Biochemia Medica, Vol. 18 No. 3, 2008.
Original scientific paper
Evaluation of the Primus Ultra2 HPLC system for HbA2 measurement and β-thalassemia screening
Eloísa Urrechaga
; Hematology Laboratory, Hospital Galdakao-Usansolo, Galdakao, Vizcaya, Spain
Abstract
Background: Primus Ultra2 is a HPLC ion exchange analyzer for qualitative and quantitative hemoglobin fraction analysis: in 4 minutes it quantifies HbF, HbA2, HA0 and flags abnormal hemoglobins. The aim of the study was to evaluate analytical performance of Primus Ultra2 analyzer for routine estimation of HbA2, a critical test to identify β-thalassemia carriers.
Methods: The imimprecision, linearity and inaccuracy studies were performed according to CLSI and manufacturer's guidelines. The reliability of HbA2 measurements for detection of β-thalassemia was studied by analysis of 300 samples from patients with previous diagnosis of the disease.
Results: Imprecision. Within run coefficient of variation (CV) was 1.9% for normal HbA2 level (2.2%) and 1.3% for elevated level (5.5%). Between run CV was 2.4% for normal level and 1.7% for elevated level. Between-day CV was 3.0% for normal level and 2.7% for elevated level. Total CV was 4.4% for normal level and 3.5% for elevated level. Linearity. Y = 1.089x + 0.01; R2 = 0.992 (range 2.4-5.0%). The measured values correlated with the expected ones; the mean proportion recovered was 99%. Inaccuracy. The mean was 1.6% (SD 0.26%) for normal control and 5.2% (SD 0.19%) for high control. Reference range was 0.9-3.0% (mean 1.9%±2.5 SD). All β-thalassemia carriers had elevated HbA2 blood concentrations (mean 4.7%, range 3.3-6.9%).
Conclusions: Primus Ultra2 provides a rapid and reliable separation of different hemoglobins. HbA2 measurement is accurate and reproducible, which is needed due to the slight difference between normal and pathologic values. There is good differentiation of HbA2 values between normal subjects and β-thalassemia carriers. The cut off limit can be set at 3.3% HbA2. This is a suitable method for rapid population screening for β-thalassemia carriers.
Keywords
HbA2 analysis; β-thalassemia screening; HPLC
Hrčak ID:
27339
URI
Publication date:
6.10.2008.
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