Clinical meaning
Systemic lupus erythematosus (SLE) management at the NP level requires comprehensive understanding of disease pathogenesis, classification criteria, organ-specific monitoring, and immunosuppressive pharmacotherapy. The 2019 EULAR/ACR classification criteria use a weighted scoring system (entry criterion: ANA ≥1:80) with additive criteria in seven clinical domains (constitutional, hematologic, neuropsychiatric, mucocutaneous, serosal, musculoskeletal, renal) and three immunologic domains (antiphospholipid antibodies, complement levels, specific antibodies). A score ≥10 classifies as SLE. Disease activity is monitored using validated instruments: SLEDAI-2K (SLE Disease Activity Index — scores clinical and laboratory parameters), BILAG (British Isles Lupus Assessment Group — organ-specific activity), and physician global assessment. Lupus nephritis is the most serious common organ manifestation, occurring in 50% of patients. It is classified by ISN/RPS system on renal biopsy: Class I (minimal mesangial), Class II (mesangial proliferative), Class III (focal proliferative — affects <50% of glomeruli), Class IV (diffuse proliferative — most severe, affects ≥50% of glomeruli), Class V (membranous), and Class VI (advanced sclerosis). Treatment of Class III/IV nephritis follows a two-phase approach: induction (mycophenolate mofetil or IV cyclophosphamide for 6 months) followed by maintenance (mycophenolate or azathioprine for ≥3 years). Belimumab (anti-BLyS/BAFF) was the first biologic approved specifically for SLE. Voclosporin (calcineurin inhibitor) combined with mycophenolate is now approved for lupus nephritis. Anifrolumab (anti-type I interferon receptor) is approved for moderate-severe SLE. The clinician must manage medication toxicity monitoring (hydroxychloroquine retinal screening, mycophenolate teratogenicity, cyclophosphamide fertility preservation), cardiovascular risk reduction (accelerated atherosclerosis is a leading cause of late SLE mortality), pregnancy management (plan flares, medication safety, antiphospholipid antibody screening), and infection prevention in immunosuppressed patients.