Inclusion Criteria:  Age ≥ 18 years old Weight ≥ 40 Kg Patients who have valid health insurance Patients with lupus diagnosis criteria (EULAR-ACR-2019) Active lupus nephritis defined by SLEDAI score >5 and joint and/or kidney involvement.  Exclusion Criteria:  Patient protected by law (minors, pregnant or breastfeeding women, subject under guardianship or curatorship, deprived of liberty or enforced hospitalized, under administrative or judicial supervision). Patient on dialysis or on plasma exchange.