Cytomegalovirus (CMV) infection complicates inflammatory bowel disease (IBD), but anti-viral therapy reduces the need for bowel surgery, researchers report in the May issue of Clinical Gastroenterology and Hepatology. The benefits of anti-viral treatment are greatest for patients with high-grade disease, they show.
CMV infection is more common in patients with severe or steroid-refractory IBD than people without IBD. IBD patients infected with CMV are more frequently hospitalized and more often required surgery.
Andrea Jones et al quantified the density of CMV inclusions in biopsy specimens (CMV disease) from patients with IBD and assessed their outcomes and response to antiviral therapy in a case–control study.
Of 1111 patients with IDB, 68 were positive for CMV disease, based on H&E-staining or other methods. Among the 50 CMV-positive cases the authors included in their analysis, 16 had high-grade infection (more than 5 viral inclusions per biopsy fragment) and 34 had low-grade infection (see figure).
Each case was matched with 3 CMV-negative patients from the same IBD population (controls), by disease type (ulcerative colitis, Crohn’s disease, or inflammatory bowel disease unclassified).
Among patients with CMV disease, treatment with antiviral therapy reduced risk of surgery by about 70%. The patients with high-grade disease, all of whom received anti-viral treatment, had the best outcomes—only 33% underwent surgery within 1 year after biopsy.
Among patients with low-grade disease, antiviral treatment reduced the risk of surgery by about 60%. About 73% of the untreated patients with low-grade CMV had undergone surgery by 1 year after biopsy, whereas patients with low-grade disease who were treated did not differ from controls in cumulative risk of bowel resection.
The overall perception of clinical improvement within 3 months was high in the treated patients (76.3% overall).
Jones et al conclude that antiviral therapy reduces the incidence of surgical resection of the bowel during the year after diagnosis. The beneficial effect of treatment was most notable in patients with high-grade CMV disease.
Low-grade CMV disease seemed to behave differently. Patients with low-grade infection underwent surgical resection earlier, and more often, than controls or those with high-grade disease—particularly patients with low-grade disease who did not receive antiviral therapy.
Consensus statements from several organizations recommend initiation of antiviral therapy when CMV is detected in the intestinal tissue of patients with IBD. However, those recommendations were based on few data from small case series, with heterogeneity in the diagnosis of CMV infection or disease and therapeutic strategies used.
Jones et al studied a larger population. They suggest that that CMV disease in patients with IBD be defined as low-grade or high-grade disease, based on tissue viral density. Grade of CMV infection appears to affect clinical presentation, response to antiviral therapy, and risk for surgical resection. Further studies are needed to determine the best criteria for low- and high-grade disease—definitions could vary with detection techniques used.