Evidence that natural autoantibodies against the nerve growth factor (NGF) may be potential carriers of NGF

Nerve growth factor (NGF) was detected by enzyme-linked immunosorbent assay using the monoclonal anti-NGF antibody 27/21 in natural NGF autoantibodies (NGF NA) purified from sera of control human subjects as well as from sera of patients with rheumatoid arthritis, autoimmune thyroiditis and to a lesser degree in patients with systemic lupus erythematosus as well as in NGF NA from the synovial fluid of patients with spondylarthropathies. Our results suggest that NGF NA may be potential carriers of NGF in the circulation.