Abstract Title: Unveiling the Cholestatic Phenotype: A Case of Autoimmune Hepatitis with Severe Hyperbilirubinemia

Background: Autoimmune hepatitis (AIH) is defined by clinical, laboratory, and histologic findings as a hepatitic syndrome rather than a cholestatic syndrome. Cholestasis in AIH is typically due to associated primary biliary cirrhosis or primary sclerosing cholangitis. However, 8% cases of AIH have unexplained cholestasis (the Cholestatic-phenotype). In this case report, we described a patient who presented with cholestasis but was later diagnosed with AIH, responding well to steroid treatment.

Case Presentation: A 52-year-old woman presented to the emergency department with a 15-day history of yellowing of the eyes and urine, accompanied by fatigue and pale-stools, following a brief febrile illness. Initial treatment with empirical antibiotics and supportive care at a local health center showed no improvement. Her medical history was unremarkable except for a similar episode of jaundice 4 years prior. Physical examination was normal, but laboratory tests revealed normocytic normochromic anemia, markedly elevated bilirubin (total 27 mg/dl, direct 15 mg/dl, indirect 12 mg/dl), and liver enzymes (AST-239 IU/L, ALT - 93 IU/L). Further evaluation showed a positive antinuclear antibody (ANA) profile with antibodies against SS-A, Scl-70 and Jo-1, but negative for anti-LKM, anti SMA and AMA. Liver ultrasound revealed altered liver echotexture without strictures or other abnormalities. Liver biopsy demonstrated features of auto-immune hepatitis(Figure 1), with interface hepatitis, cholestasis, chronic inflammatory infiltrates and portal fibrosis. Based on the Revised original scoring system for AIH, the patient had a pretreatment score of 15 (Simplifed scoring system score of 8) ,confirming the diagnosis. Treatment with azathioprine and prednisolone was initiated, with subsequent follow-up showing a positive response. Bilirubin levels normalized within two months.

Discussion: For patients with cholestasis, especially with elevated bilirubin and positive ANA profile, AIH should be one of the differential diagnosis. Even if the classic serological markers like anti LKM and anti-SMA are negative, biopsy is the key to confirm the diagnosis in patients with such atypical presentation. The standard treatment for AIH is immunosuppressive therapy using steroids and steroid sparing agent such as azathioprine. Steroids such as prednisolone reduces the inflammation acutely and azathioprine is used for long-term chronic therapy to maintain the remission without the fear of steroid dependence.