T-subset abnormalities in thalassaemia intermedia: possible evidence for a thymus functional deficiency.
Peripheral blood T-lymphocyte subsets, evaluated by means of a series of monoclonal antibodies, were assessed in 14 patients affected by thalassaemia intermedia, 7 of them previously splenectomized. A significant reduction of T+4 cells ('helper' T cells) was found in almost all patients, whereas T+8 cells ('suppressor/cytotoxic') showed a marked increase only in splenectomized subjects. Together with these quantitative T-subset abnormalities, which seemed to be partly affected by either splenectomy or high serum iron levels, an unusual circulating T-cell subpopulation labelled by T6 monoclonal antibody was detected in all patients. Complete disappearance of T+6 cells ('thymocyte-like' T lymphocytes) and normalization of the T4/T8 ratio was observed after 'in vitro' incubation of patient's lymphocytes with a crude thymus extract (Thymostimulin). This would suggest the presence of a so far unreported thymus-dependent defect of T-lymphocyte phenotypic maturation occurring in thalassaemia intermedia.
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D002648:Child; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007501:Iron / Q000097:blood; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D012397:Rosette Formation; D013156:Splenectomy; D013601:T-Lymphocytes / Q000145:classification*; D013789:Thalassemia / Q000097:blood / Q000276:immunology*; D013949:Thymus Extracts; D013950:Thymus Gland / Q000503:physiopathology*
D000911:Antibodies, Monoclonal; D013949:Thymus Extracts; C031407:thymostimulin; D005293:Ferritins; D007501:Iron