Enzyme immunoassay screening of alpha 1-antitrypsin in dried blood spots from 39 289 newborns.
We present a new, simple, and inexpensive sandwich-type double-antibody enzyme immunoassay for alpha 1-antitrypsin in dried blood collected on the fifth day post-partum. The method is very sensitive, having a detection limit of 2.84 fmol/well. Intra- and interassay CVs are 6.1% and 10.3%, respectively, for assay of 5-mm-diameter blood spots eluted into 7 mL of phosphate buffer. Since February 1984, we have used this method to systematically screen 39 289 consecutive births: 336 of these newborns (0.085%) showed values for alpha 1-antitrypsin below the cutoff value of 800 mg/L (50th percentile, 1470 mg/L). Of these 336 we were able to obtain 0.5 mL of serum from 161 for further testing. Four presented with a ZZ phenotype and 15 with a SZ phenotype, which indicates a deficiency in alpha 1-antitrypsin. Our data suggest a prevalence of 1.4% and 3.6% of Z and S alleles, respectively, in the French-speaking community of Belgium.
Schoos
R
R
C.H.U. de Liège, Laboratoire de Biochimie Génétique, Liège, Belgium.
Dodinval-Versie
J
J
Verloes
A
A
Lambotte
C
C
Koulischer
L
L
D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007231:Infant, Newborn; D007525:Isoelectric Focusing; D008107:Liver Diseases / Q000097:blood / Q000175:diagnosis; D010641:Phenotype; D000515:alpha 1-Antitrypsin / Q000235:genetics / Q000302:isolation & purification*; D019896:alpha 1-Antitrypsin Deficiency
D000515:alpha 1-Antitrypsin