Abstract: The present invention relates to a method to determine antibody-mediated autoimmune diseases in a patient, which comprises the steps of: a) determining the amount of clusterin present in a serum, saliva or tissue sample of the patient with an anti-clusterin antibody; b) comparing the amount of clusterin in step a) with normal serum, saliva or tissue sample, wherein a lower than normal amount is indicative of active antibody-mediated autoimmune disease.

Abstract: The present invention relates to the diagnosis of severe diseases based on the determination of the presence of AGE-IgG autoantibodies in patients and to a method of treatment thereof. More precisely, the invention relates to a method for the diagnosis of severe diseases in patients, which comprises the steps of: a) incubating a solid support coated with an AGE antibody with a biological sample from said patient for a time sufficient for an immunoreaction to occur; and b) determining the presence of AGE-IgG autoantibodies present in said sample; whereby the presence of AGE-IgG autoantibodies in said patient's sample is indicative of a severe disease. Such severe diseases which may be diagnosed in accordance with the present invention include Rheumatoid arthritis, atherosclerosis, amyloidosis, diabetes, Henoch Schonlein Purpura, Crohn's disease and Coeliac disease.

Abstract: The present invention relates to a novel immunoassay for measurement of rheumatoid factors (RFs) avidity for correlation with rheumatoid arthritis disease activity and for the presence of the different glycoforms of IgG.