Interleukin-11 in idiopathic pulmonary fibrosis: predictive value of prognosis and acute exacerbation

Background

Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung disease with a poor prognosis and unknown aetiology. We have recently clarified the prognostic value of the serum platelet-derived growth factor (PDGF) level in patients with IPF. Interleukin (IL)-11 is a member of the IL-6 family, and in vivo and in vitro studies have suggested that it has profibrotic effects in pulmonary fibrosis. In this study, we investigated the predictive value of the serum IL-11 level in patients with IPF for survival and occurrence of acute exacerbation (AE).

Methods

This retrospective study included 68 patients with IPF diagnosed according to the 2018 guideline. Serum PDGF levels were measured using the Bio-Plex method and serum IL-11 levels using enzyme-linked immune-sorbent assay. Cytokine production per lung volume was evaluated using the serum cytokine/percent predicted forced vital capacity (%FVC) value.

Results

Forty-six patients were male and the median age was 67 years. The serum IL-11/%FVC value was significantly correlated with the percent predicted diffusing capacity of carbon monoxide (ρ=-0.518, P<0.001) and modified Medical Research Council score for shortness of breath (mMRC) (ρ=0.335, P=0.006) by Spearman's rank correlation analysis. Multivariate Cox proportional hazard regression analysis revealed that the serum IL-11/%FVC value was a significant prognostic factor after adjustment for the serum PDGF/%FVC value and other clinical parameters including mMRC and lymphocyte percentage in bronchoalveolar lavage [hazard ratio (HR): 88.540, 95% confidence interval (CI): 1.905-4,115.686, P=0.022]. IL-11/%FVC value was also a significant predictor of AE after adjustment for age and PDGF/%FVC (HR: 1,815.443, 95% CI: 10.49-314,109.219, P=0.004).

Conclusions

The serum IL-11/%FVC value was an independent predictor of prognosis and AE occurrence in patients with IPF, and the IL-11 level appeared to show pathophysiologic value in IPF.

The Impact of Lung Cancer in Patients with Combined Pulmonary Fibrosis and Emphysema (CPFE)

Given the high risk of lung cancer (LC) in patients with combined pulmonary fibrosis and emphysema (CPFE), and the difficulty of early diagnosis, it is important to understand the impact of LC in these patients. The effect of LC on the development of acute exacerbation (AE) as a natural course of CPFE is still unknown. We retrospectively reviewed medical records of patients at the West China Hospital and enrolled 59 patients with CPFE combined with LC and 68 CPFE patients without LC for initial diagnosis matched in the same period. We compared the clinical characteristics and imaging features of CPFE patients with LC and without LC, and analyzed the associated factors for the prevalence of LC using binary logistic regression. Cox proportional hazards regression analysis was performed to explore risk factors of AE as a natural course of CPFE. Patients with CPFE combined with LC were more common among elderly male smokers. The most common pathological type of tumor was adenocarcinoma (24/59, 40.7%) and squamous cell carcinoma (18/59, 30.5%). Compared with those in the without LC group, the proportions of men, and ex- or current smokers, and the levels of smoking pack-years, serum CRP, IL-6, fibrinogen, complement C3 and C4 in patients with LC were significantly higher (p < 0.05). There was no significant difference in the proportion of natural-course-related AE (10.2% vs. 16.2%, p > 0.05) between the two groups. Logistic regression analysis demonstrated that pack-years ≥ 20 (OR: 3.672, 95% CI: 1.165-11.579), family history of cancer (OR: 8.353, 95% CI: 2.368-10.417), the level of fibrinogen > 4.81 g/L (OR: 3.628, 95% CI: 1.403-9.385) and serum C3 > 1.00 g/L (OR: 5.299, 95% CI: 1.727-16.263) were independently associated with LC in patients with CPFE. Compared to those without AE, CPFE patients with AE had significantly higher levels of PLR and serum CRP, with obviously lower DLCO and VC. The obviously increased PLR (HR: 3.731, 95% CI: 1.288-10.813), and decreased DLCO%pred (HR: 0.919, 95% CI: 0.863-0.979) and VC%pred (HR: 0.577, 95% CI: 0.137-0.918) rather than the presence of LC independently contributed to the development of natural-course-related AE in patients with CPFE. Pack-years, family history of cancer, the levels of fibrinogen and serum C3 were independently associated with LC in patients with CPFE. The presence of LC did not significantly increase the risk of AE as a natural course of CPFE. Clinicians should give high priority to CPFE patients, especially those with more severe fibrosis and systemic inflammation, in order to be alert for the occurrence of AE.

KL-6 as an Immunological Biomarker Predicts the Severity, Progression, Acute Exacerbation, and Poor Outcomes of Interstitial Lung Disease: A Systematic Review and Meta-Analysis

Object

Interstitial lung disease (ILD) is a specific form of chronic fibrosing interstitial pneumonia with various etiology. The severity and progression of ILD usually predict the poor outcomes of ILD. Otherwise, Krebs von den Lungen-6 (KL-6) is a potential immunological biomarker reflecting the severity and progression of ILD. This meta-analysis is to clarify the predictive value of elevated KL-6 levels in ILD.

Method

EBSCO, PubMed, and Cochrane were systematically searched for articles exploring the prognosis of ILD published between January 1980 and April 2021. The Weighted Mean Difference (WMD) and 95% Confidence Interval (CI) were computed as the effect sizes for comparisons between groups. For the relationship between adverse outcome and elevated KL-6 concentration, Hazard Ratio (HR), and its 95%CI were used to estimate the risk factor of ILD.

Result

Our result showed that ILD patients in severe and progressive groups had higher KL-6 levels, and the KL-6 level of patients in the severe ILD was 703.41 (U/ml) than in mild ILD. The KL-6 level in progressive ILD group was 325.98 (U/ml) higher than that in the non-progressive ILD group. Secondly, the KL-6 level of patients in acute exacerbation (AE) of ILD was 545.44 (U/ml) higher than stable ILD. Lastly, the higher KL-6 level in ILD patients predicted poor outcomes. The KL-6 level in death of ILD was 383.53 (U/ml) higher than in survivors of ILD. The pooled HR (95%CI) about elevated KL-6 level predicting the mortality of ILD was 2.05 (1.50–2.78), and the HR (95%CI) for progression of ILD was 1.98 (1.07–3.67).

Conclusion

The elevated KL-6 level indicated more severe, more progressive, and predicted the higher mortality and poor outcomes of ILD.

Baseline High-Resolution CT Findings Predict Acute Exacerbation of Idiopathic Pulmonary Fibrosis: German and Japanese Cohort Study

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is a major cause of morbidity and death in IPF. However, sensitive predictive factors of AE-IPF have not been well-investigated. To investigate whether high-resolution computed tomographic (HRCT) abnormalities predict AE-IPF in independent ethnic cohorts, this study included 121 patients with IPF (54 German and 67 Japanese; mean age, 68.5 ± 7.6 years). Two radiologists independently visually assessed the presence and extent of lung abnormalities in each patient. Twenty-two (18.2%) patients experienced AE-IPF during the follow-up. The incidence of AE-IPF was significantly higher in the Japanese patients (n = 18, 26.9%) than in the German patients (n = 4, 7.3%, p < 0.01). In the Kaplan–Meier analysis, patients with a larger extent of ground glass opacity (GGO), fibrosis, and traction bronchiectasis experienced an earlier onset of AE-IPF (p = 0.0033, 0.0088, and 0.049, respectively). In the multivariate analysis, a larger extent of GGO and fibrosis on HRCT were independent predictors of AE-IPF (p = 0.026 and 0.037, respectively). Additionally, Japanese ethnicity was independently associated with the incidence of AE-IPF after adjustment for HRCT findings (p = 0.0074). In conclusion, a larger extent of GGO and fibrosis on HRCT and Japanese ethnicity appear to be risk factors for AE-IPF.

Clinical importance of Bcl-2-like 11 deletion polymorphism in idiopathic pulmonary fibrosis

Background

Reactive oxygen species (ROS) can play a role in the pathogenesis of Idiopathic Pulmonary Fibrosis (IPF) by contributing to epithelial damage. Bcl-2-like 11 (BIM) is involved in the generation of ROS via forkhead box O3 (FOXO3), and a BIM deletion polymorphism related to apoptosis has been reported to be specific to Asians. Here we examine the clinical features of IPF in patients with BIM deletion polymorphism.

Methods

In this single-center retrospective study, we reviewed the medical records of 63 patients with IPF who were treated at our hospital from January 2006 through April 2018. Patients with and without BIM deletion polymorphism were compared in relation to clinical characteristics, pulmonary function test results, frequency of acute exacerbation (AE)-IPF, and redox status [including oxidized glutathione (GSSG), reduced glutathione (GSH), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 8-isoprostane (8-iso)] at baseline and at 1 and 2 years after treatment.

Results

No fatal AE-IPF occurred in patients with BIM deletion polymorphism (0% vs. 36.4% of polymorphism-negative cases; P=0.038). Change in forced vital capacity from baseline (ΔFVC) at 2 years was significantly lower in patients with the BIM deletion polymorphism than in those without the polymorphism (‒0.42±0.50 vs. ‒0.88±0.83 L, respectively; P=0.045). Total blood glutathione (tGSH) was significantly higher in patients with the deletion polymorphism than in those without the polymorphism (988±48.3 vs. 858±25.8 µM, respectively; P=0.042). 8-iso was significantly lower in the former group (246.1±81.6 vs. 400.9±334.1 pg/mL, respectively; P=0.022).

Conclusions

IPF patients with BIM deletion polymorphism had a good redox balance and may thus have a better clinical outcome than patients without this polymorphism.

Acute exacerbation of interstitial lung diseases secondary to systemic rheumatic diseases: a prospective study and review of the literature

Acute exacerbation (AE) is a possible manifestation of interstitial lung diseases (ILD) associated to very high mortality. It's defined as clinically significant respiratory deterioration with evidence of new widespread alveolar abnormalities on computed tomography scan. AE is better described in idiopathic pulmonary fibrosis (IPF) but also reported in ILD secondary to connective tissue diseases (CTD) and vasculitis. The main features and the real clinical impact of this severe complication in these patients are not well defined. Aim of our study was to prospectively investigate the incidence, clinical features and outcome of AE in a population of patients with ILD related to CTD and vasculitis. We consecutively enrolled all patients, with ILD secondary to rheumatic systemic diseases, referring to our multidisciplinary outpatient clinic for rare lung diseases. All patients were followed for at least 12 months (range, 12-36 months). At baseline, all patients underwent to a core set of laboratory investigations and periodically followed; data about demographic, disease onset, clinical, serological and therapeutic features were also recorded. AE occurred in 9/78 patients, with an incidence of 5.77/100 patients/year, and 5/9 patients died because of AE. The baseline value of DLCO was significantly associated to the risk of AE at Cox regression. In patients with ILD related to rheumatic systemic diseases AE can occur with an incidence similar to IPF. Rheumatologists should carefully consider this life-threatening complication as a possible natural course of all patients with ILD secondary to systemic rheumatic disease.

Serum decorin is a potential prognostic biomarker in patients with acute exacerbation of idiopathic pulmonary fibrosis

Background

Decorin is a small leucine-rich repeat proteoglycan that plays a critical role in collagen fibrillogenesis, and regulates inflammation, wound healing and angiogenesis. In idiopathic pulmonary fibrosis (IPF), decorin is expressed in fibrotic lesions; furthermore, intratracheal gene transfer of decorin has been demonstrated to inhibit bleomycin-induced pulmonary fibrosis. Although these results suggest the critical role of decorin in pulmonary fibrosis, the role of decorin in the acute exacerbation of idiopathic interstitial pneumonia (AE-IIP) has not been clarified in detail. Thus, the goal of this study was to determine the role of decorin in AE-IIP.

Methods

We retrospectively analyzed AE-IIP patients who had been admitted to our hospital. First, serum decorin levels were compared among patients with AE-IIP, patients with stable idiopathic interstitial pneumonia (SD-IIP), and healthy subjects. Next, the relationship between serum decorin levels and clinical parameters was analyzed in AE-IIP patients. Finally, the association between serum decorin levels and prognosis was evaluated in AE-IIP patients. IIP was divided into IPF and non-IPF, according to the published guidelines.

Results

The serum decorin levels of AE-IIP patients were significantly lower than those of both healthy subjects and SD-IIP patients. Serum decorin levels were not related with the clinical parameters and prognosis, when all IIP patients were analyzed. In IPF patients, serum decorin levels had a significant correlation with oxygenation, and IPF patients with low serum decorin levels had a significantly higher survival rate than those with high serum decorin levels.

Conclusions

Serum decorin levels are a potential prognostic biomarker in AE-IPF.

Accumulation of periostin in acute exacerbation of familial idiopathic pulmonary fibrosis

Periostin, an extracellular matrix molecule, is associated with idiopathic pulmonary fibrosis (IPF). It is known that the frequency of familial IPF (FIPF) ranges from 0.5% to 2.2% among IPF cases. However, the relationship between periostin and FIPF has not been previously described. We report the first case of periostin accumulation in the lungs of a patient with an acute exacerbation of FIPF. A 72-year-old woman, diagnosed with FIPF, had been followed up for 5 years. The patient experienced increased dyspnea within a 1-month period and was referred to our hospital. The patient was hypoxic, and chest computed tomography showed rapidly expanding bilateral reticular shadows. Despite pulse-steroid and intravenous-cyclophosphamide therapy, the patient died 25 days after admission. On admission, serum periostin levels were not significantly elevated, while serum fibrotic marker levels were elevated. Immunohistochemical analysis of the lungs on autopsy showed marked accumulation of periostin in the active fibrotic lesions, whereas intact and burned-out areas did not show significant expression of periostin. This case might provide insight into the role of periostin in acute exacerbation of IPF.

Acute exacerbation of idiopathic pulmonary fibrosis-a review of current and novel pharmacotherapies

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive form of lung disease of unknown etiology for which a paucity of therapies suggest benefit, and for which none have demonstrated improved survival. Acute exacerbation of IPF (AE-IPF) is defined as a sudden acceleration of the disease or an idiopathic acute injury superimposed on diseased lung that leads to a significant decline in lung function. An AE-IPF is associated with a mortality rate as high as 85% with mean survival periods of between 3 to 13 days. Under these circumstances, mechanical ventilation (MV) is controversial, unless used a as a bridge to lung transplantation. Judicious fluid management may be helpful. Pharmaceutical treatment regimens for AE-IPF include the use of high dose corticosteroids with or without immunosuppressive agents such as cyclosporine A (CsA), and broad spectrum antibiotics, despite the lack of convincing evidence demonstrating benefit. Newer research focuses on abnormal wound healing as a cause of fibrosis and preventing fibrosis itself through blocking growth factors and their downstream intra-cellular signaling pathways. Several novel pharmaceutical approaches are discussed.