LAUSR

INTRODUCTION Systemic lupus erythematosus (SLE) is a chronic autoimmune disease. Lupus nephritis (LN) is a common type of organ damage which occurs in SLE patients and is characterized by recurrent proteinuria. Activation of B lymphocytes can lead to refractory LN, which is an important pathogenic factor in SLE. B lymphocyte stimulator (BLyS) and A proliferation-inducing ligand (APRIL) are predominantly produced by myeloid cells (monocytes, dendritic cells, neutrophils, etc) to regulate B lymphocyte function. Telitacicept was the first dual-targeting biological drug which targeted both BLyS and APRIL. Telitacicept has passed a phase II clinical trial and has since been approved for the treatment of SLE. CASE PRESENTATION We report a case of SLE confirmed by renal biopsy as proliferative lupus nephritis (PLN) with massive proteinuria, which was treated with telitacicept (European League Against Rheumatism / American College of Rheumatology 2019 standard). During the 19 months of follow-up, the patient's renal function was stable, massive proteinuria was relieved, and creatinine and blood pressure did not increase. CONCLUSIONS During the 19 months of telitacicept treatment (160 mg once weekly), PLN reduced blood system damage and proteinuria without increasing the risk of infection.