4 Differentiation-linked Gene Rearrangement and Expression in Acute Lymphoblastic Leukaemia

Case report: Anterior mediastinal mass in a patient with pleural effusion and dyspnea

Background

Compound lymphoma is an uncommon type of lymphoid malignancy, and those consisting of concurrent B- and T-cell tumors are relatively rare.

Case Summary

A 41-year-old man was presented with a 1-month history of progressively worsening cough, chest tightness, and dyspnea after exercise, which could be relieved following rest. Contrast-enhanced computed tomography scan demonstrated a 7.4 × 4.9 cm² heterogeneous mass in the anterior mediastinum, where a large area of cystic liquid existed, and multiple enlarged lymph nodes in the mediastinum. Since the biopsy failed to yield an exact diagnosis and there was no sign of metastasis, the tumor was surgically resectioned. Surgical findings included obscure boundaries and consistent tumor stiffness with pericardial and pleural invasion. Further pathological examination combined with immunophenotype and gene rearrangement test found the mass composite of angioimmunoblastic T-cell lymphoma (AITL) and B-cell lymphoma. The patient recovered well after R0 resection and received chemotherapy with four cycles of CHOP combined with chidamide 2 weeks after surgery. The patient has had a complete response for over 60 months.

Conclusion

In conclusion, we reported a composite lymphoma of AITL combined with B-cell lymphomas. Our experience provides the first successful attempt to treat this rare disease with combined surgery and chemotherapy.

Elevated mRNA level of hST6Gal I and hST3Gal V positively correlates with the high risk of pediatric acute leukemia

Altered sialylation occurs in essentially all types of human and experimental cancers. Although, aberrant sialylation is believed to mainly due to altered sialyltransferase (ST) level, so far, expression pattern of different STs in acute lymphoblastic leukemia has never been investigated. Accordingly, the aim of our study was to monitor the changes in mRNA expression of ST6Gal I, ST3Gal V and ST8Sia I in patients by real-time PCR, which may provide prognostic information useful in defining appropriate therapeutic options. Our data demonstrated that ST6Gal I and ST3Gal V mRNA were up-regulated in lymphoblasts whereas its presence was negligible in non-malignant donors. In contrast, ST8SiaI was downregulated in patients. The extents of linkage-specific sialylation of glycoconjugates were found to be associated with disease establishment. Additionally, ST6Gal I and ST3Gal V were positively correlated with the high risk of the disease (P=0.0032 and 0.0016). This differential ST level can be used as biomarker with the molecular method of quantitative PCR and may be useful to discriminate normal and cancer patients.

Composite EBV negative peripheral T-cell lymphoma and diffuse large B-cell lymphoma involving the ileum: a case report and a systematic review of the literature

We report a case of an intestinal peripheral T-cell lymphoma (PTCL) with a concurrent diffuse large B-cell lymphoma (DLBL) involving the ileum and a regional lymph node. The patient presented with an abdominal mass. The terminal ileum showed a diffuse and monotonous population of small CD3-positive T cells. The T-cell receptor gamma (TCRgamma) gene was rearranged by PCR while the immunoglobulin heavy chain (IgH) gene was not. A separate section of the ileum showed a colliding large B-cell proliferation. The regional lymph node showed a diffuse proliferation of large centroblasts positive for CD20 and CD79a admixed with small T cells and showed a rearranged IgH receptor gene without evidence of a clonally rearranged TCRgamma gene. Both the PTCL and DLBL components were negative for EBV. A review and analysis of the pertinent literature describing composite T- and B-cell lymphomas is performed and reported.

B-cell gene rearrangement in benign and malignant lymphoid proliferations of mucosa-associated lymphoid tissue and lymph nodes

The polymerase chain reaction (PCR) with polyacrylamide gel electrophoresis was used to study patterns of immunoglobulin heavy chain (IgH) gene rearrangement (GR) in formalin-fixed, paraffin-embedded specimens of lymphomas and reactive conditions of mucosa-associated lymphoid tissue (MALT) and lymph node. DNA amplification was performed directly on sections obtained from paraffin blocks. Five patterns of PCR products were observed: a single band, two or more discrete bands, smearing, a single band overlying a smear, and two or more bands over a smear. A pure polyclonal pattern (smear) was observed in all of the reactive lymph nodes but in only 15% of cases of Helicobacter pylori (HP) gastritis with lymphoid hyperplasia, 25% of cases of HP gastritis without lymphoid hyperplasia, and 37% of colonic specimens of various types. Patterns consisting of multiple bands with or without background smearing were common in gastritis, colitis, and gastric lymphomas. Single bands or dominant bands were present in all lymph node and salivary gland lymphomas, 12 of 14 cases of gastric lymphoma, and 17 of 20 cases of HP gastritis with lymphoid hyperplasia. These bands were reproducible in deeper sections from the same paraffin block or similar areas sampled in different blocks in all of the lymph node and salivary gland lymphomas, 11 of 12 gastric lymphomas, but only 1 of 17 cases of HP gastritis with lymphoid hyperplasia. Bands were also found in 3 of 20 cases of HP gastritis without lymphoid hyperplasia and 17 of 38 colonic specimens, but these were not reproducible. The complexity of patterns of IgH GR in acquired MALT compared with lymph nodes may be the result of a relative paucity of B-cell clones or preferential proliferation of B-cell clones with a limited area of distribution.

Rearrangement of the immunoglobulin heavy chain gene in juvenile chronic myeloid leukaemia

Five patients with clinical and laboratory features typical for juvenile chronic myeloid leukaemia (JCML) are presented. Rearrangement of the j joining region of the immunoglobulin heavy chain (Jh) was demonstrated in three children out of five analysed. As no Vh to DhJh nor kappa light chain rearrangements were demonstrated, it is reasonable to speculate that the transforming event of the stem cell happened at the stage when Dh to Jh rearrangement took place. As the monocytic lineage is prominent in JCML, it is suggested that the transforming event happens in a unique stem cell with intermediate differentiation towards the myelomonocytic as well as the B-lymphatic lineage. This stem cell, which is present at a certain stage of embryogenesis, disappears later. Such an early 'hybrid' cell is sometimes involved in leukaemias of early infancy, and may be the transformed cell in some cases of infantile leukaemia.

The molecular genetic analysis of gene rearrangements in acute lymphoblastic leukaemia

In ALL the majority of cases possess clonal rearrangements of the Ig or TCR gene loci. Detection of these clonal markers by Southern blot analysis over a disease course has provided information on the fate and origin of leukaemic clones during treatment. Detection of these gene rearrangements has been used to detect residual disease during treatment. More recently, methods have been developed for the detection of Ig and TCR gene rearrangements using the polymerase chain reaction (PCR). This amplification technique allows for the rapid detection of gene rearrangements with a greater sensitivity than more conventional methods. The full impact and usefulness of this technique in residual disease detection has yet to be determined. The presence of the Philadelphia chromosome t(9;22) in ALL is associated with poor prognosis. Its detection by Southern blot is technically complicated due to the heterogeneity of chromosome breakpoints involved. The development of PCR-based methods for the detection of the bcr/abl mRNA associated with the Philadelphia chromosome has improved our understanding of the significance and incidence of this disease marker in ALL, emphasizing the importance of establishing Philadelphia status on all patients at diagnosis. Although longitudinal studies in CML have shown the presence of bcr/abl mRNA to be associated with residual disease, and its absence associated with long-term remission, these studies have yet to be reported for ALL. The usefulness of detection of residual disease using bcr/abl has yet to be determined.

Malignant cell detection in Burkitt's lymphoma using third-complementarity-determining region (CDRIII), clone-specific probe developed by sequencing DNA from stored slides

The DNA sequence of the third-complementarity-determining region (CDRIII) of the immunoglobulin heavy chain (IgH) gene in a case of Burkitt's lymphoma was determined by polymerase chain reaction (PCR) using template DNA extracted from a smear stored at room temperature for more than one year. The DNA sequence obtained from the stored slide was compared with that of DNA from a frozen lymph node biopsied at the initial presentation. The sequences were shown to be identical, implying that DNA from a smear on a stored slide can be used as a source of DNA for PCR amplification, sequencing, and development of a clone-specific probe. Using oligonucleotides generated from one of the CDRIII sequences of the IgH gene as molecular probes, a retrospective study for the malignant clone on the smears was carried out. Malignant cells were detectable in the peripheral blood at an early stage of bone marrow relapse but not in the peripheral blood or bone marrow at the initial presentation. No malignant clone was detected in the bone marrow when testicular infiltration was diagnosed by examination of a pathological specimen. Thus, the technique permits molecular analysis of hematologic malignancies of B-cell lineage in cases where fresh or frozen specimens are not available.

Immunoglobulin and T-cell receptor gene rearrangements in acute lymphoblastic leukemia--a higher incidence of double rearrangements in patients with myeloid antigen expression

Among 160 patients who were diagnosed as having acute lymphoblastic leukemia (ALL) by French American British (FAB) criteria, 32 patients (20%) expressed myeloid-associated antigens on leukemic blasts (My+ALL). Correlation of immunophenotype with rearrangement of immunoglobulin (Ig) heavy chain and T-cell receptor (TCR) beta chain genes was performed on 73 of these patients (21 were My+ALL). Rearrangements of both Ig and TCR genes (double rearrangements) were detected in 24 patients, including three (19%) of 16 T-lineage ALL. 17 (33%) of 52 B-lineage ALL, and four of five ALL expressing both B and T-cell surface markers. Also a higher incidence of double rearrangements in My+ALL was found as compared with My-ALL (43% vs 29%). This difference was more evident when only B-lineage ALL was considered (50% in My+ patients vs 24% in My- patients). However the difference is not statistically significant yet possibly due to the small number of patients in the study. Further studies on more patients are needed to confirm this. In My-B-lineage ALL, rearrangements of TCR beta chain gene were restricted to certain subgroups (Groups III & IV) of patients who expressed CD10 surface antigens but lacked cytoplasmic Ig. In My+ B-lineage ALL, rearrangements of TCR beta chain gene could be found in various subgroups studied (Groups II through V). Cross-lineage gene rearrangement in My+ALL may involve mechanisms different from those in My-ALL.

Human heavy chain variable region gene diversity, organization, and expression

Elucidation of the cellular and molecular mechanisms which determine the expressed antibody repertoire remains a major challenge in immunology. Knowledge of V gene diversity, organization, and expression is important to an understanding of the formation of the antibody repertoire in normal as well as diseased states. In the last few years, great advances have been made in our understanding of the human heavy chain variable region (VH) gene locus. In this review we present the current knowledge of VH gene diversity, organization, and utilization in normal individuals followed by a discussion of the possible relevance of these findings to autoimmunity.

The use of DNA probes to monitor minimal residual disease in childhood acute lymphoblastic leukaemia

DNA probes to both the joining region (JH) of the immunoglobulin heavy chain gene (IgH) and to the beta chain of the T-cell antigen receptor complex (TCR) have been used as tumour-specific markers to monitor the rearrangements of the IgH chain gene and the TCR beta gene in the blast cells of children presenting with acute lymphoblastic leukaemia (ALL) of B or T cell origin. Blast cells from 68 children with early B cell ALL and eight with T-ALL were examined at presentation, at day 28 after commencement of therapy and at varying times thereafter. An additional 43 patients (42 with B cell ALL, one with T-ALL) were studied both at presentation, at completion of their 2-year treatment course and 3 months later. Twelve patients, drawn from both these groups, were studied at relapse as were a further eight patients in whom an extramedullary relapse had occurred. Persistence of clonally-derived cells as a predictor of early relapse was seen in the day 28 bone marrows of 11/76 newly-diagnosed children (nine early B and two T-ALL) followed by rapid, overt relapse in four of the early B ALL cases. No minimal residual disease (MRD) was detected in bone marrows from any of the 43 patients completing their 2-year treatment course, but six of these subsequently relapsed at varying time periods thereafter. Identical patterns of rearrangement at both presentation and relapse were seen in most cases. Oligoclonality, or multiple IgH chain gene rearrangements was seen in the blast cells of 15% of patients with early B cell ALL. No correlation between oligoclonality, high white count, unfavourable phenotype or abnormal karyotype could, however, be ascertained.

T-cell receptor gene rearrangement and its expression in human myeloid leukemia cell lines

ML cell lines (ML-1, -2, and -3) were derived from the cells of a patient with acute myelocytic leukemia preceded by a T-cell malignant lymphoma. A deletion of chromosome 11 (11q-) was common to the affected cells in both neoplastic phases. We report here that the three ML cell lines have DNA rearrangements of the T-cell receptor (TcR)-beta and gamma-chain genes in addition to immunoglobulin heavy-chain gene rearrangement, though they do not have TcR gene messages. The findings presented here indicate that ML cell lines could be used as models for the elucidation of the bilineal nature of hematopoietic neoplastic cells, though they have a biphenotypic (myelomonocytic/T-cell) marker expression.

Biologic and cytogenetic characteristics of leukemia in infants

Clinical features, leukemic cell characterization, chromosomal findings, and treatment outcome were analyzed in a retrospective study of 30 cases with acute leukemia of infancy, 24 infants with acute lymphoblastic leukemia (ALL), and six cases with acute nonlymphoblastic leukemia (ANLL). Extensive bulky disease with organomegaly, central nervous system (CNS), and skin involvement were prominent features at diagnosis with a higher frequency in ANLL as compared to ALL. Four of six ANLL patients were classified as monocytic or myelomonocytic. In the ALL group nine of 24 (36%) were non-L1 morphology and six of 17 (33%) were common ALL antigen (CALLA) negative, the majority of them (five of six) were included in the non-L1 group. Immunophenotyping revealed four cases with early B-cell (three patients: Ia+B4+, and one patient: Ia+) and two cases with T-cell. Mixed lineage leukemia was found in five infants. Heavy chain immunoglobulin gene rearrangement was present in six cases tested, two CALLA+, two with Ia+B4+, and two were undifferentiated mixed lineage leukemia. Chromosomal aberrations were detected in ten of 18 patients, mostly in ANLL and CALLA negative ALL. Translocations were detected in six patients, involving 4q21-23 and 11q23 in three and two cases, respectively. The probability of five-year DFS were 27% for the whole group. The worst prognosis was observed in infants younger than 6 months of age, in whom the leukemia cell characteristics was compatible with stem cell: ANLL, very early pre-B, or undifferentiated mixed type. The chromosomal aberrations found in all cases included translocation with the seemingly nonrandom breakpoints at 4q21 and 11q23, and breakpoints that corresponded to known fragile sites. This finding may be suggestive of an underlying genetic predisposition associated with the poor prognosis of leukemia of infancy.

Classification of acute leukaemias

Acute leukaemias have traditionally been classified according to the nature of the predominating cells as judged by cytomorphology and cytochemistry. A codification of this classification into L1-L3 subdivisions for lymphoblastic cases (ALL) and M1-M7 for myeloid cases (AML), proposed by the FAB group of haematologists, has been used extensively in the past decade. Some criticisms of this codification are presented and other approaches to classification are discussed. Among these are included the potential importance of multiple lineage expression, measurements of cell differentiation using cytochemical criteria, the relevance of isoenzyme biochemistry of leukaemic cell populations, their surface antigenic differences as demonstrated by the use of monoclonal antibodies and the growing contribution of cytogenetics. The development and complexity of combined classifications which attempt to incorporate most of these features is illustrated. A simplified classification into broad groups is proposed, ALL being divided by surface antigenic and cytogenetic criteria and AML by morphology and cytochemistry. These groups may be further elaborated as appropriate.

Mixed acute leukaemias

In recent years immunophenotyping and analysis of clonal rearrangement of immunoglobulin and T-cell antigen receptor genes have proved valuable for the diagnosis and classification of leukaemia. These techniques aid in the assignment of cell lineage in cases of acute leukaemia in which the standard FAB criteria of morphology and cytochemistry do not reveal clear lymphoid or myeloid phenotype. These new techniques have also revealed that the leukaemic blasts in a sizable minority of otherwise typical cases of acute leukaemia express 'inappropriate' lineage-associated markers and have been termed mixed acute leukaemias. The spectrum of characteristics encompassed by mixed acute leukaemias ranges from fairly common cases expressing one or two inappropriate markers to the more extreme, rare cases of acute leukaemia termed 'hybrid' in which a truly scrambled picture is seen. A subgroup of these mixed cases have two distinct populations of blasts, e.g. one lymphoid and the other myeloid. These observations raise a number of issues about the cell of origin of these leukaemias and about the mechanisms controlling the developmental regulation of expression of different lineage-associated markers. In addition, accumulating evidence suggests that inappropriate expression of markers may identify sub-groups of both acute myeloid and lymphoblastic leukaemia with an inferior prognosis.