[Liver transplant aspiration cytology to monitor the intragraft events]

Abstract

Liver transplant aspiration cytology(TAC) contributes significantly to the differential diagnosis of transplanted liver graft dysfunction, since each of the possible causes induces characteristic cytological findings in the graft and peripheral blood. That is, TAC can differentiate various inflammatory changes as indicating acute rejection, viral infection, or bacterial infection. The key is the intensity of activated lymphocytes in the graft and in blood. Remarkable lymphocytic activation only in the liver graft indicates acute rejection, meanwhile in a case of viral infection the activation can be seen both in liver graft and blood. The patterns and degree of liver cell injury and cholestasis can also identify the reason for liver impairment. Several cases of acute rejection, viral infection, and subclinical acute rejection diagnosed by TAC were recognized on TAC slide preparations. Subclinical rejection, which means acute rejection appreciated only cytologically or histologically, can be followed without treatment unless the patient demonstrates jaundice and liver enzymes over 100 units. In a case of chronic rejection, TAC is not an appropriate method of diagnosis, because there are few infiltrating cells in the portal triad, and subsequently, no visible activated lymphocytes on TAC slides. Although TAC is not well accepted, it is an informative means preliminary to core biopsy, and its use is expected to become wide-spread in the future because it is a safe procedure with minimal invasiveness to patients, and useful for differential diagnosis. The use of TAC will lessen the frequency of performing more invasive core biopsy.