Recognition of YKL-39, a human cartilage related protein, as a target antigen in patients with rheumatoid arthritis.

[Guest guest]

Ann Rheum Dis 2001 Jan;60(1):49-54

Recognition of YKL-39, a human cartilage related protein, as a target antigen in

patients with rheumatoid arthritis.

Sekine T, Masuko-Hongo K, Matsui T, Asahara H, Takigawa M, Nishioka K, Kato T

Rheumatology, Immunology and Genetics Programme, Institute of Medical Science,

St nna University, School of Medicine 2-16-1, Sugao, Miyamae-ku, Kawasaki,

Kanagawa, 216-8512, Japan.

[Record supplied by publisher]

OBJECTIVE: To investigate whether autoimmunity to YKL-39, a recently cloned

cartilage protein, occurs in patients with rheumatoid arthritis (RA). METHODS:

Autoantibody to YKL-39 was assayed by enzyme linked immunosorbent assay (ELISA)

and western blotting in serum samples from patients with RA, systemic lupus

erythematosus (SLE), and healthy donors, using recombinant YKL-39 protein. This

reactivity was compared with that against a YKL-39 homologue, YKL-40 (human

cartilage gp-39/chondrex), which has been reported to be an autoantigen in RA.

RESULTS: Autoantibody to YKL-39 was detected in seven of 87 patients with RA

(8%), but not in serum samples from patients with SLE or healthy donors. YKL-40

reactivity was found in only one of 87 RA serum samples (1%), with no cross

reactivity to YKL-39. CONCLUSION: The existence of anti-YKL-39 antibody in a

subset of patients with RA is reported here for the first time. Further, it was

shown that the immune response to YKL-39 was independent of that to YKL-40.

Clarification of the antibody and T cell responses to autoantigens derived from

chondrocyte, cartilage, or other joint components may lead to a better

understanding of the pathophysiology of joint destruction in patients with RA.

PMID: 11114282