Gray zones around diffuse large B cell lymphoma. Conclusions based on the workshop of the XIV meeting of the European Association for Hematopathology and the Society of Hematopathology in Bordeaux, France

The term “gray-zone” lymphoma has been used to denote a group of lymphomas with overlapping histological, biological, and clinical features between various types of lymphomas. It has been used in the context of Hodgkin lymphomas (HL) and non-Hodgkin lymphomas (NHL), including classical HL (CHL), and primary mediastinal large B cell lymphoma, cases with overlapping features between nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte-rich large B cell lymphoma, CHL, and Epstein–Barr-virus-positive lymphoproliferative disorders, and peripheral T cell lymphomas simulating CHL. A second group of gray-zone lymphomas includes B cell NHL with intermediate features between diffuse large B cell lymphoma and classical Burkitt lymphoma. In order to review controversial issues in gray-zone lymphomas, a joint Workshop of the European Association for Hematopathology and the Society for Hematopathology was held in Bordeaux, France, in September 2008. The panel members reviewed and discussed 145 submitted cases and reached consensus diagnoses. This Workshop summary is focused on the most controversial aspects of gray-zone lymphomas and describes the panel’s proposals regarding diagnostic criteria, terminology, and new prognostic and diagnostic parameters

Different mechanisms of cyclin D1 overexpression in multiple myeloma revealed by fluorescence in situ hybridization and quantitative analysis of mRNA levels.

The t(11;14)(q13;q32) is the most com- mon translocation in multiple myeloma (MM), resulting in up-regulation of cyclin D1. We used a segregation fluorescence in situ hybridization (FISH) assay to de- tect t(11;14) breakpoints in primary MM cases and real-time reverse transcriptase– polymerase chain reaction (RT-PCR) to quantify cyclin D1 and MYEOV (myeloma overexpressed) expression, another puta- tive oncogene located on chromosome 11q13. High levels of cyclin D1 mRNA (cyclin D1/TBP [TATA box binding pro- tein] ratio > 95) were found exclusively in the presence of a t(11;14) translocation (11/48 cases; P < .00001). In addition, a subgroup of MM cases (15/48) with inter- mediate to low cyclin D1 mRNA (cyclin D1/TBP ratio between 2.3 and 20) was identified. FISH analysis ruled out a t(11; 14) translocation and 11q13 amplification in these cases; however, in 13 of 15 patients a chromosome 11 polysomy was demonstrated ( P < .0001). These results indicate an effect of gene dosage as an alternative mechanism of cyclin D1 de- regulation in MM. The absence of chromo- some 11 abnormalities in 2 of 15 patients with intermediate cyclin D1 expression supports that there are presumably other mechanism(s) of cyclin D1 deregulation in MM patients. Our data indicate that deregulation of MYEOV is not favored in MM and further strengthens the role of cyclin D1 overexpression in lymphoid ma- lignancies with a t(11;14)(q13;q32) trans- location

Interphase fluorescence in situ hybridization for detection of 8q24/MYC breakpoints on routine histologic sections: Validation in Burkitt lymphomas from three geographic regions: Validation in Burkitt lymphomas from three geographic regions

A chromosomal translocation involving the MYC gene is characteristic of Burkitt lymphoma (BL) and represents a molecular disease marker with diagnostic and clinical implications. The detection of MYC breakpoints is hampered by technical problems, including the distribution of the breakpoints over a very large genomic region of approximately 1,000 kb. In this article, we report on the testing and validation of a segregation fluorescence in situ hybridization (FISH) assay for MYC breakpoints on a large series of BLs. A contig of overlapping genomic clones was generated, and two probe sets flanking the MYC gene were selected. Both probe sets were tested in an interphase FISH segregation assay on 8 B-cell lymphoma cell lines and 32 lymphoma samples with proved 8q24/MYC abnormalities and validated in 47 BLs from The Netherlands, Brazil, and Uganda. MYC translocation breakpoints were identified in 98% of the tumors of the test series and in 89% of the cases of the validation series. In 89% of all positive samples, the breakpoints were located between 190 kb 5' and 50 kb 3' of MYC. Nine cases had more distant breakpoints, and in one patient an insertion of MYC into the IGH region was detected. In two of the three BLs lacking CD10 expression, no breakpoint could be detected, suggesting that CD10 is a discriminative marker of BL. We did not find consistent differences between BL and atypical BL in incidence of an MYC breakpoin

Translocations involving 8q24 in Burkitt lymphoma and other malignant lymphomas: a historical review of cytogenetics in the light of todays knowledge

Burkitt lymphoma (BL) has a characteristic clinical presentation, morphology, immunophenotype and primary chromosomal aberration, that is, the translocation t(8;14)(q24;q32) or its variants. However, diagnostic dilemmas may arise in daily practice due to overlap of BL with subsets of other aggressive, mature B-cell lymphomas such as diffuse large B-cell lymphomas (DLBCL). Recently, two gene expression studies have described a distinct molecular profile for BL, but also showed the persistence of some cases intermediate between BL and DLBCL. An alternative approach to define BL is to consider (cyto)genetic data, in particular chromosomal abnormalities other than the t(8;14) or its variants. In this review the 'Mitelman Database of Chromosome Aberrations in Cancer,' harboring the majority of all published neoplasia-related karyotypes, was explored to define a cytogenetic profile of 'true' BL. This core subset of BL showed a very low complexity of chromosomal abnormalities with 40% of the cases having the IG-MYC fusion as the sole abnormality. In the remaining cases, additional recurrent but partially exclusive abnormalities included gains at chromosomes 1q, 7 and 12, and losses of 6q, 13q32-34 and 17p. Within the core subset, no differences were found between pediatric and adult patients. In addition, the genetic profile of the core subset was significantly different from BL with an 8q24 breakpoint not affecting one of the three immunoglobulin loci, BL with a translocation involving 18q21/BCL2, 3q27/BCL6 or 11q13/BCL1, additionally to a breakpoint at 8q24/MYC, and from other morphological types of lymphomas with an 8q24/MYC breakpoint. These groups showed a higher cytogenetic complexity than the core subset of BL. BL without a detectable 8q24/MYC breakpoint might be heterogeneous and deserves further studies. We suggest that, concordant with the WHO classification to be published in 2008, the diagnosis of BL should be restricted to cases with expression of CD10 and BCL6, absence or very weak expression of BCL2 protein, a homogeneously very high proliferation index and a proven IG-MYC translocation without evidence of a chromosomal translocation typical for other lymphoma entities. In addition, a high number of nonspecific cytogenetic abnormalities should suggest need for a critical review of the diagnosis of BL

Genome-Wide Characterization of Transcriptional Patterns in High and Low Antibody Responders to Rubella Vaccination

<div><p></p><p>Immune responses to current rubella vaccines demonstrate significant inter-individual variability. We performed mRNA-Seq profiling on PBMCs from high and low antibody responders to rubella vaccination to delineate transcriptional differences upon viral stimulation. Generalized linear models were used to assess the per gene fold change (FC) for stimulated versus unstimulated samples or the interaction between outcome and stimulation. Model results were evaluated by both FC and p-value. Pathway analysis and self-contained gene set tests were performed for assessment of gene group effects.</p><p>Of 17,566 detected genes, we identified 1,080 highly significant differentially expressed genes upon viral stimulation (p<1.00E⁻¹⁵, FDR<1.00E⁻¹⁴), including various immune function and inflammation-related genes, genes involved in cell signaling, cell regulation and transcription, and genes with unknown function. Analysis by immune outcome and stimulation status identified 27 genes (p≤0.0006 and FDR≤0.30) that responded differently to viral stimulation in high vs. low antibody responders, including major histocompatibility complex (MHC) class I genes (<i>HLA-A</i>, <i>HLA-B</i> and <i>B2M</i> with p = 0.0001, p = 0.0005 and p = 0.0002, respectively), and two genes related to innate immunity and inflammation (<i>EMR3</i> and <i>MEFV</i> with p = 1.46E⁻⁰⁸ and p = 0.0004, respectively). Pathway and gene set analysis also revealed transcriptional differences in antigen presentation and innate/inflammatory gene sets and pathways between high and low responders. Using mRNA-Seq genome-wide transcriptional profiling, we identified antigen presentation and innate/inflammatory genes that may assist in explaining rubella vaccine-induced immune response variations. Such information may provide new scientific insights into vaccine-induced immunity useful in rational vaccine development and immune response monitoring.</p></div

Significant pathways differentially expressed in rubella vaccine recipients.

a<p>All presented pathways passed the FDR<0.05.</p

Overall response to rubella virus stimulation in PBMC samples of vaccines.

a<p>Gene symbol and gene description are provided for gene identification, information on immune function-related genes is provided in italic font.</p>b<p>Fold change for overall response to stimulation analysis (all stimulated samples vs. all unstimulated samples; Stim/Unstim, S/U).</p>c<p>P-value and false discovery rate (FDR) for the overall analysis.</p>d<p>Fold change for High responders, stimulated vs. unstimulated samples (HS/HU).</p>e<p>Fold change for Low responders, stimulated vs. unstimulated samples (LS/LU).</p