Scleroderma renal crisis: pathogenesis issues, disease pattern and modern approaches to the treatment

Abstract

Scleroderma renal crisis (SRC) is a major complication in patients with systemic sclerosis. SRC occurs in about 5–25 % of all patients with scleroderma. It is characterized by malignant hypertension and olig-/anuric acute renal failure. Around 10 % of SRC cases may present with normal blood pressure, termed normotensive renal crisis. The etiopathogenesis is presumed to be a series of insults to the kidneys resulting in endothelial injury, intimal proliferation, and narrowing of renal arterioles leading to decreased blood flow, hyperplasia of the juxtaglomerular apparatus, hyperreninemia, and accelerated hypertension. SRC is often triggered by nephrotoxic drugs and/or intravascular volume depletion. SRC occurs particularly in the first years of disease and in its diffuse form. The occurrence of SRC is more common in patients treated with glucocorticoids, the risk increases with increasing dose. Left ventricular insufficiency and hypertensive encephalopathy are typical clinical features. Thrombotic microangiopathy is detected in 43 % of the cases. Anti-RNA-polymerase III antibodies are present in one third of patients who develop SRC. Renal biopsy is not necessary if SRC presents with classical features. However, it can help to establish prognosis and approaches to the treatment in atypical forms. The prognosis of SRC has dramatically improved with the introduction of angiotensin-converting enzyme inhibitors. However, 5-year survival in patients with systemic sclerosis who develop the full picture of SRC remains low (65 %). The treatment of SRC is based on aggressive control of blood pressure with angiotensin-converting enzyme inhibitors, if needed, in combination with other types of antihypertensive drugs. Dialysis is frequently indicated, but can be stopped in approximately half of patients, mainly in those with good control of blood pressure. Patients who need dialysis for more than 2 years qualify for renal transplantation. SRC still remains an important cause of morbidity and mortality in scleroderma. Prompt diagnosis and treatment may help prevent adverse outcomes and improve survival.