BRUSH CYTOLOGY IN THE COURSE OF ACUTE SMALL-BOWEL ALLOGRAFT-REJECTION

OBJECTIVE: To examine the changes in brush cytology during acute small bowel allograft rejection and to evaluate the usefulness of cytology in detecting acute rejection. STUDY DESIGN: Heterotopic porcine small bowel allografts were followed by brush cytology and full-thickness bi opsies during un-modified rejection. RESULTS: The most prominent chang es in cell differential counts were an increase in the proportion of g ranulocytes and decrease in the proportion of epithelial cells. In bru shed Epithelial fragments, infiltration of granulocytes and acidophili a increased, and cell cohesion runs gradually lost with the degenerati on of nuclei and necrosis of epithelium. The cell differential count w as compared to the histologic acute rejection index, which was created on the basis of five semiquantitatively evaluated histologic paramete rs. The sensitivity of cell differentiation in detecting histologicall y moderate or severe rejection was 87% (13 of 15 cases) and the specif icity 76% (5 false positives in 21 negative cases). CONCLUSION: Suspic ion of acute rejection call be assessed with reasonable reliability by cytology, but it cannot be detected earlier than by histology. Brush cytology complements mucosal biopsies in the evaluation of rejection a nd, as a rapid and cost-effective method, may evert partly replace the m. It may also prove valuable in detecting opportunistic bowel infecti ons in immunosuppressed patients.