Observations on the relationship between gamma-globin chain content and globin chain precipitation in thalassaemic erythroblasts and on the composition of erythroblastic inclusions in HbE/beta-thalassaemia.
Electron microscope immunocytochemical studies were performed on the bone marrow from 2 patients each with beta-thalassaemia major and beta-thalassaemia intermedia and 4 patients with HbE/beta-thalassaemia, using the immunogold technique. Studies of sections that were reacted with mouse monoclonal antibodies against human gamma-globin chains showed the presence of large quantities of gamma-chains in several erythroblasts and marrow reticulocytes containing large amounts of precipitated globin chains. At least in these cells, substantial gamma-chains synthesis did not protect against the formation of erythroblastic inclusions, indicating that factors other than the rate of gamma-chain synthesis influence the extent of globin-chain precipitation. Studies of sections of marrow that were reacted with a rabbit polyclonal antibody against human alpha-globin chains and a mouse monoclonal antibody against human beta-globin chains showed that the erythroblastic inclusions in HbE/beta-thalassaemia did not contain detectable quantities of HbE and consisted only of precipitated alpha-globin chains. Thus, the generally milder phenotype of HbE/beta-thalassaemia cannot be attributed to co-precipitation of HbE and excess free alpha-globin chains.
Wickramasinghe
S N
SN
Department of Haematology, Imperial College School of Medicine, St Mary's Hospital, London, UK.
Lee
M J
MJ
D000911:Antibodies, Monoclonal; D001854:Bone Marrow Cells / Q000737:chemistry / Q000648:ultrastructure; D011232:Chemical Precipitation; D004900:Erythroblasts / Q000737:chemistry* / Q000648:ultrastructure*; D005914:Globins / Q000032:analysis*; D006446:Hemoglobin E; D006801:Humans; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000737:chemistry / Q000648:ultrastructure; D008854:Microscopy, Electron; D012156:Reticulocytes / Q000737:chemistry; D017086:beta-Thalassemia / Q000378:metabolism* / Q000473:pathology
D000911:Antibodies, Monoclonal; D005914:Globins; D006446:Hemoglobin E