| abstract |
An object of the present invention is to specifically recognize the hinge region of a polypeptide encoded by the heavy chain gene of immunoglobulin A1 containing a serine-threonine-linked sugar chain to which galactose is not bound, which is effective in the diagnosis of IgA nephropathy. There is a need for monoclonal antibodies that bind. According to the present invention, a monoclonal antibody that specifically recognizes and binds to the hinge region of a polypeptide encoded by a heavy chain gene of immunoglobulin A1 containing a serine-threonine-linked sugar chain to which galactose is not bound, or an antibody fragment thereof, A diagnostic agent using the antibody or antibody fragment and a therapeutic agent containing the antibody or antibody fragment as an active ingredient can be provided. |