Early initiation of MARS® dialysis in Amanita phalloides-induced acute liver injury prevents liver transplantation.

 Amanita phalloides is the most relevant mushroom intoxication leading to acute liver failure. The two principal groups of toxins, the amatoxins and the phallotoxins, are small oligopeptides highly resistant to chemical and physical influences. The amatoxins inhibit eukaryotic RNA polymerase II causing transcription arrest affecting mainly metabolically highly active cells like hepatocytes and renal cells. The clinically most characteristic symptom is a 6-40 h lag phase before onset of gastrointestinal symptoms and the rapid progression of acute liver failure leading to multi-organ failure and death within a week if left untreated. Extracorporeal albumin dialysis (ECAD) was reported to improve patient's outcome or facilitate bridging to transplantation. In our tertiary center, out of nine intoxicated individuals from five non-related families six patients presented with acute liver injury; all of them were treated with ECAD using the MARS® system. Four of them were listed on admission for high urgency liver transplantation. In addition to standard medical treatment for Amanita intoxication we initiated ECAD once patients were admitted to our center. Overall 16 dialysis sessions were performed. All patients survived with full native liver recovery without the need for transplantation. ECAD was well tolerated; no severe adverse events were reported during treatment. Coagulopathy resolved within days in all patients, and acute kidney injury in all but one individual. In conclusion, ECAD is highly effective in treating intoxication with Amanita phalloides. Based on these experiences we suggest early initiation and repeated sessions depending on response to ECAD with the chance of avoiding liver transplantation.

Interference of engineered nanoparticles with in vitro toxicity assays.

Accurate in vitro assessment of nanoparticle cytotoxicity requires a careful selection of the test systems. Due to high adsorption capacity and optical activity, engineered nanoparticles are highly potential in influencing classical cytotoxicity assays. Here, four common in vitro assays for oxidative stress, cell viability, cell death and inflammatory cytokine production (DCF, MTT, LDH and IL-8 ELISA) were assessed for validity using 24 well-characterized engineered nanoparticles. For all nanoparticles, the possible interference with the optical detection methods, the ability to convert the substrates, the influence on enzymatic activity and the potential to bind proinflammatory cytokines were analyzed in detail. Results varied considerably depending on the assay system used. All nanoparticles tested were found to interfere with the optical measurement at concentrations of 50 µg cm⁻² and above when DCF, MTT and LDH assays were performed. Except for Carbon Black, particle interference could be prevented by altering assay protocols and lowering particle concentrations to 10 µg cm⁻². Carbon Black was also found to oxidize H2DCF-DA in a cell-free system, whereas only ZnO nanoparticles significantly decreased LDH activity. A dramatic loss of immunoreactive IL-8 was observed for only one of the three TiO2 particle types tested. Our results demonstrate that engineered nanoparticles interfere with classic cytotoxicity assays in a highly concentration-, particle- and assay-specific manner. These findings strongly suggest that each in vitro test system has to be evaluated for each single nanoparticle type to accurately assess the nanoparticle toxicity.