Background: The significance of the nutritional status in idiopathic pulmonary fibrosis (IPF) is largely unknown. Temporal body weight (BW) change, a dynamic index of nutrition status, can detect the malnutrition more accurately than the conventional single-point body mass index evaluation. Objective: To investigate how the temporal BW change influences the clinical courses of IPF. Methods: This multicenter study enrolled IPF patients from four referral hospitals of interstitial lung diseases in Japan (the Japanese cohort, the derivation cohort) and the Royal Brompton Hospital (the UK cohort, the validation cohort). The annual rate of BW change from the initial presentation was evaluated. A > 5% decrease of BW was defined as a significant BW loss. Results: Twenty-seven out of 124 patients in the Japanese cohort and 13 out of 86 patients in the UK cohort showed significant BW loss. Patients with BW loss showed significantly worse survival in both cohorts. Multivariate analyses revealed that BW loss was an independent factor for decreased survival (Japanese cohort: p = 0.047, UK cohort: p = 0.013). A 6.1% loss of BW was chosen as the optimal cutoff value to predict the 2-year mortality from the initial presentation. The stratified analysis revealed that a 6.1% or greater BW loss could predict worse survival specifically in cases without a greater than 10% decline in forced vital capacity (FVC). Conclusions: BW loss is independently associated with the survival of IPF patients, particularly when a decline in the FVC was not observed. Further studies are needed to understand the mechanisms underlying BW loss in IPF.

BackgroundMatrix metalloproteinases (MMPs) are believed to be involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF), and MMP-7 has been described as a useful biomarker for IPF. However, little is known regarding the significance of MMP-10 as a biomarker for IPF.MethodsThis observational cohort study included 57 patients with IPF. Serum MMPs were comprehensively measured in all patients, and the relationships between these markers and both disease severity and prognosis were evaluated. Bronchoalveolar lavage fluid (BALF) MMP-7 and -10 levels were measured in 19 patients to investigate the correlation between these markers and their corresponding serum values. Immunohistochemical staining for MMP-10 was also performed in IPF lung tissue.ResultsSerum MMP-7 and -10 levels correlated significantly with both the percentage of predicted forced vital capacity (ρ = −0.31, p = 0.02 and ρ = −0.34, p < 0.01, respectively) and the percentage of predicted diffusing capacity of the lung for carbon monoxide (ρ = −0.32, p = 0.02 and ρ = −0.43, p < 0.01, respectively). BALF MMP-7 and -10 levels correlated with their corresponding serum concentrations. Only serum MMP-10 predicted clinical deterioration within 6 months and overall survival. In IPF lungs, the expression of MMP-10 was enhanced and localized to the alveolar epithelial cells, macrophages, and peripheral bronchiolar epithelial cells.ConclusionsMMP-10 may be a novel biomarker reflecting both disease severity and prognosis in patients with IPF.Electronic supplementary materialThe online version of this article (doi:10.1186/s12931-015-0280-9) contains supplementary material, which is available to authorized users.

The clinical significance of serial changes in serum biomarkers in patients with idiopathic pulmonary fibrosis (IPF) remains to be established. This retrospective study was conducted to clarify the associations of serial changes in serum Krebs von den Lungen-6 (KL-6) and surfactant protein-D (SP-D) with changes in physiological indices and overall mortality in IPF.The study subjects were 75 patients with IPF. The 6 month change in serum KL-6 was significantly correlated with changes in the percentage of the predicted forced vital capacity (FVC % pred) and the percentage of the predicted diffusing capacity of the lung for carbon monoxide (% DLCO), while the 6 month change in serum SP-D was correlated only with % DLCO. During the mean follow-up period of 647 days, 22 (29.3%) patients died. An increase in serum KL-6 over a 6 month period was a significant predictor of mortality even after adjustment for %FVC, % DLCO and serum KL-6 at the baseline (hazard ratio 1.10 per 100 U·mL−1, 95% CI 1.01–1.18, p=0.03), whereas the 6 month increase in serum SP-D was not significant.Serial measurements of serum KL-6 may provide additional prognostic information compared to that provided by physiological parameters in patients with IPF.

TLG correlated significantly with the serum sIL-2R level and may be useful for disease monitoring in IgG4-RD.

The long-term outcome of ARS-ILD was significantly better than that of IPF regardless of the presence or absence of myositis.