Fine-needle aspiration biopsy in transplantation pathology

Invasive methods are the only reliable method for diagnosis of rejection and other intragraft complications. Needle biopsy (NB) histology is considered as the "gold standard," but because of potential complications, cannot be used for frequent monitoring of organ allografts. Fine-needle aspiration biopsy (FNAB) is an invasive, but less traumatic, diagnostic method for continuous monitoring of intragraft events. The FNAB method makes it possible to evaluate the onset, intensity, and duration of inflammatory episodes of acute rejection. Parenchymal changes in the FNAB specimens give additional information of the intragraft events. As FNAB can be repeated daily, it enables not only diagnosis of the presence or absence of acute rejection, but can also monitor the effect of immunosuppressive therapy and the response to antirejection treatment. However, the diagnosis of chronic rejection and other later complications is established only by biopsy histology.