Approach to cytomegalovirus infections in patients with ulcerative colitis.

Cytomegalovirus (CMV) reactivation is common in patients with severe ulcerative colitis (UC), and may ref lect exacerbation of mucosal inf lammation and/or administration of immunosuppressants. The question of whether CMV is an active pathogen or 'an innocent bystander' in the exacerbation of UC remains controversial. Patients with UC exacerbated by reactivated CMV experience worse prognoses than those without CMV reactivation and antiviral therapy significantly reduces the need for colectomy in patients with severe UC and high-grade CMV infection, indicating that CMV plays a role in UC prognosis. Therefore, the CMV status of patients on immunosuppressants, particularly those with steroid-refractory or -dependent UC, should be tested. When CMV is detected, be performed based on should adequate treatment the extent of the viral load and the presence of certain clinical features including a large ulcer. Anti-tumor necrosis factor agents may be useful for treating CMV colitis complicating UC.