Flare of Autoimmune Hepatitis Causing Acute on Chronic Liver Failure: Diagnosis and Response to Corticosteroid Therapy

Abstract
Autoimmune hepatitis (AIH) is considered less common in the Asia Pacific region. Due to this, AIH flare as a cause of acute on chronic liver failure (ACLF) is often overlooked and treatment delayed. We aimed at the defining clinical and histopathological spectrum and role of steroid therapy in AIH‐ACLF. Patients with AIH‐ACLF, prospectively recruited and followed between 2012 and 2017, were analyzed from the Asian Pacific Association for the Study of the Liver ACLF Research Consortium (AARC) data base. Diagnosis of AIH was confirmed using International Autoimmune Hepatitis Group score or simplified AIH score with histopathological evidence. Of 2,825 ACLF patients, 82 (2.9%) fulfilled criteria of AIH (age 42.1 ± 18.1 years, 70% female). At baseline, mean bilirubin was 18.6 ± 8.2 mg/dL, Child‐Turcotte‐Pugh score was 11.7 ± 1.4, and Model for End‐Stage Liver Disease (MELD) score was 27.6 ± 6.5. Mean immunoglobulin G was 21.61 ± 7.32 g/dL, and this was elevated ≥1.1 times in 97% of cases; 49% were seronegative. Liver histology was available in 90%, with median histological activity index of 10 (interquartile range, 7‐12); 90% with moderate to severe interface activity; 56% showing significant parenchymal necrosis (bridging and confluent necrosis); and cirrhosis in 42%. Twenty‐eight (34%) patients received steroid therapy and showed shorter intensive care unit (ICU) stay (median 1.5 versus 4 days, P < 0.001) and improved 90‐day survival (75% versus 48.1%, P = 0.02) with comparable incidence of sepsis (P = 0.32) compared to those who did not. Patients of advanced age, more severe liver disease (MELD >27; 83.3% sensitivity, 78.9% specificity, area under the receiver operating characteristic curve 0.86), presence of hepatic encephalopathy, and fibrosis grade ≥F3 had an unfavorable response to corticosteroid therapy. Conclusion: AIH presenting as ACLF is not uncommon in Asian patients; a low threshold for liver biopsy is needed to confirm the diagnosis as nearly half the patients are seronegative; early stratification to steroid therapy or liver transplantation (MELD >27, hepatic encephalopathy in ≥F3) would reduce ICU stay and improve outcomes.