The role of immunohistochemistry staining and hematoxylin & eosin staining in the diagnosis of cytomegalovirus disease of the gastrointestinal tract

Invasive cytomegalovirus (CMV) diseases require accurate diagnosis. However, study evaluating the accuracy of hematoxylin and eosin (H&E) staining and the necessity of immunohistochemistry (IHC) staining in different CMV diseases of the gastrointestinal (GI) tract is limited. We analyzed specimens of the GI tract with H&E and IHC staining results from the pathology database. Patients were divided into suspected CMV infection (HEs) and no evidence of CMV infection (HEn) groups. We used IHC staining as the gold standard and analyzed sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) for H&E staining. Among 1448 specimens, the SE/SP (%) of H&E staining for the entire tract, esophagus, stomach, small intestine, and colon were 76.1%/82.1%, 76.1%/70%, 85.5%/71.7%, 60%/94.2%, and 75%/87%; the PPV/NPV (%) in the same order were 58%/91.3%, 39.3%/92%, 51.2%/93.5%, 69.2%/91.5%, and 68%/90.4%. In conclusion, for patients exhibiting high clinical suspicion, the application of IHC staining is essential in achieving an accurate diagnosis.