An LC-MS/MS analytical method for the determination of uremic toxins in patients with end-stage renal disease.

End-stage renal disease (ESRD) is the last stage of chronic kidney disease, characterized by the progressive accumulation of uremic toxins (UTs). Hemodialysis is the standard approach to remove UTs from the body. Creatinine and urea levels are important indices of hemodialysis effectiveness, but the utility of those markers to estimate the removal of UTs, especially protein-binding UTs is limited. We developed an LC-MS/MS method for the quantification of UTs and to provide markers for evaluating hemodialysis effectiveness. These substances were extracted from serum samples after acetonitrile precipitation of protein and then separated on a HILIC column. The flow rate was 0.6 mL/min with a run time of 8.0 min for the negative ion mode and positive ion mode each. In this study 26 UTs were determined in normal subjects and in patients with ESRD before and after hemodialysis; serum levels were significantly higher in patients with ESRD than in subjects with normal renal function. A significant decrease in a variety of serum UTs were observed in patients after dialysis treatment, but no change in the levels of orotic acid, CMPF, kynurenic acid, p-cresol sulfate, phenyl-ß-d-glucuronide, 4-ethylphenyl sulfate and 3-indolyl-ß-d-glucopyranoside was found. These results show that some UTs could not be completely removed by hemodialysis. In addition, some biomarkers of different types of UTs are proposed for evaluating hemodialysis effectiveness.

Modified poisoning severity score for early prognostic evaluation in acute paraquat poisoning / 解放军医学杂志

Objective To study the applied value of modified poisoning severity score (PSS) for early prognostic evaluation in acute paraquat poisoning.Methods Thirty-seven patients with acute paraquat poisoning from June 2013 to June 2016 were enrolled.The PSS score,the modified PSS score,the acute physiology and the chronic health status Ⅱ score (APACHE Ⅱ) of the patients were calculated.The relationship between modified PSS and APACHE Ⅱ was analyzed.Also the factors that affect outcome were analyzed by logistic regression analysis.The work characteristic curve (ROC curve) of the PSS,the modified PSS and the APECH Ⅱ were drawn and compared.Results There was a positive correlation between the risk of death and admission time,poisonous dose,the concentration of urine paraquat,and white blood cell count (P＜0.05).There was a significant correlation between the modified PSS and the APACHE Ⅱ (P＜0.0001).The immediate PSS score,the modified PSS score,and the APACHE Ⅱ score were significant for the prognosis of patients with acute paraquat poisoning.The area under the curve (AUC) was in turn 0.774,0.788,0.799.Among them,the best bound of the modified PSS score was 6.5 (when the score is greater than 6.5,the risk of death is higher).Further comparison of the area under the three curves showed that there was no significant difference in the area under the ROC curve between the three scores in predicting the prognosis of death [P=0.7633(PSS-DPSS),P=0.7791 (PSS-APACHE Ⅱ),P=0.8918(DPSS-APACHE Ⅱ)].Conclusion Modified PSS is helpful in early predicting the prognosis of acute paraquat poisoning.