The pathological hallmarks of systemic sclerosis (scleroderma) are uncontrolled accumulation of collagen and widespread vascular lesions characterized by thickening of the vascular wall and narrowing of the vascular lumen. (See "Pathogenesis of systemic sclerosis (scleroderma)".)
Renal involvement is common in systemic sclerosis (SSc), with most patients manifesting only mild chronic renal dysfunction. By comparison, an acute, severe, and life-threatening form of renal disease, called scleroderma renal crisis (SRC), develops in approximately 10 to 20 percent of patients with the diffuse cutaneous SSc and much less frequently in patients with limited cutaneous SSc. Despite the widespread use of angiotensin-converting enzyme (ACE) inhibitors for the treatment of SRC, morbidity and mortality remain high.
SRC is characterized by:
- Abrupt onset of moderate to severe hypertension
- Urine sediment that is normal or reveals only mild proteinuria with few cells or casts
- Progressive renal failure
Patients with SSc without overt evidence of renal disease frequently have compromised renal function. Using sensitive measures to assess renal function in such patients may show decreased renal plasma flow, elevated renal vascular resistance, and elevated plasma renin levels .