Article Text

AB0646 The Role of Serum YKL-40 in Systemic Sclerosis (SSC)
  1. T. Furukawa,
  2. K. Matsui,
  3. M. Kitano,
  4. S. Kitano,
  5. Y. Yokoyama,
  6. M. Sekiguchi,
  7. N. Azuma,
  8. H. Sano
  1. Division of Rheumatology, Department of Internal Medicine, Hyogo college of Medicine, Nishinomiya, Japan


Background SSc is a refractory of connective tissue disease that causes fibrosis of the skin and various organs. 2013 ACR/EULAR classification criteria of SSc can diagnose early phase of skin involvement. Thus we considered that YKL-40 is known to be involved in inflammation, tissue fibrosis and remodeling, is an useful marker for evaluating early diagnosis and complications in SSc. YKL-40 is expressed in the synovial membrane and cartilage fibroblast cells in Rheumatoid Arthritis. However the relationship between SSc and YKL-40 is unclear.

Objectives To clarify YKL-40 is useful marker in early diagnosis in the presence or absence of complications in Japanese SSc patients.

Methods Study I: We measured serum level of YKL-40 by ELISA (Quantikine ELISA (R&D systems) ®) in 16 healthy controls and 26 SSc patients without complications: such as asthma, infection, diabetes, malignant disease, interstitial pneumonia (IP), pulmonary arterial hypertention (PAH), arthritis and other collagen disease. These complications may be increased YKL-40 levels. Study II: We measured serum level of YKL-40 by ELISA in 76 SSc patients: 42 patients without IP or PAH,17 patients with IP, 4 patients with PAH, 13 patients with IP and PAH. We were attention to IP and PAH complications as a factor involved in the prognosis in SSc.

Results Study I: Serum YKL-40 levels were significant higher in SSc patients without complications than in healthy controls (77.3±15.8 vs 35.0±4.5ng/ml, P=0.01). On the other hand, there is no difference of YKL-40 levels due to gender, disease duration and disease type of SSc. Study II: Serum YKL-40 levels were significantly higher in SSc patients with IP and PAH than in SSc patients without IP and PAH (66.5±15.3 vs 193.4±45.3 ng/ml, P=0.01). Serum YKL-40 levels in SSc patients with IP was 92.9±28.5 ng/ml, and with PAH was 157.5±60.2 ng/ml.

Conclusions We could show increase in serum YKL-40 levels with SSc excluding complications in Japan. In contrast, Montagna reported that serum YKL-40 levels in 40 SSc patients was median 75.5ng/ml (24.2–584) including the organ complications such as heart, lung, kidney, arthritis and high CRP cases (median 0.4mg/dl, 0.3–7.5). The Complications and other factors may be influent to level of serum YKL-40. And, Nordenbaek reported SSc patients with elevated serum YKL-40 had shorter survival than patients with normal serum YKL-40 and died more often due to extensive interstisial or vascular fibrosing processes. However, there is no report on YKL-40 in SSc patients with PAH. We thought that the measure of serum YKL-40 levels in SSc patients with organ complications such as IP and/or PAH is very useful marker. We showed that YKL-40 levels are useful marker in early diagnosis of SSc with or without complications.

  1. Cross-sectional evaluation of YKL-40 serum concentrations in patients with systemic sclerosis. Relationship with clinical and serological aspects of disease. La Montagna G, D'Angelo S, Valentini G. J Rheumatol. 2003 Oct;30(10):2147–51.

  2. High serum levels of YKL-40 in patients with systemic sclerosis are associated with pulmonary involvement. Nordenbaek C, Johansen JS, Halberg P, Wiik A, Garbarsch C, Ullman S, Price PA, Jacobsen S. Scand J Rheumatol. 2005 Jul-Aug;34(4):293–7.

Disclosure of Interest None declared

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