Clinical Significance of Isolated Cytomegalovirus Infected Intestinal Cells
Linlin Wang, Jake Dennis, Zhen Yan, Christopher Doern, Jason Y Park. UT Southwestern Medical Center, Dallas, TX; Children's Medical Center, Dallas, TX
Background: Cytomegalovirus (CMV) infection of the intestinal tract is associated with high mortality in immunosuppressed patients. However, few studies have correlated peripheral whole blood CMV viral loads with histopathologic findings. Furthermore, there have been few studies determining the clinical significance of isolated CMV infected cells identified by hematoxylin & eosin staining and/or immunohistochemistry (IHC).
Design: We searched all non-consultation intestinal biopsies from 2006 to 2011 using our laboratory information system and further analyzed the cases with the diagnosis of CMV infected cells. We then selected as a control group thirty-one consecutive intestinal biopsy cases that had a negative CMV immunohistochemistry. The electronic medical record was reviewed for each case to determine peripheral blood CMV viral load detection by quantitative PCR, clinicopathologic features at time of diagnosis and clinical outcomes after discharge.
Results: Thirty-one patients with CMV positive intestinal biopsies confirmed by IHC were identified from 52% male and 48% female patients. The clinical setting of the 31 patients with CMV positive biopsies were solid organ transplantation (n=6), bone marrow transplantation (n=6), inflammatory bowel disease (n=6), ischemic colitis (n=6), chemotherapy for solid tumors (n=4), end-stage renal disease (n=3), and infection by Human Immunodeficiency Virus (n=1). CMV viral inclusions were identified by H&E stain in 26% (n=8) of cases, the remaining cases were identified by CMV IHC alone. CMV blood viral load was only positive in 16% (n=5) of cases. None of the negative control cases had positive blood viral loads. Seven cases that had only a single positive CMV infected cell; these cases had the following outcomes: worsening clinical symptoms that responded to antiviral therapy (n=3); did well without treatment (n=3); died after discharge to hospice without treatment (n=1).
Conclusions: CMV infection of the intestines is clinically significant, but will not always present with classic viral cytopathic changes. CMV IHC should be considered in any case where there is clinical suspicion. The identification of a single CMV infected cell by IHC should be regarded as clinically significant. Peripheral blood viral load has poor sensitivity in detecting CMV intestinal infection. However, future studies will investigate whether a positive viral load in patients with intestinal symptoms is predictive of intestinal CMV infection.
Monday, March 19, 2012 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 246, Monday Morning