Scleroderma Renal Crisis
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Direct answer
Scleroderma renal crisis is an abrupt onset of severe hypertension with acute kidney injury in systemic sclerosis, caused by a vasculopathy affecting the interlobular and arcuate arteries. Its central treatment is an ACE inhibitor, started promptly to lower blood pressure and restore renal perfusion, even when creatinine is raised. High-dose glucocorticoids are a recognised risk factor and are avoided.
What you must remember
- Disease type: most often in diffuse cutaneous systemic sclerosis, and usually within the first years of the disease.
- Autoantibody link: anti-RNA polymerase III antibody is the marker most strongly associated with renal crisis.
- Clinical triad: abrupt severe hypertension, acute kidney injury and proteinuria, sometimes with retinopathy or encephalopathy.
- Haematology: microangiopathic haemolytic anaemia and thrombocytopenia can occur, so a blood film is essential.
- Pathology: intimal proliferation and fibrinoid necrosis in interlobular and arcuate arteries, causing sudden reduction in renal blood flow.
- Treatment: ACE inhibitor as the cornerstone, titrated against creatinine and potassium.
- Steroid risk: high-dose glucocorticoids are a recognised trigger, so they are avoided where possible.
- Dialysis: a substantial proportion need dialysis at presentation, though some patients recover function.
A pathway for suspected renal crisis
Scleroderma renal crisis is a medical emergency, because the rise in blood pressure and fall in renal perfusion can progress over days. The pathway below puts blood pressure control and ACE inhibitor therapy first, while excluding the mimics that need different treatment.
- Confirm the context: A patient with systemic sclerosis who presents with abrupt hypertension and rising creatinine has renal crisis until shown otherwise.
- Check the blood film: Schistocytes, low platelets and a raised LDH show microangiopathic haemolysis, which can occur within renal crisis itself, so TTP is excluded with a normal ADAMTS13 level where doubt remains.
- Start the ACE inhibitor: Treatment begins early, with blood pressure lowered gradually, and potassium and creatinine checked after each dose change.
- Review the drugs: High-dose steroids are withdrawn, and cyclosporine or other nephrotoxic agents are reviewed.
- Plan for dialysis: Dialysis is started for standard indications, including oliguria, fluid overload or uraemic complications, while function is watched.
- Monitor long-term: Renal function, blood pressure and potassium are followed, because the ACE inhibitor usually continues after recovery.
Outcome depends on how early the ACE inhibitor starts and on how quickly blood pressure is brought under control. Delay in treatment is one of the main reasons a patient progresses to dialysis dependence.
Where the examiner tries to catch you
Renal crisis questions often reward the student who knows what to avoid as well as what to give.
- Trap: giving high-dose steroids for the systemic sclerosis flare. Correct: high-dose glucocorticoids are a recognised risk factor for renal crisis, so they are avoided or reduced.
- Trap: withholding an ACE inhibitor because the creatinine is high. Correct: the ACE inhibitor is the cornerstone of treatment in renal crisis, and it is titrated against creatinine and potassium rather than withheld.
- Trap: diagnosing renal crisis from creatinine alone. Correct: the diagnosis rests on abrupt severe hypertension with renal impairment in systemic sclerosis, and a blood film looks for the microangiopathic haemolysis that may accompany it, with TTP excluded where doubt remains.
Frequently asked questions
Which antibody is most strongly associated with scleroderma renal crisis?
Anti-RNA polymerase III antibody is the autoantibody most strongly associated with scleroderma renal crisis, and it is typical of diffuse cutaneous systemic sclerosis. Its presence identifies a higher-risk group who need closer blood pressure and renal monitoring.
Why is an ACE inhibitor used in scleroderma renal crisis?
ACE inhibitors are the cornerstone of treatment in scleroderma renal crisis, because the renin-angiotensin system is strongly activated in this condition. They lower blood pressure and renal vascular resistance, and creatinine and potassium are monitored after each dose change.
Which drugs should be avoided in scleroderma renal crisis?
High-dose glucocorticoids are the drug class to avoid in scleroderma renal crisis, because they are a recognised risk factor for the crisis. Nephrotoxic agents such as cyclosporine should also be reviewed, since they can mimic or worsen the renal picture.
How does thrombotic microangiopathy differ from scleroderma renal crisis?
Thrombotic microangiopathy, such as thrombotic thrombocytopenic purpura or haemolytic uraemic syndrome, causes microangiopathic haemolysis and thrombocytopenia with a different treatment pathway. Scleroderma renal crisis can itself show microangiopathic haemolysis, so the context of systemic sclerosis with abrupt severe hypertension decides, and ADAMTS13 activity helps exclude TTP.
Does scleroderma renal crisis cause permanent kidney damage?
Some patients recover renal function with prompt treatment, but many need dialysis at presentation and some remain dialysis dependent. Early ACE inhibitor therapy is an important factor in preserving function, and delay is associated with a worse outcome.