Rearrangement of T-cell receptor and immunoglobulin heavy chain genes in childhood acute mixed lineage leukaemia

Rearrangement of the beta and gamma chain genes of the TCR gene complex and of the Ig heavy chain genes were examined in three cases of childhood acute mixed lineage leukaemia. Blast cells, classified morphologically as acute lymphoblastic leukaemia (ALL) in one child and acute non-lymphocytic leukaemia (ANLL) in the other two, all co-expressed markers associated with both T (CD7, TdT) and myeloid (CD33) cells. Cytogenetic analysis detected abnormalities associated with myeloid leukaemia. Immunoglobulin heavy chain genes were not rearranged in two patients but a novel rearrangement was seen in the third. No rearrangement of the beta or gamma chains of the T-cell receptor complex were seen. Acute mixed lineage leukaemia may thus arise from a pluripotent precursor cell capable of both lymphoid and myeloid differentiation.     

Unexpected immunoglobulin light chain gene rearrangements in myeloid antigen positive acute lymphoid leukemia.

Blast cells from 10 immunologically diagnosed adult acute lymphoid leukemias expressing myeloid antigens (M+ALL) were studied for immunoglobulin heavy (IgH) and light chain as well as T-cell receptor (TCR)-beta chain gene rearrangements. All but one leukemic isolate met the FAB-criteria for ALL. DNA from 2 patients with pre-pre-B-ALL (CD10-) and 1 patient with common ALL contained rearranged Ig light chain (kappa in two, lambda in one case) in addition to rearranged IgH genes. The TCR-beta chain gene was germline in all pre-pre-B leukemias and rearranged in common ALLs (bigenotypic features). One patient with mature B-ALL showed IgH and light chain gene rearrangements. DNA from 2 pre-T-ALLs contained rearranged TCR-beta chain genes plus rearranged IgH genes in one case. Ig light chain gene rearrangements in immature M+ALL were not associated with gross chromosomal abnormalities except for one Philadelphia chromosome positive case. The occurrence of Ig light chain gene rearrangements in M+ALL with immature lymphoid immunophenotype might represent an hitherto unrecognized aberrant differentiation potential of transformed multipotential stem cells with commitment towards the lymphoid lineage.     

Terminal deoxynucleotidyl transferase and CD7 expression in acute myeloid leukemias are not associated with a high frequency of immunoglobulin and/or T cell receptor gene rearrangement.

Within normal hemopoiesis, the intranuclear DNA polymerase TdT seems to be exclusively expressed by T and B lymphoid precursor cells. Double staining experiments showed that TdT can also be expressed in blast cells of certain acute myeloid leukemias. Recent reports described a very strong association between TdT expression and rearrangements of IgH and TcR genes in such AML specimens, suggesting a predominant lymphoid commitment of these TdT positive AML blasts. When submitting 24 serologically and morphologically well-characterized TdT positive AML specimens for additional genotypic analysis to determine the IgH and TcR gene configuration, we observed that only four had clonally rearranged IgH and/or TcR genes, whereas 20 had germ line configuration. This frequency is clearly lower than previously reported and not necessarily different from rearrangement frequencies reported for TdT negative AML (4-40%). It would seem to us, therefore, that the expression of TdT in otherwise well-defined AML blasts is not necessarily associated with a higher frequency of immunoglobulin and/or T cell receptor gene rearrangement.     

Immunoglobulin and T cell receptor gene rearrangements in Philadelphia chromosome-positive leukemia: a different involvement pattern in blast crisis and acute leukemia

We have analyzed the configuration of the immunoglobulin heavy (IgH) chain gene and the T cell receptor (TCR) chain (beta, gamma, and delta) genes in a group of 22 leukemia patients with the Philadelphia (Ph) chromosome. The group consisted of 14 patients with chronic myelogenous leukemia in blast crisis (CML-BC) and eight with Ph-positive acute leukemia (Ph + AL); these diagnoses were based on hematologic and cytogenetic features. In CML-BC patients, an IgH joining region rearrangement was detected only in patients with CD10 expression; TCR-beta, -gamma, or -delta rearrangements were associated with IgH involvement. In contrast, five of the eight Ph+ AL patients had breaks within the major breakpoint cluster region (M-BCR), and four of them had IgH involvement. Of the remaining three Ph+ M-BCR nonrearranged AL patients, only one showed IgH rearrangement. In addition, TCR-beta involvement was sometimes detected in Ph+ AL patients (two of the eight patients) with or without rearranged M-BCR, and no PH+ AL case displayed rearranged TCR-gamma. These findings suggest that genotypic changes in CML-BC are usually associated with phenotypic results of the neoplastic cells: the expression of CD10 in CML-BC patients is accompanied by the involvement of IgH with frequent TCR rearrangements which possibly are due to the common recombinase activity. On the other hand, the mechanism of the involvement of IgH in Ph+ AL patients without rearranged M-BCR seems different from that observed in Ph+ leukemia patients with rearranged M-BCR, although TCR involvement could occur whether or not the leukemia cells had a rearranged M-BCR in Ph+ AL patients.     

Rearrangement of T cell receptor beta, gamma, and delta gene loci in human pre-T cell acute lymphoblastic leukemia

Configuration of the T cell receptor (TCR) beta, gamma, and delta chain genes, as well as immunoglobulin (Ig) heavy and light chain genes, was studied in 29 cases of E rosette-negative (pre-T cell) acute lymphoblastic leukemias that lack early B cell (CD19), myeloid (CD33), as well as most T cell associated membrane antigens such as CD1, C4, and CD8, but express CD7, cytoplasmic CD3 (cCD3), and TdT strongly, as well as CD5 and/or CD2 heterogeneously. Hematopoietic progenitor cell markers, namely HLA-DR, J5 (CD10), and My10 (CD34), further characterized this immature T ALL of putative prothymocytic phenotype. Eleven ALLs showed a germline configuration of TCR as well as Ig genes. In three cases, only TCR delta sequences were rearranged, and four additional cases were characterized by recombination of both, TCR gamma as well as TCR delta sequences. Eleven patients showed concurrent rearrangements of TCR beta, gamma, and delta chain genes. An Ig heavy chain rearrangement was observed in one case. These data support the hypothesis that, analogous to pre-B development, a cascade of TCR rearrangements occurs in pre-T cells. Moreover, findings reported here suggest that CD7, as well as CD2 and CD5, antigens appear on precursor cells prior to entry into the thymus and support a model for the developmental hierarchy of TCR genes during early T cell ontogeny.     

Multiparameter analysis of acute mixed lineage leukemia: correlation of a B/myeloid immunophenotype and immunoglobulin and T-cell receptor gene rearrangements with the presence of the Philadelphia chromosome translocation in acute leukemias with myeloid morphology

Morphological, immunological, cytogenetic, and molecular features of 28 cases of acute mixed lineage leukemia (AMLL), defined by the co-expression of lymphoid and myeloid cell surface antigens, were correlated in a multiparameter study. These 28 cases were identified in a series of 260 consecutive acute leukemia cases occurring predominantly in adults and were subdivided into 18 cases of AMLL with myeloid morphology and cytochemistry (AMLL-AML) and 10 cases of AMLL with lymphoid morphology and cytochemistry (AMLL-ALL). A lack of correlation was observed between the expression of B- or T-cell associated antigens with the presence of the expected immunoglobulin (Ig) or T-cell receptor (TCR) gene rearrangements in the AMLL cases with myeloid morphology. Only three of the 18 total AMLL-AML cases, each co-expressing B- and myeloid-associated cell surface antigens (B/My), had Ig heavy chain gene rearrangements with or without rearrangements of TCR genes. Ig light chain genes remained in the germline configuration. Strikingly, these three cases were the only AMLL-AML cases in our series to have the Philadelphia (Ph) chromosome translocation t(9;22)(q34;q11), suggesting that a significant percentage of acute leukemias with myeloid morphology and gene rearrangements may be Ph+ AMLL. The fact that three of the 10 B/My AMLL-AML cases in our series were Ph+ suggests that there may be an increased frequency of Ph chromosome, a translocation associated with a poor prognostic outcome, in B/My AMLL-AML occurring in the adult population. Although most AMLL cases with lymphoid morphology had Ig and TCR gene rearrangements associated with a variety of immunophenotypes and karyotypes, two Ph+ AMLL-ALL cases had many similar features (B/My immunophenotype; IgH with or without TCR rearrangements; Ig light chain genes germline) to their Ph+ AMLL-AML counterparts. However, the Ph+ AMLL-ALL cases differed from the Ph+ AMLL-AML cases by the expression of a more mature B-cell lineage immunophenotype and by their additional cytogenetic changes.     

T cell receptor delta gene rearrangements occur predominantly in immature myeloid leukemias exhibiting lineage promiscuity

T cell receptor delta (TCR) genes have been recently identified as rearranging during the early stages of T cell differentiation. We have analyzed the configuration of these genes in 47 unselected acute nonlymphoid leukemias. Morphology, phenotype, immunoglobulin heavy chain, and T cell receptor beta and gamma chain gene configuration were also studied. We have documented TCR delta gene rearrangements or deletions in eight cases using a genomic J delta 1 probe. The comparison of morphological, phenotypical, and molecular findings from these cases with those from control acute myeloid leukemias whose TCR delta genes were in germline configuration show that TCR delta rearrangements occur predominantly in immature leukemia exhibiting extensive lineage infidelity. The most striking feature was the frequent expression of the CD10 antigen. These data show that inappropriate gene rearrangements occur nonrandomly in myeloid leukemias and suggest that common mechanisms may be involved in the regulation of gene rearrangements and in the expression of some differentiation antigens.     

Rearrangement and diversification of T-cell receptor delta genes in acute lymphoblastic leukemia.

The current study was designed to determine the nucleotide sequence of two distinct T-cell-receptor delta chain (TCR delta) rearrangements which account for 95% of all rearranged alleles in common non-T, non-B lymphoid precursor acute lymphoblastic leukemia (LP-ALL). The results presented demonstrate that TCR delta rearrangements in LP-ALL are incomplete, immature, and involve V delta 2 to D delta 3 or D delta 2 to D delta 3 joints. These rearrangements are found in most cases of ALL. These results are consistent with the hypothesis that these leukemias originate in multipotent lymphoid precursor cells. The remarkable diversity of the rearrangements detected by polymerase chain reaction, cloning and sequencing demonstrates the clonal specificity and potential for detection of leukemic residual disease. However, in some cases the number of nucleotide differences may not be sufficient for the discrimination of leukemic and non-leukemic cells carrying V delta 2-(D)-D delta 3 rearrangements. A novel inversional rearrangement was demonstrated in one leukemia. This novel inversional rearrangement potentially increases the degree of diversity of the junctional region which encodes the antigen binding domain of TCR delta.     

Identical utilization of T-cell receptor gene regions in B-lymphoid blast crisis of chronic myeloid leukemia and B-precursor acute lymphoblastic leukemia.

The configuration of the T-cell receptor (TCR) beta, gamma and delta chain genes was analyzed in 16 cases of B-lymphoid blastic crisis of chronic myeloid leukemia (BC-CML) for a better definition of the biological aspects of this cellular population, in comparison with the molecular features of B-precursor acute lymphoblastic leukemia (ALL). All cases displayed B-phenotypic features, were Ph'-positive and had a rearranged configuration of the breakpoint cluster region (bcr) and of the immunoglobulin heavy chain gene region (JH). The TCR beta chain gene was rearranged in four cases (25%), all of which displayed a monoallelic rearrangement involving the J beta 2 region. The TCR gamma chain gene was rearranged in 13 cases (81%); 13 rearranged alleles utilized the J1/2 regions, while the remaining five utilized JP1. The V regions of the group I were mostly involved. The TCR delta chain gene was rearranged or deleted in 15 cases (94%); the 10 rearranged chromosomes displayed exclusively two patterns referable to partial recombinations, a V2-(D)-D3 and a (D)-D3 type. These two configurations are predominant in B-precursor ALL (75% of rearranged chromosomes) and almost absent in T-ALL. Taken together, these results document the close similarities between the genotypic features of B-lymphoid BC-CML and B-precursor ALL, not only in terms of the incidence of rearrangement but more relevantly with regard to the choice of regions involved in the recombinations. This aspect is particularly evident at the TCR delta locus level.     

The incidence of T-cell receptor gene rearrangements in childhood B-lineage acute lymphoblastic leukemia is related to immunophenotype and fusion oncogene expression

Immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangement is conventionally used for assessment of lymphoid malignant cells. TCR genes rearrangements were reported to occur at high frequency in B-lineage acute lymphoblastic leukemia (ALL). Therefore, we have analyzed 83 children with acute B-lineage ALL (67 de novo patients and 19 relapses) by PCR analysis for clonal IgH, incomplete TCRD (Vdelta2-Ddelta3 and Ddelta2-Ddelta3) and TCRG rearrangements. It was shown that clonal cross-lineage TCR rearrangements were associated with more immature immunophenotype (CD34+, CD117+, CyIgM-) of leukemic cells from patients' bone marrow (BM) samples as compared to cell samples without cross-lineage TCR rearrangements. That was equally detected both in de novo and relapsed cases of disease. Low frequency of clonal TCRG rearrangements was associated with expression of E2A/PBX chimeric oncogene. We suggest that TCRG and TCRD clonal rearrangements in leukemic B-cells are associated with early stages of their differentiation.     

Acute lymphoblastic leukemia with the (4;11) translocation: combined cytogenetic, immunological and molecular genetic analyses.

Five cases of acute leukemia (AL) with the t(4;11) translocation were investigated for the immunoglobulin heavy chain, kappa, lambda, TCR beta and TCR gamma gene rearrangements. All patients presented with high-risk features and had survival times of less than two years. Two cases were classified by immunological phenotyping as acute null-AL(L), one case as pre B-cell ALL (CD10+) and two cases expressed both immature B-cell markers CD19 and CD24 and myelomonocytic markers CD15 and CD14, suggesting mixed lineage leukemia. In two cases more than two rearranged fragments for the immunoglobulin heavy chain gene could be detected by Southern blot analysis. In the other cases at least one allele of the immunoglobulin heavy chain gene was rearranged. Germline configuration of the T-cell receptor genes and lack of light chain gene rearrangement suggest that an early B-precursor cell is involved in the transformational events in these cases of ALL. Our own and published data indicate that acute leukemia with t(4;11) translocation might be more frequently associated with more than two rearranged fragments for the immunoglobulin heavy chain genes and run a very aggressive course.     

Lack of correlation between immunoglobulin and T cell receptor gene rearrangements and TdT expression in acute myeloid leukaemia.

Thirty-two cases of acute myeloid leukaemia (AML) were examined for expression of terminal deoxynucleotidyl transferase (TdT) and rearrangements of the genes coding for the immunoglobulin heavy chain and the beta chain of the T cell receptor, in order to establish whether these two forms of lineage infidelity are linked. In 17 cases of AML with greater than or equal to 10% TdT+ cells, three cases showed evidence of gene rearrangement, two having clonal rearrangements in the immunoglobulin gene and one with a rearranged T cell receptor gene. Among 15 AML cases without significant numbers of TdT-positive blasts, three cases had rearrangements in both immunoglobulin and T cell receptor genes, while a fourth case had an immunoglobulin gene rearrangement. No relationship was seen between lymphoid gene rearrangements and expression of the lymphoid surface antigens CD7 and CD10. The lack of association between TdT expression and gene rearrangements does not support the concept of an orderly activation of the recombinase machinery in those cases of AML with features of early lymphoid differentiation.     

Different T-cell receptor gene configurations in T-cell neoplasms and acute lymphoblastic leukemia.

Southern blotting and multiple restriction enzymes were used to analyze T-cell receptor (TCR) and immunoglobulin heavy chain genes in 20 postthymic T-cell neoplasms, ten prethymic and thymic T-cell tumors, and 45 cases of precursor-B acute lymphoblastic leukemia (ALL). Immunoglobulin heavy chain, never rearranged in a postthymic specimen and only once in a prethymic/thymic sample, was rearranged in all but two cases of precursor-B ALL. In contrast, biallelic rearrangement of TCR beta with deletion of the first constant region germline fragment was regularly seen in T-cell neoplasms, but only twice in the 45 precursor-B ALL cases. TCR gamma was rearranged in all but one postthymic sample, in all prethymic/thymic samples, and in approximately half of precursor-B ALL specimens as well. Preferential use of V gamma regions was evident among the various disorders: V8 and V10 in postthymic neoplasms; and V3, V5, V7, and, particularly, V9 in precursor-B ALL. In all the studied conditions, TCR delta was rarely in germline configuration. Extensive biallelic deletion of J delta 1, J delta 2, and C delta, almost always (19 of 20 specimens) present in postthymic neoplasms, was observed in only a minority (14 of 45) of precursor-B ALL samples. In precursor-B ALL, rearranged antigen receptor genes were more frequently found in common acute lymphoblastic leukemia antigen-positive and terminal deoxynucleotidyl transferase-positive specimens. Furthermore, TCR gene rearrangement in that disorder was characterized by a hierarchical pattern: TCR beta was not rearranged without TCR gamma nor TCR gamma without TCR delta. Despite uncertainty of the mechanism, the various disorders can be distinguished on the basis of characteristic antigen receptor gene patterns.     

小儿急性淋巴细胞白血病IgH及TCRγ基因重排研究

应用ＰＣＲ对３３例小儿急性淋巴细胞白血病（ＡＬＬ）进行免疫球蛋白重链（ＩｇＨ）及Ｔ细胞受体γ（ＴＣＲγ）基因重排研究,以探讨该２种重排在小儿ＡＬＬ的发生规律及与免疫分型的关系。结果显示：ＩｇＨ阳性１９例（５７．６％）,ＴＣＲγ阳性１０例（３０．３％）。有７例ＩｇＨ及ＴＣＲγ均呈阳性,其中５例来自Ｂ系或Ｔ系分化早期的淋巴细胞白血病,提示在儿童初发淋巴细胞白血病中,ＩｇＨ基因重排的发生率明显高于ＴＣＲγ基因重排,且在免疫表型为分化早期的Ｔ或Ｂ淋巴细胞白血病中,并存上述２种基因重排的可能性很大。     

Molecular analysis of 5' J region of immunoglobulin heavy chain gene in human acute leukemias

Ig heavy chain (IgH) J (JH) region organization in 83 human acute leukemias was studied. In 31 of the 35 precursor B acute lymphocytic leukemia (ALL) the rearrangements of the IgH gene involved sites between D regions 5' to DQ52 and JH. The study of the IgH gene organization in 43 T lineage ALL showed nine cases with the rearrangement at the IgJH region, one of which involved the D region 5' to DQ52. When analyzed with another restriction enzyme (BglII), three of the remaining eight showed rearrangement between DQ52 and JH. In the remaining five samples rearrangement of the IgJH region was not shown, but the restriction fragment length polymorphism (RFLP) between MspI sites in 5'DQ52 loci was observed. Thus the RFLP in 5'DQ52 locus was identified and was distinguished from the recombination between DQ52 and JH in non-B lineage leukemias.     

Establishment of a myelodysplastic syndrome (MDS)/secondary AML-derived T lymphoid cell line K2-MDS

We have established a T lymphoid cell line, K2-MDS, from the peripheral blood mononuclear cells (PBMC) of a patient with acute myeloblastic leukemia (AML) transformed myelodysplastic syndrome (MDS). K2-MDS cells are positive for the expression of CD4, CD5, CD13, CD25, CD71, CD95, HLA-DR and cytoplasmic CD3. Southern blotting analysis shows T cell receptor (TCR) beta chain genes rearrangements, whereas immunoglobulin heavy chain (IgH) genes are not rearranged. Further, the patient PBMC contains TCR beta chain genes rearrangements in the same manner as K2-MDS cells. The data indicate that K2-MDS is a T lymphoid cell line derived from a myelodysplastic clone in the patient PBMC. This new MDS-derived cell line K2-MDS may be a useful in vitro model for studies on the pathogenetic mechanisms leading to MDS.     

Prognostic significance of immunoglobulin and T cell receptor gene rearrangements in patients with acute myeloid leukemia: Taiwan experience.

We investigated the prognostic significance of lymphoid antigen receptor gene rearrangement in patients with newly diagnosed acute myeloid leukemia (AML). Thirty-nine patients were included in the study. Clonal gene rearrangement of immunoglobulin heavy chain (IgH) and T cell receptor beta chain (TCRbeta) was found in leukemic cells in 11 (28.2%) and 10 (25.6%) patients, respectively. Five (12.8%) had both IgH and TCRbeta gene rearrangements. Three of the seven (42.9%) B-lymphoid marker-positive and eight of the 32 (25%) B-lymphoid marker-negative patients had clonal IgH gene rearrangements. Five of the 11 (45.5%) T-lymphoid marker-positive and 5 of the 28 (17.9%) T-lymphoid marker-negative patients had clonal TCRbeta gene rearrangements. All patients were treated with similar regimens. The complete remission rate (62.5% vs 65.2%, p=1.000) and median survival (13 vs 14 months, p=0.366) were similar in patients with and without clonal IgH or TCRbeta gene rearrangements. In conclusion, while clonal rearrangements of IgH or TCRbeta genes were found in AML patients, they did not appear to effect the prognosis.     

Phenotypic and genotypic heterogeneity in infant acute leukemia. I. Acute lymphoblastic leukemia

We have studied the immunophenotypic and genotypic features in 35 infants aged less than 1 year with acute lymphoblastic leukemia (ALL) or acute undifferentiated leukemia (AUL). A CD10 (common ALL antigen)-negative, CD19-positive pre-pre-B ALL phenotype was observed in 24 infants. Seventeen of them had blast cells coexpressing myeloid-associated markers such as CD15A (VIM-D5, MZ17) and/or VIM-2, but neither myeloperoxidase nor platelet peroxidase was detected in five of these cases analyzed by electron microscopy. Five patients showed a typical common ALL, five a pre-B ALL phenotype, and one infant was unclassifiable by surface-marker and morphologic analysis. Cytogenetic data, available in 21 of these patients, revealed chromosomal abnormalities involving 11q23 in 10 infants with a CD10-negative pre-pre-B ALL. Immunoglobulin (Ig) and T cell receptor (TCR) gamma, beta and delta gene analysis of 31 infants showed Ig heavy-chain gene rearrangement in all but one patient with evidence for clonal evolution in six and kappa-light-chain rearrangement in three infants. TCR beta-chain and TCR gamma-chain rearrangement occurred in six and five patients respectively, while TCR delta-chain rearrangement was identified in 15 patients. Our data indicate that ALL in infancy may present with heterogeneous immunophenotypic and genotypic features. The high frequency of coexpression of B-lineage and myeloid surface markers as well as of chromosomal rearrangement involving 11q23 suggests that the clonogenic cell of infant ALL may relate to a multipotent progenitor cell in most cases.     

T cell receptor beta chain gene rearrangements in leukemias with immature T cell phenotype

The arrangements of the T cell receptor (TCR) beta genes were studied in leukemias with immature T cell phenotype. Three cases of acute lymphocytic leukemia (ALL) and one case of chronic myelocytic leukemia in blastic crisis (CML-BC), which expressed only Tp40 antigen of cluster of differentiation (CD) 7 without erythrocyte rosette receptor (E), did not show rearrangements of TCR beta chain genes. Two of 5 ALL cases which expressed an additional T cell antigen, T1 of CD5, showed rearrangements of TCR beta genes. Two cases of CML-BC expressing T1 and Tp40, however, had unrearranged TCR beta genes. The results altogether showed that a part of E- T1+ Tp40+ ALL cases is of T cell origin.