Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2001 Jan;60(1):49-54.
doi: 10.1136/ard.60.1.49.

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

T Sekine  1 , K Masuko-Hongo, T Matsui, H Asahara, M Takigawa, K Nishioka, T Kato
Affiliations

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

T Sekine et al. Ann Rheum Dis. 2001 Jan.

Abstract

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.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Detection of anti-YKL-39 antibody. (A) Purified fusion proteins, YKL-40 (1), YKL-39 (2), and maltose binding protein (MBP) (3) were electrophoresed on a 10% SDS-PAGE gel and detected by Coomassie brilliant blue staining. (B, C) Detection of autoantibodies to YKL-39 (B) and YKL-40 (C) in serum samples of patients with RA and SLE and healthy control subjects by ELISA. Each symbol indicates a single person. Serum samples from healthy donors matched for age and sex were used as controls. Units of antibodies to YKL-40 in anti-YKL-39 positive sera (open squares in C) and to YKL-39 in anti-YKL-40 positive sera (open circles in B). Data are expressed in arbitrary units as described in "Materials and methods".
Figure 2
Figure 2
Specificity of autoantibodies to YKL-39 and YKL-40. (A) Antibodies to YKL-39 and YKL-40 were determined by ELISA using serially diluted serum samples. Selected samples are indicated by asterisks in figs 1B and C. Each OD value from maltose binding protein (MBP), YKL-40, and YKL-39 is indicated. (B) YKL-39 positive sera were processed by western blotting to assess reactivity to YKL-40. Recombinant proteins, YKL-40 (1), YKL-39 (2), and MBP (3) were electrophoresed on a 10% SDS-PAGE gel and then western blotted using serum samples from YKL-39 antibody positive patients with RA or anti-MBP antibody as a positive control (PC). (C) Antibodies to YKL-39-MBP fusion protein and those to MBP alone as a negative control were purified from pooled anti-recombinant YKL-39 positive serum samples separately. Then, native YKL-39 in the cell lysate of HCS-2/8 was immunoprecipitated by these purified antibodies and by rabbit anti-YKL-39 polyclonal antibodies as a positive control. The precipitated native YKL-39 was then detected by western blotting using the rabbit anti-YKL-39 antibodies. IP Ab = antibodies used for immunoprecipitation; WB Ab = antibodies used for western blotting; M = antibodies purified by MBP alone; Y = antibodies purified by the recombinant YKL-39 fused with MBP; R = rabbit anti-YKL-39 polyclonal antibodies which were prepared by immunisation of rabbits with the recombinant YKL-39-MBP fusion proteins and subsequent adsorption with MBP.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. J Immunol. 1999 Apr 1;162(7):4328-35 - PubMed
    1. Biochem Biophys Res Commun. 1998 Apr 28;245(3):679-83 - PubMed
    1. Clin Chem. 1998 Mar;44(3):509-16 - PubMed
    1. Arthritis Rheum. 1997 Jun;40(6):1115-25 - PubMed
    1. Arthritis Rheum. 1996 Oct;39(10):1720-7 - PubMed

Publication types