Comorbidity in idiopathic pulmonary fibrosis - what can biomarkers tell us?

Abstract

Idiopathic pulmonary fibrosis (IPF) is characterized by progressive parenchymal scarring, leading to dyspnoea, respiratory failure and premature death. Although IPF is confined to the lungs, the importance of IPF comorbidities such as pulmonary hypertension and ischaemic heart disease, lung cancer, emphysema/chronic obstructive pulmonary disease, gastroesophageal reflux, sleep apnoea and depression has been increasingly recognized. These comorbidities may be associated with increased mortality and significant loss of quality of life, so their identification and management are vital. The development of good-quality biomarkers could lead to numerous gains in the management of these patients. Biomarkers can be used for the identification of predisposed individuals, early diagnosis, assessment of prognosis, selection of best treatment and assessment of response to treatment. However, the role of biomarkers for IPF comorbidities is still quite limited, and mostly based on evidence coming from populations without IPF. The future development of new biomarker studies could be informed by those that have been studied independently for each of these conditions. For now, clinicians should be mostly attentive to clinical manifestations of IPF comorbidities, and use validated diagnostic methods for diagnosis. As research on biomarkers of most common diseases continues, it is expected that useful biomarkers are developed for these diseases and then validated for IPF populations. The reviews of this paper are available via the supplemental material section.

Disturbance of serum lipid metabolites and potential biomarkers in the Bleomycin model of pulmonary fibrosis in young mice

“…Since IPF shows significant heterogeneity in its natural course and prognosis, biomarkers can play an auxiliary role in disease diagnosis, disease assessment, treatment response, and disease risk prediction in pulmonary fibrosis based on clinical, imaging, and pathology [ 20 , 21 ]. Currently, the more studied IPF biomarkers are mainly divided into genes or protein-based markers associated with alveolar epithelial cell injury, fibroplasia, extracellular matrix remodeling, and immune dysfunction and their combined use are of great value in improving the accuracy of IPF diagnosis, disease assessment, and judgment of prognosis [ 22 , 23 ]. However, most IPF biomarkers lack specificity and reproducibility and thus are not widely accepted [ 24 ].…”

The prevalence of pulmonary hypertension assessed using the pulmonary vein‐to‐right pulmonary artery ratio and its association with survival in West Highland white terriers with canine idiopathic pulmonary fibrosis

“…CIPF shares clinical, imaging and histopathological findings from both human idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases displaying non-specific interstitial pneumonia pattern [ 1 – 5 ]. In human IPF, pulmonary hypertension (PH) occurs in up to 85 % of patients, depending on disease severity, evaluation method and diagnostic criteria employed [ 6 , 7 ]. The presence of PH in human IPF patient has been associated with poorer quality of life, reduced cardiopulmonary function and shorter survival time [ 8 – 10 ].…”

A Systematic Review of the Prognostic Significance of the Body Mass Index in Idiopathic Pulmonary Fibrosis

“…However, significant inter-individual variability exists in disease progression. This variability is at least partly related to the frequency of disease exacerbations and the presence of specific comorbid conditions [ 2 , 3 , 4 , 5 ]. Several patient characteristics, as well as measures of lung function, have also been shown to predict survival and other relevant outcomes, e.g., disease progression and exacerbation, in this patient group.…”