@conference{
author = "Beletić, Anđelo and Leković, Z. and Zivković, Z. and Radlović, N. and Perisić, V. and Ljujić, Mila and Radojković, Dragica and Đorđević, Valentina and Stanković, S.",
year = "2019",
abstract = "Background-aim
Alpha-1-antitrypsin deficiency (AATD) is an autosomal recessive
disorder characterized by the reduced alpha-1-antitrypsin (AAT)
level in blood. In pediatric patients, it is dominantly tested as a cause
of liver disease, while specific lung diseases might be potentially
regarded as additional indications. Measurement of AAT concentration is useful as a first-line test, although decreased level may be also
encountered in certain acquired conditions. Our aim was to
determine the interpretative cut-off for AAT concentration i.e. level
below which the presence of common AATD-associated alleles might
be suspected.
Methods
We included 37 subjects with clinical indications or familiar
history of AATD: 19 males and 18 females, aged between 2 months
and 19 years. Immunonephelometry was used for measurement of
AAT concentration in serum and PCR-reverse allele specific hybridization assay for detection of Z and S alleles, which are considered as
the common AATD-associated alleles. Kruskal-Wallis test and ROC
analysis were applied in statistical evaluation.
Results
Three cases of AATD (ZZ genotype) and 14 carriers (13
heterozygous for Z and one for S allele) were detected. AAT
concentration (median (min-max)) measured in AATD cases (0.35
(0.31–0.39) g/L), carriers (0.81 (0.56–1.41) g/L) and patients with
no Z and S allele (1.20 (0.91–2.24) g/L) were significantly different
(P b .001). Four carriers (three heterozygous for Z and one for S
allele) had AAT concentration in the reference range (0.9–2.0 g/L).
We identified the level 1.03 g/L as the most appropriate cut-off to
distinguish group comprising both cases of AATD and carriers from
patients in whom no common AATD-associated allele was present.
Corresponding AUC value (95% Confidence interval (CI)) was 0.929
(0.795–0.987) (P b .001). Sensitivity and specificity (95% CI) reached
94.1 (71.3–99.9)% and 90.0 (68.3–98.8)% respectively.
Conclusions
In pediatric patients AAT concentration below 1.03 g/L may be
regarded as a potential cut-off indicating the presence of common
AATD-associated alleles in homo-or heterozygous form. Nevertheless, this preliminary finding needs confirmation in a larger study.",
publisher = "Elsevier, Amsterdam",
journal = "Clinica Chimica Acta",
title = "Interpretative cut-off for alpha-1-antitrypsin concentration in detection of alpha-1-antitrypsin deficiency among pediatric patients - A pilot study",
pages = "S455-S455",
volume = "493",
doi = "10.1016/j.cca.2019.03.964"
}
