Angiogenic activity of sera from interstitial lung disease patients in relation to clinical and radiological changes

Six-SOMAmer Index Relating to Immune, Protease and Angiogenic Functions Predicts Progression in IPF

RATIONALE

Biomarkers in easily accessible compartments like peripheral blood that can predict disease progression in idiopathic pulmonary fibrosis (IPF) would be clinically useful regarding clinical trial participation or treatment decisions for patients. In this study, we used unbiased proteomics to identify relevant disease progression biomarkers in IPF.

METHODS

Plasma from IPF patients was measured using an 1129 analyte slow off-rate modified aptamer (SOMAmer) array, and patient outcomes were followed over the next 80 weeks. Receiver operating characteristic (ROC) curves evaluated sensitivity and specificity for levels of each biomarker and estimated area under the curve (AUC) when prognostic biomarker thresholds were used to predict disease progression. Both logistic and Cox regression models advised biomarker selection for a composite disease progression index; index biomarkers were weighted via expected progression-free days lost during follow-up with a biomarker on the unfavorable side of the threshold.

RESULTS

A six-analyte index, scaled 0 to 11, composed of markers of immune function, proteolysis and angiogenesis [high levels of ficolin-2 (FCN2), cathepsin-S (Cath-S), legumain (LGMN) and soluble vascular endothelial growth factor receptor 2 (VEGFsR2), but low levels of inducible T cell costimulator (ICOS) or trypsin 3 (TRY3)] predicted better progression-free survival in IPF with a ROC AUC of 0.91. An index score ≥ 3 (group ≥ 2) was strongly associated with IPF progression after adjustment for age, gender, smoking status, immunomodulation, forced vital capacity % predicted and diffusing capacity for carbon monoxide % predicted (HR 16.8, 95% CI 2.2-126.7, P = 0.006).

CONCLUSION

This index, derived from the largest proteomic analysis of IPF plasma samples to date, could be useful for clinical decision making in IPF, and the identified analytes suggest biological processes that may promote disease progression.

Angiogenic activity of sera from interstitial lung disease patients in relation to pulmonary function

OBJECTIVE

Chronic inflammation and fibrosis are characteristic of interstitial lung diseases (ILD) and are accompanied by neovascularisation. The aim of this study was to examine the relationship between the angiogenic activity of sera from ILD patients and pulmonary function tests.

MATERIAL AND METHODS

Serum samples were obtained from 225 ILD patients: 83 with sarcoidosis, 31 with idiopathic pulmonary fibrosis, 29 with extrinsic allergic alveolitis, 16 with collagen vascular diseases, 13 with scleroderma with pulmonary manifestations (SCL), 14 with Wegener's granulomatosis (WG), 12 with silicosis, 12 with pulmonary Langerhans cells histiocytosis, 10 with drug-induced pulmonary fibrosis, 5 with cryptogenic organizing pneumonia, and 36 healthy volunteers. An animal model of leukocyte induced angiogenesis assay was used as an angiogenic test. In all patients spirometry, whole body plethysmography, static lung compliance, and single breath diffusing capacity of the lungs for carbon monoxide (DLco) were performed.

RESULTS

The angiogenic properties of sera from ILD differed, depending on the disease. In the examined ILD, the most important functional disturbances were decreases in static compliance and DLco. The correlation between DLco and angiogenic activity of sera was observed (P<0.05).

CONCLUSIONS

The data show that sera from ILD patients constitute a source of mediators modulating angiogenesis. Angiogenic activity of sera of ILD patients is related to DLco.