F. Ukaji et al., Serum samples of patients with rheumatoid arthritis contain a specific autoantibody to "denatured" aldolase A in the osteoblast-like cell line, MG-63, ANN RHEUM D, 58(3), 1999, pp. 169-174
Objective-To identify rheumatoid arthritis (RA) specific autoantibody and i
ts antigen in the human osteoblast-like cell line, MG-63.
Methods-MG-63 cell extract was subjected to western blotting by using RA an
d normal serum samples as probes. The autoantigen was purified acid its N-t
erminal sequence was determined by automated Edman degradation. The reactiv
ity of denatured aldolase A was evaluated by immunoblotting. Screening by e
nzyme linked immunosorbent assay (ELISA) using the autoantibody was perform
ed.
Results-40 kDa protein was found only in the RA serum samples and it was id
entified as aldolase A. A polyclonal antibody for rabbit muscle aldolase A
bound to the 40 kDa protein and reacted in preference with the denatured en
zyme. Using ELISA for denatured rabbit aldolase A, the autoantibody was fou
nd in approximately 10% of RA patients, whereas it was not found in the oth
er arthropathy and healthy adults.
Conclusion This 40 kDa anti-aldolase A autoantibody, which was identified o
nly in serum samples of RA patients with severe bone erosion, could be rela
ted to a certain event that induces RA specific joint destructions.