Abstract
Objective Renal involvement in systemic sclerosis (SSc) range from urinary abnormalities, reduction of glomerular filtrate rate (GFR), high renal resistive index to scleroderma renal crisis (SCR). Intrarenal resistance indices are considered markers of renal scleroderma-associated vasculopathy. The aim of this study is to evaluate renal morphological parameters, such as renal length, parenchymal thickness, atrophy index, renal sinus in SSc patients and to correlate it with renal function and hemodynamic parameters.
Methods Ninety-two SSc patients and forty healthy controls (HC) were enrolled in this study. Doppler and renal ultrasound (US) including renal length, parenchymal thickness, atrophy index, renal sinus and intrarenal resistive index were measured in SSc patients and HC.
Results Renal US showed significant differences between HC and SSc patients. The renal length (106.7±5.1 vs 102.3±8.4) and renal sinus (70.7±7.9 vs 65.3±7.7) were significantly (p=0.001) higher in HC than SSc patients. The parenchymal thickness was significantly (p=0,004) higher in HC than SSc patients (18±3.1 vs 16.3±2.5). Pulsatility index, resistive index and S/D ratio were significantly (p<0.0001) lower in HC than SSc patients. The renal length was significantly higher (p=0.004) in diffuse cutaneous SSc (105±8.4) than in limited cutaneous SSc (99.5 ±7.5).
Conclusion In SSc, kidney involvement is subclinical and is related to vascular injury, Raynaud’s phenomenon and chronic hypoxia that can modify renal morphology. Serum creatinine is a poor marker of renal damage and renal US could be a useful tool - together with Doppler - to evaluate renal involvement in a systemic and chronic disease like systemic sclerosis.