Diagnosing autoimmune rheumatoid arthritis by measuring proteolytic activity of alpha 2-macroglobulin

摘要

A method for diagnosis of rheumatoid arthritis and related autoimmune diseases comprises blocking calcium ions contained in a blood sample, effecting hydrolysis of a selected substrate in the presence of alpha 2-macroglobulin ( alpha 2M) from the blood sample, and determining the extent of hydrolysis of the substrate. Preferably, alpha 2M in plasma is incubated with a hydrolyzable chromogenic substrate and the liberated chromogen is determined spectrophotometrically. A diagnostic kit is also provided.