P1555REVERSIBLE AKI AND HEART INVOLVEMENT RESULTING FROM AMANITA PROXIMA POISONING TREATED WITH HAEMODIALYSIS: A SINGLE-CENTER CASE SERIES

Abstract Background and Aims Worldwide, amatoxin-containing mushrooms account for >95% of mushroom poisoning-related death. Recently, Amanita species not containing amatoxin, such as Amanita Proxima, have been implicated in poisonings resulting in acute kidney injury. Allenic norleucine has been isolated from these fungi and accounts for their nephrotoxicity. AKI is characterized by interstitial nephritis on renal biopsy and resolves over weeks. Here we report several case of AKI associated with cardiac involvement. We aimed to describe improvement of cardiac output and resolution of AKI after replacement dialysis treatment. Method From January 2013 to January 2020, eight consecutive patients with AKI from Amanita Proxima poisoning were enrolled in a large Italian community hospital. We collected clinical data including hepatic, cardiac and renal function parameters. In all the cases studied, in addition to renal failure, there were a worsening of cardiac function. Results We identified 8 patients suffering from Amanita Proxima intoxication, with a mean age of 57.8±24.5 years (62.5% were female). All patients presented preliminary gastrointestinal symptoms occurred within 24 hours from the mushroom intake and suddenly developed kidney injury and underwent replacement dialysis treatment using standard bicarbonate dialysis. At baseline, patients' mean eGFR was 7±2.3 mL/min/1.73m, with a mean BUN of 124±41 mg/dl, AST 52,6±42,5 IU/L, ALT 115,5±105,7 IU/L,. Cardiac involvement was also found in all cases, evidenced by ECG alteration (62,5%), an increase in myocardial necrosis enzymes (87,5%) and a reduction in the ejection fraction (50%) of about 15 percent. In 25% of cases, typical chest pain was also found. Mean troponin was 3,82±7,31 ng/ml, myoglobin 243,55±275,18 ng/ml CPK 187,6±42 IU/L and CK-MB of 13,72±14,96 IU/L. Kidney failure and cardiac impairment was successfully resolved in 87.5% of poisonings. At the end of treatment all renal and cardiac parameters significantly decreased (P<0.001): mean eGFR was 57±24 mL/min/1.73m, mean BUN was 69±12.7 mg/dl, AST 23,57±9,77 IU/l, ALT 25±10,64 IU/L. Mean troponin was 0,04±0,03 ng/ml, myoglobin 111,8±93,39 ng/ml, CPK 68,33± IU/L and CK-MB 0,66± 0,61 IU/L. Only one patient died for intoxication-related complication. The mean number of dialysis treatments to achieve the resolution of renal failure was eight. Conclusions The cases reported suggest that Amanita proxima have a potential severe cardiac toxicity that request a precise cardiac evaluation. Early identification of intoxication and rapid start of dialysis therapy are crucial for the resolution of heart damage.