English 
Italian CONTRIBUTI SCIENTIFICI – Scientific Papers
Volume:
Biochimica Clinica 2011; 35(6) 458-460
Pubblicato on-line:
DOI:
Determinazione della variabilità biologica dell’emoglobina A2
AUTORI
1Centro per la Riferibilità Metrologia in Medicina di Laboratorio (CIRME), Dipartimento di Scienze e Tecnologie Biomediche, Università degli Studi di Milano
2Sezione di Biochimica Clinica, Dipartimento di Scienze della Vita e della Riproduzione, Università degli Studi di Verona
ABSTRACT
Determination of biological variation of hemoglobin A2.
Determination of biological variation of hemoglobin A2. We present an experimental report aimed to evaluate the biological variation of hemoglobin A2 (HbA2), a minor hemoglobin component in post-natal life, accounting for 2.5%-3.5% of the total hemoglobin in red cells, which is very relevant for the laboratory diagnosis of thalassemic syndromes. We took five blood specimens from 17 apparently healthy subjects (9 men and 8 women, ages 26-52 years) on the same day, every two weeks for two months. Samples were stored at -80 °C until analysis and assayed in duplicate by Bio-Rad Variant II analyzer. Data were analyzed by the ANOVA. There were no differences in HbA2 values between men and women. HbA2 exhibited marked individuality: within- (CVI) and between-subject (CVG) biological variation were 0.7% and 7.7%, respectively. Desirable analytical goals derived from biological variation for imprecision (0.5 CVI), bias [0.25 (CVI2 + CVG2)1/2] and total error [1.65 (0.5 CVI) + 0.25 (CVI2 + CVG2)1/2]were 0.4%, 1.9%, and 3.1%, respectively. In conclusion, this is the first evidence that HbA2, as well as total hemoglobin, is under a strict homeostatic control. Our data also show that stringent analytical goals are needed for the clinical application of HbA2 measurements.