RESUMEN
IGHV1-69/51p1 is expressed by â¼ 30% of unmutated chronic lymphocytic leukemia (U-CLL) and combines with selected IGHD and IGHJ genes generating stereotypes if HCDR3 amino acid homology is > 60%. We had previously revealed stereotypic IGHV1-69/IGHJ6 rearrangements in normal naive B cells, thereby identifying potential counterparts of U-CLL. A different stereotypic IGHV1-69/IGHD3-16(RF2)/IGHJ3 rearrangement carrying the CAR(GGx)YD motif in the N1-region, recurrent in 6% IGHV1-69+ve CLL, is exceptionally sequence restricted, strongly suggestive of shared antigen recognition. We have now analyzed IGHV1-69/IGHJ3 rearrangements in circulating B cells of healthy individuals using several PCR-based approaches with IGHV1-69/IGHJ3 CLL sequences for reference. Stereotypes were found, but all were distinct from CLL. Remarkably, even a highly sensitive semi-nested PCR, specific for the CLL-expressed IGHV1-69/IGHD3-16(RF2)/IGHJ3 stereotype, failed to identify the CAR(GGx)YD sequence, although similar motifs were found. These highly specific B cells are not apparent in the accessible normal repertoire and may expand in response to rarely expressed antigens important in the pathogenesis of CLL.
Asunto(s)
Linfocitos B/metabolismo , Reordenamiento Génico de Cadena Pesada de Linfocito B/genética , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/genética , Recombinación V(D)J/genética , Secuencia de Aminoácidos , Humanos , Alineación de SecuenciaRESUMEN
Hairy cell leukemia (HCL) is a distinct clinicopathologic entity that responds well to purine analogs but is sometimes difficult to differentiate from HCL-like disorders (e.g., splenic marginal zone lymphoma and HCL variant). We recently identified the BRAF-V600E mutation as the disease-defining genetic event in HCL. In this study, we describe a new, simple, and inexpensive test for genetics-based diagnosis of HCL in whole-blood samples that detects BRAF-V600E through a sensitive allele-specific PCR qualitative assay followed by agarose-gel electrophoresis. This approach detected BRAF-V600E in all 123 leukemic HCL samples investigated containing as few as 0.1% leukemic cells. BRAF-V600E was detected at different time points during the disease course, even after therapy, pointing to its pivotal role in HCL pathogenesis and maintenance of the leukemic clone. Conversely, 115 non-HCL chronic B-cell neoplasms, including 79 HCL-like disorders, were invariably negative for BRAF-V600E. This molecular assay is a powerful tool for improving the diagnostic accuracy in HCL.
Asunto(s)
Análisis Mutacional de ADN , Leucemia de Células B/diagnóstico , Leucemia de Células Pilosas/diagnóstico , Linfoma de Células B/diagnóstico , Mutación Puntual/genética , Proteínas Proto-Oncogénicas B-raf/genética , Estudios de Casos y Controles , ADN de Neoplasias/sangre , ADN de Neoplasias/genética , Citometría de Flujo , Humanos , Leucemia de Células B/sangre , Leucemia de Células B/genética , Leucemia de Células Pilosas/sangre , Leucemia de Células Pilosas/genética , Linfoma de Células B/sangre , Linfoma de Células B/genética , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas B-raf/sangreAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Alemtuzumab , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales Humanizados , Anticuerpos Antineoplásicos/administración & dosificación , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Proyectos Piloto , Resultado del Tratamiento , Proteína p53 Supresora de Tumor/fisiología , Vidarabina/administración & dosificación , Vidarabina/análogos & derivadosRESUMEN
The B cell receptor (BCR) is the functional distinguishing unit that defines any B cell. Immunoglobulin gene (IG) status is preserved in the neoplastic B cell clone and can provide an indicator of the maturation stage reached by the B cell prior to transformation. In hairy cell leukemia (HCL), several data from IG analysis provide clear hints regarding the cell of origin and the ongoing selective interactions of the tumor BCR with environmental stimuli: HCLs (i) have variable levels of IG somatic mutations, (ii) continue somatic mutations at low levels, (iii) have active processes of IG class switching after transformation, and (iv) have a relatively high frequency of selective events in the light chain of the BCR. It has recently emerged that an unmutated status of the HCL-derived IG can be associated with failure to respond to cladribine, genetic abnormalities indicative of poor outcome, and aggressive disease. These observations suggest that IG gene analysis may have biological and prognostic relevance in HCL and merits further characterization.
Asunto(s)
Genes de Inmunoglobulinas , Leucemia de Células Pilosas/inmunología , Receptores de Antígenos de Linfocitos B/genética , Cladribina/uso terapéutico , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Leucemia de Células Pilosas/diagnóstico , Leucemia de Células Pilosas/genética , PronósticoRESUMEN
The B cell receptor (BCR) is the functional distinguishing unit that defines any B cell. Immunoglobulin gene (IG) status is preserved in the neoplastic B cell clone and can provide an indicator of the maturation stage reached by the B cell prior to transformation. In hairy cell leukemia (HCL), several pieces of data from IG analysis provide clear hints regarding the cell of origin and the ongoing selective interactions of the tumor BCR with environmental stimuli. HCLs have variable levels of IG somatic mutations, and continue somatic mutations at low levels as well as IG class switching after transformation. More recent data also show the occurrence of selective events in the light chain of the BCR, suggesting a dominant role for IG status in the pathogenesis of HCL. Moreover, it has recently emerged that an unmutated status of the HCL IG can be associated with failure to respond to cladribine, genetic abnormalities indicative of poor outcome, and aggressive disease. These observations suggest that IG analysis may have biological and prognostic relevance in HCL and merits further characterization.
Asunto(s)
Antineoplásicos/uso terapéutico , Resistencia a Antineoplásicos/genética , Genes de Inmunoglobulinas/genética , Leucemia de Células Pilosas/tratamiento farmacológico , Leucemia de Células Pilosas/genética , Humanos , Leucemia de Células Pilosas/diagnóstico , PronósticoRESUMEN
Analyses of the tumour immunoglobulin (Ig) gene (IG) heavy (H) and light chains show heterogeneity of mutational status, but reveal common features of ongoing IGH isotype-switching with multiple IGH isotype expression and preference of IG lambda (IGL) light chain with selective use of IGLJ3. Phenotypic and immunogenetic analyses were performed in a series of 105 HCL patients to estimate prevalence of multiple IG light chain expression by the tumour cells. By phenotype, 3/105 HCL (2.9%) expressed double tumour-related Ig kappa (K) and L light chain proteins. By immunogenetic analysis, functional mutated double IGK(I) /IGK(II) , IGK(I) /IGL(I) and IGL(I) /IGL(II) transcripts were cloned and sequenced in 3/71 (4.2%) HCL. These latter three HCL expressed multiple IGH isotypes with mutated IGHVDJ rearrangements at the time of AID transcript expression. Most interestingly, the three cases had reinduced RAG1 transcript. In the double IGL expresser, single-cell analysis documented co-expression of the tumour-related IGLs in 5/6 cells (83%). In the IGK/IGL co-expresser, evidence of surface IgK/IgL isotype proteins confirmed functionality of the tumour-derived transcripts. The evidence of double light chain expression in single HCs and the new observation of RAG re-induction suggest ongoing selective influences on the BCR that may promote or maintain the HCL clone in the periphery.
Asunto(s)
Reordenamiento Génico de Cadena Ligera de Linfocito B , Leucemia de Células Pilosas/genética , Receptores de Antígenos de Linfocitos B/genética , Alelos , Proteínas de Homeodominio/genética , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Leucemia de Células Pilosas/inmunologíaRESUMEN
Richter syndrome (RS) represents the transformation of chronic lymphocytic leukaemia (CLL) to aggressive lymphoma. Risk factors of CLL transformation to RS are only partly known. We explored the role of the host genetic background as a risk factor for RS occurrence. Forty-five single nucleotide polimorphisms (SNPs) known to be relevant for CLL prognosis were genotyped in a consecutive cohort of 331 CLL, of which 21 had transformed to RS. After correcting for multiple testing and adjusting for previously reported RS risk factors, the LRP4 rs2306029 TT variant genotype was the sole SNP independently associated with a higher risk of RS transformation (Hazard Ratio: 4·17; P = 0·001; q = 0·047). The enrichment of LRP4 TT genotype in RS was confirmed in an independent series (n = 44) used for validation purposes. The LRP4 protein was expressed in CLL (n =66). Bioinformatic analysis scored LRP4 rs2306029 as a variant with possible deleterious and damaging variant of LRP4. LRP4 genotyping may help the recognition of patients with increased risk of RS at the time of CLL diagnosis.
Asunto(s)
Proteínas Relacionadas con Receptor de LDL/genética , Leucemia Linfocítica Crónica de Células B/genética , Linfoma/genética , Anciano , Secuencia de Aminoácidos , Animales , Progresión de la Enfermedad , Métodos Epidemiológicos , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Proteínas Relacionadas con Receptor de LDL/metabolismo , Leucemia Linfocítica Crónica de Células B/metabolismo , Linfoma/metabolismo , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Polimorfismo de Nucleótido Simple , Pronóstico , Alineación de Secuencia , SíndromeRESUMEN
Antigen stimulation may be important for splenic marginal zone lymphoma pathogenesis. To address this hypothesis, the occurrence of stereotyped B-cell receptors was investigated in 133 SMZL (26 HCV+) compared with 4,414 HCDR3 sequences from public databases. Sixteen SMZL (12%) showed stereotyped BCR; 7 of 86 (8%) SMZL sequences retrieved from public databases also belonged to stereotyped HCDR3 subsets. Three categories of subsets were identified: i) "SMZL-specific subsets" (n=5), composed only of 12 SMZL (9 HCV-from our series); ii) "Non-Hodgkin's lymphoma-like subsets" (n=5), comprising 5 SMZL (4 from our series) clustering with other indolent lymphomas; iii) "CLL-like subsets" (n=6), comprising 6 SMZL (3 from our series) that belonged to known CLL subsets (n=4) or clustered with public CLL sequences. Immunoglobulin 3D modeling of 3 subsets revealed similarities in antigen binding regions not limited to HCDR3. Overall, data suggest that the pathogenesis of splenic marginal zone lymphoma may involve also HCV-unrelated epitopes or an antigenic trigger common to other indolent lymphomas.
Asunto(s)
Linfoma de Células B de la Zona Marginal/etiología , Receptores de Antígenos de Linfocitos B/inmunología , Neoplasias del Bazo/etiología , Adulto , Anciano , Anciano de 80 o más Años , Antígenos , Epítopos , Reordenamiento Génico , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Linfoma de Células B de la Zona Marginal/inmunología , Neoplasias del Bazo/inmunologíaRESUMEN
The clinical relevance of angiopoietin-2 (Ang2) in chronic lymphocytic leukemia (CLL) was previously suggested by the association between high Ang2, and shorter progression-free survival reported in small series of patients. Here, we evaluated Ang2 glycoprotein levels in plasma samples collected from a multicentric cohort of CLL patients (n = 316) using an enzyme-linked immunosorbent assay method, and we investigated its prognostic role in relation to time to first treatment (TTFT) and overall survival. Based on a cutoff equal to 2459 pg/mL, we divided our cohort in 2 subsets (high and low Ang2) composing 100 (31.6%) and 216 (68.4%) patients, respectively. High Ang2 was predictive of reduced TTFT (P < .001) and overall survival (P = .002). Multivariate analysis confirmed that high Ang2 was an independent prognosticator for TTFT (hazard ratio = 1.739; 95% confidence interval, 1.059-2.857; P = .029). Significant associations were found between high Ang2 and advanced Binet stages (P < .001), high beta(2)-microglobulin (P < .001), unmutated variable region of immunoglobulin heavy chain gene status (P < .001), high CD38 and zeta-chain-associated protein kinase 70 expression (P < .001 and P = .003), and intermediate/high cytogenetic risk (P = .005). Moreover, Ang2 added prognostic power to other conventional prognosticators and helped to refine prognosis among CLL subsets with both high and low vascular endothelial growth factor plasma levels. Ang2 plasma level may be a useful independent prognosticator for CLL.
Asunto(s)
Angiopoyetina 2/sangre , Leucemia Linfocítica Crónica de Células B/diagnóstico , Leucemia Linfocítica Crónica de Células B/mortalidad , Leucemia Linfocítica Crónica de Células B/terapia , Adulto , Anciano , Anciano de 80 o más Años , Angiopoyetina 2/análisis , Biomarcadores de Tumor/sangre , Análisis Químico de la Sangre , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/sangre , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Pronóstico , Análisis de Supervivencia , Factores de TiempoAsunto(s)
Leucemia Linfocítica Crónica de Células B/diagnóstico , Leucemia Linfocítica Crónica de Células B/genética , Polimorfismo de Nucleótido Simple , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Supervivencia sin Enfermedad , Estudios de Seguimiento , Frecuencia de los Genes , Genotipo , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Proteínas con Dominio LIM , Leucemia Linfocítica Crónica de Células B/mortalidad , Pronóstico , Tasa de Supervivencia , Factores de Transcripción/genética , Resultado del Tratamiento , Proteínas Supresoras de Tumor/genética , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
Intrinsic apoptosis defects underlie to a large extent the extended survival of malignant B cells in chronic lymphocytic leukemia (CLL). Here, we show that the Shc family adapter p66Shc uncouples the B-cell receptor (BCR) from the Erk- and Akt-dependent survival pathways, thereby enhancing B-cell apoptosis. p66Shc expression was found to be profoundly impaired in CLL B cells compared with normal peripheral B cells. Moreover, significant differences in p66Shc expression were observed in patients with favorable or unfavorable prognosis, based on the mutational status of IGHV genes, with the lowest expression in the unfavorable prognosis group. Analysis of the expression of genes implicated in apoptosis defects of CLL showed an alteration in the balance of proapoptotic and antiapoptotic members of the Bcl-2 family in patients with CLL. Reconstitution experiments in CLL B cells, together with data obtained on B cells from p66Shc(-/-) mice, showed that p66Shc expression correlates with a bias in the Bcl-2 family toward proapoptotic members. The data identify p66Shc as a novel regulator of B-cell apoptosis which attenuates BCR-dependent survival signals and modulates Bcl-2 family expression. They moreover provide evidence that the p66Shc expression defect in CLL B cells may be causal to the imbalance toward the antiapoptotic Bcl-2 family members in these cells.
Asunto(s)
Apoptosis , Linfocitos B/metabolismo , Leucemia Linfocítica Crónica de Células B/metabolismo , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Animales , Western Blotting , Estudios de Casos y Controles , Supervivencia Celular , Metilación de ADN , Quinasas MAP Reguladas por Señal Extracelular/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Ratones , Ratones Noqueados , Regiones Promotoras Genéticas/genética , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-bcr/genética , Proteínas Proto-Oncogénicas c-bcr/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
PURPOSE: B-cell chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease whose outcome can be foreseen by investigating the mutational status of immunoglobulin heavy chain variable (IGHV) genes. Moreover, a different prognosis was reported for CLL expressing specific IGHV genes in the context or not of stereotyped B-cell receptors. Here we investigated novel associations between usage of specific IGHV genes and clinical features in CLL. EXPERIMENTAL DESIGN: Among 1,426 CLL-specific IG-rearrangements, stereotyped B-cell receptor clusters never utilized the IGHV3-23 gene. Given this notion, this study was aimed at characterizing the IGHV3-23 gene in CLL, and identifying the properties of IGHV3-23-expressing CLL. RESULTS: IGHV3-23 was the second most frequently used (134 of 1,426) and usually mutated (M; 109 of 134) IGHV gene in our CLL series. In the vast majority of M IGHV3-23 sequences, the configuration of the 13 amino acids involved in superantigen recognition was consistent with superantigen binding. Clinically, M IGHV3-23 CLL had shorter time-to-treatment than other M non-IGHV3-23 CLL, and multivariate analyses selected IGHV3-23 gene usage, Rai staging, and chromosomal abnormalities as independent prognosticators for M CLL. Compared with M non-IGHV3-23 CLL, the gene expression profile of M IGHV3-23 CLL was deprived in genes, including the growth/tumor suppressor genes PDCD4, TIA1, and RASSF5, whose downregulation is under control of miR-15a and miR-16-1. Accordingly, relatively higher levels of miR-15a and miR-16-1 were found in M IGHV3-23 compared with M non-IGHV3-23 CLL. CONCLUSIONS: Altogether, expression of the IGHV3-23 gene characterizes a CLL subset with distinct clinical and biological features.
Asunto(s)
Genes de las Cadenas Pesadas de las Inmunoglobulinas/genética , Leucemia Linfocítica Crónica de Células B/clasificación , Leucemia Linfocítica Crónica de Células B/genética , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Diagnóstico Diferencial , Perfilación de la Expresión Génica , Regulación Leucémica de la Expresión Génica , Reordenamiento Génico/fisiología , Humanos , Leucemia Linfocítica Crónica de Células B/diagnóstico , Leucemia Linfocítica Crónica de Células B/patología , MicroARNs/genética , Persona de Mediana Edad , Proteínas Mutantes/genética , Estadificación de Neoplasias , PronósticoRESUMEN
Richter's syndrome (RS) represents the transformation of chronic lymphocytic leukaemia (CLL) to aggressive lymphoma and is mostly represented by diffuse large B-cell lymphoma (DLBCL), with a post-germinal centre (GC) phenotype, clonally related to the pre-existing CLL. RS has a very poor prognosis and its pathogenetic mechanisms are poorly understood. In order to gain additional hints in RS pathogenesis, we performed a genome-wide DNA profiling study of 13 RS phases and eight matched CLL phases using the Affymetrix Human Mapping 250K NspI SNP arrays. Individual genomic profiles were heterogeneous, with no individual lesions occurring in more than half of the cases. However, several observations suggest that MYC pathway might be involved in RS. The 13q13.3-qter region containing MIRHG1 (MIR-17-92), a cluster of microRNA interacting with c-MYC, was acquired at the time of transformation. The 13q gain was coupled with the gain of c-MYC and loss of TP53. Translocation of c-MYC was acquired at transformation in a fraction of cases and this event appeared mutually exclusive with gain of MIRHG1. MYCN, a c-MYC homologue, was also recurrently gained. By comparing RS with 48 de novo DLBCL, RS presented a significantly lower prevalence of deletions affecting the PRDM1 and TNFAIP3, genes on 6q, known to be associated with a post-GC phenotype. In conclusion, the genomic profile of RS seems to differ from what observed in de novo DLBCL and in other transformed DLBCL. Genomic lesions occurring in RS are heterogeneous suggesting the existence of different RS subsets, possibly due to different transforming mechanisms. A deregulation of MYC pathway might represent one of the main transformation events in the pathogenesis of a subset of RS clonally related to the previous CLL.
Asunto(s)
Perfilación de la Expresión Génica , Linfoma de Células B Grandes Difuso/genética , Aberraciones Cromosómicas , Cromosomas Humanos Par 6/genética , Proteínas de Unión al ADN , Progresión de la Enfermedad , Reordenamiento Génico de Linfocito B , Genes myc , Genes p53 , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Linfoma de Células B Grandes Difuso/etiología , MicroARNs/genética , Proteínas Nucleares/genética , Fenotipo , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Recurrencia , Proteínas Represoras/genética , Eliminación de Secuencia , Síndrome , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfaRESUMEN
The cell of origin of chronic lymphocytic leukemia (CLL) has long been sought, and immunoglobulin gene analysis provides new clues. In the unmutated subset (U-CLL), there is increased usage of the 51p1-related alleles of the immunoglobulin heavy chain variable 1-69 gene, often combined with selected genes and with immunoglobulin heavy chain diversity IGHJ6. Stereotypic characteristics of the HCDR3 result and suggest antigen selection of the leukemic clones. We have now analyzed 51p1/IGHJ6 combinations in normal blood B cells from 3 healthy persons for parallel sequence patterns. A high proportion (33.3% of sequences) revealed stereotypic patterns, with several (15.0%) being similar to those described in U-CLL. Previously unreported CLL-associated stereotypes were detected in 4.8%. Stereotypes (13.6%) not detected in CLL also were found. The HCDR2-IGHJ6 sequences were essentially unmutated. Junctional amino acids in normal B cells were heterogeneous, as in cases of stereotyped CLL. Phenotypically, normal B cells expressing 51p1-derived immunoglobulin M were naive. This snapshot of the naive B-cell repertoire reveals subsets of B cells closely related to those characteristic of CLL. Conserved patterns in the 51p1-encoded immunoglobulin M of normal B cells suggest a restricted sequence repertoire shaped by evolution to recognize common pathogens. Proliferative pressure on these cells is the likely route to U-CLL.
Asunto(s)
Linfocitos B/inmunología , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/inmunología , Mutación/genética , Anciano , Alelos , Secuencia de Aminoácidos , Secuencia de Bases , Donantes de Sangre , Regiones Determinantes de Complementariedad/química , Regiones Determinantes de Complementariedad/genética , Regiones Determinantes de Complementariedad/inmunología , Femenino , Reordenamiento Génico de Cadena Pesada de Linfocito B/inmunología , Humanos , Cadenas Pesadas de Inmunoglobulina/química , Cadenas Pesadas de Inmunoglobulina/inmunología , Región Variable de Inmunoglobulina/química , Región Variable de Inmunoglobulina/inmunología , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , FenotipoRESUMEN
Hairy cell leukemia (HCL) is generally responsive to single-agent cladribine, and only a minority of patients are refractory and with poor prognosis. HCLs generally express mutated (M) and, in a minority, unmutated (UM) IGHV. In a multicenter clinical trial in newly diagnosed HCL, we prospectively investigated clinical and molecular parameters predicting response and event-free survival after single-agent cladribine. Of 58 HCLs, 6 expressed UM-IGHV (UM-HCL) and 52 M-IGHV (M-HCL). Beneficial responses were obtained in 53 of 58 patients (91%), whereas treatment failures were observed in 5 of 58 patients (9%). Failures were associated significantly with UM-IGHV (5 of 5 failures vs 1 of 53 beneficial responses had UM-IGHV, P < .001), leukocytosis (3 of 5 vs 3 of 53, P = .006), and bulky spleen (4 of 5 vs 4 of 53, P < .001). The UM-HCL not benefiting from cladribine characteristically had bulky spleen (4 of 5, 80%), leukocytosis (3 of 5, 60%), and TP53 defects (2 of 5, 40%), and progressed rapidly after first treatment (median event-free survival, 7.5 months). Our data suggest that UM-HCLs identify the minor subgroup failing cladribine treatment and with more aggressive disease. High incidence of TP53 dysfunction indicates a potential mechanism of resistance to cladribine in the UM-HCL group. Overall, our data provide new molecular elements relevant for treatment concerns in HCL.
Asunto(s)
Antineoplásicos/uso terapéutico , Cladribina/uso terapéutico , Resistencia a Antineoplásicos/genética , Cadenas Pesadas de Inmunoglobulina/genética , Leucemia de Células Pilosas/tratamiento farmacológico , Leucemia de Células Pilosas/genética , Adulto , Anciano , Anciano de 80 o más Años , Análisis Mutacional de ADN , Supervivencia sin Enfermedad , Femenino , Humanos , Región Variable de Inmunoglobulina , Masculino , Persona de Mediana Edad , Mutación , Pronóstico , Resultado del Tratamiento , Proteína p53 Supresora de Tumor/genéticaRESUMEN
Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic monoclonal expansion of <5.0 x 10(9)/l circulating CLL-phenotype B-cells. The relationship between MBL and Rai 0 CLL, as well as the impact of biological risk factors on MBL prognosis, are unknown. Out of 460 B-cell expansions with CLL-phenotype, 123 clinical MBL (cMBL) were compared to 154 Rai 0 CLL according to clinical and biological profile and outcome. cMBL had better humoral immune capacity and lower infection risk, lower prevalence of del11q22-q23/del17p13 and TP53 mutations, slower lymphocyte doubling time, and longer treatment-free survival. Also, cMBL diagnosis was a protective factor for treatment risk. Despite these favourable features, all cMBL were projected to progress, and lymphocytes <1.2 x 10(9)/l and >3.7 x 10(9)/l were the best thresholds predicting the lowest and highest risk of progression to CLL. Although IGHV status, CD38 and CD49d expression, and fluorescence in situ hybridization (FISH) karyotype individually predicted treatment-free survival, multivariate analysis identified the presence of +12 or del17p13 as the sole independent predictor of treatment requirement in cMBL (Hazard ratio: 5.39, 95% confidence interval 1.98-14.44, P = 0.001). Overall, these data showed that cMBL has a more favourable clinical course than Rai 0 CLL. Given that the biological profile can predict treatment requirement, stratification based on biological prognosticators may be helpful for cMBL management.
Asunto(s)
Linfocitos B , Leucemia Linfocítica Crónica de Células B , Linfocitosis , Anciano , Biomarcadores de Tumor/análisis , Regiones Determinantes de Complementariedad/genética , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Citometría de Flujo/métodos , Estudios de Seguimiento , Eliminación de Gen , Reordenamiento Génico , Genes p53 , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Hibridación Fluorescente in Situ/métodos , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/inmunología , Leucemia Linfocítica Crónica de Células B/mortalidad , Linfocitosis/genética , Linfocitosis/inmunología , Linfocitosis/mortalidad , Masculino , Persona de Mediana Edad , Familia de Multigenes , Mutación , Pronóstico , Modelos de Riesgos Proporcionales , Tasa de SupervivenciaRESUMEN
PURPOSE: Del17p13 predicts poor outcome and chemorefractoriness in chronic lymphocytic leukemia (CLL). Conversely, it is unknown whether TP53 mutations carry any prognostic value independent of del17p13. We tested the independent prognostic value of TP53 mutations in CLL. EXPERIMENTAL DESIGN: The study was based on a consecutive series of 308 CLL. DNA sequencing of TP53 exons 2 to 10 and del17p13 interphase fluorescence in situ hybridization were done at CLL diagnosis. Study end points were survival and chemorefractoriness. RESULTS: At diagnosis, TP53 mutations (n = 32) occurred in 31 of 308 (10.0%) patients. Of all CLL showing TP53 disruption by either mutation and/or deletion (n = 44), 10 cases (22.7%) showed TP53 mutations in the absence of del17p13. Multivariate analysis selected TP53 mutations (hazard ratio, 3.20; P = 0.002) as an independent predictor of overall survival after adjustment for del17p13. Also, multivariate analysis selected TP53 mutations (hazard ratio, 3.97; P < 0.001) as an independent predictor of chemorefractoriness after adjustment for del17p13. Compared with cases without TP53 alterations, CLL harboring any type of TP53 disruption (mutation only, del17p13 only, or both mutation and del17p13) uniformly displayed a high prevalence of unfavorable prognosticators and poor outcome. Analysis of sequential CLL samples showed the acquisition of new or additional TP53 alterations at the time of chemorefractoriness. CONCLUSIONS: These data show that (a) TP53 mutations are an independent predictor of short survival and chemorefractoriness, and (b) that CLL presenting with TP53 mutations without del17p13 fare as poorly as CLL carrying del17p13. Because CLL harboring TP53 mutations without del17p13 are currently not recognized by conventional diagnostic strategies, these results may be relevant for a comprehensive prognostic characterization of CLL.
Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 17 , Genes p53 , Leucemia Linfocítica Crónica de Células B/genética , Anciano , Resistencia a Antineoplásicos/genética , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/mortalidad , Masculino , Persona de Mediana Edad , Mutación , PronósticoRESUMEN
A fraction of chronic lymphocytic leukaemia (CLL) cases carry highly homologous B-cell receptors (BCR), i.e. characterized by non-random combinations of immunoglobulin heavy-chain variable (IGHV) genes and heavy-chain complementarity determining region-3 (HCDR3), often associated with a restricted selection of IGVK/L light chains. Such 'stereotyped' BCR occur more frequently in CLL with unmutated (UM) than mutated (M) IGHV genes. We analysed 1426 IG rearrangements (from 1398 CLL cases) by a clustering driven by HCDR3 similarities. Molecular findings were correlated to time-to-treatment (TTT) and presence of known prognosticators. Sixty-nine clusters (319 IG-rearrangements, 22.4%) with stereotyped BCR were identified. Among 30 confirmed clusters (>or=3 IG-rearrangements/cluster), we found 14 novel clusters, of which 11 had M IG rearrangements (M clusters) and predominantly (8/11) used IGHV3 subgroup genes. Recurrent cluster-biased amino acid changes were found throughout IGHV sequences of these 'M clusters'. Regarding clinical outcome: (i) UM CLL from the IGHV1-2/1-3/1-18/1-46/7-4-1/IGKV1-39 cluster had poorer prognosis than UM/M cases, or UM cases using the same IGHV genes but not in clusters; (ii) M CLL from the IGHV3-21/IGLV3-21 cluster had TTT similar to UM CLL, and shorter than M CLL expressing IGHV3-21 but not in cluster. Altogether, our analysis identified additional molecular and clinical features for CLL expressing stereotyped BCR.
Asunto(s)
Leucemia Linfocítica Crónica de Células B/genética , Receptores de Antígenos de Linfocitos B/genética , Adulto , Anciano , Anciano de 80 o más Años , Aberraciones Cromosómicas , Regiones Determinantes de Complementariedad/genética , Estudios de Seguimiento , Regulación Leucémica de la Expresión Génica , Reordenamiento Génico de Linfocito B , Genes de las Cadenas Pesadas de las Inmunoglobulinas , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Inmunofenotipificación , Leucemia Linfocítica Crónica de Células B/inmunología , Leucemia Linfocítica Crónica de Células B/terapia , Persona de Mediana Edad , Pronóstico , Hipermutación Somática de Inmunoglobulina , Factores de TiempoRESUMEN
Deletion of 17p (TP53) identifies a rare subset of chronic lymphocytic leukaemia (17p- CLL) with aggressive behaviour. Genome-wide DNA-profiling was performed to investigate 18 patients with 17p- CLL. All cases had multiple copy-number (CN) changes. Among the several recurrent CN changes identified, 8q24.13-q24.1-gain (MYC), 8p-loss (TNFRSF10A/B, also known as TRAIL1/2) and 2p16.1-p14-gain (REL/BCL11A) appeared frequently represented. 8p-loss and 2p16.1-p14-gain also appeared clinically relevant and predicted significant shorter time from diagnosis to treatment (8p-loss) and overall survival (8p-loss and 2p16.1-p14-gain, P < 0.05). These observations document a highly unstable genome in 17p- CLL and suggest that additional genes outside the TP53 locus may be important for tumour behaviour.
Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 17/genética , ADN de Neoplasias/genética , Leucemia Linfocítica Crónica de Células B/genética , Dermatoglifia del ADN/métodos , Femenino , Genoma , Humanos , Polimorfismo de Nucleótido Simple , Pronóstico , Análisis de SupervivenciaRESUMEN
Fludarabine plus cyclophosphamide (FC) at conventional doses is an effective treatment for chronic lymphocytic leukaemia (CLL). However, FC at standard doses may give hematological and non-hematological toxicity, predominantly in the elderly. Intravenous or oral low-dose FC regimens remain highly effective in elderly patients with Low-Grade Lymphomas other than CLL and are well tolerated. We tested efficacy and toxicity of oral FC at reduced doses in 26 elderly patients (median 71 years) with previously untreated (UT-CLL, n = 14) or relapsed/refractory CLL (R-CLL, n = 12), unfit for conventional treatments. Twentyfour-of-26 (92%) patients (14/14, 100% UT-CLL; 10/12, 83.5% R-CLL) obtained a response, with 12/26 (46%) complete responses (9/14, 64.2% in UT-CLL; 3/12, 25% in R-CLL). Non-hematological toxicity was mild and myelosuppression was documented in 8/26 (31%) patients (4/14, 28% UT-CLL; 4/12, 33% R-CLL). With a median follow-up of 24 months, median event-free survival was 48 months with no differences between UT-CLL and R-CLL and all responders were alive. Low-dose oral FC treatment showed good efficacy in both untreated and refractory/relapsed CLL. The treatment is useful in elderly patients who cannot benefit of more aggressive schedules and is easy to administer on an outpatient basis.