Comprehensive analysis of microRNA profiles in multiple sclerosis including next-generation sequencing.

BACKGROUND: MicroRNAs (miRNAs) are short, noncoding RNAs with gene regulatory functions whose expression profiles may serve as disease biomarkers. OBJECTIVE: The objective of this study was to perform a comprehensive analysis of miRNA expression profiles in blood of patients with a clinically isolated syndrome (CIS) or relapsing-remitting multiple sclerosis (RRMS) including next-generation sequencing (NGS). METHODS: miRNA expression was analyzed in whole blood samples from treatment-naïve patients with CIS (n = 25) or RRMS (n = 25) and 50 healthy controls by NGS, microarray analysis, and quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: In patients with CIS/RRMS, NGS and microarray analysis identified 38 and eight significantly deregulated miRNAs, respectively. Three of these miRNAs were found to be significantly up- (hsa-miR-16-2-3p) or downregulated (hsa-miR-20a-5p, hsa-miR-7-1-3p) by both methods. Another five of the miRNAs significantly deregulated in the NGS screen showed the same direction of regulation in the microarray analysis. qRT-PCR confirmed the direction of regulation for all eight and was significant for three miRNAs. CONCLUSIONS: This study identifies a set of miRNAs deregulated in CIS/RRMS and reconfirms the previously reported underexpression of hsa-miR-20a-5p in MS. hsa-miR-20a-5p and the other validated miRNAs may represent promising candidates for future evaluation as biomarkers for MS and could be of relevance in the pathophysiology of this disease.

GABAB receptor antibodies in paraneoplastic cerebellar ataxia.

Autoantibodies to the gamma-aminobutyric acid-B (GABAB) receptor were recently described in patients with limbic encephalitis presenting with early or prominent seizures. We report on a 64-year-old man with malignant melanoma who during adjuvant therapy with interferon (IFN)-alpha developed cerebellar ataxia. Indirect immunofluorescence on brain tissue sections revealed high-titer (1:20,000) IgG1 serum autoantibodies to the cerebellar molecular and granular layer, which were confirmed to be directed against GABAB receptor in a cell-based assay. This case highlights cerebellar ataxia in the absence of seizures as a clinical manifestation of GABAB receptor autoimmunity and extends the spectrum of tumors underlying this condition to malignant melanoma. IFN-alpha therapy may have contributed to the development of autoimmunity in this patient.