Kidney graft rejection studies with labeled platelets and lymphocytes

Area of Science:

• Nuclear Medicine
• Transplantation Immunology
• Nephrology

Background:

• Acute kidney graft rejection is a significant complication following transplantation.
• Accurate and timely diagnosis is crucial for effective treatment and graft survival.
• Cyclosporine A is a common immunosuppressive agent, but its use can lead to nephrotoxicity, complicating diagnosis.

Purpose of the Study:

• To evaluate the diagnostic utility of Indium-111 (In-111)-labelled platelets and lymphocytes in identifying acute kidney graft rejection.
• To compare the efficacy of these radiotracers in differentiating rejection from other conditions like graft dysfunction or nephrotoxicity.

Main Methods:

• One hundred fifty-five patients undergoing kidney transplantation were studied.
• Blood cells were labelled with In-111-oxine and reinjected.
• Scintigraphy was performed daily, with graft/contralateral area activity ratios (index I) calculated to assess uptake.

Main Results:

• In-111-labelled platelets demonstrated a significantly higher activity index in acute rejection (I = 1.9 +/- 0.4) compared to functioning grafts, post-operative acute renal failure, and nephrotoxicity (I = 1.1 +/- 0.1).
• Sensitivity, specificity, and accuracy for platelet scintigraphy were 97.2%, 90.2%, and 92.8%, respectively.
• Labelled lymphocytes yielded similar diagnostic differences between rejecting and non-rejecting grafts.

Conclusions:

• In-111-labelled platelet scintigraphy is a highly sensitive and specific method for diagnosing acute kidney graft rejection.
• This technique is particularly valuable in patients treated with cyclosporine, helping to distinguish rejection from nephrotoxicity.
• It is considered the method of choice for acute kidney graft rejection diagnosis.