Abstract: The invention relates to an isolated cytotoxic factor which is associated with multiple sclerosis and which is selected from the heterocomplex GM2AP/GM2/MRP14 and mutated GM2AP/GM2/MRP14, and to the method of detecting said factor in a biological sample to be tested. The inventive method comprises the following steps consisting in: (i) bringing the biological sample into contact with at least one capture antibody selected from antibodies that bind specifically to the GM2AP protein, to the mutated GM2AP protein, to the MRP14 protein, to the complex GM2AP/GM2, to the complex mutated GM2AP/GM2 and to the complex MRP14/GM2, and with at least one labeled detection antibody selected from antibodies that bind specifically to the GM2AP protein, to the mutated GM2AP protein, to the MRP14 protein, to the complex GM2AP/GM2, to the complex mutated GM2AP/GM2 and to the complex MRP14/GM2, and (ii) detecting and/or quantifying the cytotoxic factor by detecting and/or quantifying the labeled detection antibody.

Abstract: A process of concentration by precipitation of PrPsc for detecting or diagnosing PrPsc, wherein a tissue or biological fluid stemming from or obtained from an animal or human organism is brought together with an antibiotic from the family of aminoglycosides, preferably streptomycin or one of its derivatives. The use of such an antibiotic for eliminating PrPsc from a tissue or biological fluid and a kit for diagnosing pathologies associated with the presence of PrPsc is also disclosed.

Abstract: The invention concerns the use of at least one polypeptide comprising a protein fragment to obtain a diagnostic, prognostic, prophylactic or therapeutic composition for detecting, preventing or treating a pathological condition associated with a degenerative and/or neurological and/or autoimmune disease, said protein being selected among the proteins whereof the peptide sequence in native state corresponds to SEQ ID No 1, SEQ ID No 2, SEQ ID No 3, SEQ ID No 4, SEQ ID No 5, SEQ ID No 6, SEQ ID No 7, SEQ ID No 8, SEQ ID No 9, SEQ ID No 10, SEQ ID No 11, SEQ ID No 12, SEQ ID No 13, SEQ ID No 14, SEQ ID No 15, SEQ ID No 16, SEQ ID No 17, SEQ ID No 18, SEQ ID No 19, SEQ ID No 20, SEQ ID No 21, SEQ ID No 22, SEQ ID No 23, SEQ ID No 24, SEQ ID No 25, SEQ ID No 26, SEQ ID No 27, SEQ ID No 28, and SEQ ID No 29, and the peptide sequences having at least 70% identity, preferably at least 80% identity and advantageously at least 98% identity with any one of the peptide sequences SEQ ID No 1 to SEQ ID No 8 and SEQ ID No 1