Recurrent Autoimmune Hepatitis or Acute Cellular Rejection?
A 34-year-old woman underwent liver transplantation 8 months ago for autoimmune hepatitis-related cirrhosis. Maintenance immunosuppression is tacrolimus (trough 4.2 ng/mL) and mycophenolate mofetil 500 mg twice daily. She presents with fatigue and jaundice. Laboratory tests: ALT 245 U/L, AST 190 U/L, alkaline phosphatase 180 U/L, total bilirubin 2.4 mg/dL, INR 1.1, and IgG 1,850 mg/dL. Donor-specific antibodies are negative. Liver biopsy shows porto-hepatitis with interface activity, numerous plasma cells, scattered eosinophils, mild bile duct inflammation, and central perivenulitis; C4d staining is negative. She has no fever or biliary dilatation on ultrasound. She asks whether her immunosuppression should be increased or changed.
1. How do you distinguish recurrent autoimmune hepatitis from acute cellular rejection in this setting? Which features support each diagnosis?
Read the worked answer
The differential is recurrent autoimmune hepatitis versus acute cellular rejection, with infection and biliary obstruction to exclude. Features favoring recurrent AIH include plasma-cell-rich interface hepatitis, high IgG, negative donor-specific antibodies, and negative C4d. Features favoring acute cellular rejection include mixed portal inflammation with eosinophils, bile duct inflammation, and central perivenulitis/endothelialitis. This biopsy has overlap: plasma cells and interface activity favor recurrent AIH, but eosinophils and central perivenulitis are also seen in rejection. C4d negativity argues against antibody-mediated rejection but does not exclude T-cell-mediated rejection. I would have a hepatopathologist review the slides and integrate the IgG level and DSA status before committing to a single diagnosis.
2. What would you do next with immunosuppression and monitoring, and why?
Read the worked answer
First exclude infection with CMV and EBV testing and exclude biliary obstruction with MRCP if not already done. Because the graft is significantly inflamed and the features overlap, I would increase tacrolimus to a target trough of about 6-8 ng/mL and give pulse corticosteroids, for example methylprednisolone 500 mg IV daily for 3 days followed by an oral taper. I would hold mycophenolate if there is neutropenia. Recheck LFTs and IgG in 2-4 weeks. If there is no response, repeat biopsy and consider stronger therapy. If the final interpretation is recurrent AIH, I would maintain low-dose prednisone and add azathioprine or mycophenolate; if it is rejection, I would taper steroids after the pulse and optimize tacrolimus.
3. If she responds to steroids and later becomes steroid-dependent, what long-term strategy would you use?
Read the worked answer
A steroid-dependent patient needs a steroid-sparing strategy. I would maintain the lowest effective prednisone dose, add azathioprine or mycophenolate if tolerated, and optimize tacrolimus within a narrow therapeutic range. Monitor LFTs, IgG, blood counts, and renal function, and reinvestigate any rise in liver enzymes with biopsy rather than assuming rejection. Bone health, cytomegalovirus, and skin cancer surveillance are also important. Recurrent AIH can progress to graft failure, so persistent histologic activity should prompt adjustment rather than simple observation. If azathioprine is used, check thiopurine methyltransferase activity or start low and monitor.