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

Abstract

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.

• Authors: Cristina Jiménez, María Isabel Prieto-Conde, María García-Álvarez, Miguel Alcoceba, Fernando Escalante, María Del Carmen Chillón, Alfonso García de Coca, Ana Balanzategui, Alberto Cantalapiedra, Carlos Aguilar, Rocío Corral, Tomás González-López, Luis A Marín, Abelardo Bárez, Noemí Puig, Aránzazu García-Mateo, Norma C Gutiérrez, María Eugenia Sarasquete, Marcos González, Ramón García-Sanz
• Journal: Annals of hematology (Ann Hematol) Vol. 97 Issue 3 Pg. 475-484 (Mar 2018) ISSN: 1432-0584 [Electronic] Germany
• PMID: 29353304 (Publication Type: Journal Article)

Chemical References

• Immunoglobulin M

Topics

• Aged
• Aged, 80 and over
• DNA Mutational Analysis
• Disease Progression
• Female
• Gene Expression Profiling
• Genetic Heterogeneity
• High-Throughput Nucleotide Sequencing
• Humans
• Immunoglobulin M (genetics)
• Male
• Middle Aged
• Monoclonal Gammopathy of Undetermined Significance (genetics, pathology)
• Prognosis
• Waldenstrom Macroglobulinemia (genetics, pathology)