Immunoglobulin heavy chain and T-cell receptor beta chain gene rearrangements in acute non lymphoid leukemia

The occurrence of immunoglobulin heavy chain (IgH) and/or T-cell receptor (TcR) gene rearrangements has been reported in some cases of acute non lymphoid leukemia (ANLL), and variously interpreted as reflecting "aberrant gene expression" or "lineage promiscuity" of the leukemic cell. In an attempt to verify the incidence, FAB distribution and immunophenotypic correlates of gene rearrangements in ANLL, we analyzed the configuration of IgH and TcR beta chain genes in 70 patients with ANLL. In all cases myeloid (CD13, CD33, CD14, CD15) and lymphoid (CD7, CD2, CD10, CD19, TdT) antigenic determinants were analyzed in conjunction with conventional morpho-cytochemical characterization. Clonal rearrangements of the IgH gene were identified in 6/70 ANLL patients (8.6%), whereas in only 2/48 (4.2%) were T beta rearrangements documented. Concerning FAB subtypes, IgH or T beta rearrangements were detected in the less differentiated forms MO and M1 (3 cases), as well as in 2 M4 and 1 M5a cases. With the exception of a higher incidence of gene rearrangements in TdT+ ANLL, no significant correlation was found with other immunophenotypic markers.     

Distinct ongoing Ig heavy chain rearrangement processes in childhood B- precursor acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is thought to arise from the clonal expansion of a single transformed precursor cell. However, an oligoclonal Ig heavy chain (IgH) rearrangement pattern has been observed in 30% of ALL patients and was shown to be the result of ongoing rearrangement events. The extent and nature of these ongoing rearrangement processes in individual patients has so far remained obscure. We performed a detailed analysis of leukemic VHDJH rearrangements in three children with B-precursor ALL at diagnosis and one B-lymphoid blast crisis of a child with Ph+ chronic myeloid leukemia at diagnosis and relapse. The children were selected because they presented with multiple IgH rearrangements on Southern blot analysis. Polymerase chain reaction analysis of leukemic cells from two B-precursor ALL patients showed exclusively two groups of related sequences resulting from VH gene replacement events. Most VH gene replacements involved 3' located acceptor VH genes. Analysis of cells from the other B-precursor ALL patient showed exclusively related sequences as a result of VH gene joinings to a pre-existing DJH rearrangement. In the B-lymphoid blast crisis, a single germline precursor cell had generated multiple unrelated rearrangements and additional groups of related rearrangements resulting from VH to DJH joinings. Direct proof for the VH to DJH joining mechanism was obtained by amplification of the expected preexisting DJH rearrangements. Our findings suggest that the pattern of ongoing rearrangements in an individual patient reflects the IgH rearrangement status of the precursor cell at the time of malignant transformation. Sequence analysis of VHDJH rearrangements at diagnosis may therefore allow a prediction of the reliability of complementarity determining region 3 probes for the detection of minimal residual disease.     

PCR-based immunogenotyping at the Ig heavy chain CDR3 locus: improvements in resolution

Summary. An improved electrophoretic separation of products after PCR employing consensus primers to amplify the CDR3 of the immunoglobulin heavy chain variable region allows visualization of a ladder of fragments in polyclonal samples of peripheral blood as well as a single band where there is clonal proliferation.     

Clonal evolution as judged by immunoglobulin heavy chain gene rearrangements in relapsing precursor-B acute lymphoblastic leukemia.

Oligoclonality and ongoing clonal evolution are common features in patients with precursor-B (pre-B) acute lymphoblastic leukemia (ALL), as judged by immunoglobulin heavy chain (IgH) gene rearrangement analysis. These features are considered to be results of secondary rearrangements after malignant transformation or emergence of new tumor clones. In the present study we analyzed the IgH gene rearrangement status in 18 cases with relapsing pre-B ALL using variable heavy chain (V(H)) gene family specific polymerase chain reaction (PCR) amplification and single stranded conformation polymorphism (SSCP) analysis. Clonal IgH rearrangements were displayed in all leukemias but one, and altered rearrangement patterns occurred in five cases (29%), which were selected for detailed nucleotide sequence analysis. In one case, multiple subclones at diagnosis were suggested to be derived from a progenitor clone through joining of different V(H) germline gene segments to a pre-existing D-J(H) complex (V(H) to D-J(H) joining). Evidence for V(H) gene replacement with identical N-sequences at the V(H)-D junction and a common D-J(H) region was observed in one case. Diversification at the V(H)-D junction consisting of heterogeneous N-sequences were observed in one case. This molecular modification of the V(H)-D region could fit a hypothesized "open-and-shut" mechanism. Nevertheless, despite these ongoing events at least one IgH rearrangement remained unchanged throughout the disease in most patients, indicating that the immunoglobulin heavy chain locus can be a suitable marker for detection of minimal residual disease (MRD).     

Detection of T-cell receptor gamma chain V gene rearrangements using the polymerase chain reaction: application to the study of clonal disease cells in acute lymphoblastic leukemia.

This report describes the development and characterization of a method for the amplification of rearranged V-J segments of the human T-cell receptor gamma chain (TCRG) locus using an adaptation of the polymerase chain reaction (PCR) technique. The technique uses a single pair of 'consensus' primers to amplify rearrangements involving the V gamma I subgroup genes, which are common in malignant cells from acute lymphoblastic leukemia (ALL) patients. Using this method we were able to detect rearrangements in the TCRG locus in disease cells from patients with T-cell ALL (12 of 12), common ALL (10 of 14), and Null cell ALL (2 of 2) at presentation. Monoallelic and biallelic rearrangements involving V gamma I subgroup genes were identified by restriction analysis of PCR products from DNA samples from a T-cell leukemic cell line, T-cell clones, and disease cells from patients with ALL of T-and B-cell lineage at presentation. These results confirmed the presence of cell clones within the presentation samples and, in one case, confirmed the persistence of the original malignant cell clone at relapse. This is a rapid and specific method for the detection and characterization of rearrangements of the TCRG locus without recourse to Southern blotting. Therefore, the PCR technique described herein can provide the basis for the study of clonal evolution and minimal residual disease on a high proportion of patients with ALL.     

Biallelic heavy chain immunoglobulin gene rearrangement in acute nonlymphocytic leukemia

Summary Acute nonlymphocytic leukemia (ANLL) was diagnosed in 18 patients based on morphological, cytochemical and immunological criteria. Leukemic cells of these cases were subjected to Southern blot analysis and subsequent hybridization to heavy chain immunoglobulin and T-cell-receptor gene probes. A rearrangement within the immunoglobulin joining region was detected in 2 cases, while the T-cell-receptor -chain gene was in germline configuration in all samples investigated. These data confirm recent reports indicating that immunoglobulin heavy chain gene rearrangements are not restricted to B-lineage neoplasms.     

Neutrophil dysfunction in chronic neutrophilic leukemia without rearrangements of bcr and immunoglobulin heavy chain genes

A 67-year-old man was admitted to our hospital with abdominal distension due to hepatosplenomegaly. The peripheral blood revealed Hb content 6.5 g/dl, platelet count 4.7 x 10(4)/microliter, and WBC count 105.8 x 10(3)/microliter with 88% of mature neutrophils. The neutrophil alkaline phosphatase score was 421. Bone marrow aspiration revealed hypercellularity with increased megakaryocytes and myeloid hyperplasia. 46, XY, del 20(q 11) without Philadelphia chromosome was identified by cytogenetic study. The patient was diagnosed as having chronic neutrophilic leukemia and was successfully treated with busulfan, but he died of atypical mycobacteriosis about 20 months later. Analysis of neutrophil function demonstrated diminution of deformability, random mobility, and chemotaxis, but almost normal phagocytosis and bactericidal capacity. Southern analysis showed no rearrangements of breakpoint cluster region (bcr) gene and immunoglobulin heavy chain gene.     

Ig heavy chain gene rearrangements in T-cell acute lymphoblastic leukemia exhibit predominant DH6-19 and DH7-27 gene usage, can result in complete V-D-J rearrangements, and are rare in T-cell receptor alpha beta lineage.

Rearranged IGH genes were detected by Southern blotting in 22% of 118 cases of T-cell acute lymphoblastic leukemia (ALL) and involved monoallelic and biallelic rearrangements in 69% (18/26) and 31% (8/26) of these cases, respectively. IGH gene rearrangements were found in 19% (13/69) of CD3(-) T-ALL and in 50% of TCRgammadelta+ T-ALL (12/24), whereas only a single TCRalpha beta+ T-ALL (1/25) displayed a monoallelic IGH gene rearrangement. The association with the T-cell receptor (TCR) phenotype was further supported by the striking relationship between IGH and TCR delta (TCRD) gene rearrangements, ie, 32% of T-ALL (23/72) with monoallelic or biallelic TCRD gene rearrangements had IGH gene rearrangements, whereas only 1 of 26 T-ALL with biallelic TCRD gene deletions contained a monoallelic IGH gene rearrangement. Heteroduplex polymerase chain reaction (PCR) analysis with VH and DH family-specific primers in combination with a JH consensus primer showed a total of 39 clonal products, representing 7 (18%) VH-(DH-)JH joinings and 32 (82%) DH-JH rearrangements. Whereas the usage of VH gene segments was seemingly random, preferential usage of DH6-19 (45%) and DH7-27 (21%) gene segments was observed. Although the JH4 and JH6 gene segments were used most frequently (33% and 21%, respectively), a significant proportion of joinings (28%) used the most upstream JH1 and JH2 gene segments, which are rarely used in precursor-B-ALL and normal B cells (1% to 4%). In conclusion, the high frequency of incomplete DH-JH rearrangements, the frequent usage of the more downstream DH6-19 and DH7-27 gene segments, and the most upstream JH1 and JH2 gene segments suggests a predominance of immature IGH rearrangements in immature (non-TCRalpha beta+) T-ALL as a result of continuing V(D)J recombinase activity. More mature alpha beta-lineage T-ALL with biallelic TCRD gene deletions apparently have switched off their recombination machinery and are less prone to cross-lineage IGH gene rearrangements. The combined results indicate that IGH gene rearrangements in T-ALL are postoncogenic processes, which are absent in T-ALL with deleted TCRD genes and completed TCR alpha (TCRA) gene rearrangements.     

Rearrangement patterns of immunoglobulin heavy chain (IgH) and light chain genes in acute lymphoblastic leukemia and chronic myelocytic leukemia lymphoid crisis cells showing oligoclonal IgH gene rearrangements.

We investigated leukemic cells with multiple immunoglobulin heavy chain (IgH) gene rearrangements from nine B-precursor cell acute lymphoblastic leukemia (ALL) patients and three chronic myelocytic leukemia lymphoid crisis (CML.Ly-BC) patients in order to determine detailed recombination patterns of the variable (V), diversity (D), and joining (J) region genes. Southern blot study, using DNA probes for DQ52 and 5'D region genes, was useful to distinguish VDJ recombination from DJ recombination at the level of each allele. Leukemic cells from seven out of eight CD10-positive ALL patients showed biallelic VDJ recombinations. Rearrangements of Ig kappa genes were found in only one case. Leukemic cells from all of the CML.Ly-BC patients had a DJ/(V)DJ IgH genotype. These findings suggest that the multiple IgH gene rearrangements in B-precursor cell ALL occurred as a consequence of continuing V-(V)DJ rearrangements after neoplastic transformation, and were closely related to the stage of bone marrow B-precursor cell differentiation. Multiple IgH gene rearrangements in CML.Ly-BC might take place earlier in the process of IgH gene rearrangements than is the case in B-precursor cell ALL. In this sense, the genotypic oligoclonality observed in ALL and CML.Ly-BC should be regarded not as 'true', but as 'pseudo' oligoclonal leukemia.     

Rearrangement of immunoglobulin heavy chain genes in T cell acute lymphoblastic leukemia

We studied the arrangement of the immunoglobulin heavy chain genes by Southern blot analysis of DNA freshly obtained from marrow blast cells of 14 children with T cell acute lymphoblastic leukemia (T-ALL) using probes to the C mu and JH gene segments: At least one of the C mu-gene alleles was rearranged in three cases. In two of these, one C mu gene had the germ-line configuration and one was rearranged, whereas both alleles were rearranged in the third case. In one case, a rearranged heavy chain gene hybridized to the C mu-region probe, but not to the JH probe, indicating that the entire JH region had been deleted. These results demonstrate that immunoglobulin heavy chain gene rearrangements are not restricted to B lineage lymphoproliferative diseases in humans.     

A polymerase chain reaction study of the stability of Ig heavy-chain and T-cell receptor delta gene rearrangements between presentation and relapse of childhood B-lineage acute lymphoblastic leukemia

Ig heavy-chain (IgH) and partial V delta 2-D delta 3 T-cell receptor (TCR) gene rearrangements were investigated, by polymerase chain reaction (PCR) amplification and sequence analysis, in 52 patients at presentation and first relapse and in 14 at both first and second relapse of B-lineage acute lymphoblastic leukemia. In combination, these techniques amplified one or more clonal markers at presentation in 90% of patients (IgH-PCR, 75%; V delta 2-D delta 3-PCR, 46%; both, 33%). Changes in the pattern of amplification between presentation and first relapse were seen in 31% of patients positive by IgH-PCR at presentation and in 25% of those positive by TCR delta-PCR. Only 3 patients showed complete change in their rearrangements, which is suggestive of relapse with a new clone. Furthermore, despite the high reported rates of oligoclonality and clonal evolution at the IgH locus, the results presented show that false-negative minimal residual disease (MRD) detection can be avoided by designing D-N-J probes to all presentation rearrangements. Using a PCR approach for both gene markers, false-negative testing because of clonal evolution would have only occurred in 3 (8%) of the IgH-positive patients, in contrast to 5 (21%) of V delta 2-D delta 3-positive patients. Combining these two systems increases the proportion of patients open to study to 90%, allows comparative studies of the sensitive of the two methods, and reduces the rate of false-negative assessment of MRD caused by clonal evolution to less than 10%. We conclude that large prospective PCR studies of MRD detection should examine gene rearrangements at multiple loci to maximize their applicability and to minimize false-negative relapse prediction.     

The incidence of clonal T-cell receptor rearrangements in B-cell precursor acute lymphoblastic leukemia varies with age and genotype

B-cell precursor acute lymphoblastic leukemias (BCP-ALLs) are increasingly treated on risk-adapted protocols based on presenting clinical and biological features. Residual molecular positivity of clonal immunoglobulin (IG) and T-cell receptor (TCR) rearrangements allows detection of patients at an increased risk of relapse. If these rearrangements are to be used for universal follow-up, it is important to determine the extent to which they are informative in different BCP-ALL subsets. We show that IGH V-D-J rearrangements occur in 89% of 163 BCP-ALL, with no significant variation according to age or genotype (BCR-ABL, TEL-AML1, MLL-AF4, and E2A-PBX1). In contrast, TCRG rearrangements, which occur in 60% of patients overall, are frequent in BCR-ABL and TEL-AML1, are less so in MLL-AF4, and are virtually absent in infants aged predominantly from 1 to 2 years and in E2A-PBX1 ALLs. Incidence of the predominant TCRD Vdelta2-Ddelta3 rearrangement decreases with age but is independent of genotype. These differences are not due to differential recombination activating gene activity, nor can they be explained adequately by stage of maturation arrest. Analysis of MLL-AF4 BCP-ALL is in keeping with transformation of a precursor at an early stage of ontogenic development, despite the adult onset of the cases analyzed. We postulate that the complete absence of TCRG rearrangement in E2A-PBX1 cases may result from deregulated E2A function. These data also have practical consequences for the use of TCR clonality for the molecular follow-up of BCP-ALL.     

Multiple productive immunoglobulin heavy chain gene rearrangements in chronic lymphocytic leukemia are mostly derived from independent clones

In chronic lymphocytic leukemia, usually a monoclonal disease, multiple productive immunoglobulin heavy chain gene rearrangements are identified sporadically. Prognostication of such cases based on immunoglobulin heavy variable gene mutational status can be problematic, especially if the different rearrangements have discordant mutational status. To gain insight into the possible biological mechanisms underlying the origin of the multiple rearrangements, we performed a comprehensive immunogenetic and immunophenotypic characterization of 31 cases with the multiple rearrangements identified in a cohort of 1147 patients with chronic lymphocytic leukemia. For the majority of cases (25/31), we provide evidence of the co-existence of at least two B lymphocyte clones with a chronic lymphocytic leukemia phenotype. We also identified clonal drifts in serial samples, likely driven by selection forces. More specifically, higher immunoglobulin variable gene identity to germline and longer complementarity determining region 3 were preferred in persistent or newly appearing clones, a phenomenon more pronounced in patients with stereotyped B-cell receptors. Finally, we report that other factors, such as TP53 gene defects and therapy administration, influence clonal selection. Our findings are relevant to clonal evolution in the context of antigen stimulation and transition of monoclonal B-cell lymphocytosis to chronic lymphocytic leukemia.     

急性白血病受体基因重排的研究

目的：探讨急性白血病微小残留病（ＭＲＤ）与化疗效应差异及受体基因重排,在急性非淋巴细胞白血病（ＡＮＬＬ）中序列交叉现象及意义。方法：应用聚合酶链反应技术对免疫球蛋白（ＩｇＨ）及Ｔ细胞受体（ＴＣＲγ）基因重排进行定量测量。结果：４５例急性淋巴细胞白血病（ＡＬＬ）中阳性率８４．４％（３８／４５）,完全缓解（ＣＲ）后１８０ｄ检测,阳性率仍５５．６％（２５／４５）,２０例ＡＮＬＬ中５例检测到ＩｇＨ受体基因     

Trans-chromosomal recombination within the Ig heavy chain switch region in B lymphocytes

Somatic DNA rearrangements in B lymphocytes, including V(D)J gene rearrangements and isotype switching, generally occur in cis, i. e., intrachromosomally. We showed previously, however, that 3 to 7% of IgA heavy chains have the V_H and Cα regions encoded in trans. To determine whether the trans-association of V_H and Cα occurred by trans-chromosomal recombination, by trans-splicing, or by trans-chromosomal gene conversion, we generated and analyzed eight IgA-secreting rabbit hybridomas with trans-associated V_H and Cα heavy chains. By ELISA and by nucleotide sequence analysis we found that the V_H and Cα regions were encoded by genes that were in trans in the germline. We cloned the rearranged VDJ-Cα gene from a fosmid library of one hybridoma and found that the expressed V_H and Cα genes were juxtaposed. Moreover, the juxtaposed V_H and Cα genes originated from different IgH alleles. From the same hybridoma, we also identified a fosmid clone with the other expected product of a trans-chromosomal recombination. The recombination breakpoint occurred within the Sμ/Sα region, indicating that the trans-association of V_H and Cα genes occurred by trans-chromosomal recombination during isotype switching. We conclude that trans-chromosomal recombination occurs at an unexpectedly high frequency (7%) within the IgH locus of B lymphocytes in normal animals, which may explain the high incidence of B-cell tumors that arise from oncogene translocation into the IgH locus.     

Somatic recombination of heavy chain variable region transgenes with the endogenous immunoglobulin heavy chain locus in mice.

Transgenic lines of mice were derived by using plasmid constructs containing DNA encoding an antibody heavy chain variable-diversity-joining region (VH-D-JH) and various amounts of 5' and 3' flanking DNA but lacking any repetitive isotype switch (S) or constant (C) region DNA. Unexpectedly, many of the antibody VH regions expressed by B-cell hybridomas generated from immunized transgenic mice were found to be of transgenic origin. Further analyses showed that somatic events had generated hybrid genomic loci in the mice containing the transgenic VH-D-JH gene and plasmid sequences 5' of endogenous heavy chain C region genes. Thus, VH-D-JH transgenes lacking S and C region DNA can recombine with endogenous Igh DNA, leading to the expression of transgene-encoded antibody.     

Real-time polymerase chain reaction estimation of bone marrow tumor burden using clonal immunoglobulin heavy chain gene and bcl-1/JH rearrangements in mantle cell lymphoma

OBJECTIVE: In mantle cell lymphoma (MCL), detection of minimal residual disease in bone marrow (BM) samples by qualitative polymerase chain reaction (PCR) is insufficient to predict relapse. The aim of this study was to evaluate whether a quantitative estimation of tumor burden in consecutive BM samples from MCL patients was feasible and of clinical value. MATERIALS AND METHODS: In combination with standard qualitative PCR, we developed a sensitive and accurate real-time PCR for detection of bcl-1/JH (joining region) rearrangement and used a recently described real-time PCR analysis of clonal immunoglobulin rearrangement. To assess clinical utility, we quantified tumor cells in 27 BM samples from three MCL patients undergoing combined CHOP (cyclophosphamide, doxorubicin [hydroxydaunomycin], vincristine [Oncovin], prednisone) and anti-CD20 antibody treatment and three MCL patients undergoing up-front autologous stem cell transplantation. RESULTS: The approach is capable of detecting tumor cells over a wide range of BM contamination compared to qualitative PCR analysis alone. Tumor burden in consecutive BM samples decreases during therapy and either increases or stabilizes at low levels in patients who relapse or remain in continuous clinical remission, respectively. CONCLUSIONS: Dynamic range estimation of BM tumor burden is feasible in MCL patients undergoing therapy using clonal immunoglobulin heavy chain gene and bcl-1/JH rearrangement-based real-time PCR.     

DNA rearrangements in MPC-11 immunoglobulin heavy chain class-switch variants.

Immunoglobulin heavy chain class switching has been observed in vitro. In the IgG2b-producing MPC-11 mouse myeloma cell line, IgG2a-producing cells arise at a high frequency. In some cases, switch variants producing normal-sized (Mr 55,000) gamma 2a heavy chains have arisen spontaneously from a mutagen-induced "intermediate" (ICR 9.7.1) that produces an unusually large (Mr 75,000) heavy chain. Other switch variants have been isolated directly from the parent cell line. The expressed and unexpressed gamma 2b genes of MPC-11 can be distinguished in restriction endonuclease digests of total genomic DNA so that DNA rearrangements detected in MPC-11 variants can be directly associated with one or the other of these two genes. We describe here DNA rearrangements occurring on the expressed heavy chain chromosome of several MPC-11 gamma 2a switch variants and on the expressed chromosome of the ICR 9.7.1 intermediate. Our data indicate that all of these variants express the parental heavy chain variable region (VH) gene, supporting previous protein studies. We provide mapping data for the expressed gene of both ICR 9.7.1 and one of the IgG2a-producing variant cell lines (ICR 9.9.2.1) derived from it and discuss the advantages of an in vitro switching system for examining the dynamics of the immunoglobulin heavy chain class switch.