Capillary blood microsampling to determine serum biopharmaceutical concentration: Mitra® microsampler vs dried blood spot.

AIM: For assessment of concentrations of biopharmaceuticals, for example, therapeutic drug monitoring, dried blood sampling of capillary blood is a convenient alternative to traditional venepuncture sampling. We investigated an alternative to dried blood spot collection on filter paper: sampling capillary blood using the Mitra® microsampler.

MATERIALS AND

METHODS

Therapeutic monoclonal antibodies were spiked in whole blood, sampled using filter paper and Mitra microsampler and concentrations measured using specific ELISAs.

RESULTS

Good recoveries of adalimumab, infliximab, ustekinumab, vedolizumab, tocilizumab, natalizumab and rituximab were found up to 1 month of storage at room temperature, averaging 95.2% for the Mitra microsampler and 92.9% for Whatman® paper. Both hemoglobin and potassium yield satisfactory estimates for the volume of the cellular fraction of blood samples in combination with the Mitra microsampler.

CONCLUSION

We established practical protocols for the estimation of serum/plasma concentrations of therapeutic antibodies via capillary blood microsampling.