Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.

Hepatitis B Virus (HBV) reactivation in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids is emerging to be an important cause of morbidity and mortality in patients with current or prior exposure to HBV infection. These patients suffer a dual onslaught of illness: one from the primary disease for which they are receiving the culprit drug that led to HBV reactivation, and the other from HBV reactivation itself. The HBV reactivation not only leads to a compromised liver function, which may culminate into hepatic failure; it also adversely impacts the treatment outcome of the primary illness. Hence, identification of patients at risk of reactivation before starting these drugs, and starting treatment aimed at prevention of HBV reactivation is the best strategy of managing these patients. There are no Indian guidelines on management of HBV infection in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids for the treatment of rheumatologic conditions, malignancies, inflammatory bowel disease, dermatologic conditions, or solid-organ or bone marrow transplantation. The Indian National Association for Study of the Liver (INASL) had set up a taskforce on HBV in 2016, with a mandate to develop consensus guidelines for management of various aspects of HBV infection, relevant to India. In 2017 the taskforce had published the first INASL guidelines on management of HBV infection in India. In the present guidelines, which are in continuation with the previous guidelines, the issues on management of HBV infection in patients receiving chemotherapy, biologicals, immunosupressants, or corticosteroids are addressed.