Potential role of SIRT-1 and SIRT-3 as biomarkers for the diagnosis and prognosis of idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a debilitating and progressive lung disease of unknown aetiology, characterized by the relentless deposition of fibrotic tissue. Biomarkers may play a pivotal role as indicators of disease presence, progression, and treatment response. Sirtuins, a family of enzymes with ADP ribosyltransferase or deacetylase activity, have been implicated in several diseases, including pulmonary fibrosis.

METHODS

A cross-sectional, prospective, observational single-center study was conducted to investigate the potential role of serum SIRTs levels as biomarkers in patients with IPF. Demographic, clinical, and functional data and serological samples were collected from 34 patients with IPF followed at the Interstital Lung and Rare Diseases Outpatient Clinic of the Vanvitelli Pneumology Clinic, Monaldi Hospital, Naples, Italy and from 19 age-matched controls.

RESULTS

Serum SIRT-1 levels were significantly reduced in IPF patients compared to controls (median IPF 667 [435-858] pg/mL versus controls 925 [794-1173] pg/mL; p < 0.001 ). In contrast, serum SIRT-3 levels were significantly increased in IPF patients compared to controls (median IPF 338 [230-500] pg/mL versus controls 154 [99.8-246] pg/mL; p < 0.001). There were no statistically significant differences in serum SIRT-6 and SIRT-7 levels between IPF and controls. In addition, we found a significant positive correlation between SIRT-1 and lung function parameters such as FEV1% (ϱ=0.417;p = 0.016), FVC% (ϱ=0.449;p = 0.009) and DLCO% (ϱ=0.393;p = 0.024), while a significant negative correlation was demonstrated between SIR-1 and GAP score, demonstrating a significant reduction in SIRT-1 in advanced Gender-Age-Physiology (GAP) stages 2-3 compared to GAP stage 1 (p = 0.008).

CONCLUSIONS

This prospective, cross-sectional study showed that SIRT-1 was associated with lung function and IPF severity and that both SIRT-1 and SIRT-3 could be considered as potential biomarkers of IPF, whereas SIRT-6 and SIRT-7 were not associated with IPF.

Endothelial-Specific Loss of Sphingosine-1-Phosphate Receptor 1 Increases Vascular Permeability and Exacerbates Bleomycin-induced Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease which leads to significant morbidity and mortality from respiratory failure. The two drugs currently approved for clinical use slow the rate of decline in lung function but have not been shown to halt disease progression or reverse established fibrosis. Thus, new therapeutic targets are needed. Endothelial injury and the resultant vascular permeability are critical components in the response to tissue injury and are present in patients with IPF. However, it remains unclear how vascular permeability affects lung repair and fibrosis following injury. Lipid mediators such as sphingosine-1-phosphate (S1P) are known to regulate multiple homeostatic processes in the lung including vascular permeability. We demonstrate that endothelial cell-(EC) specific deletion of the S1P receptor 1 (S1PR1) in mice (EC-S1pr1-/-) results in increased lung vascular permeability at baseline. Following a low-dose intratracheal bleomycin challenge, EC-S1pr1-/- mice had increased and persistent vascular permeability compared with wild-type mice, which was strongly correlated with the amount and localization of resulting pulmonary fibrosis. EC-S1pr1-/- mice also had increased immune cell infiltration and activation of the coagulation cascade within the lung. However, increased circulating S1P ligand in ApoM-overexpressing mice was insufficient to protect against bleomycin-induced pulmonary fibrosis. Overall, these data demonstrate that endothelial cell S1PR1 controls vascular permeability in the lung, is associated with changes in immune cell infiltration and extravascular coagulation, and modulates the fibrotic response to lung injury.

Correlates of survival after autoantibody reduction therapy for acute IPF exacerbations

Background

No medical treatment has proven efficacy for acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF), and this syndrome has a very high mortality. Based on data indicating humoral autoimmune processes are involved in IPF pathogenesis, we treated AE-IPF patients with an autoantibody reduction regimen of therapeutic plasma exchange, rituximab, and intravenous immunoglobulin. This study aimed to identify clinical and autoantibody determinants associated with survival after autoantibody reduction in AE-IPF.

Methods

Twenty-four(24) AE-IPF patients received the autoantibody reduction regimen. Plasma anti-epithelial autoantibody titers were determined by HEp-2 indirect immunofluorescence assays in 22 patients.

Results

Mean age of the patients was 70 + 7 years old, and 70% were male. Beneficial clinical responses that occurred early during therapy were a favorable prognostic indicator: supplemental O₂ flows needed to maintain resting S_aO₂>92% significantly decreased and/or walk distances increased among all 10 patients who survived for at least one year. Plasma anti-HEp-2 autoantibody titers were ~-three-fold greater in survivors compared to non-survivors (p<0.02). Anti-HEp-2 titers >1:160 were present in 75% of the evaluable one-year survivors, compared to 29% of non-survivors, and 10 of 12 patients (83%) with anti-HEP-2 titers <1:160 died during the observation period (Hazard Ratio = 3.3, 95% Confidence Interval = 1.02–10.6, p = 0.047).

Conclusions

Autoantibody reduction therapy is associated with rapid reduction of supplemental oxygen requirements and/or improved ability to ambulate in many AE-IPF patients. Facile anti-epithelial autoantibody assays may help identify those most likely to benefit from these treatments.

Long-term personal air pollution exposure and risk for acute exacerbation of idiopathic pulmonary fibrosis

BACKGROUND

Urban air pollution is involved in the progress of idiopathic pulmonary fibrosis (IPF). Its potential role on the devastating event of Acute Exacerbation of IPF (AE-IPF) needs to be clarified. This study examined the association between long-term personal air pollution exposure and AE- IPF risk taking into consideration inflammatory mediators and telomere length (TL).

METHODS

All consecutive IPF-patients referred to our Hospital from October 2013-June 2019 were included. AE-IPF events were recorded and inflammatory mediators and TL measured. Long-term personal air pollution exposures were assigned to each patient retrospectively, for O₃, NO₂, PM_2.5 [and PM₁₀, based on geo-coded residential addresses. Logistic regression models assessed the association of air pollutants' levels with AE-IPF and inflammatory mediators adjusting for potential confounders.

RESULTS

118 IPF patients (mean age 72 ± 8.3 years) were analyzed. We detected positive significant associations between AE-IPF and a 10 μg/m³ increase in previous-year mean level of NO₂ (OR = 1.52, 95%CI:1.15-2.0, p = 0.003), PM_2.5 (OR = 2.21, 95%CI:1.16-4.20, p = 0.016) and PM₁₀ (OR = 2.18, 95%CI:1.15-4.15, p = 0.017) independent of age, gender, smoking, lung function and antifibrotic treatment. Introduction of TL in all models of a subgroup of 36 patients did not change the direction of the observed associations. Finally, O₃ was positively associated with %change of IL-4 (p = 0.014) whilst PM_2.5, PM₁₀ and NO₂ were inversely associated with %changes of IL-4 (p = 0.003, p = 0.003, p = 0.032) and osteopontin (p = 0.013, p = 0.013, p = 0.085) respectively.

CONCLUSIONS

Long-term personal exposure to increased concentrations of air pollutants is an independent risk factor of AE-IPF. Inflammatory mediators implicated in lung repair mechanisms are involved.

Protective function of interleukin-22 in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive scarring disease with unknown etiology. The evidence of a pathogenic role for transforming growth factor-beta (TGF-β) in the development and progression of IPF is overwhelming. In the present study, we investigated the role of interleukin-22 (IL-22) in the pathogenesis of IPF by regulating the TGF-β pathway. We measured parameters and tissue samples from a clinical cohort of IPF. IL-22R knock out (IL-22RA1-/- ) and IL-22 supplementation mouse models were used to determine if IL-22 is protective in vivo. For the mechanistic study, we tested A549, primary mouse type II alveolar epithelial cell, human embryonic lung fibroblast, and primary fibroblast for their responses to IL-22 and/or TGF-β1. In a clinical cohort, the expression level of IL-22 in the peripheral blood and lung tissues of IPF patients was lower than healthy controls, and the lower IL-22 expression was associated with poorer pulmonary function. IL-22R-/- mice demonstrated exacerbated inflammation and fibrosis. Reciprocally, IL-22 augmentation by intranasal instillation of recombinant IL-22 repressed inflammation and fibrotic phenotype. In vitro, IL-22 treatment repressed TGF-β1 induced gene markers representing epithelial-mesenchymal-transition and fibroblast-myofibroblast-transition, likely via the inhibition of TGF-β receptor expression and subsequent Smad2/3 activation. IL-22 appears to be protective against pulmonary fibrosis by inhibiting TGF-β1 signaling, and IL-22 augmentation may be a promising approach to treat IPF.

Monocyte Count as a Prognostic Biomarker in Patients with Idiopathic Pulmonary Fibrosis

Rationale: There is an urgent need for simple, cost-effective prognostic biomarkers for idiopathic pulmonary fibrosis (IPF); biomarkers that show potential include monocyte count. Objectives: We used pooled data from pirfenidone and IFNγ-1b trials to explore the association between monocyte count and prognosis in patients with IPF. Methods: This retrospective pooled analysis included patients (active and placebo arms) from the following four phase III, randomized, placebo-controlled trials: ASCEND (NCT01366209), CAPACITY (NCT00287729 and NCT00287716), and INSPIRE (NCT00075998). Outcomes included IPF progression (≥10% absolute decline in FVC% predicted, ≥50 m decline in 6-minute-walk distance, or death), all-cause hospitalization, and all-cause mortality over 1 year. The relationship between monocyte count (defined as time-dependent) and outcomes was assessed using bivariate and multivariable models. Measurements and Main Results: This analysis included 2,067 patients stratified by monocyte count (at baseline: <0.60 × 109 cells/L [n = 1,609], 0.60 to <0.95 × 109 cells/L [n = 408], and ≥0.95 × 109 cells/L [n = 50]). In adjusted analyses, a higher proportion of patients with monocyte counts of 0.60 to <0.95 × 109 cells/L or ≥0.95 × 109 cells/L versus <0.60 × 109 cells/L experienced IPF progression (P = 0.016 and P = 0.002, respectively), all-cause hospitalization (P = 0.030 and P = 0.003, respectively), and all-cause mortality (P = 0.005 and P < 0.001, respectively) over 1 year. Change in monocyte count from baseline was not associated with any of the outcomes over 1 year and did not appear to be affected by study treatment. Conclusions: In patients with IPF, elevated monocyte count was associated with increased risks of IPF progression, hospitalization, and mortality. Monocyte count may provide a simple and inexpensive prognostic biomarker in IPF.

Extracellular Vesicle Surface Signatures in IPF Patients: A Multiplex Bead-Based Flow Cytometry Approach

Background: Extracellular vesicles (EVs) are secreted by cells from their membrane within circulation and body fluids. Knowledge of the involvement of EVs in pathogenesis of lung diseases is increasing. The present study aimed to evaluate the expression of exosomal surface epitopes in a cohort of idiopathic pulmonary fibrosis (IPF) patients followed in two Italian Referral Centres for Interstitial Lung Diseases, comparing them with a group of healthy volunteers. Materials and Methods: Ninety IPF patients (median age and interquartile range (IQR) 71 (66–75) years; 69 males) were selected retrospectively. Blood samples were obtained from patients before starting antifibrotic therapy. A MACSPlex Exosome Kit, human, (Miltenyi Biotec, Bergisch-Gladbach, Germany), to detect 37 exosomal surface epitopes, was used. Results: CD19, CD69, CD8, and CD86 were significantly higher in IPF patients than in controls (p = 0.0023, p = 0.0471, p = 0.0082, and p = 0.0143, respectively). CD42a was lower in IPF subjects than in controls (p = 0.0153), while CD209, Cd133/1, MCSP, and ROR1 were higher in IPF patients than in controls (p = 0.0007, p = 0.0050, p = 0.0139, and p = 0.0335, respectively). Kaplan-Meier survival analysis for IPF patients: for median values and a cut-off of 0.48 for CD25, the two subgroups showed a significant difference in survival rate (p = 0.0243, hazard ratio: 0.52 (95%CI 0.29–0.92); the same was true for CD8 (cut-off 1.53, p = 0.0309, hazard ratio: 1.39 (95%CI 0.75–2.53). Conclusion: Our multicenter study showed for the first time the expression of surface epitopes on EVs from IPF patients, providing interesting data on the communication signatures/exosomal profile in serum from IPF patients and new insights into the pathogenesis of the disease and a promising reliability in predicting mid-term survival of IPF patients.

Gremlin-1 for the Differential Diagnosis of Idiopathic Pulmonary Fibrosis Versus Other Interstitial Lung Diseases: A Clinical and Pathophysiological Analysis

PURPOSE

The differential diagnosis of interstitial lung diseases (ILDs), particularly idiopathic pulmonary fibrosis (IPF) versus other non-IPF ILDs, is important for selecting the appropriate treatment. This retrospective study aimed to explore the utility of gremlin-1 for the differential diagnosis.

METHODS

Serum gremlin-1 concentrations were measured using an ELISA in 50 patients with IPF, 42 patients with non-IPF ILD, and 30 healthy controls. The baseline clinical data, including pulmonary functions, prognosis, and three serum biomarkers (Krebs von den Lungen-6 [KL6], surfactant protein-D [SP-D], and lactate dehydrogenase [LDH]), were obtained through a medical record review for analyzing their associations with serum gremlin-1 concentrations. To evaluate the origin of gremlin-1, we performed immunostaining on lung sections.

RESULTS

Serum gremlin-1 concentrations were significantly higher in patients with IPF (mean concentration, 14.4 ng/mL), followed by those with non-IPF ILD (8.8 ng/mL) and healthy controls (1.6 ng/mL). The area under the curve for IPF versus non-IPF ILDs was 0.759 (95% confidence interval, 0.661-0.857), which was superior to that of KL6/SP-D/LDH. The sensitivity and specificity for gremlin-1 (cutoff, 10.4 ng/mL) was 72 and 69%, respectively. By contrast, serum gremlin-1 concentrations were not associated with the pulmonary functions nor the prognosis in all patients with ILDs. In immunostaining, the gremlin-1 was broadly upregulated in IPF lungs, particularly at myofibroblasts, bronchiolar/alveolar epithelium, and CD163-positive M2-like macrophages.

CONCLUSIONS

Gremlin-1 may be a useful biomarker to improve the diagnostic accuracy for IPF compared to non-IPF ILDs, suggesting a role of this molecule in the pathogenesis of IPF.

Elevated Serum Amyloid a Levels Are not Specific for Sarcoidosis but Associate with a Fibrotic Pulmonary Phenotype

Elevated Serum Amyloid A (SAA) levels have been found in several inflammatory diseases, including sarcoidosis. SAA is suggested to be involved in sarcoidosis pathogenesis by involvement in granuloma formation and maintenance. We hypothesized that SAA serum levels would be higher in sarcoidosis compared to other non-infectious granulomatous and non-granulomatous diseases. SAA levels were measured in serum from sarcoidosis, Hypersensitivity pneumonitis (HP), and (eosinophilic) granulomatosis with polyangiitis ((E)GPA) patients. Idiopathic pulmonary fibrosis (IPF) patients were included as non-granulomatous disease group. SAA levels of patients with sarcoidosis (31.0 µg/mL), HP (23.4 µg/mL), (E)GPA (36.9 µg/mL), and IPF (22.1 µg/mL) were all higher than SAA levels of healthy controls (10.1 µg/mL). SAA levels did not differ between the diagnostic groups. When SAA serum levels were analyzed in sarcoidosis subgroups, fibrotic sarcoidosis patients showed higher SAA levels than sarcoidosis patients without fibrosis (47.8 µg/mL vs. 29.4 µg/mL, p = 0.005). To conclude, the observation that fibrotic sarcoidosis patients have higher SAA levels, together with our finding that SAA levels were also increased in IPF patients, suggests that SAA may next to granulomatous processes also reflect the process of fibrogenesis. Further studies should clarify the exact role of SAA in fibrosis and the underlying mechanisms involved.

Prognostic Significance of Red Cell Distribution Width in Idiopathic Pulmonary Fibrosis and Combined Pulmonary Fibrosis Emphysema

OBJECTIVE

The red cell distribution width (RDW) is an inexpensive, readily available prognostic indicator of several diseases. RDW has been assessed as a prognostic biomarker in patients with idiopathic pulmonary fibrosis (IPF) in only one study; furthermore, the relationship between the RDW and combined pulmonary fibrosis emphysema (CPFE) has yet to be reported.

SUBJECTS AND METHODS

This single-center study was conducted between January 2015 and December 2018 in the Atatürk Chest Diseases and Chest Surgery Education and Research Hospital. Baseline characteristics, laboratory results, and survival status of patients were recorded.

RESULTS

The RDW value was significantly higher in the CPFE group than in the IPF group (median [IQR 25-75]; 16.8 [15.5-19] vs. 15.3 [13.7-16.8], p = 0.028). High RDW values were correlated with carbon monoxide diffusion capacity (DLCO) (r: -0.653 p = 0.001), 6-minute walking test (6MWT) distance (r: -0.361 p = 0.017), arterial partial oxygen pressure (PaO2) (r: -0.692 p < 0.001), and systolic pulmonary arterial pressure (SPAP) (r: 0.349 p = 0.022) in patients with fibrotic lung disease. The RDW value was significantly higher in the exitus group than in the survivors (median [IQR 25-75]; 18.4 [15.4-19] vs. 15.2 [13.5-17.2], p = 0.016). A univariate Cox regression analysis identified DLCO, SPAP, PaO2, and RDW as potential covariates of mortality. In a multivariate analysis, the DLCO (HR 1.21, 95% CI 1.11-1.47, p = 0.012) and RDW level (HR 1.65, 95% CI 1.09-2.47, p = 0.023) remained independent predictors of mortality.

CONCLUSION

High RDW values appear to be a simple prognostic factor in patients with IPF or CPFE.

Local and Systemic Concentrations of Pattern Recognition Receptors of the Lectin Pathway of Complement in a Cohort of Patients With Interstitial Lung Diseases

Background

The role of the lectin pathway of complement in the pathogenesis of interstitial lung diseases (ILDs) is largely unknown. Pattern recognition receptors (PRR) of the lectin pathway are involved in the clearance of apoptotic cells either via activation of the complement system or as direct opsonins. As recent findings suggest a role of apoptosis in the development of pulmonary fibrosis, the influence of plasma lectins has lately been considered in various ILDs, but data on local concentrations in the lungs are lacking. This study investigated the role of mannose-binding lectin (MBL), ficolin-2 and ficolin-3 in ILD patients with a focus on idiopathic pulmonary fibrosis (IPF) and sarcoidosis.

Methods

A case control study was conducted involving 80 patients with different forms of ILD as well as 40 control patients undergoing routine flexible bronchoscopy with bronchoalveolar lavage (BAL). Plasma and BAL fluid (BALF) levels of MBL, ficolin-2 and ficolin-3 as well as complement split products C4d and C5a (only in BALF) were measured by enzyme-linked immunosorbent assays. Eight single-nucleotide polymorphisms (SNPs) of MBL and ficolin-2 were determined by genotyping and tested for their association with ILDs.

Results

We included 35, 35, 10, and 40 patients with sarcoidosis, idiopathic pulmonary fibrosis (IPF), other ILD, and a control group, respectively. BALF but not plasma levels of the three PRR were significantly elevated in sarcoidosis patients compared to a control group without ILD (MBL: median 66.8 vs. 24.6 ng/ml, p = 0.02, ficolin-2: 140 vs. 58.8 ng/ml, p = 0.01, ficolin-3: 2523 vs. 1180 ng/ml, p = 0.02), whereas the frequency of the investigated SNPs was similar. In line, complement split products were markedly elevated in BALF of sarcoidosis patients (C4d, median 97.4 vs. 0 ng/ml, p = 0.10; C5a, 23.9 vs. 9.1 ng/ml, p = 0.01). There was a weak positive correlation of BALF ficolin-3 with serum neopterin, a marker of sarcoidosis activity. In IPF patients, we observed numerically higher MBL plasma and BALF levels (plasma, median 1511 vs. 879 ng/ml, p = 0.44; BALF, 37.5 vs. 24.6 ng/ml, p = 0.7) as well as lower ficolin-2 plasma levels (plasma 1111 vs. 1647 ng/ml, p = 0.11). Ficolin-2 plasma levels were inversely correlated with the forced vital capacity (r = 0.55, p = 0.1).

Conclusion

This is the first study to simultaneously assess systemic and local lectin pathway protein levels in ILD patients. Our data suggest an involvement of PRR of the lectin pathway in the pathogenesis of sarcoidosis given the significantly higher BALF levels compared to a control group. Additional analyses in a larger patient cohort are required to confirm or refute a potential effect of local and/or systemic ficolin-2 levels in IPF patients.

The Transcription Factor SCX is a Potential Serum Biomarker of Fibrotic Diseases

Fibrosing diseases are causes of morbidity and mortality around the world, and they are characterized by excessive extracellular matrix (ECM) accumulation. The bHLH transcription factor scleraxis (SCX) regulates the synthesis of ECM proteins in heart fibrosis. SCX expression was evaluated in lung fibroblasts and tissue derived from fibrotic disease patients and healthy controls. We also measured SCX in sera from 57 healthy controls, and 56 Idiopathic Pulmonary Fibrosis (IPF), 40 Hypersensitivity Pneumonitis (HP), and 100 Systemic Sclerosis (SSc) patients. We report high SCX expression in fibroblasts and tissue from IPF patients versus controls. High SCX-serum levels were observed in IPF (0.663 ± 0.559 ng/mL, p < 0.01) and SSc (0.611 ± 0.296 ng/mL, p < 0.001), versus controls (0.351 ± 0.207 ng/mL) and HP (0.323 ± 0.323 ng/mL). Serum levels of the SCX heterodimerization partner, TCF3, did not associate with fibrotic illness. IPF patients with severely affected respiratory capacities and late-stage SSc patients presenting anti-topoisomerase I antibodies and interstitial lung disease showed the highest SCX-serum levels. SCX gain-of-function induced the expression of alpha-smooth muscle actin (α-SMA/ACTA2) in fibroblasts when co-overexpressed with TCF3. As late and severe stages of the fibrotic processes correlated with high circulating SCX, we postulate it as a candidate biomarker of fibrosis and a potential therapeutic target.

The association between white blood cell count and outcomes in patients with idiopathic pulmonary fibrosis

BACKGROUND

The course of idiopathic pulmonary fibrosis (IPF) is uncertain with variable patterns of disease progression. We sought to evaluate the prognostic utility of the WBC, a routinely performed lab test, in a well-defined cohort of outpatient IPF subjects.

METHODS

We reviewed IPF patient records from two independent ILD centers (Inova Fairfax in Falls Church, VA, USA and Ege University Hospital in Izmir, Turkey) between 2007 and 2018. Demographics, CBC data, and patient outcomes were obtained. Survival differences were analyzed.

RESULTS

There were 436 IPF outpatients in the cohort with a median WBC of 8.9 × 10⁹ cells per liter. For pragmatic purposes, patients were categorized into two groups, WBC ≥9 or WBC <9. Patients with WBC <9 had a median transplant-free survival of 50.5 months from the time of the CBC, compared to 32.4 months for those with WBC ≥9 (p < 0.0001). The association between WBC and attenuated survival remained significant after adjusting for GAP stage, steroid use, and antifibrotic use when WBC was analyzed both as a continuous (HR: 1.11; 95% CI: 1.05-1.17) and a dichotomized variable (high (WBC ≥9) vs. low (WBC <9), (HR: 1.53; 95% CI:1.09-2.15). WBC and absolute neutrophil count (ANC) were highly correlated suggesting that PMNs account for most of this association (r = 0.92).

CONCLUSIONS

Baseline WBC may impart important and readily available prognostic information in outpatients with IPF. Further studies are warranted to validate this as a potential biomarker for IPF, as well as to define the biologic basis for the association.

Monocyte count and the risk for acute exacerbation of fibrosing interstitial lung disease: A retrospective cohort study

Recent studies have suggested that an increased peripheral monocyte count predicts a poor outcome in fibrosing interstitial lung disease (ILD). However, the association between an increased monocyte count and acute exacerbations (AEs) of fibrosing ILD remains to be elucidated. Our retrospective cohort study aimed to assess the impact of peripheral monocyte count on AEs of fibrosing ILD. We analyzed the electronic medical records of 122 consecutive patients with fibrosing ILD and no prior history of an AE, who were treated with anti-fibrotic agents from August 2015 to December 2018. We determined their peripheral monocyte counts at anti-fibrotic agent initiation and performed univariate and multivariate Cox regression analyses of time-to-first AE after anti-fibrotic agent initiation to assess the impact of monocyte count on AEs of fibrosing ILD. Twenty-six patients developed an AE during the follow-up period, and there was an increased monocyte count at anti-fibrotic agent initiation in these patients compared to those who did not develop an AE. There was also a significantly shorter time-to-first AE of fibrosing ILD in patients with a higher absolute monocyte count. Subgroup analyses indicated similar results regardless of the idiopathic pulmonary fibrosis diagnoses. This association was independently significant after adjusting for the severity of the fibrosing ILD. Using our results, we developed a simple scoring system consisting of two factors-monocyte count (<>380 µL-1) and ILD-gender, age, physiology score (<>4 points). Our findings suggest that the absolute monocyte count is an independent significant risk factor for AE in patients with fibrosing ILD. Our simple scoring system may be a predictor for AEs of fibrosing ILD, although further studies are needed to verify our findings.

The senescence-associated matricellular protein CCN1 in plasma of human subjects with idiopathic pulmonary fibrosis

INTRODUCTION

Cellular senescence has been linked to the pathogenesis of idiopathic pulmonary fibrosis (IPF). CCN1 is a matricellular protein that has been shown to induce cellular senescence and contribute to lung fibrosis in pre-clinical models. In this report, we determined plasma CCN1 levels in patients with IPF and its potential role in clinical outcomes.

METHODS AND RESULTS

We evaluated 88 patients diagnosed with IPF at the University of Alabama at Birmingham. CCN1 levels were measured in plasma specimens by ELISA. The primary outcome measure was transplant-free survival (TFS) duration. High-CCN1 levels were associated with a lower transplant-free survival independent of %FVC and %D_LCO compared to patients with low plasma CCN1 (HR = 2.15; 95%CI 1.04-4.45, p = 0.04).

CONCLUSION

This study demonstrates that plasma levels of CCN1 may be predictive of survival in IPF. Given the plausible role of CCN1 in cellular senescence and pathobiology of IPF, the predictive value of CCN1 in disease progression among patients with IPF warrants further investigation.

Antinuclear antibodies in interstitial lung disease: Prevalence and clinical significance

INTRODUCTION

The diagnosis of interstitial lung disease (ILD) requires elimination of underlying connective tissue disease. Consequently, antinuclear antibodies (ANA) are routinely screened in patients with idiopathic interstitial pneumonia. However the clinical usefulness of this practice is not well clear.

AIM

In this study, we evaluated the frequency of ANA in ILD's patients and investigated the clinical significance of the ANA's presence in these patients.

METHODS

We conducted a retrospective study of hospitalized patients diagnosed ILD at pulmonary department and for which ANA was performed in the immunology laboratory of our institution. Demographic features, clinical symptoms, biological and radiologic findings and CTD-ILD diagnoses were compared between patients with positive ANA versus negative ANA.

RESULTS

We enrolled 73 patients. The ANA's prevalence was 32%. There were no significant differences in demographics, pulmonary function test values and radiologic findings between patients with and without ANA. Patients with positive ANA had more cutaneous manifestations (p꞊0.011) and Raynaud's phenomenon (p꞊0.029). The diagnosis of connective tissue disease was made in 42% of patients with positive ANA versus 8% with negative ANA (p꞊ 0.001). ANA's titer higher than 1/320 was predictive of CTD diagnosis (OR꞊14.4) (p<0.001).

CONCLUSIONS

The research of ANA in PID's patients is an important tool of CTD diagnosis specially in those with suggestive symptoms of autoimmune disease.

Decrements of body mass index are associated with poor outcomes of idiopathic pulmonary fibrosis patients

BACKGROUND

The processes that result in progression of idiopathic pulmonary fibrosis (IPF) remain enigmatic. Moreover, the course of this disease can be highly variable and difficult to accurately predict. We hypothesized analyses of body mass index (BMI), a simple, routine clinical measure, may also have prognostic value in these patients, and might provide mechanistic insights. We investigated the associations of BMI changes with outcome, plasma adipokines, and adaptive immune activation among IPF patients.

METHODS

Data were analyzed in an IPF discovery cohort (n = 131) from the University of Pittsburgh, and findings confirmed in patients from the University of Alabama at Birmingham (n = 148). Plasma adipokines were measured by ELISA and T-cell phenotypes determined by flow cytometry.

RESULTS

Transplant-free one-year survivals in subjects with the greatest rates of BMI decrements, as percentages of initial BMI (>0.68%/month), were worse than among those with more stable BMI in both discovery (HR = 1.8, 95%CI = 1.1-3.2, p = 0.038) and replication cohorts (HR = 2.5, 95%CI = 1.2-5.2, p = 0.02), when adjusted for age, baseline BMI, and pulmonary function. BMI decrements >0.68%/month were also associated with greater mortality after later lung transplantations (HR = 4.6, 95%CI = 1.7-12.5, p = 0.003). Circulating leptin and adiponectin levels correlated with BMI, but neither adipokine was prognostic per se. BMI decrements were significantly associated with increased proportions of circulating end-differentiated (CD28null) CD4 T-cells (CD28%), a validated marker of repetitive T-cell activation and IPF prognoses.

CONCLUSIONS

IPF patients with greatest BMI decrements had worse outcomes, and this effect persisted after lung transplantation. Weight loss in these patients is a harbinger of poor prognoses, and may reflect an underlying systemic process, such as adaptive immune activation.

[PROGNOSTIC VALUE OF BLOOD AND BRONCHOALVEOLAR LAVAGE FLUIDS BIOMARKERS FOR IDIOPATHIC PULMONARY FYBROSIS (REVIEW)]

The article reveals the modern aspects of IPF pathogenesis in with an emphasis on the main proposed prognostic biomarkers. IPF remains the leader among diseases with unknown etiology, the diagnosis and management of which are not very successful, despite the obvious progress in molecular medicine. There is presented analysis of the significance of IPF potential biomarkers and their concentrations in the blood and bronchoalveolar lavage fluids (BAL): endothelin-1, CC-chemokine ligand 18, interleukin-1, surfactant protein SP-D in the review. The role of their changing levels in the blood and BAL for assessing the course of the IPF and its prognosis, as well as the prevailing importance of the polymorphism of the genes encoding them, is shown. Obviously, the progressive accumulation of fibroblast-myofibroblast cells in the lungs IPF patients worsens the prognosis of disease, forms its own environment with a set of cytokines, growth factors, collagen, fibronectin in the extracellular matrix of fibrous lungs. The insufficient amount of studies in the face of the rarity of the disease leaves a lot of controversial issues for solution in the future. Obviously, to assess the prognosis of IPF mortality, it is necessary to include a very large number of patients, to extend the observation period, which increases their cost and reduces the opportunities and desire of pharmaceutical companies to participate in these studies.

Increased monocyte count as a cellular biomarker for poor outcomes in fibrotic diseases: a retrospective, multicentre cohort study

BACKGROUND

There is an urgent need for biomarkers to better stratify patients with idiopathic pulmonary fibrosis by risk for lung transplantation allocation who have the same clinical presentation. We aimed to investigate whether a specific immune cell type from patients with idiopathic pulmonary fibrosis could identify those at higher risk of poor outcomes. We then sought to validate our findings using cytometry and electronic health records.

METHODS

We first did a discovery analysis with transcriptome data from the Gene Expression Omnibus at the National Center for Biotechnology Information for 120 peripheral blood mononuclear cell (PBMC) samples of patients with idiopathic pulmonary fibrosis. We estimated percentages of 13 immune cell types using statistical deconvolution, and investigated the association of these cell types with transplant-free survival. We validated these results using PBMC samples from patients with idiopathic pulmonary fibrosis in two independent cohorts (COMET and Yale). COMET profiled monocyte counts in 45 patients with idiopathic pulmonary fibrosis from March 12, 2010, to March 10, 2011, using flow cytometry; we tested if increased monocyte count was associated with the primary outcome of disease progression. In the Yale cohort, 15 patients with idiopathic pulmonary fibrosis (with five healthy controls) were classed as high risk or low risk from April 28, 2014, to Aug 20, 2015, using a 52-gene signature, and we assessed whether monocyte percentage (measured by cytometry by time of flight) was higher in high-risk patients. We then examined complete blood count values in the electronic health records (EHR) of 45 068 patients with idiopathic pulmonary fibrosis, systemic sclerosis, hypertrophic cardiomyopathy, or myelofibrosis from Stanford (Jan 01, 2008, to Dec 31, 2015), Northwestern (Feb 15, 2001 to July 31, 2017), Vanderbilt (Jan 01, 2008, to Dec 31, 2016), and Optum Clinformatics DataMart (Jan 01, 2004, to Dec 31, 2016) cohorts, and examined whether absolute monocyte counts of 0·95 K/μL or greater were associated with all-cause mortality in these patients.

FINDINGS

In the discovery analysis, estimated CD14+ classical monocyte percentages above the mean were associated with shorter transplant-free survival times (hazard ratio [HR] 1·82, 95% CI 1·05-3·14), whereas higher percentages of T cells and B cells were not (0·97, 0·59-1·66; and 0·78, 0·45-1·34 respectively). In two validation cohorts (COMET trial and the Yale cohort), patients with higher monocyte counts were at higher risk for poor outcomes (COMET Wilcoxon p=0·025; Yale Wilcoxon p=0·049). Monocyte counts of 0·95 K/μL or greater were associated with mortality after adjusting for forced vital capacity (HR 2·47, 95% CI 1·48-4·15; p=0·0063), and the gender, age, and physiology index (HR 2·06, 95% CI 1·22-3·47; p=0·0068) across the COMET, Stanford, and Northwestern datasets). Analysis of medical records of 7459 patients with idiopathic pulmonary fibrosis showed that patients with monocyte counts of 0·95 K/μL or greater were at increased risk of mortality with lung transplantation as a censoring event, after adjusting for age at diagnosis and sex (Stanford HR=2·30, 95% CI 0·94-5·63; Vanderbilt 1·52, 1·21-1·89; Optum 1·74, 1·33-2·27). Likewise, higher absolute monocyte count was associated with shortened survival in patients with hypertrophic cardiomyopathy across all three cohorts, and in patients with systemic sclerosis or myelofibrosis in two of the three cohorts.

INTERPRETATION

Monocyte count could be incorporated into the clinical assessment of patients with idiopathic pulmonary fibrosis and other fibrotic disorders. Further investigation into the mechanistic role of monocytes in fibrosis might lead to insights that assist the development of new therapies.

FUNDING

Bill & Melinda Gates Foundation, US National Institute of Allergy and Infectious Diseases, and US National Library of Medicine.

Possible Serological Markers to Predict Mortality in Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Background and objectives: Idiopathic pulmonary fibrosis (IPF) has a particularly poor prognosis, and most IPF-related deaths are due to acute exacerbation (AE) of this condition. Few reports about biomarkers to predict prognosis of AE-IPF have been published since the release of the new AE-IPF criteria in 2016. The present study investigated relationships between serological markers and in-hospital mortality after the onset of AE-IPF. Methods: Demographic, serological, and imaging data from patients hospitalized at the Maebashi Red Cross Hospital (Gunma, Japan) between 1 January 2013, and 31 December 2017, were retrospectively reviewed. Subjects fulfilling the diagnostic criteria for AE-IPF were divided into those who survived or died; statistical analysis of risk factors was performed using data from these two groups. Results: Diagnostic criteria for AE-IPF were fulfilled by 84 patients (59 males (70.2%)), with a median age of 78 years (range, 56-95 years). IPF was diagnosed before hospitalization in 50 (59.5%) patients and 38 (45.2%) died in hospital. Among the serological markers at hospitalization in the deceased group, C-reactive protein (CRP) was significantly higher than in the survivor group (p = 0.002), while total serum protein (p = 0.031), albumin (p = 0.047) and total cholesterol (p = 0.039) were significantly lower. Cox hazard analysis of factors predicting mortality, corrected for age, sex and BMI, revealed the following: CRP (hazard ratio (HR) 1.080 (95% confidence interval (CI) 1.022-1.141); p = 0.006), LDH (HR 1.003 (95% CI 1.000-1.006); p = 0.037), and total cholesterol (HR 0.985 (95% CI 0.972-0.997); p = 0.018). Conclusions: Our data suggest that CRP, LDH, and total cholesterol may be biomarkers predicting mortality in patients with AE-IPF. However, only prospective controlled studies can confirm or not our observation as a generalizable one.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of GLPG1690, a novel autotaxin inhibitor, to treat idiopathic pulmonary fibrosis (FLORA): a phase 2a randomised placebo-controlled trial

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) causes irreversible loss of lung function. People with IPF have increased concentrations of autotaxin in lung tissue and lysophosphatidic acid (LPA) in bronchoalveolar lavage fluid and exhaled condensate. GLPG1690 (Galapagos, Mechelen, Belgium) is a novel, potent, selective autotaxin inhibitor with good oral exposure. We explored the effects of GLPG1690 in patients with IPF.

METHODS

This was a randomised, double-blind, placebo-controlled phase 2a study done in 17 centres in Italy, Ukraine and the UK. Eligible patients were aged 40 years or older, non-smokers, not taking pirfenidone or nintedanib, and had a centrally confirmed diagnosis of IPF. We used a computer-generated randomisation schedule to assign patients 1:3 to receive placebo or 600 mg oral GLPG1690 once daily for 12 weeks. The primary outcomes were safety (adverse events), tolerability, pharmacokinetics, and pharmacodynamics. Spirometry was assessed as a secondary outcome. This trial is registered with ClinicalTrials.gov, number NCT02738801.

FINDINGS

Between March 24, 2016, and May 2, 2017, 72 patients were screened., of whom 49 were ineligible and 23 were enrolled in eight centres (six in Ukraine and two in the UK). Six patients were assigned to receive placebo and 17 to receive GLPG1690. 20 patients completed the study after one in each group discontinued because of adverse events and one in the GLPG1690 group withdrew consent. Four (67%) patients in the placebo group and 11 (65%) in the GLPG1690 group had treatment-emergent adverse events, most of which were mild to moderate. The most frequent events in the GLPG1690 group were infections and infestations (ten events) and respiratory, thoracic, and mediastinal disorders (eight events) with no apparent differences from the placebo group. Two (12%) patients in the GLPG1690 group had events that were judged to be related to treatment. Serious adverse events were seen in two patients in the placebo group (one had a urinary tract infection, acute kidney injury, and lower respiratory tract infection and the other had atrioventricular block, second degree) and one in the GLPG1690 group (cholangiocarcinoma that resulted in discontinuation of treatment). No patients died. The pharmacokinetic and pharmacodynamic profiles of GLPG1690 were similar to those previously shown in healthy controls. LPA C18:2 concentrations in plasma were consistently decreased. Mean change from baseline in forced vital capacity at week 12 was 25 mL (95% CI -75 to 124) for GLPG1690 and -70 mL (-208 to 68 mL) for placebo.

INTERPRETATION

Our findings support further development of GLPG1690 as a novel treatment for IPF.

FUNDING

Galapagos.

Association of serum high-mobility group box protein 1 level with outcomes of acute exacerbation of idiopathic pulmonary fibrosis and fibrosing nonspecific interstitial pneumonia

BACKGROUND AND OBJECTIVE

High-mobility group box 1 (HMGB1) protein is important in acute lung injury. However, the role of HMGB-1 in acute exacerbation of fibrosing interstitial pneumonia (AE-FIP) has not been adequately studied.

METHODS

We prospectively measured serum HMGB1 level from disease onset to day 7 in 36 patients with AE-FIP6 patients had missing data because of early death (within 7 days). We then examined the association of HMGB1 level and outcome, and the associations of rhTM with HMGB1 level and outcome in 19 patients who were treated with rhTM (rhTM group) and 11 patients who were not (control group).

RESULTS

Data from 36 AE-FIP patients (mean age, 73.5±6.7years) were analyzed. Serum HMGB1 level was significantly higher in patients with AE-FIP than in those with stable idiopathic pulmonary fibrosis (16.4±13.5 vs 5.7±2.6 ng/ml, respectively; p = 0.003). HMGB1 was significantly lower on day 7 than at AE-FIP onset in survivors (6.5±4.8 vs 14.7±12.9 ng/ml, respectively; p = 0.02) but not in nonsurvivors (14.6±10.5 vs 9.2±4.8 ng/ml, respectively; p = 0.08). Although HMGB1 level at day 7 was significantly lower after rhTM treatment than at AE-FIP onset (8.4±6.1 vs 15.2±12.5 ng/ml, respectively; p = 0.02), it did not significantly decrease in patients receiving treatments other than rhTM (11.3±11.3 vs 8.3±5.3 ng/ml, respectively; p = 0.37). Three-month survival was 60.0% in the rhTM group and 36.4% in the control group (p = 0.449). In multivariate analysis, a decrease in HMGB1 was a significant independent predictor of 3-month survival (Odds ratio, 12.4; p = 0.007).

CONCLUSION

rhTM lowers serum HMGB1 level and may improve survival after AE-FIP. HMGB1 may be a promising therapeutic target for AE-FIP.

Serum metabolic profiling identified a distinct metabolic signature in patients with idiopathic pulmonary fibrosis - a potential biomarker role for LysoPC

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease of unknown etiology. Patients present loss of lung function, dyspnea and dry cough. Diagnosis requires compatible radiologic imaging and, in undetermined cases, invasive procedures such as bronchoscopy and surgical lung biopsy. The pathophysiological mechanisms of IPF are not completely understood. Lung injury with abnormal alveolar epithelial repair is thought to be a major cause for activation of profibrotic pathways in IPF. Metabolic signatures might indicate pathological pathways involved in disease development and progression. Reliable serum biomarker would help to improve both diagnostic approach and monitoring of drug effects.

METHOD

The global metabolic profiles measured by ultra high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) of ten stable IPF patients were compared to the ones of ten healthy participants. The results were validated in an additional study of eleven IPF patients and ten healthy controls.

RESULTS

We discovered 10 discriminative metabolic features using multivariate and univariate statistical analysis. Among them, we identified one metabolite at a retention time of 9.59 min that was two times more abundant in the serum of IPF patients compared to healthy participants. Based on its ion pattern, a lysophosphatidylcholine (LysoPC) was proposed. LysoPC is a precursor of lysophosphatidic acid (LPA) - a known mediator for lung fibrosis with its pathway currently being evaluated as new therapeutic drug target for IPF and other fibrotic diseases.

CONCLUSIONS

We identified a LysoPC by UHPLC-HRMS as potential biomarker in serum of patients with IPF. Further validation studies in a larger cohort are necessary to determine its role in IPF.

TRIAL REGISTRATION

Serum samples from IPF patients have been obtained within the clinical trial NCT02173145 at baseline and from the idiopathic interstitial pneumonia (IIP) cohort study. The study was approved by the Swiss Ethics Committee, Bern (KEK 002/14 and 246/15 or PB_2016-01524).

Regulation of TERRA on telomeric and mitochondrial functions in IPF pathogenesis

BACKGROUND

Aging is a known risk factor of idiopathic pulmonary fibrosis (IPF). However, the pathogenic mechanisms underlying the effects of advanced aging remain largely unknown. Telomeric repeat-containing RNA (TERRA) represents a type of long noncoding RNA. In this study, the regulatory roles of TERRA on human telomeres and mitochondria and IPF epithelial injury model were identified.

METHODS

Blood samples were collected from patients with IPF (n = 24) and matched control individuals (n = 24). The significance of clinical research on the TERRA expression correlated with pulmonary fibrosis was assessed. The expression levels of TERRA in vivo and in vitro were determined through quantitative real-time polymerase chain reaction analysis. Telomerase activity was observed using a fluorescent quantitative TRAP assay kit. The functions of telomeres, mitochondria, and associated genes were analyzed through RNA interference on TERRA.

RESULTS

TERRA expression levels significantly increased in the peripheral blood mononuclear cells of IPF patients. The expression levels also exhibited a direct and significantly inverse correlation with the percentage of predicted force vital capacity, which is a physiological indicator of fibrogenesis during IPF progression. This finding was confirmed in the epithelial injury model of IPF in vitro. RNA interference on TERRA expression can ameliorate the functions of telomeres; mitochondria; associated genes; components associated with telomeres, such as telomerase reverse transcriptase, telomerase, and cell nuclear antigen, cyclin D1; and mitochondria-associated cyclin E genes, including the MMP and Bcl-2 family. The RNA interference on TERRA expression can also improve the functions of oxidative-stress-associated genes, such as reactive oxygen species, superoxide dismutase, and catalase, and apoptosis-related genes, such as cytochrome c, caspase-9, and caspase-3.

CONCLUSIONS

In this study, the regulation of TERRA expression on telomeres and mitochondria during IPF pathogenesis was identified for the first time. The results may provide valuable insights for the discovery of a novel biomarker or therapeutic approach for IPF treatment.

Divergent roles for Clusterin in Lung Injury and Repair

Lung fibrosis is an unabated wound healing response characterized by the loss and aberrant function of lung epithelial cells. Herein, we report that extracellular Clusterin promoted epithelial cell apoptosis whereas intracellular Clusterin maintained epithelium viability during lung repair. Unlike normal and COPD lungs, IPF lungs were characterized by significantly increased extracellular Clusterin whereas the inverse was evident for intracellular Clusterin. In vitro and in vivo studies demonstrated that extracellular Clusterin promoted epithelial cell apoptosis while intercellular Clusterin modulated the expression of the DNA repair proteins, MSH2, MSH6, OGG1 and BRCA1. The fibrotic response in Clusterin deficient (CLU-/-) mice persisted after bleomycin and it was associated with increased DNA damage, reduced DNA repair responses, and elevated cellular senescence. Remarkably, this pattern mirrored that observed in IPF lung tissues. Together, our results show that cellular localization of Clusterin leads to divergent effects on epithelial cell regeneration and lung repair during fibrosis.

High levels of IL-6 and IL-8 characterize early-on idiopathic pulmonary fibrosis acute exacerbations

INTRODUCTION

Controversy exists about the pathogenesis of idiopathic pulmonary fibrosis acute exacerbations (IPF-AEs). According to one hypothesis IPF-AEs represent the development of any etiology diffuse alveolar damage (DAD) upon usual interstitial pneumonia (UIP), whilst other researchers argue that an accelerated phase of the intrinsic fibrotic process of unknown etiology prevails, leading to ARDS. Different cytokines might be involved in both processes. The aim of this study was to assess pro-inflammatory and pro-fibrotic cytokines in the peripheral blood from stable and exacerbated IPF patients.

METHODS

Consecutive IPF patients referred to our department were included. Diagnoses of IPF and IPF-AE were based on international guidelines and consensus criteria. The interleukins (IL)-4, IL-6, IL-8, IL-10, and IL-13 as well asactive transforming growth factor-beta (TGF-β) were measured in blood from both stable and exacerbated patients on the day of hospital admission for deterioration. Subjects were followed for 12months. Mann-Whitney test as well as Tobit and logistic regression analyses were applied.

RESULTS

Among the 41 patients studied, 23 were stable, and 18 under exacerbation; of the latter, 12 patients survived. The IL-6 and IL-8 levels were significantly higher in exacerbated patients (p=0.002 and p=0.046, respectively). An increase in either IL-6 or IL-8 by 1pg/ml increases the odds of death by 5.6% (p=0.021) and 6.7% (p=0.013), respectively, in all patients. No differences were detected for the other cytokines.

CONCLUSION

High levels of IL-6 and IL-8 characterize early-on IPF-AEs and an increase in the levels of IL-6 and IL-8 associates with worse outcome in all patients. However, as the most representative pro-fibrotic cytokines, TGF-β, IL-10, IL-4 and IL-13 were not increased and given the dualistic nature, both pro-inflammatory and pro-fibrotic of IL-6 further studies are necessary to clarify the enigma of IPF-AEs etiopathogenesis.

Impact of serum SP-A and SP-D levels on comparison and prognosis of idiopathic pulmonary fibrosis: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Idiopathic pulmonary fibrosis (IPF) has a poor prognosis in general; however, it is heterogeneous to detect relative biomarkers for predicting the disease progression. Serum biomarkers can be conveniently collected to detect and help to differentially diagnose IPF and predict IPF prognosis. This meta-analysis aimed to evaluate the use of serum surfactant proteins A and D (SP-A and SP-D) for differential diagnosis and prognosis of IPF.

METHODS

Relevant articles were searched in PubMed, Embase, and Chinese National Knowledge Infrastructure databases and reviewed by 2 independent readers. Standard mean difference (SMD) and 95% confidence interval (CI) were calculated to assess the difference in serum levels of SP-A/D among patients with IPF, when compared to patients with non-IPF interstitial lung disease (ILD), pulmonary infection, and healthy control. Hazard ratio (HR) and 95% CI were used to compare the relative risk of mortality.

RESULTS

Twenty-one articles (totalling 1289 IPF patients) were included in final meta-analysis. Serum SP-A levels were significantly higher in patients with IPF than in patients with non-IPF ILD (SMD: 1.108 [0.584, 1.632], P < .001), or pulmonary infection (SMD: 1.320 [0.999, 1.640], P < .001) and healthy controls (SMD: 2.802 [1.901, 3.702], P < .001). There was no significant difference in serum SP-D levels between patients with IPF and those with non-IPF ILD patients (SMD: 0.459 [-0.000, 0.919], P = .050). Serum SP-D levels were significantly higher in patients with IPF than in patients with pulmonary infection (SMD: 1.308 [0.813, 1.803], P < .001) and healthy controls (SMD: 2.235 [1.739, 2.731], P < .001). Risk of death in patients with IPF and elevated serum SP-A was increased 39% compared to patients with low SP-A groups. Elevated SP-D increased risk by 111% when compared to low SP-D. In acute exacerbation of IPF, serum SP-A/D were higher than those in stable stage. The comparisons and prognosis might be different in Asian and Caucasian patients.

CONCLUSIONS

Serum SP-A/D detection might be useful for differential diagnosis and prediction of survival in patients with IPF.

Arterial Carboxyhemoglobin Measurement Is Useful for Evaluating Pulmonary Inflammation in Subjects with Interstitial Lung Disease

Objective The arterial concentration of carboxyhemoglobin (CO-Hb) in subjects with inflammatory pulmonary disease is higher than that in healthy individuals. We retrospectively analyzed the relationship between the CO-Hb concentration and established markers of disease severity in subjects with interstitial lung disease (ILD). Methods The CO-Hb concentration was measured in subjects with newly diagnosed or untreated ILD and the relationships between the CO-Hb concentration and the serum biomarker levels, lung function, high-resolution CT (HRCT) findings, and the uptake in gallium-67 (⁶⁷Ga) scintigraphy were evaluated. Results Eighty-one non-smoking subjects were studied (mean age, 67 years). Among these subjects, (A) 17 had stable idiopathic pulmonary fibrosis (IPF), (B) 9 had an acute exacerbation of IPF, (C) 44 had stable non-IPF, and (D) 11 had an exacerbation of non-IPF. The CO-Hb concentrations of these subjects were (A) 1.5±0.5%, (B) 2.1±0.5%, (C) 1.2±0.4%, and (D) 1.7±0.5%. The CO-Hb concentration was positively correlated with the serum levels of surfactant protein (SP)-A (r=0.38), SP-D (r=0.39), and the inflammation index (calculated from HRCT; r=0.57) and was negatively correlated with the partial pressure of oxygen in the arterial blood (r=-0.56) and the predicted diffusion capacity of carbon monoxide (r=-0.61). The CO-Hb concentrations in subjects with a negative heart sign on ⁶⁷Ga scintigraphy were higher than those in subjects without a negative heart sign (1.4±0.5% vs. 1.1±0.3%, p=0.018). Conclusion The CO-Hb levels of subjects with ILD were increased, particularly during an exacerbation, and were correlated with the parameters that reflect pulmonary inflammation.

Increased erythrocyte aggregation and oxidative stress in patients with idiopathic interstitial pneumonia

BACKGROUND

Hemorheological properties are important determinants of tissue oxygenation. Although hemorheological alterations in various lung diseases have been well-defined, no information is available about the effects of idiopathic interstitial pneumonia (IIP) on hemorheological parameters.

OBJECTIVES

The aim of this study was to investigate hemorheological parameters (erythrocyte deformability, aggregation, and plasma viscosity -PV) and associated oxidative stress indices in patients with IIP.

METHODS

The study enrolled 31 patients (9 Idiopathic pulmonary fibrosis (IPF), 10 non-specific Interstitial Pneumonia (NSIP), 12 Cryptogenic Organising Pneumonia (COP) and 33 healthy controls. Erythrocyte deformability and aggregation were measured by an ektacytometer. PV was determined by a cone-plate rotational viscometer and oxidative stress via a commercial kit.

RESULTS

Erythrocyte aggregation, total oxidant status (TOS) and oxidative stress index (OSI) of IIP patients were higher than controls whereas erythrocyte deformability, PV and total antioxidant status (TAS) were unaltered.

CONCLUSIONS

Increment of oxidative stress in IIP seems to depend on enhancement of oxidants, rather than alteration of antioxidants. The issue that, elevated erythrocyte aggregation may further impair tissue oxygenation by disturbing microcirculation in IIP, may be considered in the follow up and development of new treatment protocols for this disease.

Increased Expression of CC16 in Patients with Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a devastating disease of unknown etiology. The pathogenic mechanisms are unclear, but evidence indicates that aberrantly activated alveolar epithelial cells secrete a variety of mediators which induce the migration, proliferation and activation of fibroblasts and finally the excessive accumulation of extracellular matrix with the consequent destruction of the lung parenchyma. CC16 (approved symbol SCGB1A1), a putative anti-inflammatory protein produced by “club” cells in the distal airways, has not been evaluated in IPF lungs. In this study, we determined the serum and bronchoalveolar lavage (BAL) levels as well as the lung cell localization of this protein. Also, we explored the usefulness of serum levels of CC16 for the differential diagnosis of IPF (n = 85), compared with non-IPF interstitial lung diseases [chronic hypersensitivity pneumonitis (cHP; n = 85) and connective tissue diseases (CTD-ILD; n = 85)]. CC16 was significantly increased in serum and BAL fluids of IPF patients and was found not only in club cells but also in alveolar epithelial cells. When compared with non-IPF patients and controls, serum levels were significantly increased (p<0.0001). Sensitivity and specificity for CC16 (cut-off 41ng/mL) were 24% and 90%, positive predictive value 56% and negative predictive value 69%. These findings demonstrate that CC16 is upregulated in IPF patients suggesting that may participate in its pathogenesis. Although higher than the serum levels of non-IPF patients it shows modest sensitivity to be useful as a potential biomarker for the differential diagnosis.

Prognostic significance of surfactant protein A, surfactant protein D, Clara cell protein 16, S100 protein, trefoil factor 3, and prostatic secretory protein 94 in idiopathic pulmonary fibrosis, sarcoidosis, and chronic pulmonary obstructive disease

BACKGROUND

Identification of serum and bronchoalveolar lavage fluid (BALF) biomarkers may facilitate diagnosis and prognostication in various lung disorders.

OBJECTIVE

Serum and BALF levels of surfactant protein A (SP-A), surfactant protein D (SP-D), Clara cell protein 16 (CC16), S100 protein, trefoil factor 3 (TFF3), and prostatic secretory protein 94 (PSP94) were evaluated in 94 consecutive patients (idiopathic pulmonary fibrosis (IPF; n=18), sarcoidosis (n=25), chronic obstructive pulmonary disease (COPD; n=51)), and in 155 healthy controls.

METHODS

Biomarkers were measured at diagnosis and compared with disease characteristics. Both uniparametric and multiparametric analyses were used.

RESULTS

Seven significant correlations were found: 1) BALF PSP94 level correlated with prognosis of sarcoidosis (P=0.035); 2) BALF SP-D level with pulmonary functions in IPF (P=0.032); 3) BALF SP-D and TFF3 with IPF mortality (P=0.049 and 0.017, respectively); 4) serum TFF3 level with COPD mortality (P=0.006,); 5) serum SP-A with pulmonary functions impairment in IPF (P=0.011); 6) serum SP-D level was associated with HRCT interstitial score in IPF (P=0.0346); and 7) serum SP-A was associated with staging of COPD according to spirometry (P<0.001). Moreover, our analysis showed that some biomarker levels differed significantly among the diseases: 1) BALF SP-D level differed between sarcoidosis and IPF; 2) serum SP-A level differed among IPF, sarcoidosis, COPD and was also different from healthy controls; 3) serum S100A6, S100A11 levels differed among IPF, sarcoidosis, COPD from healthy controls 4) serum SP-D, CC16, TFF-3 levels distinguished IPF patients from healthy controls; and 5) serum CC16, TFF3, PSP94 distinguished COPD patients from healthy controls. Our study shows that some of selected biomarkers should have prognostic value in the analysed lung disorders. On the other hand, these biomarkers do not appear to be unequivocally suitable for differential diagnosis of these disorders.

The predictors of mortality in IPF - Does emphysema change the prognosis?

BACKGROUND

Combined idiopathic pulmonary fibrosis (IPF) and emphysema (CPFE) has been reported to be more common in male smokers. A number of studies comparing CPFE patients with fibrosis-only patients have reported a similar prognosis while others have reported a significantly shorter survival.

OBJECTIVES

In present study, we aimed to compare baseline characteristics of patients with IPF according to emphysema presence. We asssessed the prognostic value of emphysema along with each other parameter.

METHODS

We retrospectively reviewed the clinical, baseline radiological, laboratory and physiological parameters of 92 patients who were diagnosed with IPF. The patients were divided into two groups: those without emphysema (Group 1) and with emphysema (Group 2). All-cause mortality was recorded, and the impact of the variables on survival was evaluated.

RESULTS

Emphysema was recorded in 23 patients, all of whom were male. While ever-smoker rate was higher in Group 2 laboratory and physiologic parameters were similar. Radiologically, the presence of honeycombing, ground glass opacity, the extension and symmetry of involvement did not differ between the Groups. The median survival time was 29±4 months. Patients in Group 1 and 2 had a median survival of 34 and 9 months, respectively. In univariate analysis; radiological presence of emphysema and honeycombing, male gender, lower baseline levels of albumin and oxygen saturation, forced vital capacity and carbon monoxide diffusing capacity were detected as predictors of mortality.

CONCLUSION

In present study, IPF with emphysema was more common in male smokers. When emphysema accompanies IPF, life expectancy is remarkably worse, but not independently so.

Protein S is protective in pulmonary fibrosis

Essentials Epithelial cell apoptosis is critical in the pathogenesis of idiopathic pulmonary fibrosis. Protein S, a circulating anticoagulant, inhibited apoptosis of lung epithelial cells. Overexpression of protein S in lung cells reduced bleomycin-induced pulmonary fibrosis. Intranasal therapy with exogenous protein S ameliorated bleomycin-induced pulmonary fibrosis.

SUMMARY

Background Pulmonary fibrosis is the terminal stage of interstitial lung diseases, some of them being incurable and of unknown etiology. Apoptosis plays a critical role in lung fibrogenesis. Protein S is a plasma anticoagulant with potent antiapoptotic activity. The role of protein S in pulmonary fibrosis is unknown. Objectives To evaluate the clinical relevance of protein S and its protective role in pulmonary fibrosis. Methods and Results The circulating level of protein S was measured in patients with pulmonary fibrosis and controls by the use of enzyme immunoassays. Pulmonary fibrosis was induced with bleomycin in transgenic mice overexpressing human protein S and wild-type mice, and exogenous protein S or vehicle was administered to wild-type mice; fibrosis was then compared in both models. Patients with pulmonary fibrosis had reduced circulating levels of protein S as compared with controls. Inflammatory changes, the levels of profibrotic cytokines, fibrosis score, hydroxyproline content in the lungs and oxygen desaturation were significantly reduced in protein S-transgenic mice as compared with wild-type mice. Wild-type mice treated with exogenous protein S showed significant decreases in the levels of inflammatory and profibrotic markers and fibrosis in the lungs as compared with untreated control mice. After bleomycin infusion, mice overexpressing human protein S showed significantly low caspase-3 activity, enhanced expression of antiapoptotic molecules and enhanced Akt and Axl kinase phosphorylation as compared with wild-type counterparts. Protein S also inhibited apoptosis of alveolar epithelial cells in vitro. Conclusions These observations suggest clinical relevance and a protective role of protein S in pulmonary fibrosis.

MFAP4: a candidate biomarker for hepatic and pulmonary fibrosis?

BACKGROUND

Several comparable mechanisms have been identified for hepatic and pulmonary fibrosis. The human microfibrillar associated glycoprotein 4 (MFAP4), produced by activated myofibroblasts, is a ubiquitous protein playing a potential role in extracellular matrix (ECM) turnover and was recently identified as biomarker for hepatic fibrosis in hepatitis C patients. The current study aimed to evaluate serum levels of MFAP4 in patients with pulmonary fibrosis in order to test its potential as biomarker in clinical practice. A further aim was to determine whether MFAP4 deficiency in mice affects the formation of pulmonary fibrosis in the bleomycin model of lung fibrosis.

METHODS

91 patients with idiopathic pulmonary fibrosis (IPF), 23 with hypersensitivity pneumonitis (HP) and 31 healthy subjects were studied. In the mouse model, C57BL/6 Mfap4+/+ and Mfap4-/- mice between 6-8 weeks of age were studied. Serum levels of MFAP4 were measured by ELISA in patients and in mice. Surfactant protein D (SP-D) and LDH were measured as comparison biomarkers in patients with pulmonary fibrosis. Morphometric assessment and the Sircol kit were used to determine the amount of collagen in the lung tissue in the mouse model.

RESULTS

Serum levels of MFAP4 were not elevated in lung fibrosis - neither in the patients with IPF or HP nor in the animal model. Furthermore no significant correlations with pulmonary function tests of IPF patients could be found for MFAP4. MFAP4 levels were increased in BAL of bleomycin treated mice with pulmonary fibrosis.

CONCLUSIONS

MFAP4 is not elevated in sera of patients with pulmonary fibrosis or bleomycin treated mice with pulmonary fibrosis. This may be due to different pathogenic mechanisms of liver and lung fibrogenesis. MFAP4 seems to be useful as serum biomarker for hepatic but not for lung fibrosis.

Biomarkers to identify ILD and predict lung function decline in scleroderma lung disease or idiopathic pulmonary fibrosis

BACKGROUND

SSc-ILD and IPF demonstrate significant morbidity and mortality. Predicting disease progression is challenging in both diseases.

OBJECTIVES

We sought a serum biomarker that could identify patients with SSc-ILD or IPF and prospectively predict short-term decline in lung function in these patients.

METHODS

10 healthy controls, 5 SSc w/o ILD, 6 SSc-ILD and 13 IPF patients underwent venesection. An array of cytokines including KL-6, SP-D and MMP7 were measured. PFTs were obtained at baseline and six months. Cytokine measurements were correlated with PFTs.

RESULTS

KL-6 in IPF patients (633 ng/ml, IQR 492-1675) was significantly elevated compared to controls (198 ng/ml, IQR 52-360, p<0.01) and SSc w/o ILD patients (192 ng/ml, IQR 0-524, p<0.05); KL-6 in SSc-ILD patients (836 ng/ml, IQR 431-1303) was significantly higher than in controls (p<0.05). SP-D was significantly higher in IPF patients (542 ng/ml, IQR 305-577) compared to controls (137 ng/ml, IQR 97-284, p<0.01) or to SSc w/o ILD patients (169 ng/ml, IQR 137-219, p<0.05). In comparison with controls (0.0 ng/ml, IQR 0.0-0.6), MMP7 was significantly higher in both IPF patients (2.85 ng/ml, IQR 1.5-3.6, p<0.05) and SSc-ILD patients (5.41 ng/ml, IQR 2.6-7.2, p<0.001). Using a cut-off level of 459ng/ml for KL-6 and of 1.28 ng/ml for MMP7, 18 out of 19 patients with ILD had a serum value of either KL-6 or MMP7 above these thresholds. For all ILD patients, baseline serum SP-D correlated with ΔFVC %pred over six months (r=-0.63, p=0.005, 95% CI -0.85 to -0.24).

CONCLUSIONS

Combining KL-6 with MMP7 may be a useful screening tool for patients at risk of ILD. SP-D may predict short-term decline in lung function.

Levels of circulating MMP-7 degraded elastin are elevated in pulmonary disorders

OBJECTIVES

Elastin is a signature protein of the lungs. Matrix metalloproteinase-7 (MMP-7) is important in lung defence mechanisms and degrades elastin. However, MMP-7 activity in regard to elastin degradation has never been quantified serologically in patients with lung diseases. An assay for the quantification of MMP-7 generated elastin fragments (ELM7) was therefore developed to investigate MMP-7 derived elastin degradation in pulmonary disorders such as idiopathic pulmonary fibrosis (IPF) and lung cancer.

DESIGN AND METHODS

Monoclonal antibodies (mABs) were raised against eight carefully selected MMP-7 cleavage sites on elastin. After characterisation and validation of the mABs, one mAB targeting the ELM7 fragment was chosen. ELM7 fragment levels were assessed in serum samples from patients diagnosed with IPF (n=123, baseline samples, CTgov reg. NCT00786201), and lung cancer (n=40) and compared with age- and sex-matched controls.

RESULTS

The ELM7 assay was specific towards in vitro MMP-7 degraded elastin and the ELM7 neoepitope but not towards other MMP-7 derived elastin fragments. Serum ELM7 levels were significantly increased in IPF (113%, p<0.0001) and lung cancer (96%, p<0.0001) compared to matched controls.

CONCLUSIONS

MMP-7-generated elastin fragments can be quantified in serum and may reflect pathological lung tissue turnover in several important lung diseases.

Disordered breathing during sleep and exercise in idiopathic pulmonary fibrosis and the role of biomarkers

BACKGROUND AND OBJECTIVE

Idiopathic pulmonary fibrosis (IPF) patients report fatigue, possibly reflecting sleep disturbance, but little is known about sleep-related changes. We compared ventilation and gas exchange during sleep and exercise in a cohort of IPF patients, and evaluated associations with selected biological markers.

METHODS

Twenty stable IPF patients (aged 67.9 ± 12.3 [SD]) underwent overnight polysomnography following an acclimatization night. Cardiopulmonary exercise testing was performed and inflammatory markers measured including TNF-α, IL-6, CXCL8, C-C motif ligand 18 (CCL-18) and C-reactive protein (CRP) RESULTS: Nine patients had sleep-disordered breathing (SDB) with an apnea-hypopnea frequency (AHI) ≥ 5/h, but only two had Epworth sleepiness score ≥ 10, thus having an obstructive sleep apnea syndrome. Sleep quality was poor. Transcutaneous carbon dioxide tension (PtcCO2) rose by 2.56 ± 1.59 kPa overnight (P = 0.001), suggesting hypoventilation. Oxygen saturation (SaO2) was lower during sleep than exercise (P < 0.01), and exercise variables correlated with resting pulmonary function. CCL-18 and CRP levels were elevated and correlated with PtcCO2 rise during sleep (P < 0.05). CCL-18 negatively correlated with diffusion capacity of carbon monoxide (DLCO), arterial oxygen (PaO2) and mean arterial carbon dioxide (PaCO2) (P < 0.05) and CRP negatively correlated with DLCO, PaO2, sleep SaO2 and oxygen uptake (VO2) during exercise (P < 0.05).

CONCLUSIONS

IPF patients desaturate more during sleep than exercise; thus, nocturnal pulse oxymetry could be included in clinical assessment. CCL-18 and CRP levels correlate with physiological markers of fibrosis.

Discovery and validation of extracellular/circulating microRNAs during idiopathic pulmonary fibrosis disease progression

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic fibrosing interstitial lung disease of unknown etiology that is currently untreatable. In this study we aim to characterize the potential of extracellular/circulating microRNAs (miRNAs) in serum as biomarkers for IPF.

METHODS

Total serum RNAs were isolated from serum from healthy control subjects (n=12), rapid progressive (n=12) and slowly progressive IPF patients (n=12). Serum RNA was analyzed by using TaqMan microRNA assays containing probes for 366 human miRNAs, and selected findings were validated with quantitative RT-PCR. Target prediction and pathway analysis on the significant differential miRNAs were performed using DIANA-mirPath.

RESULTS

We found 47 significantly differentially expressed serum miRNAs (p<0.05) in rapid progressive or slowly progressive IPF patients compared to healthy controls, including 21 up-regulated miRNAs and 26 down-regulated miRNAs. Bioinformatic analysis by DIANA-mirPath demonstrated that 53 KEGG biological processes were significantly enriched (p < 0.05, FDR corrected) among differentially expressed serum miRNAs, including TGF-beta signaling pathway (p < 0.0001), MAPK signaling pathway (p < 0.0001), PI3K-Akt signaling pathway (p < 0.0001), Wnt signaling pathway (p < 0.0001), HIF-1 signaling pathway (p < 0.0001), Regulation of actin cytoskeleton (p < 0.0001), Jak-STAT signaling pathway (p < 0.0001), Notch signaling pathway (p < 0.0001), and Cytokine-cytokine receptor interaction (p = 0.0062). We further validated six miRNAs (miR-21, miR-199a-5p, miR-200c, miR-31, let-7a, and let-7d) for further validation using an independent cohort of 20 rapid progressive IPF, 24 slowly progressive IPF patients and 20 healthy controls. In agreement with the preliminary data from miRNA assay, miR-21, miR-199a-5p, and miR-200c were significantly increased in serums of IPF patients while miR-31, let-7a, and let-7d were significantly under expressed in serums of IPF patients compared to healthy controls.

CONCLUSIONS

These studies demonstrated that extracellular/circulating miRNAs in serum could be potentially served as novel regulators influencing disease progression of IPF.

Increased platelet reactivity in idiopathic pulmonary fibrosis is mediated by a plasma factor

Introduction

Idiopathic Pulmonary Fibrosis (IPF) is a progressive, incurable fibrotic interstitial lung disease with a prognosis worse than many cancers. Its pathogenesis is poorly understood. Activated platelets can release pro-fibrotic mediators that have the potential to contribute to lung fibrosis. We determine platelet reactivity in subjects with IPF compared to age-matched controls.

Methods

Whole blood flow cytometry was used to measure platelet-monocyte aggregate formation, platelet P-selectin expression and platelet fibrinogen binding at basal levels and following stimulation with platelet agonists. A plasma swap approach was used to assess the effect of IPF plasma on control platelets.

Results

Subjects with IPF showed greater platelet reactivity than controls. Platelet P-selectin expression was significantly greater in IPF patients than controls following stimulation with 0.1 µM ADP (1.9% positive ±0.5 (mean ± SEM) versus 0.7%±0.1; p = 0.03), 1 µM ADP (9.8%±1.3 versus 3.3%±0.8; p<0.01) and 10 µM ADP (41.3%±4.2 versus 22.5%±2.6; p<0.01). Platelet fibrinogen binding was also increased, and platelet activation resulted in increased platelet-monocyte aggregate formation in IPF patients. Re-suspension of control platelets in plasma taken from subjects with IPF resulted in increased platelet activation compared to control plasma.

Conclusions

IPF patients exhibit increased platelet reactivity compared with controls. This hyperactivity may result from the plasma environment since control platelets exhibit increased activation when exposed to IPF plasma.

Gastrointestinal symptoms in idiopathic pulmonary fibrosis patients treated with pirfenidone and herbal medicine

Pirfenidone is an antifibrotic agent for patients with pulmonary fibrosis, but this drug has adverse gastrointestinal (GI) effects. The first aim of this study was to assess GI symptoms due to pirfenidone by using a new questionnaire for reflux symptoms and dismotility symptoms. Whether adding herbal medicine of rikkunshi-to improved GI symptoms due to pirfenidone therapy was also investigated. This was a randomized controlled trial performed on 17 IPF patients. The patients were assigned to two groups, and the study period was 8 weeks. The pirfenidone group received pirfenidone therapy for 8 weeks with add-on rikkunshi-to from 4 weeks, while the control group did not receive either of these agents. To assess the effects of RK, plasma levels of acyl-ghrelin and des-acyl-ghrelin, serum KL-6 and surfactant protein-D, and pulmonary function tests were monitored. GI symptoms were most severe during the initial 2 weeks of pirfenidone therapy at a dose of 600 mg/day. Both reflux symptoms and dismotility symptoms deteriorated. Rikkunshi-to improved GI symptoms to the level prior to pirfenidone therapy. Plasma levels of des-acyl-ghrelin and acyl-/des-acyl-ghrelin ratio changed significantly at 8 weeks compared to 2 weeks. GI adverse events due to PFD were most severe in the first 2 weeks of treatment at a dose of 600 mg/day, and both reflux and dismotility symptoms deteriorated, but the drug was well tolerated at 1200 mg/day. Rikkunshi-to contributed to improvement of GI symptoms, but plasma ghrelin levels did not reflect the improvement of GI symptoms.

Exercise limitation in IPF patients: a randomized trial of pulmonary rehabilitation

BACKGROUND

Patients with idiopathic pulmonary fibrosis (IPF) have severely limited exercise capacity due to dyspnea, hypoxemia, and abnormal lung mechanics. This pilot study was designed to determine whether pulmonary rehabilitation were efficacious in improving the 6-min walk test (6-MWT) distance, exercise oxygen uptake, respiratory muscle strength [maximum inspiratory pressure (MIP)], and dyspnea in patients with IPF. Underlying physiological mechanisms and effects of the intervention were investigated.

METHODS

Subjects were randomly assigned to a 3-month pulmonary rehabilitation program (n = 11) or to a control group (n = 10). All subjects initially underwent the 6-MWT and constant load exercise gas exchange studies.

RESULTS

Subjects in the rehabilitation group increased treadmill exercise [metabolic equivalent of task-minutes] over the first 14 sessions. Beneficial effects on physical function resulted in those who completed rehabilitation. Subjects who completed the program increased cycle ergometer time and maintained exercise oxygen consumption (exercise VO(2)) at the baseline level over 3 months, while the control group suffered a significant decrease in exercise VO(2). Rehabilitation subjects also increased their MIP. Plasma lactate doubled and brain natriuretic peptide levels increased significantly after exercise, as did the plasma amino acids glutamic acid, arginine, histidine, and methionine. These changes were associated with significant decreases in arterial oxygen saturation and increases in 15-F(2t)-isoprostanes after exercise.

CONCLUSIONS

Pulmonary rehabilitation effectively maintained exercise oxygen uptake over 3 months and lengthened constant load exercise time in patients with moderately severe IPF. Exercise endurance on cycle ergometry testing was limited by dyspnea and severe hypoxemia associated with systemic oxidant stress.

Frequency and implication of autoimmune serologies in idiopathic pulmonary fibrosis

OBJECTIVE

To assess the frequency and clinical implications of positive autoimmune serologies in patients with biopsy-confirmed idiopathic pulmonary fibrosis (IPF).

PATIENTS AND METHODS

We reviewed the records of patients at our institution with biopsy-confirmed usual interstitial pneumonia (UIP) from January 1, 1995, through December 31, 2010, for frequency and distribution of autoimmune serologies. Patients with IPF with and without positive serologies were compared.

RESULTS

Three hundred eighty-nine consecutive patients with biopsy-confirmed IPF underwent serologic testing, with positive serologic test results being found in 112 (29%). Of 2051 individual screening serologic tests performed, results of 163 tests were positive (8%), with antinuclear antibody being the most frequent (47%). There was no difference in age at biopsy (P=.21), gender (P=.21), or presenting radiologic features between those with or without positive serology. More frequent use of immunosuppressive treatment (P=.02) was noted in those with positive serology. No survival difference was observed (log-rank; P=.43). Median follow-up for the whole cohort was 43.5 months.

CONCLUSION

Positive autoimmune serology may occur in as much as one-third of the patients with biopsy-confirmed IPF with no associated clinical implication or survival advantage. Systematic use of autoimmune laboratory panels in patients without clinical features of connective tissue disease should be reconsidered in patients with suspected UIP on chest computed tomography scan or confirmed UIP on biopsy.

Increased platelet binding to circulating monocytes in idiopathic pulmonary fibrosis

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonia and its prognosis is poor. Epidemiological evidence suggests an association of IPF with vascular disease and thrombotic tendency, which may be related to platelet activation.

METHODS

Platelet-monocyte adhesion in peripheral blood was examined by flow cytometry in patients with IPF (n = 19), interstitial lung disease (ILD) other than IPF (n = 9), and control subjects without pulmonary fibrosis (n = 14). Expression of platelet activation markers P-selectin (CD62P), PSGL-1 (CD162), and CD40 ligand (CD40L) on leukocytes and platelets were studied. Plasma concentrations of soluble P-selectin and CD40L were measured by ELISA.

RESULTS

Significantly elevated levels of platelet-monocyte binding were found in patients with IPF (35.6 ± 4.34 % [mean ± SEM]) compared with patients with non-IPF ILD (23.5 ± 3.68 %) and non-ILD control subjects (16.5 ± 2.26 %; P < 0.01). There was a trend towards increased divalent cation-independent platelet-monocyte binding in IPF (6.0 ± 0.77 % [mean ± SEM]) compared with non-IPF ILD (4.3 ± 1.38 %) and control subjects without ILD (3.1 ± 1.75 %; P = 0.058). There was no differential surface expression of platelet activation markers on subsets of leukocytes or platelets. Plasma concentrations of CD40L and soluble P-selectin did not differ between IPF and control subjects. Platelet-monocyte binding had no significant correlation with percent predicted TLco or FVC.

CONCLUSIONS

Platelet-monocyte binding is increased in IPF, suggesting increased platelet activation. This conjugation is predominantly calcium-dependent, but there may be more calcium-independent adhesion in IPF. These findings support further research into the role of platelet activation in IPF.

[Interstitial pulmonary fibrosis: the role of angiogenic factors, the inhibitory pathways of progression]

AIM

To assess the role of angiogenic factors (vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) in interstitial lung diseases (ILD), such as fibrosing alveolitis, sarcoidosis.

SUBJECTS AND METHODS

The blood levels of endothelial dysfunction and neoangiogenesis markers (ET-1 and VEGF) were investigated in 96 patients with different clinical forms of ILD at it different stages; the found changes were compared with the clinical and morphological manifestations of the disease.

RESULTS

It has been ascertained that regardless of the clinical type of ILD, there is a correlation between the blood levels of VEGF and ET-1 and the intensity of lung neoangiogenesis, the expression of VEGF by the endothelium of newly formed blood vessels, the production of angiogenic factors, the degree of endothelial dysfunction, the extent of pulmonary fibrosis, the degree of pulmonary vascular remodeling, and the severity of pulmonary hypertension. The findings suggest that the markers of neoangiogenesis play an important role in the mechanisms of ILD progression.

CONCLUSION

The study of these parameters in the blood may be used to clarify the activity and prognosis of ILD.

Cartilage oligomeric matrix protein in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and life threatening disease with median survival of 2.5-3 years. The IPF lung is characterized by abnormal lung remodeling, epithelial cell hyperplasia, myofibroblast foci formation, and extracellular matrix deposition. Analysis of gene expression microarray data revealed that cartilage oligomeric matrix protein (COMP), a non-collagenous extracellular matrix protein is among the most significantly up-regulated genes (Fold change 13, p-value <0.05) in IPF lungs. This finding was confirmed at the mRNA level by nCounter® expression analysis in additional 115 IPF lungs and 154 control lungs as well as at the protein level by western blot analysis. Immunohistochemical analysis revealed that COMP was expressed in dense fibrotic regions of IPF lungs and co-localized with vimentin and around pSMAD3 expressing cells. Stimulation of normal human lung fibroblasts with TGF-β1 induced an increase in COMP mRNA and protein expression. Silencing COMP in normal human lung fibroblasts significantly inhibited cell proliferation and negatively impacted the effects of TGF-β1 on COL1A1 and PAI1. COMP protein concentration measured by ELISA assay was significantly increased in serum of IPF patients compared to controls. Analysis of serum COMP concentrations in 23 patients who had prospective blood draws revealed that COMP levels increased in a time dependent fashion and correlated with declines in force vital capacity (FVC). Taken together, our results should encourage more research into the potential use of COMP as a biomarker for disease activity and TGF-β1 activity in patients with IPF. Hence, studies that explore modalities that affect COMP expression, alleviate extracellular matrix rigidity and lung restriction in IPF and interfere with the amplification of TGF-β1 signaling should be persuaded.