Systems and methods for purification and concentration of autologous alpha-2-macroglobulin (A2M) from whole blood are provided. Also provided are diagnostic methods for identifying sites in the synovial joints, spine, tendons or ligaments for treatment of pain, degeneration, or inflammation with autologous A2M. Methods for utilizing autologous A2M in combination with other autologous treatments (e.g. platelets and other growth factors) are provided in addition to combinations with exogenous drugs or carriers. Also provided is a method of producing recombinant A2M wild type or variants thereof where the bait region was modified to enhance the inhibition characteristics of A2M and/or to prolong the half life of the protein in joints and spine disc or epidural space.