Cytomegalovirus in liver biopsies of marrow transplant recipients: detection methods, clinical, histological and immunohistological features.

In a retrospective analysis liver biopsy specimens obtained from 44 marrow transplant recipients were studied to evaluate the frequency of local presence of human cytomegalovirus (CMV) and graft-versus-host disease (GvHD)-like histological and immunohistological alterations in patients with and without liver dysfunction following bone marrow transplantation (BMT). In 22 of 28 patients with marked liver dysfunction after BMT and histopathological alterations described as typical for acute GvHD CMV could be detected in the liver biopsy specimen. The polymerase chain reaction (PCR) technique revealed the highest sensitivity for CMV detection in liver biopsy samples, but in 20 of 22 PCR-positive specimens CMV infection could be confirmed by at least one additional technique. All the liver biopsies obtained from 16 patients with normal liver function lacking histopathological signs of GvHD were CMV negative. In all 3 patients with CMV-positive liver biopsy started on antiviral therapy liver function improved and no generalized CMV disease occurred. All the 4 patients without local presence of CMV started on severe immunosuppressive therapy showed an improvement of liver dysfunction without occurrence of CMV infection. Local CMV infection of the liver could not be differentiated from hepatic GvHD by clinical and histopathological features, nor by immunohistological analysis of the bile duct epithelium. In contrast, only in liver biopsy with local viral presence could an increase in HLA class II- and ICAM-1 expression be demonstrated on hepatocytes. Thus, especially the high negative predictive value of the PCR technique helps to manage the patient with liver dysfunction after BMT.