Method and reagents for diagnosing Membranous Nephropathy

A method, comprising:

• detecting the presence or absence of an autoantibody binding specifically to SEQ ID NO:
• 1 or to a complex comprising a polypeptide having SEQ ID NO:
• 1 and a polypeptide having SEQ ID NO:
• 2, in a liquid sample comprising antibodies from a subject having or suspected of having membranous nephropathy.

A device for removing an autoantibody to a polypeptide having SEQ ID NO:

• 1 or a complex comprising the polypeptide having SEQ ID NO:
• 1 and a polypeptide having SEQ ID NO:
• 2, from blood, wherein the device comprises:
• a carrier coated with the polypeptide comprising SEQ ID NO:
• 1 or a complex comprising the polypeptide comprising SEQ ID NO:
• 1 and the polypeptide comprising SEQ ID NO:
• 2 or a variant thereof.

An ex vivo method for removing an autoantibody to a polypeptide having SEQ ID NO:

• 1 or a complex comprising the polypeptide having SEQ ID NO:
• 1 and a polypeptide having SEQ ID NO:
• 2, from blood, the method comprising:
• contacting the blood to a carrier coated with the polypeptide having SEQ ID NO:
• 1 or the complex.