Cellular injury leading to oxidative stress in acute poisoning with potassium permanganate/oxalic acid, paraquat, and glyphosate surfactant herbicide.

Previous studies on human acute kidney injury (AKI) following poisoning with potassium permanganate/oxalic acid (KMnO4/H2C2O4), paraquat, and glyphosate surfactant herbicide (GPSH) have shown rapid and large increases in serum creatinine (sCr) that cannot be entirely explained by direct nephrotoxicity. One plausible mechanism for a rapid increase in sCr is oxidative stress. Thus, we aimed to explore biomarkers of oxidative stress, cellular injury, and their relationship with sCr, after acute KMnO4/H2C2O4, paraquat, and GPSH poisonings. Serum biomarkers [sCr, creatine (sCn), cystatin C (sCysC)] and urinary biomarkers [cytochrome C (CytoC), 8-isoprostane (8-IsoPs)] were evaluated in 105 patients [H2C2O4/KMnO4 (N = 57), paraquat, (N = 21), GPSH (N = 27)] recruited to a multicenter cohort study. We used area under the receiver operating characteristics curve (AUC-ROC) to quantify the extent of prediction of moderate to severe AKI (acute kidney injury network stage 2/3 (AKIN2/3)). Patients with AKIN2/3 showed increased levels of CytoC. Early high CytoC predicted AKIN2/3 in poisoning with KMnO4/H2C2O4 (AUC-ROC4-8h: 0.81), paraquat (AUC-ROC4-8h: 1.00), and GPSH (AUC-ROC4-8h: 0.91). 8-Isoprostane levels were not significantly elevated. Reduced sCn and increased sCr/sCn ratios were observed for 48 h post KMnO4/H2C2O4 ingestion. Paraquat exhibited a similar pattern (N = 11), however only 3 were included in our study. Increased CytoC suggests there is mitochondrial injury coupled with energy depletion. The increased sCr within 24 h could be due to increased conversion of cellular creatine to creatinine during the process of adenosine triphosphate (ATP) generation and then efflux from cells. Later increases of sCr are more likely to represent a true decrease in kidney function.

Epidemiology, toxicokinetics and biomarkers after self-poisoning with Gloriosa superba.

Introduction: Gloriosa superba is a flowering plant that contains colchicine. Deliberate self-poisoning with this plant in Sri Lanka is common and potentially fatal. The objective of this study was to describe the epidemiology, toxicokinetics and selected biomarkers in these patients. Materials and methods: The study consisted of three parts; epidemiologic and outcome data (n = 297), concentrations and toxicokinetics (n = 72), evaluation of urinary and serum biomarkers (n = 45). Plasma colchicine levels were measured by high-performance liquid chromatography (HPLC). We also measured serum biomarkers: creatinine (sCr), cystatin C (sCysC) and creatine kinase (CK), and urinary biomarkers: creatinine, kidney injury molecule-1 (KIM - 1), clusterin, albumin, beta-2-microglobulin (ß2M), cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN) and trefoil factor 3 (TFF3). Results: The case fatality was 10% (29/297), and death was much more common in older patients. Median concentrations of colchicine were higher in those over 65 [median 4.7 ng/mL (IQR: 1.7-6.6) vs. 1.2 (IQR: 0.2-2.7) for those <35]. Admission colchicine concentrations were highly correlated with a fatal outcome [median 7.8 ng/ml (IQR: 5.8-18.7) vs 1.2 (0-2.3) in survivors]. The area under the receiver operating characteristic curve (AUC-ROC) for uncorrected admission colchicine level was highly predictive of a fatal outcome, and this improved even further with two methods we developed to correct for the expected change with time. The best method had an AUC-ROC of 0.98 (95%CI 0.94-1.00) in predicting death, with 100% sensitivity and 96% specificity at the best cut-point. Discussion: Fatal outcomes and high concentrations were both much more common in the elderly following poisoning with Gloriosa superba. Our findings are consistent with kinetic data after medicinal colchicine ingestion. Conclusions: Gloriosa superba self-poisoning causes significant mortality. High concentration of colchicine is highly predictive of a fatal outcome. Ingestion of Gloriosa superba caused only mild acute kidney injury (AKI) and rhabdomyolysis.

Serum creatinine and cystatin C provide conflicting evidence of acute kidney injury following acute ingestion of potassium permanganate and oxalic acid.

AIM: Acute kidney injury (AKI) is common following deliberate self-poisoning with a combination washing powder containing oxalic acid (H2C2O4) and potassium permanganate (KMnO4). Early and rapid increases in serum creatinine (sCr) follow severe poisoning. We investigated the relationship of these increases with direct nephrotoxicity in an ongoing multicenter prospective cohort study in Sri Lanka exploring AKI following poisoning. METHODS: Multiple measures of change in kidney function were evaluated in 48 consenting patients who had serial sCr and serum cystatin C (sCysC) data available. RESULTS: Thirty-eight (38/48, 79%) patients developed AKI (AKIN criteria). Twenty-eight (58%) had AKIN stage 2 or 3. Initial increases in urine creatinine (uCr) excretion were followed by a substantial loss of renal function. The AKIN stage 2 and 3 (AKIN2/3) group had very rapid rises in sCr (a median of 118% at 24 h and by 400% at 72 h post ingestion). We excluded the possibility that the rapid rise resulted from the assay used or muscle damage. In contrast, the average sCysC increase was 65% by 72 h. CONCLUSIONS: In most AKI, sCysC increases to the same extent but more rapidly than sCr, as sCysC has a shorter half-life. This suggests either a reduction in Cystatin C production or, conversely, that the rapid early rise of sCr results from increased production of creatine and creatinine to meet energy demands following severe oxidative stress mediated by H2C2O4 and KMnO4. Increased early creatinine excretion supports the latter explanation, since creatinine excretion usually decreases transiently in AKIN2/3 from other causes.