[Renal involvement in patients with systemic sclerosis].

Scleroderma renal crisis is characterized by malignant hypertension and oligo-anuric acute renal failure. Scleroderma renal crisis occurs in 2 to 5% of patients with systemic sclerosis, particularly those with diffuse cutaneous systemic sclerosis in the first years of disease evolution. High-dose corticosteroid therapy (> 15 mg/d) is associated with an increased risk of scleroderma renal crisis. Patients present with prominent left heart failure and hypertensive encephalopathy. Renal failure can be associated with moderate proteinuria, without hematuria. Thrombotic microangiopathy is detected in 43% of the cases. Anti-RNA polymerase III antibodies are present in one third of patients with scleroderma renal crisis. In case of renal failure, iatrogenic or functional origin must be investigated, as well as crescentic glomerulonephritis associated with antineutrophil cytoplasm antibodies (ANCA) or thrombotic microangiopathy. Renal biopsy is not necessary to establish the diagnosis in typical forms of scleroderma renal crisis. However, it can help to evaluate the prognosis and it is recommended when clinical presentation of scleroderma renal crisis is unusual. The prognosis of scleroderma renal crisis dramatically improved with the use of angiotensin-converting enzyme (ACE) inhibitors. However, 5-year survival of patients who developed a scleroderma renal crisis is only 65%. The treatment relies on the early control of blood pressure with increasing doses of ACE inhibitors, in association with calcium channel blockers if necessary. In case of severe renal failure and/or hypertension, dialysis can help to quickly control the vascular overload and the blood pressure. Dialysis can be stopped in about half of cases. After 2 years on dialysis, eligible patients should be considered for renal transplantation. The prevention of scleroderma renal crisis lacks consensus. Corticosteroids and/or nephrotoxic drugs should be avoided in patients with diffuse cutaneous systemic sclerosis.