A comparative study of two histological techniques for the identification of cytomegalovirus infection in colorectal biopsies from patients with chronic inflammatory bowel disease

Cytomegalovirus infection associated with inflammatory bowel disease

Refractory colitis in patients with inflammatory bowel disease is a complicated clinical disorder that might, in some patients, even necessitate surgery. Hence the diagnosis of additional complications is of utmost importance. Colitis mediated by cytomegalovirus is one such complication. The high seroprevalence and latent nature of cytomegalovirus, with the possibility of viral replication without mediating disease, poses a real challenge for the diagnosis of cytomegalovirus-mediated colitis. The challenge in daily clinical practice is to distinguish cytomegalovirus replication from cytomegalovirus-mediated colitis in patients with inflammatory bowel disease who have refractory colitis. This Review discusses the scientific literature and provides a diagnostic and therapeutic algorithm for clinical practice.

CMV Disease in IBD: Comparison of Diagnostic Tests and Correlation with Disease Outcome

BACKGROUND

Significance of cytomegalovirus (CMV) in inflammatory bowel disease (IBD) is unclear due to pathobiology, numerous CMV tests, and disparate treatment outcomes.

METHODS

Retrospective chart review was done on patients with positive qualitative CMV tissue polymerase chain reaction (PCR) from 2005-2013 at a tertiary referral hospital. Frequency of PCR+, hematoxylin and eosin staining(HE)+, histopathology and immunohistochemistry (IHC)+ was assessed. IHC was assessed on a sample of PCR- tissues. Surgery rates were correlated with CMV testing and treatment.

RESULTS

PCR was done on 310 samples from 180 patients. Thirty-seven samples were PCR+ (51.4% PCR+ only, 35.1% IHC/PCR+, 13.5% HE/IHC/PCR+). The H&E frequently failed to detect CMV identified on extensive IHC. Of 13 PCR- samples tested with IHC, 100% were negative. Twenty-five patients were CMV+ (40% PCR+, 40% IHC/PCR+, 20% HE/IHC/PCR+). Surgery rates increased with number of positive tests: 60% in IHC/PCR+ and 80% in HE/IHC/PCR+, compared to 26.8% in PCR- or PCR+ (P = 0.03, P = 0.02, respectively). There were 20/25 PCR+ patients who received CMV treatment. Surgery occurred in 80% of HE+ patients despite treatment and 100% of IHC+ patients without treatment.

CONCLUSIONS

Rates of CMV+ testing and surgical risk varied by test modality. PCR+ results were most frequent but alone did not detect clinically significant CMV. HE+ testing was least frequent and associated with highest surgical rate, despite treatment. CMV treatment may benefit IHC+ patients most, supporting immunostaining as optimal diagnostic test for clinically significant CMV in IBD. In PCR+ samples, HE frequently did not detect CMV identified on extensive IHC. In PCR- samples, data suggest IHC is likely negative. Consider using qualitative PCR to guide extensive immunostaining.

Management of cytomegalovirus infection in inflammatory bowel diseases

Cytomegalovirus is a deoxyribonucleic acid virus that infects a large part of the human population; after primary infection, it develops a latent state and can be reactivated, notably after a decrease in host immune defences. In patients with inflammatory bowel diseases, cytomegalovirus is frequently involved, either as an agent of colitis or through local asymptomatic reactivation. Due to the immune context of inflammatory bowel diseases and to the immunosuppressive therapies that are used to treat them, cytomegalovirus entertains complex relationships with these diseases. Whereas Crohn's disease seems little impacted by cytomegalovirus, this agent interferes strongly with the natural progression of ulcerative colitis. While immune treatments have a clear influence on the occurrence of cytomegalovirus colitis in ulcerative colitis (favourable for steroids and cyclosporine and rather inhibitory for infliximab), the role of cytomegalovirus infection on ulcerative colitis is more debated with roles ranging from innocent bystander to key pathogen suggested. There is however growing evidence for a participation of intestinal cytomegalovirus infection in the resistance of ulcerative colitis to steroids and the investigation of cytomegalovirus infection in intestinal biopsies by immunohistochemistry or quantitative polymerase chain reaction assay is strongly recommended. In several studies, treatment of cytomegalovirus infection by ganciclovir was shown to restore the response to immunomodulatory therapies and even to prevent the need for colectomy. All of these recently acquired data need to be validated by randomised clinical trials conducted on a large panel of ulcerative colitis patients.

Gastric ulcer associated with cytomegalovirus in an immunocompetent patient: method for diagnosis

Cytomegalovirus (CMV)-associated gastric ulcers can be found not only in immunocompromised hosts but also in normal individuals. The accurate endoscopic diagnosis of CMV ulcers is not easy because of the absence of characteristic morphological features. We present a case of CMV-associated gastric ulcer in an immunocompetent patient. He was a 33-year-old male with epigastralgia. Upper gastrointestinal endoscopy showed multiple erupted papules and a large irregularly shaped shallow ulcer. We did not find intracellular inclusion bodies characteristic of CMV in hematoxylin-eosin-stained gastric biopsy specimens, while CMV antigens corresponding to intracellular inclusion bodies were confirmed using an immunoperoxidase method with the monoclonal CMV antibody. If CMV ulcers are suspected, it is important to examine for inclusion bodies using not only hematoxylin-eosin staining, but also CMV immunohistochemistry for a sensitive diagnosis.