Transferrin glycosylation analysis from dried blood spot cards and capillary blood samples

Abstract

Background: Congenital disorders of glycosylation (CDG) are a growing group of inherited diseases causing manifold symptoms. Routine diagnostic procedures are high performance liquid chromatography (HPLC) or isoelectric focusing (IEF) of serum transferrin.

Methods: We introduce a modified method to screen for glycosylation abnormalities from dried blood spot (DBS) samples based on isoelectric focusing. In PGM1-CDG, glycosylation analysis and enzyme activity measurement were performed from a single DBS sample. Furthermore, we present the possibility to use capillary blood samples for quantification of transferrin isoforms.

Results: IEF from DBS samples is possible and results are identical to the ones obtained in serum samples. Gel analysis using the ImageJ software allows quantification of IEF results. Storage at -20 °C ensures stable samples for more than six months. Capillary blood samples are equally suitable for glycosylation analysis and show no inferiority to serum samples.

Conclusion: In view of a growing number of treatable CDG subtypes, the proposed methods allow reliable diagnosis and therapy control of CDG while being easily applicable. Capillary blood samples can be taken at home and sent in for follow-up. DBS are widely used in new-born screening programs and have the potential to broaden the knowledge of glycosylation abnormalities in early infancy. By its possible application in the context of alcohol abuse, the proposed method bears the potential for widespread use in a non-metabolic context.

Keywords: Alcohol abuse; Congenital disorders of glycosylation; Dried blood spots; High performance liquid chromatography; Isoelectric focusing.