Lupus nephritis.

Lupus nephritis (LN) is a type of glomerulonephritis and one of the most serious complications of systemic lupus erythematosus (SLE). LN affects 25-60% of patients with SLE, with incidence and prevalence varying by age, sex, ethnicity and socioeconomic factors. LN predominantly develops within 5 years of an SLE diagnosis and, for many patients, it is the initial manifestation that leads to the recognition of SLE. In some patients, LN may develop late in the disease course, highlighting the importance of persistent awareness of its symptoms and signs. Despite an increasing understanding of disease biology and more effective treatment options, LN remains a substantial cause of morbidity and mortality as it can lead to irreversible kidney failure and associated complications. Risk factors for progression to kidney failure include persistent proteinuria, low glomerular filtration rate, hypertension at diagnosis and frequent disease flares. LN pathogenesis involves complex immune dysregulation, with key pathways including type I interferon signalling, calcineurin activation, and B and T cell dysfunction. Several immunomodulatory drugs are used for the management of LN, and treatment paradigms are increasingly shifting towards multi-agent regimens. Along with appropriate pharmacotherapy, multidisciplinary care tailored to the patient's individual needs, involving rheumatologists, nephrologists, social workers and other health professionals, is crucial for holistically addressing both the immune and non-immune risk factors for progressive kidney function loss and for maximizing kidney lifespan in LN.