Systemic sclerosis is a generalized disorder affecting the connective tissue of the skin and internal organs associated with alterations of the microvasculature. Scleroderma renal crisis involves almost 50% of patients with a 25% of which developing renal failure.
In our study we evaluated utility of intrarenal quantitative parameters (Resistive Index: R.I.; Pulsatility Index: P.I.) during renal color Doppler sonography, as prognostic indicators of renal involvement in systemic sclerosis.
Methods: The study was conducted between January 2003 and November 2008, in the Casa Sollievo della Sofferenza Hospital in San Giovanni Rotondo, Italy, referral center for patients with autoimmune disease. We examinated 101 patients (92 females and 9 males) (median age 67 year) affected by systemic sclerosis and 100 controls, with an Esaote Technos MPX scanner equipped a 3.5 MHz convex scanner. All subjects underwent intrarenal color Doppler sonography with evaluation of R.I. and P.I. every 12 mounths. Correlated these parameters with renal functional tests (creatinine clearance and GFR), microalbuminuria and urine test.
Results: We found a significantly higher R.I. (average 0.83±10) in 94 patients (93 females and 1 male) in respect to controls (p<0.05).
Conclusions: Even if our preliminary findings have to be confirmed in larger patient groups, they suggest that evaluation of R.I. by color Doppler sonography in patients with systemic sclerosis could allow a selection of those patients at major risk of developing renal vascular involvement and, by consequence, renal crisis as a complication of systemic sclerosis.