Comment on "Determination of Orellanine in Human Biological Matrices Using Liquid Chromatography with High-Resolution Mass Spectrometry Detection: A Validated Method Applied to Suspected Poisoning Cases".

Abstract

To the Editor, Following our recent published article presenting an analytical method to detect orellanine in human fluids (i.e., urine, plasma and whole blood) (1), we would like to provide additional information regarding the detection of orellanine in kidney biopsies. Indeed, renal biopsy analysis in order to demonstrate orellanine intoxication was proposed decades ago (2, 3), but the elements presented here make us consider this approach likely to be questionable. Some Cortinarius mushrooms contain a nephrotoxic mycotoxin called orellanine. Known since a massive poisoning in Poland in 1957, orellanus syndrome after a consumption of Cortinarius mushrooms is characterized by the long latency period (2–14 days) between intake and first symptoms (4). Renal damage observed from biopsies has shown acute tubular necrosis, interstitial nephritis and fibrosis (5). The mechanism of orellanine toxicity is not clearly understood. Proposed mechanisms include inhibition of different cellular enzymes, inhibition of RNA and DNA synthesis and production of oxygen free radicals generated via oxidated orellanine. It is also unclear whether it is orellanine that is toxic to kidney cells or a degradation product such as orellinine or an unidentified metabolite (1, 4, 5). Diagnosis of orellanine poisoning is based on a suspicion of ingestion of Cortinarius mushrooms and acute kidney injury. Therefore, the clinical diagnosis is difficult and deserves analytical confirmation. Some have proposed kidney biopsy to detect orellanine on the belief that orellanine or its metabolites persist in renal cells (2, 3). This was based on the postulate that the release of orellanine and its metabolites from renal cells was very slow, allowing for a greater detection window range.