Use of elastographic techniques as noninvasive tools in assessment of renal allograft fibrosis

Abstract

Context Chronic allograft dysfunction is still the main cause of late allograft loss in kidney transplantation. Increased serum creatinine could be an indicator of progressive damage of the renal allograft and tubular atrophy and interstitial fibrosis, which need to be confirmed by the invasive, sometimes hazardous renal allograft biopsy. Aims We aimed to assess the possibility of using transient elastography (fibroscan) either based on ultrasound or MRI as noninvasive tools for evaluation of renal allograft fibrosis and chronic allograft index (CAI). Setting and design A prospective cohort study was conducted. Patients and methods The study included 15 patients with renal allograft. Pelvi-abdominal sonar, renal Doppler, and fibroscan have been performed for the included patients. Serum urea and creatinine have been measured, and estimated glomerular filtration rate (eGFR) has been calculated for all patients. Renal biopsies were done in seven cases. Statistical analysis Statistical package for the social sciences (version 13.0) was used for statistical analysis. Results Stiffness was significantly correlated with interstitial fibrosis (P<0.05) and inversely related with eGFR (P<0.05). Stiffness values of patients with eGFR more than 50 ml/min were lower than those patients with eGFR less than 50 ml/min (P<0.05). Patients classed as CAI Banff grade 0 had significantly less parenchymal stiffness than patients with Banff grade 1 or grade 2 CAI (P<0.05). Stiffness values of patients have insignificant relationship between parenchymal stiffness and resistive index (P<0.225). Conclusion Parenchymal renal allograft stiffness by TE is an effective method for identifying patients with CAI indicative for biopsy and modification of the immunosuppressive regimen.

Keywords

• chronic allograft index
• renal allograft
• renal biopsy
• renal fibrosis
• transient elastography