Serum IL-33 levels are raised in patients with systemic sclerosis: association with extent of skin sclerosis and severity of pulmonary fibrosis

Clin Rheumatol. 2011 Jun;30(6):825-30. doi: 10.1007/s10067-011-1686-5. Epub 2011 Jan 19.


To determine serum interleukin-33 (IL-33) levels and their associations with clinical parameters in patients with systemic sclerosis (SSc). Serum IL-33 levels were examined by enzyme-linked immunosorbent assay in 69 patients with SSc and 30 healthy individuals. In a retrospective longitudinal study, sera from 14 patients with SSc were analyzed (follow-up, 1-7 years). Serum IL-33 levels were elevated in SSc patients (261.7 ± 141.9 pg/ml) compared with healthy individuals (174.9 ± 72.4 pg/ml; P < 0.001). Patients with diffuse cutaneous SSc had higher levels of IL-33 (287.5 ± 146.6 pg/ml) than those with limited cutaneous SSc (221.5 ± 126.5 pg/ml; P < 0.05). Pulmonary fibrosis and decreased forced vital capacity were more commonly found in patients with elevated IL-33 levels than in those with normal IL-33 levels. IL-33 levels correlated positively with the extent of skin sclerosis, and inversely with percent predicted forced vital capacity. IL-33 levels were increased in SSc patients and correlated with the extent of skin sclerosis and the severity of pulmonary fibrosis. Therefore, IL-33 possibly plays a role in cutaneous and pulmonary fibrosis in SSc patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Case-Control Studies
  • Endothelium, Vascular / pathology
  • Female
  • Fibrosis
  • Humans
  • Interleukin-33
  • Interleukins / blood*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Pulmonary Fibrosis / pathology*
  • Pulmonary Fibrosis / physiopathology
  • Retrospective Studies
  • Scleroderma, Systemic / blood*
  • Scleroderma, Systemic / pathology*
  • Scleroderma, Systemic / physiopathology
  • Severity of Illness Index*
  • Skin / pathology*
  • Vital Capacity / physiology
  • Young Adult


  • IL33 protein, human
  • Interleukin-33
  • Interleukins