Diagnostic significance of cytomegalovirus DNA quantitation in gastrointestinal biopsies: comparison with histopathological data and blood cytomegalovirus DNA

OBJECTIVES This study aims to improve the diagnosis of gastrointestinal (GI) cytomegalovirus (CMV) disease. It presents the results of a novel study in which CMV blood viral load (BVL), tissue viral load (TVL) determined by PCR and hematoxylin-eosin (HE)/immunohistochemistry (IHC) results of GI biopsies are examined comparatively. METHODS CMV DNA was investigated by quantitative real-time PCR in blood and GI biopsy specimens of 76 patients suspected of CMV disease. Biopsies were also performed HE/IHC stainings in the pathology laboratory. RESULTS This study included 76 patients whose median age was 34.5 years and 58% (44) were male. Tissue CMV PCR positivity was detected in the highest colon (40/53;75.5%) samples. HE, IHC, blood and tissue CMV PCR positivity rates of all samples were 15.8, 25, 50 and 71.1%, respectively. When IHC was used as the gold standard test for ROC analysis, the optimal cutoff values for the maximum sensitivity and specificity for BVL and TVL were 1.91 log10 copies/ml and 3.82 log10 copies/mg, respectively. Sensitivity and specificity for the cutoff value of tissue CMV DNA were 78.9 and 74.3%, respectively (P < 0.001). CONCLUSION In this study, CMV DNA was detected in 71.1% of the tissue samples of the cases by PCR. Since the sensitivity of the histopathological examinations accepted as the gold standard is low, simultaneous with the histopathological examinations, determination of BVL, TVL and the identification of optimal cutoff values [ZERO WIDTH SPACE][ZERO WIDTH SPACE]have been shown to support the diagnosis of GI CMV disease.