Contributions
Abstract: EP1563
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Biomarkers
Introduction: The clinical course of multiple sclerosis is heterogeneous and the presence of anti-myelin lipid specific oligoclonal IgM bands (LS-OCMBs) have been defined as an accurate predictor of an aggressive evolution. The detection of this biomarker is performed in cerebrospinal fluid (CSF), a quite invasive liquid biopsy.
MicroRNAs are single-stranded small non-coding RNAs that regulate gene expression and have been reported to be differentially expressed in MS patients both in blood and CSF, suggesting a role in the disease.
Objectives: The aim of the study was to analyze miRNA expression profile in PBMC from MS patients with positive and negative LS-OCMBs in order to evaluate whether a subset of miRNA could reflect the status of LS-OCMBs in a more accessible liquid biopsy.
Methods: Patients were recruited in the Hospital Ramon y Cajal after giving informed consent. Blood samples were obtained and peripheral blood mononuclear cells (PBMCs) were isolated following a standard Ficol gradient separation protocol and frozen.. CSF was obtained to analyze the status of LS-OCMBs as previously described.
RNA was extracted using miRNeasy mini kit and quantity and quality was evaluated using Nanodrop ND-1000 spectrophotometer.
Total RNA (200ng) was labeled using the FlashTag Biotin labelling kit and hybridized to the GeneChip miRNA array 4.0 (Affymetrix) following the manufacturer's protocol.
Microarray data analysis was performed using Transcriptome Analysis Console.
Candidate miRNA were validated by quantitative PCR using TaqMan Advanced microRNA assays.
Results: In microarray exploratory analysis 11 MS patients were included (5 with positive LS-OCMB and 6 without LS-OCMB). 42% of the probes were detected in at least one sample. Twenty probesets showed at least two-fold change (7 upregulated and 13 downregulated) in patients with LS-OCMBs (p< 0.05). Interestingly, this subset of miRNA was able to distinguish patients with LS-OCMBs from those without LS-OCMBs according to a hierarchical clustering analysis.
Validation of the more promising candidates will be performed in a bigger cohort.
Conclusion: The expression pattern in PBMCs of a subset of 20 miRNAs is able to distinguish patients with LS-OCMBs. Thus, it is worth to follow this line of research aiming at establishing a new biomarker of a more aggressive disease course in a more accessible sample.
Disclosure: Maider Muñoz-Culla: nothing to disclose.
Leire Iparraguirre: nothing to disclose.
Tamara Castillo-Triviño: nothing to disclose.
Mercedes Espiño: nothing to disclose.
Lucienne Costa-Frossard: received payment for lecturing from Novartis, Biogen, Roche, Bayer and Sanofi- Genzyme.
Álvaro Prada: nothing to disclose.
Luisa Maria Villar: received payment for lecturing or research grants from Merck, Novartis, Biogen, Roche and Sanofi- Genzyme.
David Otaegui: nothing to disclose.
This work is supported by Instituto de Salud Carlos III (PI17/00189, PI15/00513, RD16/0015/0007, RD16/0015/0001), Basque Government (ELKARTEK MALTA). Leire Iparraguirre is supported by a grant from the Education department from the Basque Government.
Abstract: EP1563
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Biomarkers
Introduction: The clinical course of multiple sclerosis is heterogeneous and the presence of anti-myelin lipid specific oligoclonal IgM bands (LS-OCMBs) have been defined as an accurate predictor of an aggressive evolution. The detection of this biomarker is performed in cerebrospinal fluid (CSF), a quite invasive liquid biopsy.
MicroRNAs are single-stranded small non-coding RNAs that regulate gene expression and have been reported to be differentially expressed in MS patients both in blood and CSF, suggesting a role in the disease.
Objectives: The aim of the study was to analyze miRNA expression profile in PBMC from MS patients with positive and negative LS-OCMBs in order to evaluate whether a subset of miRNA could reflect the status of LS-OCMBs in a more accessible liquid biopsy.
Methods: Patients were recruited in the Hospital Ramon y Cajal after giving informed consent. Blood samples were obtained and peripheral blood mononuclear cells (PBMCs) were isolated following a standard Ficol gradient separation protocol and frozen.. CSF was obtained to analyze the status of LS-OCMBs as previously described.
RNA was extracted using miRNeasy mini kit and quantity and quality was evaluated using Nanodrop ND-1000 spectrophotometer.
Total RNA (200ng) was labeled using the FlashTag Biotin labelling kit and hybridized to the GeneChip miRNA array 4.0 (Affymetrix) following the manufacturer's protocol.
Microarray data analysis was performed using Transcriptome Analysis Console.
Candidate miRNA were validated by quantitative PCR using TaqMan Advanced microRNA assays.
Results: In microarray exploratory analysis 11 MS patients were included (5 with positive LS-OCMB and 6 without LS-OCMB). 42% of the probes were detected in at least one sample. Twenty probesets showed at least two-fold change (7 upregulated and 13 downregulated) in patients with LS-OCMBs (p< 0.05). Interestingly, this subset of miRNA was able to distinguish patients with LS-OCMBs from those without LS-OCMBs according to a hierarchical clustering analysis.
Validation of the more promising candidates will be performed in a bigger cohort.
Conclusion: The expression pattern in PBMCs of a subset of 20 miRNAs is able to distinguish patients with LS-OCMBs. Thus, it is worth to follow this line of research aiming at establishing a new biomarker of a more aggressive disease course in a more accessible sample.
Disclosure: Maider Muñoz-Culla: nothing to disclose.
Leire Iparraguirre: nothing to disclose.
Tamara Castillo-Triviño: nothing to disclose.
Mercedes Espiño: nothing to disclose.
Lucienne Costa-Frossard: received payment for lecturing from Novartis, Biogen, Roche, Bayer and Sanofi- Genzyme.
Álvaro Prada: nothing to disclose.
Luisa Maria Villar: received payment for lecturing or research grants from Merck, Novartis, Biogen, Roche and Sanofi- Genzyme.
David Otaegui: nothing to disclose.
This work is supported by Instituto de Salud Carlos III (PI17/00189, PI15/00513, RD16/0015/0007, RD16/0015/0001), Basque Government (ELKARTEK MALTA). Leire Iparraguirre is supported by a grant from the Education department from the Basque Government.