What is the management approach for a patient with a history of liver transplant and immunosuppression (e.g. prednisone, tacrolimus, or mycophenolate mofetil) who presents with bowel swelling?

Management of Bowel Swelling in Post-Liver Transplant Patients

In a liver transplant recipient presenting with bowel swelling, immediately evaluate for post-transplant lymphoproliferative disorder (PTLD), cytomegalovirus (CMV) enteritis, and medication-related gastrointestinal toxicity, with urgent endoscopy and biopsy as the diagnostic cornerstone, followed by reduction of immunosuppression if PTLD or severe enteritis is confirmed.

Initial Diagnostic Approach

Immediate Evaluation Required

• Obtain contrast CT of chest, abdomen, and pelvis to identify masses, lymphadenopathy, or bowel wall thickening 1
• Check EBV PCR as 80-90% of PTLD cases are EBV-associated 1
• Measure serum lactate dehydrogenase for prognostic assessment 1
• Perform endoscopy with multiple biopsies (minimum 6 total) even if mucosa appears normal, as early pathology may not be endoscopically apparent 1
• Rule out CMV enteritis through biopsy with immunohistochemistry, as it can mimic other pathologies clinically and histologically 1

Critical Differential Diagnoses to Consider

• PTLD: Occurs in 2% of adult liver transplant recipients, typically within first year, presenting with fever, night sweats, malaise, weight loss, and constitutional symptoms 1
• CMV enteritis: Most common infectious cause of allograft dysfunction in early post-transplant period 1
• Inflammatory bowel disease (IBD) flare: Particularly relevant in patients transplanted for primary sclerosing cholangitis with underlying ulcerative colitis 2, 3
• Mycophenolate mofetil toxicity: Can cause gastritis, esophagitis, duodenal ulcer, and diarrhea 4

Immunosuppression Management Strategy

If PTLD is Confirmed

• Reduce immunosuppression immediately while monitoring for allograft dysfunction 1
• Expect symptomatic improvement within 1-2 weeks and clinical response within 4 weeks of immunosuppression reduction 1
• Contact the transplant center to coordinate immunosuppression minimization while preventing rejection 1
• Patients unable to tolerate immunosuppression reduction require alternative therapies 1

If CMV Enteritis is Confirmed

• Initiate antiviral therapy while adjusting immunosuppression in consultation with transplant center 1
• Distinguish from rejection through experienced pathology review 1

If IBD Flare in PSC Patients

• Consider switching from tacrolimus/mycophenolate mofetil to cyclosporine A/azathioprine, as dual treatment with tacrolimus and mycophenolate mofetil significantly increases IBD activity risk 3
• Young age at IBD diagnosis increases risk of post-transplant IBD flare 3
• IBD activity frequently worsens after liver transplantation in PSC patients, with 40% experiencing increased inflammation 3

Medication-Related Considerations

Mycophenolate Mofetil Toxicity Assessment

• Gastrointestinal side effects occur in approximately 59% of patients (10 of 17 in dose escalation studies), including gastritis, esophagitis, and duodenal ulcer 4
• Consider dose reduction or temporary discontinuation if severe GI symptoms present 4
• Diarrhea is one of the most common adverse events requiring intervention 4

Drug Interaction Review

• Avoid NSAIDs as they potentiate calcineurin inhibitor-induced nephrotoxicity 1
• Review all medications for cytochrome P-450 3A4 and P-glycoprotein interactions before prescribing new agents 1
• Contact transplant center before initiating any new medication 1

Monitoring and Follow-Up Protocol

Short-Term Monitoring (First 4 Weeks)

• Weekly clinical assessment for symptom improvement after immunosuppression adjustment 1
• Monitor liver function tests to detect early allograft dysfunction from reduced immunosuppression 1
• Repeat endoscopy if symptoms are refractory despite treatment 1

Long-Term Surveillance

• Biweekly endoscopy with biopsies initially in intestinal transplant patients, as early rejection may not be endoscopically apparent 1
• Maintain therapeutic calcineurin inhibitor levels while minimizing overall immunosuppression burden 5

Critical Pitfalls to Avoid

• Do not delay endoscopy with biopsy: Visual inspection alone is insufficient, as pathology may be present in normal-appearing mucosa 1
• Do not assume single etiology: CMV can coexist with rejection or PTLD 1
• Do not reduce immunosuppression without transplant center coordination: Risk of precipitating acute rejection 1, 5
• Do not continue tacrolimus/mycophenolate mofetil in PSC patients with active IBD: This combination significantly worsens IBD activity 3