BCL3 rearrangements in B-cell lymphoid neoplasms occur in two breakpoint clusters associated with different diseases

The t(14;19)(q32;q13) often juxtaposes BCL3 with immunoglobulin heavy chain (IGH) resulting in overexpression of the gene. In contrast to other oncogenic translocations, BCL3 rearrangement (BCL3-R) has been associated with a broad spectrum of lymphoid neoplasms. Here we report an integrative whole-genome sequence, transcriptomic, and DNA methylation analysis of 13 lymphoid neoplasms with BCL3-R. The resolution of the breakpoints at single base-pair revealed that they occur in two clusters at 5' (n=9) and 3' (n=4) regions of BCL3 associated with two different biological and clinical entities. Both breakpoints were mediated by aberrant class switch recombination of the IGH locus. However, the 5' breakpoints (upstream) juxtaposed BCL3 next to an IGH enhancer leading to overexpression of the gene whereas the 3' breakpoints (downstream) positioned BCL3 outside the influence of the IGH and were not associated with its expression. Upstream BCL3-R tumors had unmutated IGHV, trisomy 12, and mutated genes frequently seen in chronic lymphocytic leukemia (CLL) but had an atypical CLL morphology, immunophenotype, DNA methylome, and expression profile that differ from conventional CLL. In contrast, downstream BCL3-R neoplasms were atypical splenic or nodal marginal zone lymphomas (MZL) with mutated IGHV, complex karyotypes and mutated genes typical of MZL. Two of the latter four tumors transformed to a large B-cell lymphoma. We designed a novel fluorescence in situ hybridization assay that recognizes the two different breakpoints and validated these findings in 17 independent tumors. Overall, upstream or downstream breakpoints of BCL3-R are mainly associated with two subtypes of lymphoid neoplasms with different (epi)genomic, expression, and clinicopathological features resembling atypical CLL and MZL, respectively.

LAG3 genotype of the donor and clinical outcome after allogeneic transplantation from HLA-identical sibling donors

Introduction

The association of polymorphisms in molecules involved in the immune response (checkpoint inhibitors) with the clinical outcome after allogeneic transplantation (alloHSCT) has been described. Lymphocyte Activation 3 (LAG3) is a surface protein that plays a regulatory role in immunity as an inhibitory immune checkpoint molecule.

Methods

To determine its role in the alloHSCT setting, we analyzed 797 patients transplanted from HLA-identical sibling donors. The LAG3 rs870849 C>T polymorphism was genotyped in donors.

Results

We detected a higher incidence of severe acute GVHD in patients transplanted from donors with TT genotype (p: 0.047, HR 1.64; 95% CI 1.01 - 2.67). Overall survival (OS) was worse for patients transplanted from donors with the rs870849 CT/TT genotype (0.020; HR, 1.44; 95% CI 1.06 - 1.96), as well as disease-free survival (DFS) (p: 0.002; HR 1.58, 95%CI: 1.18 - 2.14) and transplant-related mortality (TRM) (p< 0.001; HR: 1.88, 95% CI 1.29 - 2.74). When combining the LAG3 rs870849 and the PDCD1 rs36084323 genotypes of the donor, three genetic groups were well defined, allowing a good stratification of the risk of acute GVHD, TRM, OS and DFS.

Discussion

We conclude that the LAG3 genotype of the donor may be considered in donors' selection. As this selection may be limited in the HLA-identical sibling donor scenario, further studies exploring the impact of LAG3 genotype of the donor in unrelated transplantation are warranted.

5'-nucleotidase, cytosolic ii genotype and clinical outcome in patients with acute myeloid leukemia with intermediate-risk cytogenetics

Acute myeloid leukemia (AML) is a complex disease, and its treatment needs to be adjusted to the risk, which is conferred by cytogenetics and molecular markers. Cytarabine is the main drug to treat AML, and it has been suggested that the genotype of cytarabine metabolizing enzymes may have a prognostic relevance in AML. Here we report the association between the 5'-nucleotidase, cytosolic II (NT5C2) rs10883841, cytidine deaminase (CDA) rs2072671 and rs532545 genotypes and the clinical outcome of 477 intermediate-risk cytogenetic AML patients receiving cytarabine-based chemotherapy. Patients younger than 50 years old with the NT5C2 rs10883841 AA genotype had lower overall survival (OS) (p: 0.003; HR 2.16, 95%CI 1.29 - 3.61) and lower disease-free survival (DFS) (p: 0.002; HR 2.45, 95%CI 1.41 - 4.27), associated to a higher relapse incidence (p: 0.010; HR 2.23, 95%CI 1.21 - 4.12). Interestingly, subgroup analysis showed that the negative effect of the NT5C2 rs10883841 AA genotype was detected in all subgroups except in patients with nucleophosmin mutation without high ratio FLT-3 internal tandem duplication. CDA polymorphisms were associated with the complete remission rate after induction chemotherapy, without influencing OS. Further studies are warranted to determine whether this pharmacogenomic approach may be helpful to individualize AML treatment.

Kinetics of the CTLA-4 isoforms expression after T-lymphocyte activation and role of the promoter polymorphisms on CTLA-4 gene transcription

Cytotoxic T lymphocyte antigen 4 (CTLA-4) plays a key inhibitory role during T lymphocyte activation. The CTLA4 gene is translated into two proteic isoforms: a full-length protein (flCTLA-4) and a soluble counterpart. We explored the expression of both isoforms on healthy subjects. Whereas in non-stimulated cells the flCTLA-4 isoform is predominant, after stimulation the expression of the soluble form rapidly increases, reaching its maximum 24h after and falling again to the basal levels 72 h after stimulation. In contrast, the flCTLA-4 mRNA levels increase is slower, reaching the maximum level 72 h after stimulation. The presence of the T allele in the promoter positions -1722 and -318 is associated with an increased transcriptional activity and this effect seems to be synergic. We conclude that the kinetics of CTLA-4 isoform expression are sequential, and that the promoter polymorphisms -1722(C/T) and -318(C/T) are involved in the control of the CTLA4 transcription.

[Persistent polyclonal B-cell lymphocytosis: study of 35 cases]

BACKGROUND AND OBJECTIVES

Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare entity, presenting especially in adult smoker women. It is characterized by an increase of serum IgM, DR7-HLA haplotype, cytogenetic abnormalities and multiple IgH/BCL-2 rearrangements. To date, it has not been elucidated whether this is a benign or premalignant disorder. We analyzed the PPBL characteristics with especial attention to its evolution.

PATIENTS AND METHODS

Thirty-five PPBL patients from 5 hospitals in Catalonia were retrospectively analyzed. A simultaneous morphologic review of the blood smears was performed by members of the GCCH in a 16 multiple-observer optic microscope. Clinical and biological data were also analyzed.

RESULTS

PPBL presents in the majority of cases with persistent polyclonal B-cell lymphocytosis and affects primarily smoker women. The morphologic hallmark, in absence of viral infections, is the presence of activated lymphocytes with bilobulated and/or cleaved nuclei, and nuclear pockets in the ultrastructural study. Increased serum IgM, HLA-DR7 haplotype, chromosomal abnormalities such as i(3)(q10) and multiple IgH/BCL-2 rearrangements were detected. Thirty-four out of 35 patients are alive after a median follow up of 70.7 months. One patient died because of lung adenocarcinoma and another developed a follicular lymphoma without relation to PPBL.

CONCLUSIONS

PPBL has an asymptomatic and stable evolution, although it frequently presents genetic abnormalities. It remains unknown whether it is a premalignant entity, similar to monoclonal gammopathies of unknown significance. Hence, accurate cytologic diagnosis and follow-up are essential.

Genetic changes including gene copy number alterations and their relation to prognosis in childhood acute myeloid leukemia

We studied a series of 68 subjects diagnosed with childhood acute myeloid leukemia (AML) using conventional cytogenetics and fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) to analyze mutations in FLT3 and NPM1 genes, and/or array comparative genomic hybridization (CGH). Cytogenetic/FISH abnormalities were observed in 71% of subjects, FLT3-ITD mutations in 15%, and NPM1 mutations in 13%. The array CGH alterations (average 3.6 per case) were observed in 96% of the tested subjects. The most frequent alterations were gains of 8q24.3 and 11p15.5-p15.4 in 16% of the samples. Six genes (AKT1, RUNX1, LTB, SDC1, RUNX1T1, and JAK2) from the imbalanced regions have been reported to be involved in AML, whereas other 30 cancer genes, not previously reported in an AML context, were identified as imbalanced. They probably correspond to non passenger alterations that cooperate with the recurrent translocations. The clinical data and genetic changes were tested to find out the possible association with prognosis. Genomic instability (four or more genomic imbalances) was correlated with poor patient outcome (p = 0.029).

Differential expression of genes mapping to recurrently abnormal chromosomal regions characterize neuroblastic tumours with distinct ploidy status

Background

Neuroblastic tumours (NBTs) represent a heterogeneous spectrum of neoplastic diseases associated with multiple genetic alterations. Structural and numerical chromosomal changes are frequent and are predictive parameters of NBTs outcome. We performed a comparative analysis of the biological entities constituted by NBTs with different ploidy status.

Methods

Gene expression profiling of 49 diagnostic primary NBTs with ploidy data was performed using oligonucleotide microarray. Further analyses using Quantitative Real-Time Polymerase Chain Reaction (Q-PCR); array-Comparative Genomic Hybridization (aCGH); and Fluorescent in situ Hybridization (FISH) were performed to investigate the correlation between aneuploidy, chromosomal changes and gene expression profiles.

Results

Gene expression profiling of 49 primary near-triploid and near-diploid/tetraploid NBTs revealed distinct expression profiles associated with each NBT subgroup. A statistically significant portion of genes mapped to 1p36 (P = 0.01) and 17p13-q21 (P < 0.0001), described as recurrently altered in NBTs. Over 90% of these genes showed higher expression in near-triploid NBTs and the majority are involved in cell differentiation pathways. Specific chromosomal abnormalities observed in NBTs, 1p loss, 17q and whole chromosome 17 gains, were reflected in the gene expression profiles. Comparison between gene copy number and expression levels suggests that differential expression might be only partly dependent on gene copy number. Intratumoural clonal heterogeneity was observed in all NBTs, with marked interclonal variability in near-diploid/tetraploid tumours.

Conclusion

NBTs with different cellular DNA content display distinct transcriptional profiles with a significant portion of differentially expressed genes mapping to specific chromosomal regions known to be associated with outcome. Furthermore, our results demonstrate that these specific genetic abnormalities are highly heterogeneous in all NBTs, and suggest that NBTs with different ploidy status may result from different mechanisms of aneuploidy driving tumourigenesis.

Idiopathic hypereosinophilic syndrome in children: report of a 7-year-old boy with FIP1L1-PDGFRA rearrangement

Idiopathic hypereosinophilic syndrome (HES) in children is a very rare disorder; certain clinical differences with adult HES have been described, with no pediatric case with the imatinib-responsive FIP1L1-PDGFRA fusion gene reported to date. The authors describe the clinical course of three children with HES in whom FIP1L1-PDGFRA fusion gene was studied and report the first child with this rearrangement.

Acute erythroid neoplastic proliferations. A biological study based on 62 patients

BACKGROUND AND OBJECTIVES

The terms acute erythroleukemia and AML-M6 are defined in the FAB classification as proliferations of dysplastic erythroid elements mixed with blasts of myeloid origin, but pure erythroid leukemias are not included. The recent WHO classification has a category of acute myeloid leukemia not otherwise categorized, which includes acute erythroid leukemia (M6) of two subtypes: M6a-erythroleukemia (erythroid/myeloid) and M6b-pure erythroid leukemia. The aims of this co-operative study were to discover the incidences of these different subtypes, and pay special attention to the morphology of these entities.

DESIGN AND METHODS

We reviewed a series of 62 patients with erythroid neoplastic proliferations. Previous medical history, age, sex, peripheral blood and bone marrow cell counts, cytochemical stains, immunophenotype, and cytogenetics were evaluated at presentation. We analyzed the incidence of erythrocyte, leukocyte and platelet abnormalities in the peripheral blood. In bone marrow we analyzed dysplastic features of erythroblasts, granulocytic elements and the megakaryocytic lineage.

RESULTS

Fifty-three patients met the criteria of M6a subtype of the WHO classification, and 2 were classified as having pure erythremia (M6b); 7 cases could not be classified according to the WHO criteria. Fifty-five patients presented with de novo acute leukemia, and seven patients had secondary acute leukemia. The most frequent dysplastic features in blood smears were: schistocytes, tear-drop and pincered cells in erythrocytes; hypogranulation and hyposegmentation in leukocytes; gigantism and hypogranulation in platelets. In bone marrow, megaloblastic changes, multinuclearity, karyorrhexis and basophilic stippling in erythroblasts; hypogranulation and gigantism in granulocytic series, and micromegakaryocytes and unconnected nuclei in megakarocytes were the most dysplastic features. A positive PAS reaction and increase of bone marrow iron with ring sideroblasts were common features. Trilineage dysplasia was present in 54% of cases. Dysplastic features in granulocytic elements were absent in 26% of patients and minimal erythroblastic dysplasia was observed in seven patients. A complex karyotype was seen in 27% of patients; chromosomes 5 and 7 were the most frequently involved.

INTERPRETATION AND CONCLUSIONS

De novo acute erythroid leukemia was more frequent than secondary cases in our series. The most frequent type of acute erythroid proliferation was the WHO M6a subtype and the least the pure erythroid leukemia. We found a group of seven patients (11%) who could not be classified according to the WHO criteria. Morphologic findings of erythrocytes in peripheral blood, such as schistocytes, tear-drop and pincered cells, were outstanding features. Morphologic aspects remain one of the most important tools for diagnosing these entities.

Immunophenotype changes and loss of CD52 expression in two patients with relapsed T-cell prolymphocytic leukaemia

T-cell prolymphocytic leukaemia (T-PLL) is an aggressive disease often resistant to conventional chemotherapy. Long lasting remissions with the monoclonal antibody CAMPATH-1H (anti-CD52) have been documented. We describe two unusual T-PLL patients treated successfully first with CAMPATH-1H in whom, at the time of relapse, the cells underwent a phenotypic switch with loss of CD52 expression. In one of them, cytogenetic analysis demonstrated the same chromosome abnormalities in the cells at diagnosis and relapse. The reasons for the immunophenotypic changes are unknown but it is likely that loss of CD52 antigen expression contributed to the resistance to CAMPATH-1H in one of the patients when re-treated.

p53 abnormalities in splenic lymphoma with villous lymphocytes

The incidence and role of p53 abnormalities have not been reported in splenic lymphoma with villous lymphocytes (SLVL), the leukemic counterpart of splenic marginal zone lymphoma. Because p53 abnormalities correlate with progressive and refractory disease in cancer and isochromosome 17q has been described in SLVL, a low-grade lymphoma that behaves aggressively in a minority of patients, this study investigated p53 changes by molecular and immunophenotypic methods in samples from 59 patients. The p53 deletion was analyzed by fluorescence in situ hybridization, and p53 protein expression was assessed by immunocytochemistry in 35 of 59 cases and by flow cytometry in 20 of 35 patients. Ten patients (17%) had a monoallelic p53 loss, 3 (9%) of 35 nuclear protein expression by immunocytochemistry, and 2 (10%) of 20 by flow cytometry. Two patients had both deletion and protein expression. Direct sequencing of all p53 exons was used to delineate mutations in 9 of 11 patients with an identified abnormality. Mutations, both compromising p53 DNA binding, were identified in the 2 patients with deletion and protein accumulation. Kaplan-Meier analysis revealed a significantly worse survival for patients with p53 abnormalities. Although p53 abnormalities are infrequent in SLVL, they underlie a more aggressive disease course and poor prognosis. (Blood. 2001;97:3552-3558)

[Organizational models for the hematology areas of the district hospitals of Catalonia]

PURPOSE

The haematological assistance in Catalonia is based upon the district hospitals, in the first step, and the stage III hospitals located usually in higher population nuclei, in the second step. The purpose of this work was to analyse the resources of the "primary haematological assistance" network provided by the district hospitals, to evaluate them and to propose a model for their organisation.

MATERIAL AND METHODS

An enquiry was carried out to all members of the Grup de Treball d'Hospitals Comarcals de Catalunya (Catalonia's District Hospitals Task Force). The evaluable data included demographic figures of the population assisted, personnel of each haematological area, organising structure, clinical activity, cytomorphology, blood banks, laboratories and continuous formation activities.

RESULTS

The enquiry was answered by 15 of the 21 district hospitals (71.4%) with haematologists in Catalonia. The population assisted in those hospitals is 2,100,000 (ranging between 55,000 an 450,000). All centres are integrated in the National Health network. Eleven of the hospitals analysed have only one haematologist (73.3%). If his dedication is 100% of the time, this would represent a doctor for 105,000 people. The time devoted to work is 690 hours a week for all the population, with a mean of 3,043. Four patients assisted per hour. The total number of hospital beds is 3,353 (50-450), with a mean number of 1 haematologist for every 167.6 beds. The number of patients hospitalized due to blood diseases ranges between 3 and 13 per month. Six of the 15 centres are adjunct to the outpatient clinic. Two centres have a blood bank and 7 have developed an autotransfusion programme. All the centres but one perform oral anticoagulant treatment follow-up, the number of patients assisted ranging from 20 to 210 per week. None of the hospitals has a separate Haematology Service; in most of them haematology is structurally and functionally dependent from Laboratories and in some there is a mixed Laboratory/Internal Medicine functional organisation, depending of the Medical Direction. No haematologist is ever on call specifically for his specialty. Continuous formation activities are carried out in 9 of the 15 centres (60%).

COMMENT

Several measures are proposed to improve the haematological assistance, acting on different levels: continuous formation, patient flows and circuits, resident doctors training, anticoagulant treatment network, organisation models, credit cards from the Spanish Association of Haematology.

[Pseudotumorous hyperplasia of the caudate lobe of the liver in a patient with Alagille syndrome]

The Alagille's syndrome consists in hypoplasia of the intrahepatic biliary ducts associated to congenital abnormalities of different organs. It is usually diagnosed in infancy due to cholestasis with good prognosis. The case of a 31-year old women who presented prominent chin, micrognathia, flattening of the nasal bone, infundibular stenosis of the pulmonary artery and cholestasis is reported. Ultrasonography demonstrated a lesion in the space of the hepatic caudate lobe with punction showing sinusoidal dilatation and infiltration of some portal spaces by lymphocytes, eosinophils and neutrophils. Samples of liver tissue obtained during laparotomy showed an absence of intrahepatic biliary ducts in the right and left lobes and preservation of those of the caudate lobe, which was also increased in size with a pseudotumoral appearance. The patients was asymptomatic with slight anicteric cholestasis at 16 months of diagnosis. The rarity of these forms of Alagille's syndrome with areas free of hypoplasia of the intrahepatic biliary ducts are of note.

[Granulocytic sarcoma: a study of 5 cases]

Granulocytic sarcoma (GS) is a solid tumor of extramedullary localization constituted by immature precursors from the granulocytic series. GS may be diagnosed in different malignant blood diseases involving the granulocytic series, acute non lymphoblastic leukemia (ANLL) being the most frequent, followed by myelodysplastic syndromes (MDS) and chronic myeloproliferative syndromes, specially chronic myeloid leukemia (CML) in blastic crisis. Although the diagnosis of GS is suspected with conventional cytologic and anatomopathologic studies, histochemical staining and immunohistochemical techniques are often required for definitive diagnosis. Five cases (4 males, 1 female; age range 22-77 years) diagnosed with GS in one center over a period of nine years (1984-1993) are described. The GS were located in the lymph nodes, the jaw, paravertebral region, gallbladder and retroperitoneum, respectively. Two patients had refractory anemia with excess of blasts (RAEB). Three patients had ANLL; in one GS constituted the form of relapse, in another GS presented at the time of diagnosis and in the remaining patient GS preceded the diagnosis of ANLL. All the patients died from 2 to 8 months after diagnosis of GS with no response to treatment being observed. Immunohistochemical study of the tumor was performed in 4 patients, being positive for lysozyme and the monocytic MAC-387 monoclonal antibody. Immunocytochemical study of the tumor blasts was carried out with positivity for CD15 being observed. Although uncommon, GS should be suspected in patients with ANLL or MDS with tumors of any localization and at any time during its evolution. Immunocytochemical and immunohistochemical studies are of great value to differentiate GS from other tumors, particularly anaplastic non Hodgkin's lymphomas.