Gammapatías monoclonales

El objetivo de la presente guía es confeccionar pautas de diagnóstico y tratamiento de los desórdenes a células plasmáticas, teniendo en cuenta las recomendaciones de expertos así como las publicaciones internacionales relacionadas al tema, la disponibilidad de recursos locales y la experiencia de los especialistas convocados, La misma contempla: establecer pautas diagnósticas, clasificar y establecer factores pronósticos, unificar recomendaciones terapéuticas y contribuir a la toma de decisiones.Fil: Arriola, Juan. No especifíca;Fil: Duarte, Patricio. No especifíca;Fil: Fantl, Dorotea. No especifíca;Fil: Garate, Gonzalo. No especifíca;Fil: Lopresti, Sergio. No especifíca;Fil: Ochoa, Paola. No especifíca;Fil: Quiroga, Luis. No especifíca;Fil: Remaggi, Guillermina. No especifíca;Fil: Schutz, Natalia. No especifíca;Fil: Seehaus, Cristian. No especifíca;Fil: Slavutsky, Irma Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Zabaljauregui, Soledad. No especifíca

International Myeloma Working Group risk stratification model for smoldering multiple myeloma (SMM)

Smoldering multiple myeloma (SMM) is an asymptomatic precursor state of multiple myeloma (MM). Recently, MM was redefined to include biomarkers predicting a high risk of progression from SMM, thus necessitating a redefinition of SMM and its risk stratification. We assembled a large cohort of SMM patients meeting the revised IMWG criteria to develop a new risk stratification system. We included 1996 patients, and using stepwise selection and multivariable analysis, we identified three independent factors predicting progression risk at 2 years: serum M-protein >2 g/dL (HR: 2.1), involved to uninvolved free light-chain ratio >20 (HR: 2.7), and marrow plasma cell infiltration >20% (HR: 2.4). This translates into 3 categories with increasing 2-year progression risk: 6% for low risk (38%; no risk factors, HR: 1); 18% for intermediate risk (33%; 1 factor; HR: 3.0), and 44% for high risk (29%; 2–3 factors). Addition of cytogenetic abnormalities (t(4;14), t(14;16), +1q, and/or del13q) allowed separation into 4 groups (low risk with 0, low intermediate risk with 1, intermediate risk with 2, and high risk with ≥3 risk factors) with 6, 23, 46, and 63% risk of progression in 2 years, respectively. The 2/20/20 risk stratification model can be easily implemented to identify high-risk SMM for clinical research and routine practice and will be widely applicable

Differential Expression of Non-Shelterin Genes Associated with High Telomerase Levels and Telomere Shortening in Plasma Cell Disorders.

Telomerase, shelterin proteins and various interacting factors, named non-shelterin proteins, are involved in the regulation of telomere length (TL). Altered expression of any of these telomere-associated genes can lead to telomere dysfunction, causing genomic instability and disease development. In this study, we investigated the expression profile of a set of non-shelterin genes involved in essential processes such as replication (RPA1), DNA damage repair pathways (MRE11-RAD50-NBS1) and stabilization of telomerase complex (DKC1), in 35 patients with monoclonal gammopathy of undetermined significance (MGUS) and 40 cases with multiple myeloma (MM). Results were correlated with hTERT expression, TL and clinical parameters. Overall, a significant increase in DKC1, RAD50, MRE11, NBS1 and RPA1 expression along with an upregulation of hTERT in MM compared with MGUS was observed (p≤0.032). Interestingly, in both entities high mRNA levels of non-shelterin genes were associated with short TLs and increased hTERT expression. Significant differences were observed for DKC1 in MM (p ≤0.026), suggesting an important role for this gene in the maintenance of short telomeres by telomerase in myeloma plasma cells. With regard to clinical associations, we observed a significant increase in DKC1, RAD50, MRE11 and RPA1 expression in MM cases with high bone marrow infiltration (p≤0.03) and a tendency towards cases with advanced ISS stage, providing the first evidence of non-shelterin genes associated to risk factors in MM. Taken together, our findings bring new insights into the intricate mechanisms by which telomere-associated proteins collaborate in the maintenance of plasma cells immortalization and suggest a role for the upregulation of these genes in the progression of the disease

DNA methylation analysis of tumor suppressor genes in monoclonal gammopathy of undetermined significance

Aberrant DNA methylation is considered an important epigenetic mechanism for gene inactivation. Monoclonal gammopathy of undetermined significance (MGUS) is believed to be a precursor of multiple myeloma (MM). We have analyzed methylation status of p15INK4B, p16INK4A, ARF, SOCS-1, p27KIP1, RASSF1A, and TP73 genes in bone marrow DNA samples from 21 MGUS and 44 MM patients, in order to determine the role of aberrant promoter methylation as one of the steps involved in the progression of MGUS to MM. Methylation specific polymerase chain reaction assay followed by DNA sequencing of the resulting product was performed. SOCS-1 gene methylation was significantly more frequent in MM (52%) than in MGUS (14%; p=0,006). Methylation frequencies of TP73, ARF, p15INK4B, p16INK4A, and RASSF1A were comparable in MGUS: 33%, 29%, 29%, 5%, and 0%, to that observed in MM: 45%, 29%, 32%, 7%, and 2%. All patients lacked methylation at p27KIP1 gene. In both entities, a concurrent methylation of p15INK4B and TP73 was observed. The mean methylation index of MGUS was lower (0.16) than that of MM (0.24; p<0.05). Correlations with clinicopathologic characteristics showed a higher mean age in MGUS patients with SOCS-1 methylated (p<0.001); meanwhile in MM, methylation of p15INK4B was more frequent in males (p=0.009) and IgG isotype (p=0.038). Our findings suggest methylation of TP73, ARF, p15INK4B, and p16INK4A as early events in the pathogenesis and development of plasma cell disorders; meanwhile, SOCS-1 methylation would be an important step in the clonal evolution from MGUS to MM. © Springer-Verlag 2009.Fil: Stanganelli, Carmen Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas "Mariano R. Castex"; ArgentinaFil: Arbelbide, Jorge. Hospital Italiano; ArgentinaFil: Fantl, Dorotea Beatriz. Hospital Italiano; ArgentinaFil: Corrado, Claudia. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas "Mariano R. Castex"; ArgentinaFil: Slavutsky, Irma Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas "Mariano R. Castex"; Argentin

Quantitative analysis of CKS1B mRNA expression and copy number gain in patients with plasma cell disorders

In this study, we have examined CKS1B gene expression and copy number in a total of 114- patients at diagnosis: 83 with multiple myeloma (MM) and 31 with monoclonal gammopathy of undetermined significance (MGUS). Results were correlated with cytogenetics, FISH and clinical characteristic. Significant CKS1B mRNA levels in MM compared to MGUS cases (p < 0.048) were detected. In MM, the frequency of 1q21 (CKS1B) copy gain was significantly higher in cases with abnormal karyotype compared to patients with normal karyotype (p = 0.021). Global analysis showed a positive correlation between CKS1B expression and 1q21 copy number (p < 0.0001). No association between CKS1B mRNA expression and clinical parameters was found. However, a significantly higher level of β2 microglobulin in cases with 1q21 gains than those without (p = 0.0094) was observed. Overall survival was shorter in cases with 1q21 gain compared to those with normal 1q21 region (p = 0.0082). Our results suggest a role for CKS1B in the multiple step process of progression of MGUS to MM and show that CKS1B copy gain has a more significant prognostic value than its overexpression. This adverse impact on survival probably reflects the genetic instability associated to chromosome 1q alterations resulting in a more aggressive behavior of the disease.Fil: Stella, Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Pedrazzini, Estela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Baialardo, Edgardo. Centro de Estudios Genéticos. Buenos Aires; ArgentinaFil: Fantl, Dorotea. Hospital Italiano; ArgentinaFil: Schutz, Natalia. Hospital Italiano; ArgentinaFil: Slavutsky, Irma Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

Glutathione S-transferase P1 mRNA expression in plasma cell disorders and its correlation with polymorphic variants and clinical outcome

BACKGROUND: Glutathione S-transferase P1 (GSTP1) is an important phase II enzyme involved in detoxification of carcinogens. GSTP1 gene overexpression has been observed in a variety of human cancers but there are no studies in plasma cell disorders. The aim of this study was to examine GSTP1 mRNA expression level in multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS). In addition, we have determined GSTP1 polymorphic variants in order to estimate MM risk and their relationship with the expression level. Results were also correlated with laboratory parameters and clinical outcome. METHODS: Bone marrow mononuclear cells from 125 patients with plasma cell disorders were studied. Peripheral blood samples of 110 age and sex matched healthy controls were also evaluated. Real-Time Quantitative RT-PCR and PCR-RFLP assays were used. RESULTS: Upregulation of GSTP1 was observed in 37.7% MM and in 22.6% MGUS patients. A significant increase of GSTP1 expression in MM with respect to MGUS was detected (p=0.0427). Most MM patients that achieved complete remission had low transcription levels (77.8%) compared to those who did not reach this condition (44.4%) (p=0.0347). GSTP1 heterozygous carriers showed reduced expression compared to those with homozygous wild type genotype (p=0.0135). CONCLUSION: Our findings suggest, for the first time, a role for GSTP1 expression in development and/or progression of plasma cell disorders, and a probable influence of functional capacity of the enzyme on clinical outcome. These results and those of the literature support GSTP1 as an interesting tumor marker and a potential therapeutic target.Fil: Stella, Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Weich, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Panero, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fantl, Dorotea Beatriz. Hospital Italiano; ArgentinaFil: Schutz, Natalia. Hospital Italiano; ArgentinaFil: Fundia, Ariela Freya. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Slavutsky, Irma Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

Relationship between telomere length (TL) and gene expression.

<p>A) TL was measured in 30 normal controls (NC), 33 patients with MGUS and 34 with MM. Solid lines indicated in each group represent the mean TL. Results showed significantly reduced TL in MM and MGUS patients compared with normal controls (p≤0.0005 and p≤0.002, respectively). There was no significant difference in TL between pathologies. B) Influence of TL on gene expression in MM. Patients were divided into two groups with a cutoff value of 6.15 kb, obtained by ROC curve analysis. Short TL: telomeres ≤6.15kb; Long TL: telomeres >6.15kb. *Significant differences were observed for <i>DKC1</i> expression (p = 0.026).</p