[Lupus nephritis].

Lupus nephritis (LN) is one of the most frequent organ manifestations of systemic lupus erythematosus. Urine analysis is suitable for screening and proteinuria or an active sediment with acanthocytes can be indicative for LN. The gold standard for confirming the diagnosis is a kidney biopsy. The type and extent of the histological alterations are decisive for treatment. The LN is histologically classified into six classes, whereby classes III, IV and V in particular require immunosuppressive treatment. The treatment of LN consists of the administration of hydroxychloroquine, angiotensin-converting enzyme (ACE) inhibitors for nephroprotection and further antihypertensive drugs in cases of arterial hypertension. For prognostically unfavorable forms of LN an immunosuppressive treatment is necessary and a variety of substances are available for this. The immunosuppressive treatment is spread over several years, whereby intensive treatment can mostly be de-escalated after 3-6 months. Despite good treatment options the risk of recurrence and also for chronic renal damage with terminal renal failure is elevated and continuous monitoring is absolutely necessary.