Primary Cutaneous Marginal Zone Lymphoproliferative Disorder of Donor Origin after Allogeneic Hematopoietic Stem Cell Transplantation.

ABSTRACT: Primary cutaneous posttransplant lymphoproliferative disorders (PTLDs) after allogeneic hematopoietic stem cell transplant (allo-HSCT) are exceedingly rare, with only 6 published cases, all of them consisting in T-cell neoplasms. In this report, we present for the first time a donor-derived B-cell PTLD consisting in a primary, cutaneous, B-cell, marginal zone, lymphoproliferative disorder (PCMZLPD). The patient, a 37-year-old woman with a history of Hodgkin lymphoma received an allo-HSCT from her healthy, matched, related father, achieving complete host chimerism in the bone marrow and peripheral blood. However, 8 years after the allo-HSCT, she presented asymptomatic skin lesions consisting in oval, well-defined, slightly raised erythematous plaques, located on the arms, trunk, and legs. Skin biopsies of 2 lesions demonstrated a class-switched IgG+, EBV-, PCMZLPD, showing kappa light chain restriction and monoclonal rearrangement of the IgH gene. Microsatellite genotyping and 2-color fluorescence in situ hybridization (X and Y chromosomes) confirmed that the origin of the neoplastic cells was the donor graft. The lesions showed an indolent behavior, good response to topical corticosteroids, and no need for systemic treatment. Our case broadens the spectrum of PTLD, a diverse group of lymphoid and/or plasmacytic proliferations with variable clinical presentations and histopathological features.

Identification of relapse-associated gene mutations by next-generation sequencing in low-risk acute myeloid leukaemia patients.

Recommended genetic categorization of acute myeloid leukaemias (AML) includes a favourable-risk category, but not all these patients have good prognosis. Here, we used next-generation sequencing to evaluate the mutational profile of 166 low-risk AML patients: 30 core-binding factor (CBF)-AMLs, 33 nucleophosmin (NPM1)-AMLs, 4 biCEBPα-AMLs and 101 acute promyelocytic leukaemias (APLs). Functional categories of mutated genes differed among subgroups. NPM1-AMLs showed frequent variations in DNA-methylation genes (DNMT3A, TET2, IDH1/2) (79%), although without prognostic impact. Within this group, splicing-gene mutations were an independent factor for relapse-free (RFS) and overall survival (OS). In CBF-AML, poor independent factors for RFS and OS were mutations in RAS pathway and cohesin genes, respectively. In APL, the mutational profile differed according to the risk groups. High-risk APLs showed a high mutation rate in cell-signalling genes (P = 0·002), highlighting an increased incidence of FLT3 internal tandem duplication (ITD) (65%, P < 0·0001). Remarkably, in low-risk APLs (n = 28), NRAS mutations were strongly correlated with a shorter five-year RFS (25% vs. 100%, P < 0·0001). Overall, a high number of mutations (≥3) was the worst prognostic factor RFS (HR = 2·6, P = 0·003). These results suggest that gene mutations may identify conventional low-risk AML patients with poor prognosis and might be useful for better risk stratification and treatment decisions.

Richter transformation driven by Epstein-Barr virus reactivation during therapy-related immunosuppression in chronic lymphocytic leukaemia.

The increased risk of Richter transformation (RT) in patients with chronic lymphocytic leukaemia (CLL) due to Epstein-Barr virus (EBV) reactivation during immunosuppressive therapy with fludarabine other targeted agents remains controversial. Among 31 RT cases classified as diffuse large B-cell lymphoma (DLBCL), seven (23%) showed EBV expression. In contrast to EBV- tumours, EBV+ DLBCLs derived predominantly from IGVH-hypermutated CLL, and they also showed CLL-unrelated IGVH sequences more frequently. Intriguingly, despite having different cellular origins, clonally related and unrelated EBV+ DLBCLs shared a previous history of immunosuppressive chemo-immunotherapy, a non-germinal centre DLBCL phenotype, EBV latency programme type II or III, and very short survival. These data suggested that EBV reactivation during therapy-related immunosuppression can transform either CLL cells or non-tumoural B lymphocytes into EBV+ DLBCL. To investigate this hypothesis, xenogeneic transplantation of blood cells from 31 patients with CLL and monoclonal B-cell lymphocytosis (MBL) was performed in Rag2-/- IL2γc-/- mice. Remarkably, the recipients' impaired immunosurveillance favoured the spontaneous outgrowth of EBV+ B-cell clones from 95% of CLL and 64% of MBL patients samples, but not from healthy donors. Eventually, these cells generated monoclonal tumours (mostly CLL-unrelated but also CLL-related), recapitulating the principal features of EBV+ DLBCL in patients. Accordingly, clonally related and unrelated EBV+ DLBCL xenografts showed indistinguishable cellular, virological and molecular features, and synergistically responded to combined inhibition of EBV replication with ganciclovir and B-cell receptor signalling with ibrutinib in vivo. Our study underscores the risk of RT driven by EBV in CLL patients receiving immunosuppressive therapies, and provides the scientific rationale for testing ganciclovir and ibrutinib in EBV+ DLBCL. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Unraveling the heterogeneity of IgM monoclonal gammopathies: a gene mutational and gene expression study.

Immunoglobulin M (IgM) monoclonal gammopathies show considerable variability, involving three different stages of presentation: IgM monoclonal gammopathy of undetermined significance (IgM-MGUS), asymptomatic Waldenström's macroglobulinemia (AWM), and symptomatic WM (SWM). Despite recent findings about the genomic and transcriptomic characteristics of such disorders, we know little about the causes of this clinical heterogeneity or the mechanisms involved in the progression from indolent to symptomatic forms. To clarify these matters, we have performed a gene expression and mutational study in a well-characterized cohort of 69 patients, distinguishing between the three disease presentations in an attempt to establish the relationship with the clinical and biological features of the patients. Results showed that the frequency of genetic alterations progressively increased from IgM-MGUS to AWM and SWM. This means that, in contrast to MYD88 p.L265P and CXCR4 WHIM mutations, present from the beginning of the pathogenesis, most of them would be acquired during the course of the disease. Moreover, the expression study revealed a higher level of expression of genes belonging to the Toll-like receptor (TLR) signaling pathway in symptomatic versus indolent forms, which was also reflected in the disease presentation and prognosis. In conclusion, our findings showed that IgM monoclonal gammopathies present higher mutational burden as the disease progresses, in parallel to the upregulation of relevant pathogenic pathways. This study provides a translational view of the genomic basis of WM pathogenesis.

High-resolution copy number analysis of paired normal-tumor samples from diffuse large B cell lymphoma.

Copy number analysis can be useful for assessing prognosis in diffuse large B cell lymphoma (DLBCL). We analyzed copy number data from tumor samples of 60 patients diagnosed with DLBCL de novo and their matched normal samples. We detected 63 recurrent copy number alterations (CNAs), including 33 gains, 30 losses, and nine recurrent acquired copy number neutral loss of heterozygosity (CNN-LOH). Interestingly, 20 % of cases acquired CNN-LOH of 6p21 locus, which involves the HLA region. In normal cells, there were no CNAs but we observed CNN-LOH involving some key lymphoma regions such as 6p21 and 9p24.1 (5 %) and 17p13.1 (2.5 %) in DLBCL patients. Furthermore, a model with some specific CNA was able to predict the subtype of DLBCL, 1p36.32 and 10q23.31 losses being restricted to germinal center B cell-like (GCB) DLBCL. In contrast, 8p23.3 losses and 11q24.3 gains were strongly associated with the non-GCB subtype. A poor prognosis was associated with biallelic inactivation of TP53 or 18p11.32 losses, while prognosis was better in cases carrying 11q24.3 gains. In summary, CNA abnormalities identify specific DLBCL groups, and we describe CNN-LOH in germline cells from DLBCL patients that are associated with genes that probably play a key role in DLBCL development.

Subjects with chronic lymphocytic leukaemia-like B-cell clones with stereotyped B-cell receptors frequently show MDS-associated phenotypes on myeloid cells.

An increasing body of evidence suggests the potential occurrence of antigen encounter by the cell of origin in chronic lymphocytic leukaemia (CLL) and CLL-like monoclonal B-cell lymphocytosis (MBL). However, the scenario in which this event might occur remains unknown. In order to gain insight into this scenario we investigated the molecular, cytogenetic and haematological features of 223 CLL-like (n = 84) and CLL (n = 139) clones with stereotyped (n = 32) versus non-stereotyped (n = 191) immunoglobulin heavy chain variable region (IGHV) amino acid sequences. Overall, stereotyped CLL-like MBL and CLL clones showed a unique IGHV profile, associated with higher IGHV1 and lower IGHV3 gene family usage (P = 0·03), longer IGHV complementary determining region 3 (HCDR3) sequences (P = 0·007) and unmutated IGHV (P < 0·001) versus non-stereotyped clones. Whilst the overall size of the stereotyped B-cell clones in peripheral blood did not appear to be associated with the CLL-related cytogenetic profile of B-cells (P > 0·05), it did show a significant association with the presence of myelodysplastic syndrome (MDS)-associated immunophenotypes on peripheral blood neutrophils and/or monocytes (P = 0·01). Altogether our results point to the potential involvement of different selection forces in the expansion of stereotyped vs. non-stereotyped CLL and CLL-like MBL clones, the former being potentially favoured by an underlying altered haematopoiesis.

HLA specificities are related to development and prognosis of diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease influenced by genetic and environmental factors. The role of the HLA system in tumor antigen presentation could be involved in susceptibility and disease control. We analyzed the phenotypic frequencies of HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 in 250 DLBCLs, comparing them with 1940 healthy individuals. We also evaluated the influence of HLA polymorphisms on survival in those patients treated with curative intention using cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP)-like regimen without (n = 64, 26%) or with (n = 153, 61%) rituximab. DLBCL patients have a higher phenotypic frequency of HLA-DRB1*01 (29% vs 19.5%, P = .0008, Pc = .0104) and a lower frequency of HLA-C*03 (6.4% vs 17.9%, P < .0005, Pc = .007) compared with healthy individuals. Irrespective of the age-adjusted International Prognostic Index, those patients receiving a CHOP-like plus rituximab regimen and carrying the HLA-B44 supertype had worse 5-year progression-free (54% vs 71%, P = .019) and 5-year overall (71% vs 92%, P = .001) survival compared with patients without this supertype. Our data suggest that some HLA polymorphisms influence the development and outcome of DLBCL, allowing the identification of an extremely good-risk prognostic subgroup. However, these results are preliminary and need to be validated in order to exclude a possible population effect.

Circulating clonotypic B cells in multiple myeloma and monoclonal gammopathy of undetermined significance.

The B-cell compartment in which multiple myeloma stem cells reside remains unclear. We investigated the potential presence of mature, surface-membrane immunoglobulin-positive B lymphocytes clonally related to the tumor bone marrow plasma cells among different subsets of peripheral blood B cells from ten patients (7 with multiple myeloma and 3 with monoclonal gammopathies of undetermined significance). The presence of clonotypic immunoglobulin heavy chain gene rearrangements was determined in multiple highly-purified fractions of peripheral blood B-lymphocytes including surface-membrane IgM(+) CD27(-) naïve B-lymphocytes, plus surface-membrane IgG(+), IgA(+) and IgM(+) memory CD27(+) B cells, and normal circulating plasma cells, in addition to (mono)clonal plasma cells, by a highly-specific and sensitive allele-specific oligonucleotide polymerase chain reaction directed to the CDR3 sequence of the rearranged IGH gene of tumor plasma cells from individual patients. Our results showed systematic absence of clonotypic rearrangements in all the different B-cell subsets analyzed, including M-component isotype-matched memory B-lymphocytes, at frequencies <0.03 cells/µL (range: 0.0003-0.08 cells/µL); the only exception were the myeloma plasma cells detected and purified from the peripheral blood of four of the seven myeloma patients. These results indicate that circulating B cells from patients with multiple myeloma and monoclonal gammopathies of undetermined significance are usually devoid of clonotypic B cells while the presence of immunophenotypically aberrant myeloma plasma cells in peripheral blood of myeloma patients is a relatively frequent finding.

Molecular characterization of immunoglobulin gene rearrangements in diffuse large B-cell lymphoma: antigen-driven origin and IGHV4-34 as a particular subgroup of the non-GCB subtype.

The pathogenesis of diffuse large B-cell lymphoma (DLBCL) remains partially unknown. The analysis of the B-cell receptor of the malignant cells could contribute to a better understanding of the DLBCL biology. We studied the molecular features of the immunoglobulin heavy chain (IGH) rearrangements in 165 patients diagnosed with DLBCL not otherwise specified. Clonal IGH rearrangements were amplified according to the BIOMED-2 protocol and PCR products were sequenced directly. We also analyzed the criteria for stereotyped patterns in all complete IGHV-IGHD-IGHJ (V-D-J) sequences. Complete V-D-J rearrangements were identified in 130 of 165 patients. Most cases (89%) were highly mutated, but 12 sequences were truly unmutated or minimally mutated. Three genes, IGHV4-34, IGHV3-23, and IGHV4-39, accounted for one third of the whole cohort, including an overrepresentation of IGHV4-34 (15.5% overall). Interestingly, all IGHV4-34 rearrangements and all unmutated sequences belonged to the nongerminal center B-cell-like (non-GCB) subtype. Overall, we found three cases following the current criteria for stereotyped heavy chain VH CDR3 sequences, two of them belonging to subsets previously described in CLL. IGHV gene repertoire is remarkably biased, implying an antigen-driven origin in DLBCL. The particular features in the sequence of the immunoglobulins suggest the existence of particular subgroups within the non-GCB subtype.

The use of CD138 positively selected marrow samples increases the applicability of minimal residual disease assessment by PCR in patients with multiple myeloma.

We have evaluated the use of CD138+ positively selected bone marrow samples to identify a molecular target for minimal residual disease assessment by polymerase chain reaction (PCR) in 25 untreated patients with multiple myeloma. A fraction of each sample was used for CD138+ selection, and the rest served as a reference control. VDJH, DJH, and Kde gene rearrangements were tested for amplification according to the BIOMED-2 Concerted Action. PCR products were directly sequenced in an automated ABI 3130 DNA sequencer using Big-Dye terminators. Within the CD138+ selected group, VDJH rearrangements were detected in all cases (100 %), DJH in 16 (64 %), and Kde in 18 (72 %) cases; whereas in the control samples, VDJH, DJH, and Kde rearrangements were detected in 19 (76 %), 11 (44 %), and 12 (48 %) cases, respectively. After sequencing, 24 (96 %) cases within the CD138+ group had a PCR target for MRD detection compared with 15 (60 %) cases in the control group. We conclude that the use of CD138+ positively selected bone marrow samples increases the applicability of minimal residual disease studies by PCR in patients with multiple myeloma.

Pediatric primary follicular mucinosis: further evidence of its relationship with mycosis fungoides.

Follicular mucinosis (FM) is an uncommon reaction pattern in which the accumulation of mucin in the follicular epithelium is the main pathologic finding. FM may be idiopathic (primary follicular mucinosis [PFM]), in association with mycosis fungoides or cutaneous T-cell lymphoma, or in association with other neoplastic and inflammatory conditions. Herein we report a case of PFM with identical T-cell clone rearrangement at anatomically distinct sites, supporting the idea that some authors have proposed, that FM may represent a low-grade lymphoproliferative disease related to mycoses fungoides with favorable prognosis.

Detection and characterization of the novel HLA-DPA1*02:66:02N allele, with a premature stop codon in exon 2.

The failure to identify HLA null alleles in bone marrow transplantation could be life-threatening because this could result in an HLA mismatch with the ability to trigger the graft-vs-host disease (GVHD) and to reduce patient's survival. In this report we describe the identification and characterization of the novel HLA-DPA1*02:66:02N allele with a non-sense codon in exon 2. This new allele was discovered in two unrelated bone marrow donors during routine HLA-typing using next-generation sequencing (NGS). DPA1*02:66:02N is homologous to DPA1*02:01:01:03 with a single nucleotide difference in exon 2, codon 50, where the replacement of C located at genomic position 3825 by T, causes the formation of a premature stop codon (TGA), resulting in a null allele. This description illustrates the benefits of HLA typing by NGS since it permits to reduce ambiguities, identify new alleles, analyze multiple HLA loci and improve transplantation outcome.

Single-Cell DNA Sequencing and Immunophenotypic Profiling to Track Clonal Evolution in an Acute Myeloid Leukemia Patient.

Single-cell DNA sequencing can address the sequence of somatic genetic events during myeloid transformation in relapsed acute myeloid leukemia (AML). We present an NPM1-mutated AML patient with an initial low ratio of FLT3-ITD (low-risk ELN-2017), treated with midostaurin combined with standard chemotherapy as front-line treatment, and with salvage therapy plus gilteritinib following allogenic stem cell transplantation after relapse. Simultaneous single-cell DNA sequencing and cell-surface immunophenotyping was used in diagnostic and relapse samples to understand the clinical scenario of this patient and to reconstruct the clonal composition of both tumors. Four independent clones were present before treatment: DNMT3A/DNMT3A/NPM1 (63.9%), DNMT3A/DNMT3A (13.9%), DNMT3A/DNMT3A/NPM1/FLT3 (13.8%), as well as a wild-type clone (8.3%), but only the minor clone with FLT3-ITD survived and expanded after therapy, being the most represented one (58.6%) at relapse. FLT3-ITD was subclonal and was found only in the myeloid blast population (CD38/CD117/CD123). Our study shows the usefulness of this approach to reveal the clonal architecture of the leukemia and the identification of small subclones at diagnosis and relapse that may explain how the neoplastic cells can escape from the activity of different treatments in a stepwise process that impedes the disease cure despite different stages of complete remission.

Kappa deleting element as an alternative molecular target for minimal residual disease assessment by real-time quantitative PCR in patients with multiple myeloma.

BACKGROUND AND OBJECTIVES: Minimal residual disease (MRD) assessment by PCR in multiple myeloma (MM) has several shortcomings, including the lack of a suitable target. Kappa deleting element (KDE) rearrangements occur in virtually all Ig-lambda B-cell malignancies and in 1/3 of Ig-kappa are not affected by somatic hypermutation and, as in ALL, could be used as PCR targets. METHODS: We have first investigated the incidence, gene segment usage, and CDR3 composition of IGK-KDE rearrangements in 96 untreated myeloma patients. Second, we tested 16 KDE gene rearrangements as molecular targets for MRD assessment by RQ-PCR using a germline reverse primer and a germline Taqman probe in combination with allele-specific oligonucleotides (ASO) as forward primers. RESULTS: Monoclonal KDE rearrangements were amplified in 45% (43/96) of cases, monoallelic in 2/3 of them (29 cases), and biallellic in the remaining 14 cases. Overall, 88% of cases were successfully sequenced, KDE being equally frequently rearranged with VK and with intron-Recombination signal sequence (RSS). Median numbers of inserted and deleted nucleotides in the junctional region were one and five, respectively. CONCLUSIONS: Using KDE rearrangements as additional PCR target for MRD assessment in MM improves the applicability of these studies in 9% of cases overall and in 20% of lambda cases. Its use in the latter subset could represent a significant advance.

Identification and characterization of the novel HLA-B*49:78 allele by next-generation sequencing.

The novel HLA class I allele, HLA-B*49:78, was detected in a Spanish Caucasian individual.

Molecular stratification model for prognosis in cytogenetically normal acute myeloid leukemia.

We have evaluated 9 new molecular markers (ERG, EVI1, MLL-PTD, MN1, PRAME, RHAMM, and WT1 gene-expression levels plus FLT3 and NPM1 mutations) in 121 de novo cytogenetically normal acute myeloblastic leukemias. In the multivariate analysis, high ERG or EVI1 and low PRAME expressions were associated with a shorter relapse-free survival (RFS) and overall survival (OS). A 0 to 3 score was given by assigning a value of 0 to favorable parameters (low ERG, low EVI1, and high PRAME) and 1 to adverse parameters. This model distinguished 4 subsets of patients with different OS (2-year OS of 79%, 65%, 46%, and 27%; P = .001) and RFS (2-year RFS of 92%, 65%, 49%, and 43%; P = .005). Furthermore, this score identified patients with different OS (P = .001) and RFS (P = .013), even within the FLT3/NPM1 intermediate-risk/high-risk subgroups. Here we propose a new molecular score for cytogenetically normal acute myeloblastic leukemias, which could improve patient risk-stratification.

Flow cytometry immunophenotyping of fine-needle aspiration specimens: utility in the diagnosis and classification of non-Hodgkin lymphomas.

AIMS: To establish the utility of flow cytometry (FCM) for screening and diagnosis of B cell non-Hodgkin lymphoma (B-NHL) from lymphoid tissue samples obtained by fine-needle aspiration (FNA). METHODS AND RESULTS: We compared prospectively FCM versus cytology/histology analysis of FNA samples for the diagnostic screening and further World Health Organization (WHO) subclassification of B-NHL. FCM and cytology showed a high degree of agreement (93%); however, diagnosis of reactive processes (RP), B-NHL and T-NHL by FCM showed higher sensitivity than cytology (92-100% versus 64-94%, respectively), without false positive NHL cases. The antibody combination used did not allow a positive diagnosis of Hodgkin lymphoma as distinct from a RP. A high concordance rate was found between FCM and histopathology (74%) in subtyping B-NHL. In this regard, mantle-cell lymphoma and chronic lymphocytic leukaemia/small lymphocytic lymphoma showed the highest degree of agreement (100% concordant rates). In turn, FCM showed higher sensitivity/specificity in classifying follicular lymphoma (FL) and large B cell lymphomas, while the opposite occurred for marginal-zone and lymphoplasmacytic lymphomas. CONCLUSIONS: FCM enhances the diagnostic ability of FNA cytology, playing a crucial role in a rapid and accurate differential diagnosis between RP, B-NHL and T-NHL. In addition, immunophenotyping of FNA samples contributes to a more precise subclassification of B-NHL when combined with histopathology and genetic/molecular data.

Anti-TRBC1 Antibody-Based Flow Cytometric Detection of T-Cell Clonality: Standardization of Sample Preparation and Diagnostic Implementation.

A single antibody (anti-TRBC1; JOVI-1 antibody clone) against one of the two mutually exclusive T-cell receptor ß-chain constant domains was identified as a potentially useful flow-cytometry (FCM) marker to assess Tαß-cell clonality. We optimized the TRBC1-FCM approach for detecting clonal Tαß-cells and validated the method in 211 normal, reactive and pathological samples. TRBC1 labeling significantly improved in the presence of CD3. Purified TRBC1+ and TRBC1- monoclonal and polyclonal Tαß-cells rearranged TRBJ1 in 44/47 (94%) and TRBJ1+TRBJ2 in 48 of 48 (100%) populations, respectively, which confirmed the high specificity of this assay. Additionally, TRBC1+/TRBC1- ratios within different Tαß-cell subsets are provided as reference for polyclonal cells, among which a bimodal pattern of TRBC1-expression profile was found for all TCRVß families, whereas highly-variable TRBC1+/TRBC1- ratios were observed in more mature vs. naïve Tαß-cell subsets (vs. total T-cells). In 112/117 (96%) samples containing clonal Tαß-cells in which the approach was validated, monotypic expression of TRBC1 was confirmed. Dilutional experiments showed a level of detection for detecting clonal Tαß-cells of ≤10-4 in seven out of eight pathological samples. These results support implementation of the optimized TRBC1-FCM approach as a fast, specific and accurate method for assessing T-cell clonality in diagnostic-FCM panels, and for minimal (residual) disease detection in mature Tαß+ leukemia/lymphoma patients.

Expanded cells in monoclonal TCR-alphabeta+/CD4+/NKa+/CD8-/+dim T-LGL lymphocytosis recognize hCMV antigens.

Recent studies suggest the potential involvement of common antigenic stimuli on the ontogeny of monoclonal T-cell receptor (TCR)-alphabeta(+)/CD4(+)/NKa(+)/CD8(-/+dim) T-large granular lymphocyte (LGL) lymphocytosis. Because healthy persons show (oligo)clonal expansions of human cytomegalovirus (hCMV)-specific TCRVbeta(+)/CD4(+)/cytotoxic/memory T cells, we investigate the potential involvement of hCMV in the origin and/or expansion of monoclonal CD4(+) T-LGL. Peripheral blood samples from patients with monoclonal TCR-alphabeta(+)/CD4(+) T-LGL lymphocytosis and other T-chronic lymphoproliferative disorders were evaluated for the specific functional response against hCMV and hEBV whole lysates as well as the "MQLIPDDYSNTHSTRYVTVK" hCMV peptide, which is specifically loaded in HLA-DRB1*0701 molecules. A detailed characterization of those genes that underwent changes in T-LGL cells responding to hCMV was performed by microarray gene expression profile analysis. Patients with TCR-alphabeta(+)/CD4(+) T-LGL displayed a strong and characteristic hCMV-specific functional response, reproduced by the hCMV peptide in a subset of HLA-DRB1*0701(+) patients bearing TCRVbeta13.1(+) clonal T cells. Gene expression profile showed that the hCMV-induced response affects genes involved in inflammatory and immune responses, cell cycle progression, resistance to apoptosis, and genetic instability. This is the first study providing evidence for the involvement of hCMV in the ontogeny of CD4(+) T-LGL, emerging as a model disorder to determine the potential implications of quite a focused CD4(+)/cytotoxic immune response.

Bisphosphonate-related osteonecrosis of the jaw is associated with polymorphisms of the cytochrome P450 CYP2C8 in multiple myeloma: a genome-wide single nucleotide polymorphism analysis.

We have explored the potential role of genetics in the development of osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients under bisphosphonate therapy. A genome-wide association study was performed using 500 568 single nucleotide polymorphisms (SNPs) in 2 series of homogeneously treated MM patients, one with ONJ (22 MM cases) and another without ONJ (65 matched MM controls). Four SNPs (rs1934951, rs1934980, rs1341162, and rs17110453) mapped within the cytochrome P450-2C gene (CYP2C8) showed a different distribution between cases and controls with statistically significant differences (P = 1.07 x 10(-6), P = 4.231 x 10(-6), P = 6.22 x 10(-6), and P = 2.15 x 10(-6), respectively). SNP rs1934951 was significantly associated with a higher risk of ONJ development even after Bonferroni correction (P corrected value = .02). Genotyping results displayed an overrepresentation of the T allele in cases compared with controls (48% vs 12%). Thus, individuals homozygous for the T allele had an increased likelihood of developing ONJ (odds ratio 12.75, 95% confidence interval 3.7-43.5).