Potential value of urinary amatoxin quantification in patients with hepatotoxic mushroom poisoning

Abstract

Backgorund & aims: Mushroom poisoning with Amanita phalloides or similar species can lead to liver failure with 10-30% mortality rates. We aimed at defining the prognostic value of urinary amatoxin quantification in patients with hepatotoxic mushroom poisoning.

Methods: Data from 32 patients with hepatotoxic mushroom poisoning (Hospital Clínic Barcelona, 2002-16) in whom urinary amatoxins were determined (ELISA) were retrospectively reviewed. Correlations between urinary amatoxin and collected baseline variables with outcomes including hepatotoxicity (ALT>1000 U/L), severe acute liver injury (ALI, prothrombin <50%), acute liver failure (ALF, ALI and encephalopathy), transplantation/death and hospital length-of-stay, were evaluated.

Results: 12/32 patients developed increased aminotransferase activity. Among the 13/32 amatoxin negative patients, 1 developed ALI and 12/13 no hepatotoxicity. Among the 19/32 amatoxin positive patients, 8/19 (42%) developed hepatotoxicity, including 5 who progressed to severe ALI, of whom 3 developed ALF (2 deaths, 1 transplantation). Urinary amatoxin and prothrombin were independent predictors of hepatotoxicity, ALT peak values (along with age) and hospital length-of-stay. In positive amatoxins patients, urinary concentrations > 55 ng/ml (or a baseline prothrombin ≤ 83%), were associated to hepatotoxicity (presented by 8/9 patients with ALT>1000 U/L). Among 5 patients with urinary amatoxin ≥ 70 ng/ml, 4 developed severe ALI.

Conclusions: In patients with hepatotoxic mushroom poisoning, a negative urinary amatoxin quantification within 72h of intake ruled out the risk of hepatotoxicity in 92% of patients, whereas positive urinary amatoxins were associated with hepatotoxicity and severe ALI. Concentrations >55 ng/ml and ≥ 70 ng/ml were predictive of hepatotoxicity and severe ALI, respectively.

Keywords: amanitin; hepatotoxicity; liver failure; severe liver injury.