Acoustic Radiation Force Impulse Elastography May Predict Acute Rejection in Kidney Transplantation

Allograft biopsy that is done as indicated by clinical and laboratory clues about graft rejection provides a definitive diagnosis. Noninvasive methods that may be useful for predicting or diagnosing rejection are important for early diagnosis of possible rejection.

The aim of this study is to investigate the relationship between changes in shear wave velocity (SWV) values and renal allograft kidney biopsy findings.

Thirty-four end-stage renal failure patients who underwent living donor renal transplantation between January 2015 and July 2015 were enrolled in this prospective cohort study. Implantation, sixth-month protocol, and biopsies that were performed with suspicion of acute rejection were evaluated with renal Doppler ultrasound and elastography findings of recipients' preimplantation donor ultrasonography findings.

Comparison of renal ultrasound and elastography findings of 2 groups revealed a significant elevation in the resistive index (0.81 vs 0.63, P = .005) and pulsatility index (2.08 vs 1.20, P = .008) values in the rejection group, and no significant difference in the SWV values between the 2 groups. Delta (Δ)-SWV was calculated using the difference between acute rejection values and preimplantation, implantation, and sixth-month values showed a positive correlation between acute rejection (Δ-sixth month, r = 0.498, P = .030), tubulitis (Δ-pretransplant, r = 0.509, P = .037), and inflammation (Δ-pretransplant, r = 0.657, P = .004) scores. However, there were no correlations between Δ-SWV values and glomerulitis and peritubular capillaritis score.

Changes in SWV may predict acute rejection in kidney transplantation patients if the reference measurements were done at a more stable time after the transplantation.