=====Acute Cellular=====
  * Mechanism: T-cell mediated
  * Lab abnormalities: AST/ALT elevations, Alk Phos/bilirubin if severe
  * Dx:
    * based on pathology not chronology with duct injury, mixed cellular infiltrate, endothelialitis
    * each component scored out of 3 points to give RAI score (max 9)
  * Timeline: usually within 1st year
  * Tx: steroids and tacrolimus or mycophenolate

=====Chronic Ductopenic=====
  * Lab abnormalities: Alk Phos + Bili, LFT usually later
  * Pathology: portal dyads seen instead of triads due to affect on ducts
  * Presentation: pruritus, jaundice if severe
  * Tx: calcineurin inhibitors

=====Humoral=====
  * Mechanism: B-cell mediated
  * Epidemiology: Rare
  * Pathophysiology: high donor-specific antigen
  * Tx: Plasmapharesis

=====Miscellaneous=====
  * RAI: three components scored out of 3 each
  * Differential for LFT elevations in transplant population
    * Rejection
    * Bile duct injury/anastomotic strictures
    * Infection: CMV, EBV causing PTLD, bacterial/fungal, HepE
    * Recurrence of original disease
    * Vascular: hepatic vein stricture, portal vein stricture
    * de novo transplant hepatitis: probably form of rejection, presents as autoimmune hepatitis
  * Evaluation
    * Abdominal US
    * MRCP