Enarodustat

Pure red cell aplasia (PRCA) is a rare complication of erythropoietin (EPO) therapy, characterized by a severe deficiency in red blood cell production. There is no guideline on the treatment for PRCA because there have been too few cases to perform prospective cohort studies. The main treatments for PRCA include immediate cessation of EPO, restrictive transfusion, and immunosuppressive therapies. A 35-year-old male patient with type 1 diabetic nephropathy was diagnosed with PRCA. Enarodustat and roxadustat were administered successively after discontinuation of EPO, but anemia did not improve, and the patient was maintained with weekly blood transfusions. Subsequently, the EPO-mimetic peptide pegmolesatide was administered, and the patient's hemoglobin started to increase after 1 week and increased from 50 g/L to 92 g/L over approximately 3 months. Based on these findings, we speculate that pegmolesatide can provide a safe, effective, and convenient therapeutic strategy for PRCA in Chinese patients with chronic kidney disease.

Dried urine spots have recently been proposed as an alternative matrix in the anti-doping field. Drying urine may open the opportunity to limit microbial and thermal degradation of the prohibited substances during transportation to the anti-doping laboratories without the need for refrigeration or freezing. In this study, a multi-targeted initial testing procedure was developed for the determination of 237 prohibited drugs/metabolites from 11 different classes in dried urine spots. The comparability between two different microsampling techniques (i.e., Whatman^® FTA DMPK-C cards and Mitra^® tips) was evaluated. The developed method was then used to evaluate the stability of the target compounds in urine for 7 days under different environmental conditions to simulate the transportation of the urine samples from the collection sites to anti-doping laboratories. Sample preparation consists of (i) extraction of the analytes from the collection device using a mixture of acetonitrile/methanol (1/1) for 30 min at 40 °C, (ii) enzymatic hydrolysis, and (iii) sample concentration by solid-phase extraction. Analysis was performed using liquid chromatography coupled to high-resolution mass spectrometry. The entire workflow was validated in terms of specificity (analytes were distinguishable from the matrix interferences), sensitivity (only with the Mitra^® tips the limits of detection comply with the World Anti-Doping Agency's requirements for the majority of the target compounds), carry-over (no signals in the negative urine injected after the positive urine), matrix effect (16-28% for Mitra^® tips and 22-35% for DMPK-C cards), and extraction yield (Mitra^® tips: 51-88%; DMPK-C cards: 40-76%). As proof of concept, authentic urine samples were analyzed: results obtained in dried urine were compared with those of fluid urine, providing good agreement. Stability studies showed that the target compounds were stable for the whole duration of the study (7 days) at -20 and 4 °C in both fluid and dried urine. At 50 °C or at 20-25 °C, several thiazide-based compounds were completely degraded to their degradation product in the first 24 h or after 3-4 days in fluid urine, whereas in dried urine the compounds were detectable for the entire duration of the study.