[Renal involvement in systemic lupus erythematosus].

Lupus nephropathy belongs to the most severe clinical manifestations of systemic lupus erythematosus (SLE). In 40-60% of patients impairment in renal function is stated on diagnosis and in 10-25% of them the disease progresses to the end-stage renal failure. There is an ample of evidence that the kidney is involved very early in the course of SLE and the occurrence of low-level proteinuria and haematuria may be associated with a significant renal disease. Glomerular lesions are the main prognostic factor. Two classifications of these lesions exist at present, i.e.: the World Health Organization classification from 1982 and the new one developed by the International Society of Nephrology/Renal Pathology Society in 2003. Since new morphological presentations with glomerular necrosis and crescent formation, associated with the presence of anti-neutrophil cytoplasmic antibodies have been reported, some difficulties in the interpretation of glomerular lesions further exist. Despite this complexity, the assessment of the kidney biopsy specimen remains the "gold standard" in handling with patients with lupus nephropathy.