Karyotype and T-cell receptor expression in T-lineage acute lymphoblastic leukemia

Detection of LIM domain only 2 (LMO2) in normal human tissues and haematopoietic and non-haematopoietic tumours using a newly developed rabbit monoclonal antibody

AIMS

We describe a new rabbit monoclonal antibody, raised against a fixation-resistant epitope of the transcription regulator LIM domain only 2 (LMO2).

METHODS AND RESULTS

Lymphoma cell lines and a large series of normal and neoplastic samples were investigated by Western blot and immunohistochemistry. The antibody detected nuclear positivity for the protein, with the exception of a proportion of classical Hodgkin lymphomas (HLs), peripheral T cell lymphomas (PTCLs) and solid tumours that showed granular cytoplasmic staining. In normal lympho-haematopoietic tissues, LMO2 was expressed at different intensities by CD34(+) blasts, haematopoietic precursors, germinal centre (GC), mantle and splenic marginal zone B cells. While reactive with only scattered elements in the thymus and nine of 237 PTCLs, the antibody stained 31 of 39 T-acute lymphoblastic lymphoma/leukaemias (T-ALLs) and the T-ALL-derived human leukaemic cell line, CCRF-CEM. LMO2 was found in 88% of B-acute lymphoblastic lymphoma/leukaemias (B-ALLs), 5% chronic lymphocytic leukaemias (CLLs) and 14%, 57% and 41% of mantle, follicular and Burkitt lymphomas, respectively. In the setting of diffuse large B cell lymphomas (DLBCLs), LMO2-positivity was related strongly to a GC phenotype. LMO2 was found in 83% primary mediastinal large B cell lymphomas (PMBLs) and 100% nodular lymphocyte predominant Hodgkin lymphomas (NLPHLs), whereas only 10% of classical HLs were stained. Acute and chronic myeloid leukaemias were usually positive.

CONCLUSIONS

The new anti-LMO2 antibody can be applied confidently to routine sections, contributing to the differential diagnosis of several lymphoma subtypes, subtyping of DLBCLs and potential development of innovative therapies.

t(4;11)(q21;p15), including one complex translocation t(1;4;11)(p32;q21;p15), in adult T-cell acute lymphoblastic leukemia

We report two adults with T-cell acute lymphoblastic leukemia (ALL). Cytogenetic studies at diagnosis with R banding showed a 46,XX,t(4;11)(q21;p15)/46,XX karyotype in one patient and 46,XY,t(1;4;11)(p32;q21;p15)/46,XY in the other. Fluorescence in situ hybridization with whole chromosome paints (WCP1, WCP4, and WCP11) confirmed the complex rearrangement in the latter patient. Only 10 T-cell ALL patients with the t(4;11)(q21;p15) have been described, all, but one of them, being over 15 years old. Although recurrent in T-cell ALL, its frequency appears to be very low; indeed, it has been identified in only 4 of 193 adults and in 1 of 734 children with T-cell ALL thus far reported in the literature.

New recurring cytogenetic abnormalities and association of blast cell karyotypes with prognosis in childhood T-cell acute lymphoblastic leukemia: a Pediatric Oncology Group report of 343 cases

To further define the cytogenetic differences between B-cell lineage (B-lineage) acute lymphoblastic leukemia (ALL) and T-cell lineage ALL (T-ALL) and to determine the prognostic value of cytogenetics in childhood T-ALL, the blast cell karyotypes of 343 cases of pediatric T-ALL, the largest series reported to date, were evaluated. Cytogenetics were performed in a single central laboratory, and the children were treated using a single Pediatric Oncology Group protocol. Clear differences between the karyotypic characteristics of B-lineage ALL and T-ALL were confirmed. This study suggests that there may be survival differences associated with some T-ALL blast cell karyotypes. Better survival is associated with only normal karyotypes and with t(10;14) (translocation of chromosomes 10 and 14); worse survival is associated with the presence of any derivative chromosome. Two new recurring chromosome aberrations previously not reported in T-ALL were found: del(1)(p22) and t(8;12)(q13;p13). Ten aberrations found in this series, which were reported only once previously in T-ALL, can now be considered recurring abnormalities in T-ALL. All 12 of these new recurring aberrations are targets for discovery and characterization of new genes that are important in T-cell development and leukemogenesis.

New recurring cytogenetic abnormalities and association of blast cell karyotypes with prognosis in childhood T-cell acute lymphoblastic leukemia: a Pediatric Oncology Group report of 343 cases

To further define the cytogenetic differences between B-cell lineage (B-lineage) acute lymphoblastic leukemia (ALL) and T-cell lineage ALL (T-ALL) and to determine the prognostic value of cytogenetics in childhood T-ALL, the blast cell karyotypes of 343 cases of pediatric T-ALL, the largest series reported to date, were evaluated. Cytogenetics were performed in a single central laboratory, and the children were treated using a single Pediatric Oncology Group protocol. Clear differences between the karyotypic characteristics of B-lineage ALL and T-ALL were confirmed. This study suggests that there may be survival differences associated with some T-ALL blast cell karyotypes. Better survival is associated with only normal karyotypes and with t(10;14) (translocation of chromosomes 10 and 14); worse survival is associated with the presence of any derivative chromosome. Two new recurring chromosome aberrations previously not reported in T-ALL were found: del(1)(p22) and t(8;12)(q13;p13). Ten aberrations found in this series, which were reported only once previously in T-ALL, can now be considered recurring abnormalities in T-ALL. All 12 of these new recurring aberrations are targets for discovery and characterization of new genes that are important in T-cell development and leukemogenesis.

Translocations involving 9p and/or 12p in acute lymphoblastic leukemia. United Kingdom Cancer Cytogenetics Group (UKCCG)

Fifteen cases of acute lymphoblastic leukemia (ALL) with translocations involving 9p and/or 12p are described. Four children, three males and one female, age range 1-8 yrs, had translocations involving 9p but not 12p. Of these, three had B-lineage ALL and one had biphenotypic T-ALL/acute myeloid leukemia. Six patients, three males and three females, age range 1-49 yrs, had translocations involving 12p but not 9p. Five had B-lineage ALL and one had T-ALL. One patient had dic(7;12)(p11;p11), confirming that this previously reported translocation is nonrandom in ALL. One patient had t(2;12)(q14;p13), and it is suggested that this may also be a new nonrandom abnormality. Five patients, four males and one female, age range 11-21 yrs, had common ALL and dic(9;12). The dic(9;12) appears to confer a better prognosis than do other translocations involving 9p or 12p.