[Renal involvement in systemic sclerosis]. / Sclerosi sistemica e coinvolgimento renale.

ABSTRACT

Systemic sclerosis is an autoimmune disease characterized by fibrosis of the skin and internal organs. Raynaud's phenomenon generally precedes other disease manifestations. The distribution of skin lesions and the internal organ involvement are the basis for the classification into limited and diffuse forms of the disease. Clinically evident renal disease is observed in 10-40% of patients. The most common renal presentation is renal crisis, characterized by acute onset of renal failure and severe hypertension; some patients remain normotensive, showing microangiopathic hemolytic anemia. Renal complications due to penicillamine may occur in some patients. Finally, ANCA-associated glomerulonephritis is a rare complication of the disorder. In spite of treatment with ACE inhibitors, 20-50% of patients with renal crisis progress to end-stage renal disease. In the absence of a specific therapy, there is accumulating evidence supporting the effectiveness of prostacyclin derivatives, antifibrotic and immunosuppressive drugs. The evidence is strong that the ACE inhibitors that are used in renal crisis are disease modifying. In our series including 193 patients with systemic sclerosis, renal involvement was observed in 19 patients; 11 presented renal crisis (hypertensive in 8; normotensive in 3); 5 had chronic nephropathy; 2 developed penicillamine-induced nephrotic syndrome, and 1 ANCA-associated glomerulonephritis. Renal disease occurs in a minority of patients with systemic sclerosis, and may have a variable clinicopathological picture. As renal involvement is associated with a worse prognosis, careful monitoring of blood pressure, urine chemistry and renal function is required, particularly in patients with diffuse skin disease.