Production of monoclonal and polyclonal antibodies against various haemoglobins for the detection of thalassaemias.

The thalassaemias are a major group of genetic disorders in Southeast Asia that affect the production of the alpha-globin chain (alpha-thalassaemia) or the beta-globin chain (beta-thalassaemia) of the haemoglobin. As a result of defective globin chain synthesis, individuals with this disorder show varying degrees of anaemia due to ineffective erythropoiesis and haemolysis. The presence of abnormal haemoglobins in thalassaemia patients has enabled the detection of thalassaemia using immunological methods which have certain advantages over the conventional diagnostic methods. This paper reviews the application of various types of antibodies against the different types of haemoglobins used for the detection of thalassaemia. The developed antibodies include the polyclonal antibodies against Hb Bart's and Hb H; monoclonal antibodies (mab) against Hb H, used in a sandwich enzyme-linked immunosorbent assay (ELISA), for detecting carriers of (--SEA/) deletion and deletions involving the complete zeta-alpha-globin gene cluster, such as (--alpha FIL/), (--alpha THAI/) and (--HW/), which are the common deletional alpha-thalassaemias in Southeast Asians; mab against zeta-globin chains used in an immunocytological test, for the detection of adult carriers of (--SEA/) deletion except for (alpha 20.5/), (--alpha FIL/) and (--alpha THAI/) (this simple test is useful in identifying couples at risk of conceiving foetuses afflicted with the Hb Bart's hydrops foetalis syndrome due to homozygous alpha-thalassaemia); mab against Hb A2 and beta- and gamma-globin chains used for the quantitation of Hb A2 in beta-thalassaemia and the diagnosis of beta-thalassaemia major in foetuses respectively; other mabs produced to date include those specific to haemoglobins D-Los Angeles, J-Baltimore, O-Arab and J-Paris-I.