Renal transplant fine needle aspiration and cytokine gene expression

Fine needle aspiration of renal transplants is a safe effective means of obtaining intragraft material for diagnostic evaluation of transplant dysfunction in the first 3-6 months post engraftment. Aspiration can be performed daily as an outpatient to assess causes of renal insufficiency and response to therapeutic intervention. Aspiration also provides a unique tool for the investigation of pathogenetic mechanisms in acute rejection; samples can be subjected to reverse transcriptase-polymerase chain reaction with quantitation of cytokine gene expression. We have utilized this technique to demonstrate the strong, likely causal, relationship between gamma-interferon and acute rejection. The ability to perform aspirates frequently affords an opportunity to map the cytokine cascade prior to and during episodes of acute rejection. This may identify new areas for therapeutic intervention during the process of rejection.