Abstract

Roger Klein Moreira*, Christine Norton, Flavia Nunes Rosado, Cynthia Cohen and Frederick Nolte

Cytomegalovirus (CMV) infection of the gastrointestinal (GI) tract is associated with high mortality in immunosuppressed patients. Few studies have correlated serum viral load with histopathological findings in this setting. Gastrointestinal biopsies from 28 immunosuppressed patients showing CMV cytopathic effect were studied by immunohistochemistry (IHC) and IN SITU hybridization (ISH). Quantitative evaluation of CMV-infected cells was correlated with clinicopathologic data, including plasma PCR. 85.7% (24/28) of our patients had detectable viremia. Viral load did not correlate with concentration of CMV-infected cells in tissue, type of infected cell (endothelial, epithelial, smooth muscle, or stromal), microscopic mucosal ulceration, CMV inclusions in multiple sites within the GI tract, endoscopic findings, or presence of systemic symptoms. All PCR-negative cases (4/28) occurred in late onset CMV infection or disease. Most cases of biopsy-proven GI CMV infection and disease are associated with positive viremia by plasma PCR. We found no correlation between viral load and any of the clinicopathologic parameters analyzed in our study. Some cases of late-onset CMV infection and disease may have no detectable CMV viremia by PCR.