Immune reconstitution inflammatory syndrome as a cause of autoimmune hepatitis and acute liver failure.

Acute liver failure is a rare syndrome with high mortality and is often diagnosed late. Intensivist physicians play fundamental roles in the diagnostic suspicion and the management of the multiple-organic dysfunctions characteristic of this entity. Immune reconstitution inflammatory syndrome is an entity that is characterized by the paradoxical worsening of the patient's previous condition, after the initiation of antiretrovirals, triggered against either pathogens present in the host or autoantigens.

Acute tubulointerstitial nephritis with severe renal impairment associated with multisystem IgG4-related disease.

The IgG4-related disease has a wide clinical spectrum where multiple organs can be affected, and the diagnosis depends on typical histopathological findings and an elevated IgG4 expression in plasma cells in the affected tissue. We describe the clinical presentation and evolution of a patient with acute tubulointerstitial nephritis, severe kidney failure and systemic manifestations such as lymphadenomegaly and chronic pancreatitis. The diagnosis was confirmed by the clinical picture and kidney and lymph node histopathology, in which immunohistochemistry of the lymphoid tissue showed policlonality and increased expression of IgG4, with a IgG4/total IgG ratio > 80%.