Data di Pubblicazione:
2013
Citazione:
Intervals for the new Brahms Chromogranin A (CGA) assay / S. Ferraro, S. Mozzi, C. Michelazzo, D. Basco, M. Panteghini. - In: BIOCHIMICA CLINICA. - ISSN 0393-0564. - 37:suppl.13(2013), pp. M168.S169-M168.S169. ((Intervento presentato al convegno EUROMEDLAB tenutosi a Milano nel 2013.
Abstract:
neuroendocrine tumours. To improve analytical performance
and decrease test turnaround time, we introduced the new fully
automated Brahms CGA assay performed on Kryptor platform.
As CGA results from different assays are not comparable, we
performed a study for establishing reference intervals for the
new assay.
Methods: Fresh serum samples were obtained from 200
healthy blood donors and immediately measured for CGA.
Shapiro-Wilk and Wilcoxon rank sum tests were employed to
assess distribution of CGA values and compare groups,
respectively. Multiple regression models were used to evaluate
the influence of age and sex on CGA concentrations, including
the interaction between the two factors.
Results: 4 elevated CGA values were statistical outliers and in
3 of those individuals an interfering condition possibly
increasing CGA was identified (hyperthyroidism, vitamin D
supplementation, use of hormonal contraceptives). After their
exclusion the remaining values from 196 subjects [99 males
and 97 females; median age (range) 44 years (19-67)] were
analyzed. Median (range) CGA concentration was 41.6 μg/L
(15.9-146.2), with no gender-related difference. Although
deviating from normal frequency distribution, the visual
examination of data did not suggest log transformation.
Regression analysis confirmed the lack of gender influence,
showing however that CGA concentrations increased with age
(P <0.001). The lack of biological interaction between age and
sex excluded the hypothesis that menopausal status may
influence CGA release. Aiming to decide if reference values
should be partitioned by age, we compared CGA
concentrations in subjects <45 (n=99) and ≥45 years (n=97).
Higher CGA concentrations were found in older people
(mean±SD: 49.1±18.6 μg/L vs. 41.8±19.4 μg/L, P=0.0006).
Accounting for manufacturer’s declared imprecision at CGA
range of 80-120 μg/L (CV <7%) and the estimated upper
reference limit (97.5th percentile - URL) for subjects ≥45 (98.5
μg/L) and <45 (87.0 μg/L), we however decided to adopt a
single URL for overall population (93.7 μg/L; 90%CI: 79.0-
114.1).
Conclusions: In healthy subjects age but not gender may affect
CGA release. However this does not appear to require agerelated
reference limits.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
S. Ferraro, S. Mozzi, C. Michelazzo, D. Basco, M. Panteghini
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