IMMUNOHISTOCHEMICAL DETECTION OF VIRAL-ANTIGENS IN SMOOTH-MUSCLE, STROMAL, AND EPITHELIAL-CELLS FROM ACUTE HUMAN CYTOMEGALOVIRUS GASTRITIS

To analyze the expression of different human cytomegalovirus (HCMV) an tigens in gastric biopsy samples from a renal transplant recipient suf fering from HCMV gastritis, monoclonal antibodies (MAbs) were used in immunohistochemical analyses. In samples obtained before the start of specific therapy with ganciclovir, MAbs against immediate-early (E13), early (CCH2), and late antigen (XP1) reacted with cells in the smooth muscle, stromal, and epithelial layers. MAb E13 stained morphological ly altered and unaltered cells; MAbs CCH2 and XP1 predominantly staine d cytomegalic cells. After therapy with ganciclovir was begun, the thr ee viral antigens were almost exclusively found in the epithelial cell layer, whereas viral antigen appeared to be cleared from smooth muscl e and stromal cells. All cells stained by MAb E13 in these samples sho wed characteristic morphologic alterations, in contrast to cells in ea rlier samples. The changes in the pattern of viral antigen expression may reflect the effects of antiviral therapy.