Protocol liver biopsy and acute cellular rejection grading

The measurement of resistive index (RI) by Doppler ultrasonography was performed in all patients on days 1, 2, and 3. Protocol liver biopsies and CT scans were performed routinely on postoperative day 7 to check the status of the liver graft and post-LT vasculature as well as abdominal complications. The following indications were considered for liver biopsy after discharge; (1) worsening of liver function or elevation in enzymes, (2) an abnormal increase in liver enzymes after the initial decrease, (3) unexpected abnormality of liver enzymes following a treated event, and (4) follow-up to a prior biopsy.

The histologic findings were graded according to the Banff schema. For statistical analysis, the rejection activity index (RAI) score was subsequently grouped as follows: RAI score < 2, no rejection; RAI = 2, indeterminate rejection; RAI score = 3–4, mild rejection; RAI score = 5–6, moderate rejection; and RAI score > 6, severe rejection [21]. The definition of ACR used in this study was more than 3 scores of RAI.