enrollment per protocol,
* Male or female aged 18 or over at initiation of belimumab,
* Participants received belimumab in any formulation (subcutaneous or intravenous) for the treatment of active LN prescribed as per local label in combination with standard immunosuppressive therapy/ies at initiation of belimumab,
* Participants initiated belimumab 6 to 24 months prior to study enrollment,
* Accessibility of medical records starting at belimumab initiation (including accessibility of medical records for the prior 12 months and confirmatory biopsy at any time prior to belimumab initiation),
* Biopsy-confirmed LN diagnosis at any time prior to belimumab initiation for treatment of LN
* Class III (focal LN) with or without Class V (membranous LN),
* Class IV (diffuse LN) with or without Class V,
* Class V.

Exclusion Criteria:

* Participants receiving renal replacement therapy (i.e., dialysis, kidney transplant, or those in end-stage kidney disease) at initiation of belimumab,
* Participant is concomitantly receiving another SLE targeted monoclonal antibody (MAb), or a MAb expected to compromise immune responses, at initiation of belimumab,
* Participants in a clinical trial during the observation period (with the exception of allowing participation in other non-interventional studies),
* Participant is pregnant at the initiation of belimumab,
* Participant with a kidney transplant at the initiation of belimumab,
* Participants will be excluded from the study if they are planning to become pregnant or are pregnant at study enrollment.