Monitoring renal allograft rejection with duplex sonography

Area of Science:

• Nephrology
• Transplant Surgery
• Medical Imaging

Background:

• Early detection of renal allograft rejection is crucial for graft survival.
• Duplex Doppler ultrasound provides non-invasive assessment of renal allograft hemodynamics.
• Resistive index (RI) is a key Doppler parameter reflecting intrarenal arterial resistance.

Purpose of the Study:

• To evaluate the utility of serial duplex Doppler ultrasound measurements of resistive index (RI) in predicting early renal allograft rejection.
• To determine if RI values can differentiate between grafts requiring single versus multiple anti-rejection treatments.

Main Methods:

• Serial duplex Doppler ultrasound studies were performed on 36 renal allograft recipients.
• Reproducibility of RI measurements was assessed.
• RI values were analyzed in relation to rejection episodes and treatment response.

Main Results:

• Grafts experiencing rejection within 3 weeks showed greater RI increases from day 2 to day 5 post-transplant.
• Patients with persistent rejection had significantly higher RI values on diagnosis day and day 2 post-transplant compared to those with single-course treatment.
• An RI > 70 on day 2 post-transplant predicted rejection requiring additional treatment with 100% sensitivity and 80% specificity.

Conclusions:

• Serial RI measurements are valuable for early detection of renal allograft rejection.
• Elevated RI on day 2 post-transplant is a strong predictor of rejection requiring intensified therapy.
• These findings suggest potential for earlier or alternative anti-rejection strategies in high-risk patients.