Detection of cytomegalovirus by immunohistochemistry of colonic biopsies and quantitative blood polymerase chain reaction: evaluation of agreement in ulcerative colitis.

Objectives: Cytomegalovirus (CMV) often reactivates in ulcerative colitis (UC). In diagnostics, along with immunohistochemistry (IHC) of colonic biopsies, blood CMV polymerase chain reaction (PCR) is gaining increasing application. We aimed to assess agreement between the density of infected colonic cells by IHC and the viral load in the blood by PCR.