Demonstration of aberrant T‐cell and natural killer‐cell antigen expression in all cases of granular lymphocytic leukaemia

• Published in: British journal of haematology 2003-03, Vol.120 (6), p.1026-1036
• Main Authors: Morice, William G., Kurtin, Paul J., Leibson, Paul J., Tefferi, Ayalew, Hanson, Curtis A.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, CD - analysis; Antigens, Surface - analysis; Biological and medical sciences; Case-Control Studies; Child; Clone Cells; Female; flow cytometry; Gene Rearrangement, T-Lymphocyte; Hematologic and hematopoietic diseases; Hematology; Humans; immunophenotype; Immunophenotyping; Killer Cells, Natural - immunology; killing inhibitory receptor; Lectins, C-Type - analysis; Leukemia, T-Cell - diagnosis; Leukemia, T-Cell - immunology; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; LGL; Male; Medical sciences; Middle Aged; NK cell; NK Cell Lectin-Like Receptor Subfamily B; NK Cell Lectin-Like Receptor Subfamily D; Receptors, Immunologic - analysis; Receptors, KIR; Receptors, KIR2DL1; Receptors, KIR2DL3; Receptors, KIR3DL1; T-Lymphocytes - immunology
• ISSN: 0007-1048; 1365-2141
• DOI: 10.1046/j.1365-2141.2003.04201.x

The diagnosis of granular lymphocytic leukaemia (GLL) requires the presence of an immunophenotypically distinct T‐cell (T‐GLL) or natural killer‐cell (NK‐GLL) population. Flow cytometric immunophenotyping was performed on 21 T‐GLL patients, 11 NK‐GLL patients and 20 normal control subjects using antibodies to T and NK cell‐associated antigens in order to accurately identify the distinguishing features of T‐GLL and NK‐GLL. The NK antigens evaluated included: CD16, CD57, CD94, CD161, and the killing inhibitory receptors (KIRs) CD158a, CD158b and CD158e (p70). Abnormal T‐antigen expression was present in all T‐GLL patients. CD57 was frequently expressed in T‐GLL, however, one‐third of patients showed partial CD57 expression similar to that seen in T cells from normal control subjects. Ten T‐GLL were KIR positive; all expressed a single KIR isoform. All NK‐GLL showed a distinctive, abnormal immunophenotype. Four NK‐GLL expressed a single KIR isoform; the remaining seven patients lacked all tested KIRs, which is also a distinct, abnormal finding. Immunoperoxidase staining of bone marrow biopsy specimens from NK‐GLL patients with antibodies to CD8, TIA‐1 and granzyme B revealed the disease‐specific distinctive staining patterns previously found in T‐GLL. These studies delineate the unique immunophenotypic features diagnostic of T‐GLL and provide strong evidence that NK‐GLL, like T‐GLL, represents a clonal lymphoproliferative disorder.