Total Posts: 11
|Posted: Fri Feb 01, 2008 03:16 am|
There is a lot of confusion regarding the levels of HbA2 in beta Thalassemia Major. We all know that the level of HbA2 (alpha2, delta2) is increased in thalassemia minor due to compensatory rise in delta chain synthesis. However, you will find that in thalassemia major, different text books mention different status of HbA2 level. For example, in O.P.Ghai it is mentioned that HbA2 level is normal in Thalassemia Major, while according to Harrison, its level is increased. The problem is, if HbA2 level increases in thalassemia minor, then why not in thalassemia major.
Actually, both books are correct, but correct partially. According to Hoffman's Hematology, the level of HbA2 in Thalassemia Major is variable. It is probably because of increase in the number of Fetal cells that have low HbA2 content. So different results will be obtained in different individuals depending on the number of circulating fetal cells.