Simultaneous quantitation of folic acid and 5-methyltetrahydrofolic acid in human plasma by HPLC–MS/MS and its application to a pharmacokinetic study

A sensitive method based on high-performance liquid chromatography-tandem mass spectrometry （LC- MS/MS） has been developed for the simultaneous determination of folic acid （FA） and its active meta- bolite, 5-methyltetrahydrofolic acid （5-M-THF）, in human plasma. The analytes were extracted from plasma with methanol solution containing 10 mg/mL of 2-mercaptoethanol and 0.025% （v/v） ammonium hydroxide. FA and 5-M-THF were more stable after the addition of 2-mercaptoethanol and ammonium hydroxide in the sample preparation procedures of this study than they were in the previously published methods. Chromatographic separation was performed on a Hedera ODS-2 column using a gradient elution system of acetonitrile and 1 mM ammonium acetate buffer solution containing 0.6% formic acid as mobile phase. LC-MS/MS was carried out with an ESI ion-source and operated in the multiple reaction monitoring （MRM） mode. The assay was linear over the concentration ranges of 0.249-19.9 ng/mL for FA, and 5.05-50.5 ng/mL for 5-M-THF. The developed LC-MS/MS method offers increased sensitivity for quantification of FA and 5-M-THF in human plasma and was applicable to a pharmacokinetic study of FA and 5-M-THF.

Efficacy and safety of chimeric antigen receptor-T cells in the treatment of B cell lymphoma:a systematic review and meta-analysis

Background:Conventional treatment has limited efficacy in relapsed/refractory B-cell lymphoma.Since chimeric antigen receptor T-cell(CAR-T)technology has shown high safety and results in high remission rates,we investigated its efficacy and safety in B-cell lymphoma treatment and analyzed potential affecting factors to provide evidence for therapeutic strategies and applications.Methods:We searched databases including PubMed,Embase,and Cochrane up to July 2019.Meta-analysis 1 was conducted to study the efficacy of CAR-T cell for treating B-cell lymphoma,measuring the response rate and complete remission rate as outcomes.Sub-group analysis was performed for age,pathological type,target antigen,co-stimulatory molecule,and conditioning chemotherapy.Meta-analysis 2 was undertaken on the safety of the treatment with the incidence rate of toxicity(cytokine-releasing syndrome[CRS],neurotoxicity)as an outcome.Results:Seventeen studies were included in the systematic review and meta-analysis.It was found that CAR-T cells had good therapeutic effects in the following cases:B-cell lymphoma(patients≥65 years old);diffuse large B-cell lymphoma pathological type;patients with treatment target antigen other than CD19;patients treated with co-stimulatory molecules other than CD28,including 4-1BB+CD28 or 4-1BB;and patients treated with cyclophosphamide/fludarabine pre-treatment protocol conditioning chemotherapy.Although the CRS and neurotoxicity incidences were high,most were reversible with minimal risk of death.Conclusion:CAR-T cell treatment is safe for clinical application;however,toxicity effects should be monitored.