[Values of MCV,MCH,ROFT and HbA2 for Screening α-Thalassemia in Guangdong Area].

OBJECTIVE: To investigate the values of mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), red cell osmotic fragility test(ROFT) and hemoglobin A2(HbA2) in screening of α-thalassemia in Guangdong area. METHODS: A total of 285 peripheral blood samples in patients treated in our hospital from January 2017 to December 2017 were collected. The detection of thalassemia gene was used as the gold standard, while blood routine examination, hemoglobin electrophoresis, and red cell osmotic fragility test were simultaneously performed. The optimal cut-off values in MCV, MCH, ROFT and HbA2 in α-thalassemia were determined by receiver operator characteristic curve (ROC curve). RESULTS: The most common types of α-thalassemia gene was --SEA/αα (54.59%). Compared with the control group, the differences in MCV, MCH, ROFT and HbA2 showed statistically significantce between different types of α-thalassemia (P<0.05). The best cut-off values of MCV, MCH, ROFT, and HbA2 in the diagnosis of α-thalassemia were 81.45 fl, 27.35 pg, 79.95%, and 2.55% respectively. CONCLUSION: For different laboratories, the cut-off values need to be established for screening α-thalassemia suitable in their own local region．The values of MCV, MCH, ROFT and HbA2 shows higher accuracy and sensitivity in the diagnosis of α-thalassemia. It is recommended to use MCV<81.45fl, MCH<27.35 pg, ROFT<79.95% and HbA2<2.55% as the standards for screening α-thalassemia in Guangdong area.