3164 The Unhelpful Biopsy: Autoimmune Hepatitis in a Young Woman With Kikuchi Fujimoto Disease

Abstract

INTRODUCTION: Kikuchi Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare, immune-mediated condition usually seen in young Asian females. There are only two reported cases of autoimmune hepatitis (AIH) in a patient with KFD. Systemic lupus erythematosus (SLE) has a strong association with KFD and introduces diagnostic uncertainty in differentiating AIH and SLE-hepatitis. We present a challenging case of acute hepatitis in a woman with KFD, positive rheumatologic signal and bland liver biopsy. CASE DESCRIPTION/METHODS: A 33-year-old female presented with non-bloody emesis. Her history was significant for KFD and exam was notable for jaundice and a diffuse maculopapular rash involving palms and soles. She had normal vitals and was previously known to have a positive ANA (1:640) and anti-dsDNA. Labs were notable for ALT 843, AST 646, alkaline phosphatase 173, total bilirubin 10.6 with direct bilirubin 8.6. Given her elevation in transaminases, additional serologies and imaging were performed demonstrating a mildly elevated transferrin, no sign of viral hepatitis and a right upper quadrant ultrasound and MRCP with nonspecific hepatitis. She was admitted for expedited workup and further laboratory evaluation was notable for a mildly elevated IgG and negative for abnormalities in ASMA as well as p-ANCA, Anti-LKM1, and ALC-1. Serologies were overall consistent with a probable diagnosis of AIH and a liver biopsy was planned to secure a definitive diagnosis. However this demonstrated non-specific necrosis and cholestasis, inconsistent with AIH. After a prompt response to steroids and a negative antiribosomal P antibody, probable AIH was suggested and she recovered uneventfully. DISCUSSION: Diagnosis of AIH can be made with clinical presentation, laboratory evaluation and biopsy. Our patient presented with a probable diagnosis of AIH (score of 14 by AASLD guidelines), yet a negative ASMA, bland biopsy and a positive SLE signal (though not meeting formal diagnostic criteria) were significant confounders. Treatment response to steroids suggested AIH by AASLD scoring, yet SLE hepatitis is also steroid responsive. Negative anti-ribosomal P antibody may suggest decreased likelihood of SLE hepatitis, and this distinction is critical given the more benign course of SLE-hepatitis. This is a rare case of KFD associated, probable AIH, yet there remains much overlap with SLE-hepatitis. We recommend additional research to determine clinical or laboratory criteria to differentiate these diagnoses.