Abstract: A method can be used for detecting, in a sample, an autoantibody binding to a polypeptide having the sequence SEQ ID NO: 1, SEQ ID NO: 11 or SEQ ID NO: 24. A carrier containing said polypeptide and an autoantibody binding to said polypeptide are useful. The autoantibody may be used for the diagnosis of a disease, and a method can be used for isolating an autoantibody binding to said polypeptide. The polypeptide and a kit containing said polypeptide are useful, and can be used for the manufacture of a kit or medical device. A method involves contacting a medical or diagnostic device containing said polypeptide with a buffered solution containing an antibody binding specifically to said polypeptide. A sample containing said autoantibody as a positive control and a diluted sample containing said autoantibody are useful.