Open AccessClinical significance of surfactant protein D as a serum marker for evaluating pulmonary fibrosis in patients with systemic sclerosis
Author(s) -
Asano Yoshihide,
Ihn Hironobu,
Yamane Kenichi,
Yazawa Norihito,
Kubo Masahide,
Fujimoto Manabu,
Tamaki Kunihiko
Publication year - 2001
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/1529-0131(200106)44:6<1363::aid-art229>3.0.co;2-5
Subject(s) - medicine , gastroenterology , surfactant protein d , clinical significance , diffusing capacity , pulmonary fibrosis , lung , fibrosis , pathology , lung function , receptor , innate immune system
Objective To determine the clinical significance of surfactant protein D (SP‐D), a useful marker for evaluating various lung diseases, in patients with systemic sclerosis (SSc) and to clarify any clinical significance between SP‐D and KL‐6, which is known to be correlated with pulmonary fibrosis (PF) in SSc patients. Methods We used a specific enzyme‐linked immunosorbent assay to measure serum SP‐D levels in 83 patients with SSc and 31 healthy control subjects. Results The serum levels of SP‐D were significantly higher in patients with SSc than in healthy controls (mean ± SD 81.9 ± 59.2 versus 34.8 ± 13.7 ng/ml). Serum SP‐D levels in patients with diffuse cutaneous SSc were significantly higher than those in patients with limited cutaneous SSc (98.8 ± 72.1 versus 66.8 ± 40.0 ng/ml). Serum SP‐D levels in patients with PF were significantly elevated compared with those in patients without PF (99.7 ± 64.1 versus 65.3 ± 49.4 ng/ml). Moreover, the incidences of decreased percentage diffusing capacity for carbon monoxide and decreased percentage vital capacity were also significantly greater in patients with elevated SP‐D levels than in those with normal levels (67% versus 43% and 36% versus 17%, respectively). There was a significant positive correlation between serum levels of SP‐D and KL‐6. Serum SP‐D and KL‐6 levels showed almost the same sensitivities and specificities in the diagnosis of PF (68% versus 73% and 70% versus 74%, respectively). These two markers also predicted PF to almost the same degree (31% versus 33%, respectively). Conclusion These results suggest that SP‐D, as well as KL‐6, may be a useful serum marker for evaluating PF in patients with SSc.