Editing Systemic scleroderma (section)

===Kidney disease===
Scleroderma renal crisis (SRC) is a life-threatening complication of systemic sclerosis that may be the initial manifestation of the disease.  Renal vascular injury (due in part to collagen deposition) leads to renal ischemia, which results in activation of the renin-angiotensin-aldosterone system (RAAS).  This raises blood pressure and further damages the renal vasculature, causing a vicious cycle of worsening hypertension and renal dysfunction (e.g., elevated creatinine, edema).  Hypertensive emergency with end-organ dysfunction (e.g., encephalopathy, retinal hemorrhage) is common.  Thrombocytopenia and microangiopathic hemolytic anemia can be seen.  Urinalysis is usually normal but may show mild proteinuria, as in this patient; casts are unexpected.{{citation needed|date=September 2021}}

The mainstay of therapy for SRC includes ACE inhibitors, which reduce RAAS activity and improve renal function and blood pressure.  Short-acting ACE inhibitors (typically captopril) are used because they can be rapidly uptitrated.  An elevated serum creatinine level is not a contraindication for ACE inhibitors in this population, and slight elevations in creatinine are common during drug initiation.

Scleroderma renal crisis, the occurrence of [[acute kidney injury]], and [[malignant hypertension]] (very high blood pressure with evidence of organ damage) in people with scleroderma are effectively treated with drugs from the class of the ACE inhibitors. The benefit of ACE inhibitors extends even to those who have to commence [[hemodialysis|dialysis]] to treat their kidney disease, and may give sufficient benefit to allow the discontinuation of renal replacement therapy.<ref name=Zandberg/>