Association of musculoskeletal involvement with lung function and mortality in patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease associated with high mortality. Low muscle mass, frailty and sarcopenia lead to functional impairment that negatively impact quality of life and survival but are not used in clinical practice. We aimed to determine the association of Fat-free mass index (FFMI) and frailty with lung function, exercise tolerance and survival in patients with IPF. In this study, 70 patients with IPF underwent assessment of body composition, lung function, 6-min walk distance (6MWD) testing, hand grip strength, quality of life (QoL) assessment by St. George's Respiratory questionnaire (SGRQ) and frailty assessment using the SHARE-FI tool. FFMI was calculated using pectoralis muscle cross-sectional area (PM-CSA) on CT chest images and the lowest quartile defined reduced muscle mass. Sarcopenia was defined as low FFMI and handgrip strength. Regression analyses were conducted to determine predictive value of frailty, low FFMI and sarcopenia on clinical outcomes. The Cox proportional hazards model was used to analyze the impact of FFMI and frailty score on survival. The mean age was 70 years with moderate impairment in lung function (mean ppFVC 68.5%, ppDLCO 45.6%). Baseline forced vital capacity (p < 0.001), diffusion capacity of lung for carbon monoxide (p = < 0.01), 6WMD (p < 0.05) were significantly lower in frail patients compared to non-frail patients. BMI was found to closely correlate with FFMI (r = 0.79, p < 0.001), but not with frailty score (r = - 0.2, p = 0.07). Frailty was a significant predictor of FVC, DLCO, 6MWD, SGRQ scores when adjusted for age and gender. Muscle mass and sarcopenia were significant predictors of FVC, DLCO, but not 6MWD or QoL scores. Multivariate cox-proportional hazards ratio model adjusting for age and gender showed that frailty was significantly associated with increased mortality (HR = 2.6, 95% CI 1.1-6.1). Low FFMI (HR = 1.3, 95% CI 0.6-2.8), and sarcopenia (HR = 2.1, 95% CI 0.8-5.3), though associated with a trend to increased mortality, were not statistically significant. Frailty is associated with lower lung function and higher mortality in patients with IPF. Longitudinal evaluations are necessary to further determine the associations between low FFMI, sarcopenia and frailty with outcomes in IPF.

Lung function trajectories in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease characterised by decline in lung function. We evaluated trajectories of forced vital capacity (FVC) and diffusing capacity (DLco) in a cohort of patients with IPF. METHODS: Patients with IPF that was diagnosed or confirmed at the enrolling centre in the previous 6 months were enrolled into the IPF-PRO Registry between June 2014 and October 2018. Patients were followed prospectively, with lung function data collected as part of routine clinical care. Mean trajectories of FVC and DLco % predicted in all patients and in subgroups by characteristics assessed at enrolment were estimated using a joint model that accounted for factors such as disease severity and visit patterns. RESULTS: Of 1002 patients in the registry, 941 had ≥ 1 FVC and/or DLco measurement after enrolment. The median (Q1, Q3) follow-up period was 35.1 (18.9, 47.2) months. Overall, mean estimated declines in FVC and DLco % predicted were 2.8% and 2.9% per year, respectively. There was no evidence that the mean trajectories of FVC or DLco had a non-linear relationship with time at the population level. Patients who were male, white, had a family history of ILD, were using oxygen, or had prior/current use of antifibrotic therapy at enrolment had greater rates of decline in FVC % predicted. Patients who were male or white had greater rates of decline in DLco % predicted. CONCLUSIONS: Data from the IPF-PRO Registry suggest a constant rate of decline in lung function over a prolonged period, supporting the inexorably progressive nature of IPF. A graphical abstract summarising the data in this manuscript is available at: https://www.usscicomms.com/respiratory/IPF-PRORegistry_LungFunctionTrajectories . TRIAL REGISTRATION: NCT01915511.

Integrative multi-omics analysis reveals novel idiopathic pulmonary fibrosis endotypes associated with disease progression.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is characterized by the accumulation of extracellular matrix in the pulmonary interstitium and progressive functional decline. We hypothesized that integration of multi-omics data would identify clinically meaningful molecular endotypes of IPF. METHODS: The IPF-PRO Registry is a prospective registry of patients with IPF. Proteomic and transcriptomic (including total RNA [toRNA] and microRNA [miRNA]) analyses were performed using blood collected at enrollment. Molecular data were integrated using Similarity Network Fusion, followed by unsupervised spectral clustering to identify molecular subtypes. Cox proportional hazards models tested the relationship between these subtypes and progression-free and transplant-free survival. The molecular subtypes were compared to risk groups based on a previously described 52-gene (toRNA expression) signature. Biological characteristics of the molecular subtypes were evaluated via linear regression differential expression and canonical pathways (Ingenuity Pathway Analysis [IPA]) over-representation analyses. RESULTS: Among 232 subjects, two molecular subtypes were identified. Subtype 1 (n = 105, 45.3%) and Subtype 2 (n = 127, 54.7%) had similar distributions of age (70.1 +/- 8.1 vs. 69.3 +/- 7.6 years; p = 0.31) and sex (79.1% vs. 70.1% males, p = 0.16). Subtype 1 had more severe disease based on composite physiologic index (CPI) (55.8 vs. 51.2; p = 0.002). After adjusting for CPI and antifibrotic treatment at enrollment, subtype 1 experienced shorter progression-free survival (HR 1.79, 95% CI 1.28,2.56; p = 0.0008) and similar transplant-free survival (HR 1.30, 95% CI 0.87,1.96; p = 0.20) as subtype 2. There was little agreement in the distribution of subjects to the molecular subtypes and the risk groups based on 52-gene signature (kappa = 0.04, 95% CI= -0.08, 0.17), and the 52-gene signature risk groups were associated with differences in transplant-free but not progression-free survival. Based on heatmaps and differential expression analyses, proteins and miRNAs (but not toRNA) contributed to classification of subjects to the molecular subtypes. The IPA showed enrichment in pulmonary fibrosis-relevant pathways, including mTOR, VEGF, PDGF, and B-cell receptor signaling. CONCLUSIONS: Integration of transcriptomic and proteomic data from blood enabled identification of clinically meaningful molecular endotypes of IPF. If validated, these endotypes could facilitate identification of individuals likely to experience disease progression and enrichment of clinical trials. TRIAL REGISTRATION: NCT01915511.

Focal adhesion kinase signaling determines the fate of lung epithelial cells in response to TGF-ß.

Alveolar epithelial cell (AEC) injury and apoptosis are prominent pathological features of idiopathic pulmonary fibrosis (IPF). There is evidence of AEC plasticity in lung injury repair response and in IPF. In this report, we explore the role of focal adhesion kinase (FAK) signaling in determining the fate of lung epithelial cells in response to transforming growth factor-ß1 (TGF-ß1). Rat type II alveolar epithelial cells (RLE-6TN) were treated with or without TGF-ß1, and the expressions of mesenchymal markers, phenotype, and function were analyzed. Pharmacological protein kinase inhibitors were utilized to screen for SMAD-dependent and -independent pathways. SMAD and FAK signaling was analyzed using siRNA knockdown, inhibitors, and expression of a mutant construct of FAK. Apoptosis was measured using cleaved caspase-3 and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. TGF-ß1 induced the acquisition of mesenchymal markers, including α-smooth muscle actin, in RLE-6TN cells and enhanced the contraction of three-dimensional collagen gels. This phenotypical transition or plasticity, epithelial-myofibroblast plasticity (EMP), is dependent on SMAD3 and FAK signaling. FAK activation was found to be dependent on ALK5/SMAD3 signaling. We observed that TGF-ß1 induces both EMP and apoptosis in the same cell culture system but not in the same cell. While blockade of SMAD signaling inhibited EMP, it had a minimal effect on apoptosis; in contrast, inhibition of FAK signaling markedly shifted to an apoptotic fate. The data support that FAK activation determines whether AECs undergo EMP vs. apoptosis in response to TGF-ß1 stimulation. TGF-ß1-induced EMP is FAK- dependent, whereas TGF-ß1-induced apoptosis is favored when FAK signaling is inhibited.

Alveolar epithelial disintegrity in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterized by progressive decline in lung function, resulting in significant morbidity and mortality. Current concepts of the pathogenesis of IPF primarily center on dysregulated epithelial cell repair and altered epithelial-mesenchymal communication and extracellular matrix deposition following chronic exposure to cigarette smoke or environmental toxins. In recent years, increasing attention has been directed toward the role of the intercellular junctional complex in determining the specific properties of epithelia in pulmonary diseases. Additionally, recent genomewide association studies suggest that specific genetic variants predictive of epithelial cell dysfunction may confer susceptibility to the development of sporadic idiopathic pulmonary fibrosis. A number of genetic disorders linked to pulmonary fibrosis and familial interstitial pneumonias are associated with loss of epithelial integrity. However, the potential links between extrapulmonary clinical syndromes associated with defects in epithelial cells and the development of pulmonary fibrosis are not well understood. Here, we report a case of hereditary mucoepithelial dysplasia that presented with pulmonary fibrosis and emphysema on high-resolution computed tomography. This case illustrates a more generalizable concept of epithelial disintegrity in the development of fibrotic lung diseases, which is explored in greater detail in this review article.

Systemic sclerosis-associated fibrosis: an accelerated aging phenotype?

PURPOSE OF REVIEW: Systemic sclerosis (SSc) is an autoimmune disease with fibrosis seen in multiple organs. Although not traditionally regarded as a disease of aging, SSc-associated fibrosis shares many of the hallmarks of aging seen in other age-related fibrotic disorders. Here, we review the current literature of the potential role of aging and age-related cellular processes in the development of SSc and fibrosis. RECENT FINDINGS: Accumulating evidence supports a role for immune dysregulation, epigenetic modifications, cellular senescence, mitochondrial dysregulation and impaired autophagy in fibrosis that occurs in aging and SSc. SUMMARY: Cellular alterations linked to aging may promote the development and/or progression of SSc-associated fibrosis.

Therapeutic targeting of SRC kinase in myofibroblast differentiation and pulmonary fibrosis.

Myofibroblasts are effector cells in fibrotic disorders that synthesize and remodel the extracellular matrix (ECM). This study investigated the role of the Src kinase pathway in myofibroblast activation in vitro and fibrogenesis in vivo. The profibrotic cytokine, transforming growth factor ß1 (TGF-ß1), induced rapid activation of Src kinase, which led to myofibroblast differentiation of human lung fibroblasts. The Src kinase inhibitor AZD0530 (saracatinib) blocked TGF-ß1-induced Src kinase activation in a dose-dependent manner. Inhibition of Src kinase significantly reduced α-smooth muscle actin (α-SMA) expression, a marker of myofibroblast differentiation, in TGF-ß1-treated lung fibroblasts. In addition, the induced expression of collagen and fibronectin and three-dimensional collagen gel contraction were also significantly inhibited in AZD0530-treated fibroblasts. The therapeutic efficiency of Src kinase inhibition in vivo was tested in the bleomycin murine lung fibrosis model. Src kinase activation and collagen accumulation were significantly reduced in the lungs of AZD0530-treated mice when compared with controls. Furthermore, the total fibrotic area and expression of α-SMA and ECM proteins were significantly decreased in lungs of AZD0530-treated mice. These results indicate that Src kinase promotes myofibroblast differentiation and activation of lung fibroblasts. Additionally, these studies provide proof-of-concept for targeting the noncanonical TGF-ß signaling pathway involving Src kinase as an effective therapeutic strategy for lung fibrosis.

Canine acquired pneumonia caused by Bordetella bronchiseptica.

Here, we present the case of a 55-year-old male with HIV and persistent lymphopenia who developed a paroxysmal severe cough for over three weeks. Microbiology studies were positive for abundant colonies of Bordetella bronchiseptica. He reports that his dog was also ill with a severe cough, suggesting a possible canine-to-human transmission. This zoonosis has been increasingly recognized and possesses significant morbidity and mortality, especially in immunocompromised hosts.

Evaluating the consistency with guideline recommendations for diagnosis and management of idiopathic pulmonary fibrosis in non-academic settings.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with elevated mortality. Delay in diagnosis lead to worse outcomes. Guidelines developed at academic medical centers are difficult to replicate in the community. OBJECTIVES: Our primary objective was to ascertain consistency with the 2011 IPF guidelines. Our secondary objective was to conduct an interdisciplinary review to ascertain whether the evidence supported the original diagnosis of IPF or not. METHODS: We asked permission from pulmonologists to review records of patients diagnosed with IPF after 2011. We collected physician demographics and training data; patient demographics, clinical and diagnostic/management data. The clinical data and available images were reviewed by the interdisciplinary review panel. RESULTS: 26 practicing pulmonologists located in the Southeast of the United States consented to participate. Mean age was 48, 70% were male and all had current certification. We reviewed data from 96 patients. The mean age was 71.4 and most were male. Only 23% had the recommended screening for a connective tissue disease and 42.6% were screened for exercise-induced hypoxemia. Among patients with available images for review (n=66), only 50% had a high-resolution CT scan. 22% of patients underwent a surgical biopsy and in only 33% of the cases three lobes were sampled. No patient had documentation that a multidisciplinary discussion occurred. In 20% of the cases with available images, the evidence supported an alternative diagnosis. 56% of eligible candidates were ever started on anti-fibrotics. CONCLUSIONS: Our findings suggest that consistency with the IPF guidelines is low in non-academic settings.

Neuronal Wiskott-Aldrich syndrome protein (N-WASP) is critical for formation of α-smooth muscle actin filaments during myofibroblast differentiation.

Myofibroblasts are implicated in pathological stromal responses associated with lung fibrosis. One prominent phenotypic marker of fully differentiated myofibroblasts is the polymerized, thick cytoplasmic filaments containing newly synthesized α-smooth muscle actin (α-SMA). These α-SMA-containing cytoplasmic filaments are important for myofibroblast contractility during tissue remodeling. However, the molecular mechanisms regulating the formation and maturation of α-SMA-containing filaments have not been defined. This study demonstrates a critical role for neuronal Wiskott-Aldrich syndrome protein (N-WASP) in regulating the formation of α-SMA-containing cytoplasmic filaments during myofibroblast differentiation and in myofibroblast contractility. Focal adhesion kinase (FAK) is activated by transforming growth factor-ß1 (TGF-ß1) and is required for phosphorylation of tyrosine residue 256 (Y256) of N-WASP. Phosphorylation of Y256 of N-WASP is essential for TGF-ß1-induced formation of α-SMA-containing cytoplasmic filaments in primary human lung fibroblasts. In addition, we demonstrate that actin-related protein (Arp) 2/3 complex is downstream of N-WASP and mediates the maturation of α-SMA-containing cytoplasmic filaments. Together, this study supports a critical role of N-WASP in integrating FAK and Arp2/3 signaling to mediate formation of α-SMA-containing cytoplasmic filaments during myofibroblast differentiation and maturation.

Macrophage migration inhibitory factor promotes tumor growth in the context of lung injury and repair.

RATIONALE: Tissue injury and repair involve highly conserved processes governed by mechanisms that can be co-opted in tumors. We hypothesized that soluble factors released during the repair response to lung injury would promote orthotopic tumor growth. OBJECTIVES: To determine whether lung injury promoted growth of orthotopic lung tumors and to study the molecular mechanisms. METHODS: We initiated lung injury in C57Bl6 mice using different stimuli, then injected Lewis lung carcinoma cells during the repair phase. We assessed tumor growth 14 days later. We measured tumor angiogenesis, cytokine expression, proliferation, and apoptosis. MEASUREMENTS AND MAIN RESULTS: Regardless of the mechanism, injured lungs contained more numerous and larger tumors than sham-injured lungs. Tumors from injured lungs were no more vascular, but had higher levels of proliferation and reduced rates of apoptosis. The cytokine macrophage migration inhibitory factor (MIF) was highly expressed in both models of tissue injury. We observed no increase in tumor growth after lung injury in MIF knockout mice. We induced lung-specific overexpression of MIF in a double-transgenic mouse, and observed that MIF overexpression by itself was sufficient to accelerate the growth of orthotopic Lewis lung carcinoma tumors. CONCLUSIONS: Lung injury leads to increased expression of the cytokine MIF, which results in protection from apoptosis and increased proliferation in orthotopic tumors injected after the acute phase of injury.

Latent herpesvirus infection augments experimental pulmonary fibrosis.

RATIONALE: No effective treatment exists for idiopathic pulmonary fibrosis, and its pathogenesis remains unclear. Accumulating evidence implicates herpesviruses as cofactors (either initiating or exacerbating agents) of fibrotic lung disease, but a role for latent herpesvirus infection has not been studied. OBJECTIVES: To develop a murine model to determine whether latent herpesvirus infection can augment fibrotic responses and to gain insight into potential mechanisms of enhanced fibrogenesis. METHODS: Mice were infected with murine gammaherpesvirus 14 to 70 days before a fibrotic challenge with fluorescein isothiocyanate or bleomycin so that the virus was latent at the time of fibrotic challenge. Measurements were made after viral infection alone or after the establishment of fibrosis. MEASUREMENTS AND MAIN RESULTS: gammaHerpesvirus is latent by 14 days post infection, and infection 14 to 70 days before fibrotic challenge augmented fibrosis. Fibrotic augmentation was not dependent on reactivation of the latent virus to a lytic state. Total cell numbers and fibrocyte numbers were increased in the lungs of latently infected mice administered fibrotic challenge compared with mock-infected mice that received fibrotic challenge. Latent infection up-regulates expression of proinflammatory chemokines, transforming growth factor-beta1, and cysteinyl leukotrienes in alveolar epithelial cells. CONCLUSIONS: Latent gammaherpesvirus infection augments subsequent fibrotic responses in mice. Enhanced fibrosis is associated with the induction of profibrotic factors and the recruitment of fibrocytes. Our data complement existing human and animal data supporting the hypothesis that gammaherpesviruses can serve as initiating cofactors in the pathogenesis of pulmonary fibrosis.

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 SaO2>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.

Updated Evaluation of the Safety, Efficacy and Tolerability of Pirfenidone in the Treatment of Idiopathic Pulmonary Fibrosis.

Idiopathic Pulmonary Fibrosis (IPF) is a chronic fibrotic disease characterized by a progressive decline in lung function with a median survival of 3-5 years after diagnosis. The course of disease is highly variable and unpredictable, often punctuated by episodes of acute respiratory failure, known as acute exacerbations. The incidence of IPF is on the rise due to the aging population, as age is the most important risk factor for this disease. Pirfenidone and nintedanib are the two anti-fibrotic drugs approved for IPF which have shown reduction in lung function decline. This review will discuss the efficacy, safety and tolerability profile of pirfenidone from clinical trials and the real-world clinical experience. Pirfenidone reduces the decline in lung function and improves progression-free survival in patients with IPF. It is generally well tolerated with the most common side effects being gastrointestinal and phototoxicity.

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 %DLCO 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.

Predicting Outcome in Idiopathic Pulmonary Fibrosis: Addition of Fibrotic Score at Thin-Section CT of the Chest to Gender, Age, and Physiology Score Improves the Prediction Model.

PURPOSE: To assess the impact of adding thin-section CT-derived semiquantitative fibrotic score to gender, age, and physiology (GAP) model for predicting survival in idiopathic pulmonary fibrosis (IPF). MATERIALS AND METHODS: In this retrospective study of 194 patients with IPF, primary outcome was transplant-free survival. Two thoracic radiologists visually estimated the percentage of reticulation and honeycombing at baseline thin-section CT, which were added to give fibrotic score. For analysis, fibrotic score cutoff (x) determined by using receiver operating characteristic analysis categorized patients into group A (3). Combining the above categories gave four groups (A1, A2, B1, B2). Kaplan-Meier survival analysis was performed with comparison statistics (log-rank test), and hazard ratios were calculated by using the Cox model. RESULTS: The study patients included 141 men (72.7%), with average age of 66.1 years ± 9.1 (standard deviation). Eighty-four patients (43.3%) has stage I disease with a median follow up of 3.3 years. The interobserver agreement for thin-section CT fibrotic score was substantial (83.3%; κ = 0.64). The optimal cutoff for fibrotic score was 25% (x), with area under the curve of 0.654 (95% confidence interval [CI]: 0.569, 0.74). Survival for group A1 was significantly better than in the other three groups (P < .001). The hazard ratios for respective groups were as follows: B1 was 4.03 (95% CI: 2.02, 8.07), A2 was 4.10 (95% CI: 1.89, 8.87), and B2 was 5.62 (95% CI: 2.86, 11.06) (P < .001 for all). Within the group with GAP score less than or equal to 3 (A1, B1), participants with higher fibrotic score (B1) had four times the increased risk of death or transplantation (P < .001). CONCLUSION: Incorporating semiquantitative fibrotic score from thin-section CT to GAP score provides an improved prediction model for survival in idiopathic pulmonary fibrosis.© RSNA, 2019See also the commentary by Chung in this issue.

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.