Power of the MAC (morphology-antibody-chromosomes) method in distinguishing reactive and clonal cells: report of a patient with acute lymphatic leukemia, eosinophilia, and t(5;14)

B-ALL With t(5;14)(q31;q32); IGH-IL3 Rearrangement and Eosinophilia: A Comprehensive Analysis of a Peculiar IGH-Rearranged B-ALL

Background: B-cell acute lymphoblastic leukemia associated with t(5;14)(q31;q32); IGH-IL3 is an exceptional cause of eosinophilia. The IGH enhancer on 14q32 is juxtaposed to the IL3 gene on 5q31, leading to interleukin-3 overproduction and release of mature eosinophils in the blood. Clinical, biological and outcome data are extremely scarce in the literature. Except for eosinophilia, no relevant common feature has been highlighted in these patients. However, it has been classified as a distinct entity in the World Health Organization classification.

Cases Presentation: Eight patients with t(5;14)(q31;q32) treated by French or Austrian protocols were retrospectively enrolled. Array comparative genomic hybridization, multiplex ligation-dependent probe amplification or genomic PCR search for IKZF1 deletion were performed in 7. Sixteen patients found through an exhaustive search in the literature were also analyzed.

For those 24 patients, median age at diagnosis is 14.3 years with a male predominance (male to female ratio = 5). Eosinophilia-related symptoms are common (neurologic in 26%, thromboembolic in 26% or pulmonary in 50%). Median white blood cells count is high (72 × 10⁹/L) and linked to eosinophilia (median: 32 × 10⁹/L). Peripheral blasts are present at a low level or absent (median: 0 × 10⁹/L; range: 0–37 × 10⁹/L). Bone marrow morphology is marked by a low blast infiltration (median: 42%). We found an IKZF1 deletion in 5 out of 7 analyzable patients Outcome data are available for 14 patients (median follow-up: 28 months): 8 died and 6 are alive in complete remission.

Some of these features are concordant with those seen in patients with other IGH-rearranged B-cell acute lymphoblastic leukemias: young age at onset, male sex, low blast count, high incidence of IKZF1 deletion and intermediate prognosis.

Conclusion: Based on shared epidemiological and biological features, B-cell acute lymphoblastic leukemia with t(5;14)(q31;q32) is a peculiar subset of IGH-rearranged B-cell acute lymphoblastic leukemia with an intermediate prognosis and particular clinical features related to eosinophilia.

Incidence of TCR and TCL1 gene translocations and isochromosome 7q in peripheral T-cell lymphomas using fluorescence in situ hybridization

Translocations involving the T-cell receptor (TCR) and TCL1 genes occur in T-cell precursor lymphoblastic leukemia/lymphoma and prolymphocytic leukemia; isochromosome 7q has been associated with hepatosplenic T-cell lymphoma. However, the incidence of these abnormalities in peripheral T-cell lymphomas (PTCLs) as a whole has not been well defined. We studied genetic abnormalities in 124 PTCLs seen at the Mayo Clinic, Rochester, MN, between 1987 and 2007. Tissue microarrays were screened using 2-color break-apart fluorescence in situ hybridization probes flanking the TCRalpha (TCRA, 14q11), TCRbeta (TCRB, 7q35), and TCRgamma (TCRG, 7p15) genes and the TCL1 gene (14q32). Isochromosome 7q was analyzed by using a 2-color probe to 7p and 7q32.1. Translocations involved TCRA in 3 (2.9%) of 102 cases and TCRB in 1 (1%) of 88. Isochromosome 7q was detected in 2 cases of extranodal NK/T-cell lymphoma, nasal type, and 2 cases of anaplastic lymphoma kinase-negative anaplastic large cell lymphoma. One of the latter cases also had a translocation of TCRA, and further studies confirmed a novel t(5;14) translocation.

Imatinib therapy for hypereosinophilic syndrome and eosinophilia-associated myeloproliferative disorders

A pathogenetic mutation, FIP1L1-PDGFRA, that results from an interstitial chromosome 4q12 deletion, leads to a constitutive activation of the platelet-derived growth factor receptor-alpha (PDGFRA) tyrosine kinase as well as a disease phenotype that mimics both the hypereosinophilic syndrome (HES) and systemic mast cell disease associated with eosinophilia (SMCD-eos). Complete remissions, in response to treatment with low-dose imatinib mesylate (100 mg/day or less) have now been documented in all cases of FIP1L1-PDGFRA(+) eosinophilic disorder as well as other eosinophilic disorders that carry activation mutations of the PDGFRB gene that is located on chromosome 5q33. Furthermore, response to therapy has been rapid (within days) and durable. Interestingly, imatinib mesylate treatment, at a higher dose level (400 mg/day), might induce either partial or short-lived complete remissions in HES that is not associated with the aforementioned PDGFR mutations. These observations make it necessary to re-examine current disease classification and treatment algorithms in eosinophilic disorders.

Acute lymphoblastic leukemia with hypereosinophilia: report of a case with 5q deletion and review of the literature

Peripheral blood eosinophilia as a presentation of acute lymphoblastic leukemia (ALL) has only rarely been reported. The eosinophilia is thought to be a nonneoplastic reaction to the neoplastic lymphoblasts. We present the case of a 5-year-old girl who developed peripheral hypereosinophilia with no circulating blasts prior to her diagnosis of B-cell lineage ALL. Cytogenetic study showed a hyperdiploid blast population with 5q deletion. Persistent peripheral hypereosinophilia should always be fully investigated, the possibility of a malignancy including ALL needs to be excluded, even in the absence of peripheral cytopenias and circulating blasts.

Syntenic homology of human unique DNA sequences within chromossome regions 5q31, 10q22, 13q32-33 and 19q13.1 in the great apes

Homologies between chromosome banding patterns and DNA sequences in the great apes and humans suggest an apparent common origin for these two lineages. The availability of DNA probes for specific regions of human chromosomes (5q31, 10q22, 13q32-33 and 19q13.1) led us to cross-hybridize these to chimpanzee (Pan troglodytes, PTR), gorilla (Gorilla gorilla, GGO) and orangutan (Pongo pygmaeus, PPY) chromosomes in a search for equivalent regions in the great apes. Positive hybridization signals to the chromosome 5q31-specific DNA probe were observed at HSA 5q31, PTR 4q31, GGO 4q31 and PPY 4q31, while fluorescent signals using the chromosome 10q22-specific DNA probe were noted at HSA 10q22, PTR 8q22, GGO 8q22 and PPY 7q22. The chromosome arms showing hybridization signals to the Quint-EssentialTM 13-specific DNA probe were identified as HSA 13q32-33, PTR 14q32-33, GGO 14q32-33 and PPY 14q32-33, while those presenting hybridization signals to the chromosome 19q13.1-specific DNA probe were identified as HSA 19q13.1, PTR 20q13, GGO 20q13 and PPY 20q13. All four probes presumably hybridized to homologous chromosomal locations in the apes, which suggests a homology of certain unique DNA sequences among hominoid species.

Flow cytometric identification of candidate normal stem cell populations in CD45-negative B-cell precursor acute lymphoblastic leukaemia

CD45-negative B-cell precursor acute lymphoblastic leukaemia (ALL) provides a unique model to study the stem cell compartment in ALL as leukaemic CD34-positive cells, unlike their normal counterparts, do not express CD45. By increasing the number of events analysed to 10(6), storing only the events in the region of interest (storage gate), using appropriate isotype controls and stringent washing procedures, a flow cytometric protocol was established to characterize rare CD34+ CD19- events. In eight of 12 patients (67%) with CD45-negative B-cell precursor ALL, a distinct CD34+ CD19- CD45+ candidate normal stem cell population could be detected. In one patient analysed by four-colour staining, the CD34+ CD19- CD45+ cells, unlike the CD45-negative leukaemic cells, expressed CD117 (c-kit), providing further evidence that these cells represent residual nonleukaemic normal cells. By multiparameter analysis, this population of candidate normal stem cells could be separated from contaminating leukaemic CD34+ CD19- CD45- cells, which were detected in 11 of the 12 patients within the CD34+ CD19- compartment.

Clonal eosinophilic disorders and the hypereosinophilic syndrome

An increase in the blood eosinophil count may occur in a number of disease states including allergies, parasitic infections, vascular disease and as a reaction to the presence of malignant tumours. This article defines those disorders that are not purely reactive, and describes in detail the diagnosis and features of clonal eosinophilic disorders and the hypereosinophilic syndrome. The clonal disorders that are associated with eosinophilia are discussed, in particular the acute and chronic eosinophilic leukaemias and clonal eosinophilias in association with acute myeloid leukaemia, myeloproliferative disorders and myelodysplastic syndromes. Whether eosinophilia is produced by a clonal or reactive disorder, the end result can often be the same, i.e. end organ damage produced by sustained hypereosinophilia in the presence of eosinophil activation. When no cause for the eosinophilia leading to the end organ damage is found, this disease is termed 'idiopathic hypereosinophilic syndrome'. Its pathogenesis, clinical features and management are discussed with particular reference to the possibility of it being a T-cell-associated disorder.

Metaphase fluorescence in situ hybridization (FISH) in the follow-up of 60 patients with haemopoietic malignancies

Metaphase DNA fluorescence in situ hybridization (metaphase-FISH) was performed on follow-up samples from 60 patients suffering from haemopoietic malignancies (acute and chronic myeloid leukaemia, acute lymphoblastic leukaemia, non-Hodgkin's lymphoma and myelodysplastic syndrome). All patients had clonal chromosomal trisomies or translocations at diagnosis, and were treated by bone marrow transplantation (BMT), chemotherapy (CT) or interferon-alpha therapy. Metaphase-FISH was performed during therapy-induced complete haematological remission (CR) (BMT and CT patients) using biotin-labelled whole chromosome paint probes. 28% of all patients in CR were shown by FISH to have abnormal metaphase cells, and 62% of this group suffered a clinical relapse. Of those with negative FISH results (72%), 12% relapsed. In three CML patients treated with BMT a small population of t(9;22)-positive cells was demonstrated. These cells disappeared during follow-up without causing a relapse. One ALL patient had abnormal cells a short time after start of therapy but was also later found FISH-negative. Furthermore, we demonstrated that metaphase-FISH is a suitable method for quantifying the proportion of abnormal cells in CML patients during interferon-alpha therapy. Metaphase-FISH was also employed to detect a local relapse in an ALL patient. Thus, metaphase-FISH was found reliable and sensitive for detection of minimal residual disease in patients with haemopoietic malignancies.

Lineage involvement and karyotype in a patient with myelodysplasia and blood basophilia

We report a 63-year-old woman with myelodysplastic syndrome (MDS), refractory anaemia with ring sideroblasts (RARS), and blood basophilia with pathological forms. Karyotype analysis revealed a complex rearrangement: 46,XX,del(3)(p13p25),del(5)(q13q33),der(16)t(1;16) (p13;q12)/47,idem,add(20)(?p11)/49,idem, + add(1)(q32),add(20)(?p11), + mar/46,XX. Karyotype, immunophenotype and in situ hybridization studies by the MAC (morphology antibody chromosomes) combination technique revealed the chromosomal abnormality in granulocytic/monocytic and erythrocytic metaphase cells. Also mature basophils and other granulocytes were involved with the abnormality. We suggest that our patient with the MDS has a stem cell disorder affecting all myeloid cell lineages and that basophilia constitutes a part of the malignant process.

Cell lineage involvement of recurrent chromosomal abnormalities in hematologic neoplasms

Analysis of most hematologic neoplasms indicates the involvement of one or more cell lineages in the bone marrow and/or the blood but rules out the involvement of all lineages in any one neoplasm. It is important to detect lineage involvement in order to clarify which stem cells are involved in leukemia, to predict prognosis, and to select appropriate treatment. Our aim was to study the cell lineage involvement of some of the recurrent chromosomal abnormalities seen in hematological neoplasms. The direct morphology-antibody-chromosomes (MAC) method was used. The deletion 20q in myeloproliferative diseases (MPD), the deletion of 5q and t(1;7) in myelodysplastic syndromes (MDS), and t(3;3) in acute myeloid leukemia subtype M7 (AML-M7) were seen in all or at least in two myeloid lineages. These were interpreted as stem cell abnormalities. Deletion 13q in MPD, t(8;21) in AML-M2 and t(15;17) in AML-M3 were seen in granulocytic lineages only; t(14;18) in non-Hodgkin's lymphoma and trisomy 12 as the sole abnormality in chronic lymphocytic leukemia (B-CLL) were seen only in immunoglobulin light chain clonal B cells; inversion 14 in T-CLL was seen only in T cells, whereas t(15;14) in acute lymphocytic leukemia with eosinophilia (ALL-EO) was seen in lymphoid stem cells but not in mature granulocytes or lymphocytes. Additional abnormalities (in addition to the Philadelphia chromosome) in chronic myeloid leukemia (CML) were seen in all myeloid cell lineages and also in mature granulocytes, B cells, and large granular lymphocytes. Abnormalities in Hodgkin's disease were restricted to CD30-positive Reed-Sternberg cells. Trisomy 8 and monosomy 7 are abnormalities that may be present in either stem cells or any of the single cell lineages.