Expression of TIA-1 and TIA-2 in T cell malignancies and T cell lymphocytosis.
OBJECTIVE
To investigate the reactivity with TIA-1 and TIA-2, two monoclonal antibodies that recognise, respectively, granular structures in T lymphocytes and the T cell receptor chain in cells from a variety of T cell disorders.


METHODS
Cytoplasmic staining with TIA-1 and TIA-2 was carried out by the immunoalkaline phosphatase anti-alkaline phosphatase technique in 67 cases with a T cell disorder: 31 large granular lymphocyte (LGL) leukaemia, nine T-prolymphocytic leukaemia (T-PLL), five Sezary syndrome, four peripheral T cell lymphoma (PTCL), 13 T cell lymphocytosis, and five T-acute lymphoblastic leukaemia (T-ALL). All had over 75% abnormal T cells which were CD2+, CD3+, CD5+, CD7+, and negative with B cell markers.


RESULTS
TIA-1 was positive in 77% cases of LGL leukaemia and half of the PTCL and T-ALL, whereas it was negative in all Sezary syndrome and most T-PLL (8/9) and reactive T-lymphocytosis (10/13). In LGL leukaemia, TIA-1 was positive irrespective of the membrane phenotype, whether CD8+, CD4- or CD4+, CD8-, and was more often positive in cases where cells were CD16+, CD56+, or CD57+. TIA-2 was positive in 60% of cases encompassing all diagnostic types of T cell disorder. There was no correlation between TIA-2 expression and that of other T cell markers, activation antigens, and natural killer markers.


CONCLUSIONS
The pattern of TIA-1 expression in T cell malignancies may help in the differential diagnosis among LGL leukaemia (high expression), T cell lymphocytosis and other T cell diseases (low expression). As TIA-2 is expressed in over 95% mature T lymphocytes and thymic cells, its assessment may be useful to demonstrate aberrant phenotypes which can be exploited for detecting minimal residual disease.
Matutes
E
E
Academic Department of Haematology and Cytogenetics, Royal Marsden Hospital, London.
Coelho
E
E
Aguado
M J
MJ
Morilla
R
R
Crawford
A
A
Owusu-Ankomah
K
K
Catovsky
D
D
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor / Q000032:analysis*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D003937:Diagnosis, Differential; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology; D015458:Leukemia, T-Cell / Q000276:immunology*; D008218:Lymphocytosis / Q000276:immunology*; D016399:Lymphoma, T-Cell / Q000276:immunology*; D008565:Membrane Proteins / Q000032:analysis*; D009363:Neoplasm Proteins / Q000032:analysis; D039102:Poly(A)-Binding Proteins; D011506:Proteins; D016601:RNA-Binding Proteins / Q000032:analysis*; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D000074019:T-Cell Intracellular Antigen-1
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D039102:Poly(A)-Binding Proteins; D011506:Proteins; D016601:RNA-Binding Proteins; D011948:Receptors, Antigen, T-Cell; D000074019:T-Cell Intracellular Antigen-1; C071558:TIA1 protein, human