Dried blood spot sampling for monitoring children with immune-mediated glomerulopathies and after kidney transplantation

Abstract

BackgroundMonitoring kidney function and immunosuppressant levels in children post-kidney transplantation or those with glomerulopathies is challenging due to frequent venipunctures and clinic visits. Capillary dried blood spot sampling (DBS) offers a potential alternative. MethodsIn this prospective single-center study, 89 children (38 % female, 62 % male) requiring therapeutic drug monitoring (TDM) and kidney function assessment were enrolled. 79 % of the patients were kidney transplant recipients, and 21 % suffered from immune-mediated glomerulopathies. The mean age was 13.4 years (range 5.7-18.0). DBS and standard venous serum samples were collected simultaneously for tacrolimus (TAC), cyclosporine A (CsA), everolimus (EVR), and creatinine levels. Further, patient feedback on pain perception and feasibility was collected via questionnaire. ResultsNo significant differences in parameter values between DBS and standard methods were found (creatinine -1.7±14.5 μmol/l; EVR 0.1±1.2 μg/L; TAC 0.3±1.1μg/L; CsA 2.8±9.8 μg/L). DBS demonstrated sufficient accuracy compared to standard methods. Patients favored DBS and telehealth consultations, especially due to less travel and school absences. Patients preferred finger pricking over ear pricking. ConclusionsCapillary DBS proves reliable for TDM and kidney function assessment in pediatric kidney disease. It reduces patient and family burden compared to venous blood collection, while also enabling telehealth consultations.