Clonality of T cell and phenotypically undefined lymphoid neoplasms: the value of genotypic analyses.
The value of genotypic analysis for routine assessment of leukaemia and lymphoma was shown by the findings in a selected series of 30 cases. T cell receptor (TcR) gene rearrangements were observed in six out of nine cases of CD3+ CD8+ lymphocytoses and provided clear evidence for clonality in this group. The T cell proliferations in two of the remaining cases masked B cell lymphocytic leukaemia and hairy cell leukaemia, while in the third case no cause was found for the polyclonal proliferation. Heterogeneity of phenotype and genotype were observed in peripheral T cell lymphomas: one out of six cases showed TcR gene rearrangement, one case retained its germline configuration, a further case masked B cell lymphoma and the remainder were polyclonal. Genotypic analysis was helpful in the analysis of a tumour of mixed T cell and myeloid phenotype which was shown to be germline for TcR and immunoglobulin genes, consistent with a myeloid origin. Two histiocytic tumours were found to have clonal rearrangement of TcR genes. Nine out of 11 B cell tumours showed immunoglobulin gene rearrangement. It is concluded that genetic analyses are useful in the analysis of T cell, histiocytic, and B cell tumours in which an immunoglobulin phenotype cannot be defined.
Hodges
E
E
Regional Immunology Service, Southampton General Hospital.
Stacey
G N
GN
Howell
W M
WM
Jones
D B
DB
Smith
J L
JL
D015703:Antigens, CD / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D017252:CD3 Complex; D016827:CD8 Antigens; D002999:Clone Cells; D015329:Gene Rearrangement, T-Lymphocyte; D005838:Genotype; D006801:Humans; D008218:Lymphocytosis / Q000235:genetics; D008228:Lymphoma, Non-Hodgkin / Q000235:genetics* / Q000276:immunology; D008562:Membrane Glycoproteins / Q000032:analysis; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D014408:Biomarkers, Tumor; D017252:CD3 Complex; D016827:CD8 Antigens; D008562:Membrane Glycoproteins; D011948:Receptors, Antigen, T-Cell