Determination of orellanine and muscarine in biological fluids in suspected or proven poisoning cases: About several cases

Abstract

To present the application of validated methods for determination of (i) orellanine, a highly nephrotoxic molecule responsible of the toxicity of some Cortinarius mushroom and (ii) muscarine, another mushroom toxin, acting as a neurotoxin not reaching the central nervous system, in biological fluids using LC-HRMS/MS technology in poisoning case context. These toxins are annually responsible of poisoning cases or even cases of death. We developed analytical methods using LC-HRMS/MS with Orbitrap technology and a liquid/liquid extraction. These two validated methods were applied to 17 suspecting or proven mushroom intoxication cases (12 for orellanine determination and 5 for muscarine). Biological fluids (whole blood and/or plasma and/or urine) were obtained from the national study CHAMPITOX or from the classical patient care. For orellanine cases, because of the long latency period between intake and first symptoms, the delay between intake and sample collection was particularly long (average of 8.5 days). As muscarinic syndrome is one of the short latency syndromes, a shorter sample collection delay was related to these cases (average of 14.5 hours). A full quantitative validation was performed for orellanine in plasma and urine (LOD: 0.1 μg/L, LLOQ 0.5 μg/L) and a qualitative in whole blood (LOD: 0.5 μg/L) [Flament E. J Anal Toxicol 2022:bkac018.]. Applied to our cases, we have highlighted orellanine in 8 out of the 12 cases with very low concentrations (near to the LLOQ or between the LLOQ and the LOD). Concerning the muscarine, a full quantitative validation was performed in the three matrices (in whole blood and plasma, the LOD and LLOQ were 0.05 and 0.1 μg/L, respectively, and in urine, LOD and LLOQ were 0.5 and 1 μg/L, respectively). Muscarine was identified and quantified in all cases. Concentrations (ranging from 0.12 to 752 μg/L in the three matrices) were much higher than those for orellanine. For orellanine cases, concentrations were very low owing to the high delay between intake and sample collection. In addition, orellanine half-life was estimated to be 109 ± 6 min with reabsorption by proximal tubular cells (in rats) [Najar D. Toxins 2018;10(8):333.]. This reabsorption phenomenon allows the detection of the toxin for up to 17 days in whole blood and 24 days in urine. Concentrations of muscarine were higher because of the shorter sample collection delay after the intake. To our knowledges, these results are (i) the first identification reports of orellanine in biological fluids with quantification in urines, and also (ii) the first identification and quantification reports of muscarine in blood matrices (whole blood and/or plasma). These analytical methods are (i) essential tools for clinicians in order to document mushroom poisoning cases (ii) but also for analysts to fill the knowledge gap about these mycotoxins, and (iii) tools which can be applied to post-mortem cases.