title: Determination of adenosine deaminase activity in dried blood spots by a nonradiochemical assay using reversed-phase high-performance liquid chromatography.
abstract: Adenosine deaminase (ADA) deficiency is a rare metabolic disease causing severe combined immunodeficiency (SCID). An assay to determine ADA activity in dried blood spots was developed using reversed-phase HPLC. The assay was linear with reaction times up to at least 4 hours, and protein concentrations up to at least 2.2 mg/ml. The intra-assay CV and the inter-assay CV for the complete assay was 3.5 and 8.4%, respectively. The ADA activity in a control blood spot, stored at 4 degrees C, remained stable for at least one year. Only a slightly decreased ADA activity (35 +/- 13 nmol/mg/h, n = 4) was observed in heterozygotes for a c.704G > A mutation in the ADA gene when compared to that observed in controls (41 +/- 13 nmol/mg/h, n = 108). In addition, increased ADA activity as found in a rare form of congenital anemia can be assessed, as observed in a bloodspot from a patient diagnosed with Diamond Blackfan anemia (ADA activity 150 nmol/mg/h).
authors.affiliation: Academic Medical Center, Emma Children's Hospital, Laboratory Genetic Metabolic Diseases, Amsterdam, the Netherlands. a.b.vankuilenburg@amc.uva.nl
authors.forename: A B P
authors.initials: AB
authors.lastname: van Kuilenburg
authors.forename: L
authors.initials: L
authors.lastname: Zoetekouw
authors.forename: J
authors.initials: J
authors.lastname: Meijer
authors.forename: T W
authors.initials: TW
authors.lastname: Kuijpers
mesh_terms: D000243:Adenosine Deaminase / Q000097:blood* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D057075:Enzyme Assays / Q000379:methods*; D006801:Humans; D011134:Polysaccharides / Q000097:blood; D016511:Severe Combined Immunodeficiency / Q000097:blood
chemical_list: D011134:Polysaccharides; C046197:anemaran; D000243:Adenosine Deaminase