RT Journal Article SR Electronic T1 Comparative study of serum surfactant protein-D and KL-6 concentrations in patients with systemic sclerosis as markers for monitoring the activity of pulmonary fibrosis. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 1112 OP 1120 VO 31 IS 6 A1 Koichi Yanaba A1 Minoru Hasegawa A1 Kazuhiko Takehara A1 Shinichi Sato YR 2004 UL http://www.jrheum.org/content/31/6/1112.abstract AB OBJECTIVE: To clarify the clinical significance of surfactant protein-D (SP-D) and KL-6 in the diagnosis and monitoring of pulmonary fibrosis (PF) in patients with systemic sclerosis (SSc), and to evaluate the differences between SP-D and KL-6. METHODS: Serum SP-D and KL-6 concentrations were determined by ELISA in 42 SSc patients. In a retrospective longitudinal study, 83 serum samples from 6 SSc patients were analyzed during a followup period of 0.6-6.3 years. RESULTS: SP-D and KL-6 concentrations at the first visit were higher in patients with SSc, especially those with PF, compared with healthy controls. Increased concentrations of SP-D were associated with decreased DLCO and decreased vital capacity in SSc patients more strongly than those of KL-6. The sensitivity and specificity for PF were 91% and 88% for SP-D and 39% and 100% for KL-6, respectively. In the longitudinal study, both SP-D and KL-6 concentrations were associated with activity of PF in patients with SSc. SP-D concentrations changed more rapidly than KL-6 concentrations, in parallel with the PF activity. CONCLUSION: SP-D was a more sensitive marker for PF than KL-6. By contrast, KL-6 showed higher specificity than SP-D. Combined use of these 2 serum markers would be more helpful to diagnose and monitor the PF activity in patients with SSc than single use of each marker.