Renal complications and scleroderma renal crisis

Scleroderma renal crisis (SRC) occurs in 5-10% of SSc patients, who may present with an abrupt onset of hypertension, acute renal failure, headaches, fevers, malaise, hypertensive retinopathy, encephalopathy and pulmonary oedema. Patients at greatest risk of developing SRC are those with diffuse cutaneous or rapidly progressive forms of SSc, and treatment with a recently commenced high dose of corticosteroid. Laboratory tests may demonstrate hypercreatinaemia, microangiopathic haemolytic anaemia (MAHA), thrombocytopaenia and hyperreninaemia. Renal crisis is also linked to a positive ANA speckled pattern, antibodies to RNA polymerase I and II, and an absence of anti-centromere antibodies. Early, aggressive treatment with angiotensin-converting enzyme inhibitors has improved prognosis in SRC, although 40% of the patients may require dialysis, and mortality at 5 yrs is 30-40%. Median time to recovery is 1 yr, and typically occurs within 3 yrs. Prognosis is worse for males, but may not be related to corticosteroid use, presence of MAHA or severity of renal pathology. Modification of endothelin over-activity, which is implicated in the pathogenesis of SRC, may offer a future therapeutic approach.