What is the recommended treatment for Cytomegalovirus (CMV) colitis?

Treatment of Cytomegalovirus (CMV) Colitis

The recommended treatment for CMV colitis is intravenous ganciclovir 5 mg/kg twice daily for 3-5 days followed by oral valganciclovir 900 mg twice daily for 2-3 weeks, with consideration for discontinuation of immunosuppressive therapy in severe cases. 1

Diagnosis

Before initiating treatment, accurate diagnosis is essential:

• Gold standard diagnostic method: Colonic biopsy with histology and immunohistochemistry (IHC) showing "owl's eye" inclusions 1
• Supporting diagnostic tests:
  • Colonic tissue CMV DNA PCR (improves sensitivity)
  • Whole blood leukocyte DNA PCR (sensitivity 65-100%, specificity 40-92%)
  • Contrast-enhanced CT scan (bowel thickening is common) 1

Note: Blood serology has no diagnostic value for CMV colitis as CMV seroprevalence in adults is at least 70% 1

Treatment Algorithm

First-line Treatment

1. Initiate antiviral therapy:

   • Intravenous ganciclovir 5 mg/kg twice daily for 3-5 days 1
   • Then transition to oral valganciclovir 900 mg twice daily for 2-3 weeks 1

2. Immunosuppression management:

   • In localized CMV colitis: Immunosuppressants generally do not need to be discontinued 1
   • In steroid-refractory IBD with CMV: Consider tapering steroids 1
   • In symptomatic disseminated CMV infection: Discontinue immunosuppressive therapy 1

3. Consult infectious disease specialist early 1

Special Populations

• Pediatric patients: 14-21 days of parenteral ganciclovir is recommended; early switch to oral treatment may promote CMV reactivation 1

• Inflammatory Bowel Disease (IBD) patients:

  • CMV reactivation is common in steroid-refractory IBD 1
  • Higher colonic viral load correlates with higher risk of colectomy 1
  • Consider rapid steroid tapering 1

Alternative Treatments

• For ganciclovir-intolerant patients: Foscarnet (requires strict monitoring of renal function and electrolytes) 1
• For resistant cases: High-dose valganciclovir (1800 mg twice daily) with immunosuppression reduction may be effective in cases with UL97 and UL54 mutations 2

Monitoring During Treatment

• Laboratory monitoring:

  • Complete blood counts and serum electrolytes twice weekly during induction therapy and once weekly thereafter 3
  • Monitor for neutropenia, thrombocytopenia, and renal dysfunction (common side effects of ganciclovir) 3

• Clinical monitoring:

  • Assess for resolution of symptoms (diarrhea, rectal bleeding, fever, abdominal pain)
  • Consider repeat colonoscopy in non-responsive cases

Surgical Considerations

A subtotal or partial colectomy is indicated in severe conditions characterized by:

• Toxic megacolon
• Fulminant colitis
• Perforation
• Ischemia 1

Treatment Outcomes

Evidence suggests that a full two-week course of IV ganciclovir is associated with better outcomes than shorter IV courses or oral treatment alone, with:

• Higher clinical response rates (95.8% vs 74% for one-week IV treatment)
• Lower colectomy rates within 3 months (6.25% vs 27.3%) 4

Common Pitfalls

• Delayed diagnosis: CMV colitis should be considered in all patients with acute severe ulcerative colitis 1
• Premature discontinuation of antiviral therapy can lead to relapse 3
• Underestimating severity: Untreated CMV disease in immunodeficient patients is associated with higher morbidity and mortality 1
• Overlooking drug interactions: Monitor for interactions between antivirals and other medications

In-hospital mortality of immunocompetent severely ill patients with CMV colitis is almost 70% despite treatment, with even worse outcomes in immunocompromised patients, highlighting the importance of prompt diagnosis and appropriate treatment 1.