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Background: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with an overall poor prognosis. A simple-to-use staging system for IPF may improve prognostication, help guide management, and facilitate research. Objective: To develop a multidimensional prognostic staging system for IPF by using commonly measured clinical and physiologic variables. Design: A clinical prediction model was developed and validated by using retrospective data from 3 large, geographically distinct cohorts. Setting: Interstitial lung disease referral centers in California, Minnesota, and Italy. Patients: 228 patients with IPF at the University of California, San Francisco (derivation cohort), and 330 patients at the Mayo Clinic and Morgagni-Pierantoni Hospital (validation cohort). Measurements: The primary outcome was mortality, treating transplantation as a competing risk. Model discrimination was assessed by the c-index, and calibration was assessed by comparing predicted and observed cumulative mortality at 1, 2, and 3 years. Results: Four variables were included in the final model: gender (G), age (A), and 2 lung physiology variables (P) (FVC and Dlco). A model using continuous predictors (GAP calculator) and a simple point-scoring system (GAP index) performed similarly in derivation (c-index of 70.8 and 69.3, respectively) and validation (c-index of 69.1 and 68.7, respectively). Three stages (stages I, II, and III) were identified based on the GAP index with 1-year mortality of 6%, 16%, and 39%, respectively. The GAP models performed similarly in pooled follow-up visits (c-index >=71.9). Limitation: Patients were drawn from academic centers and analyzed retrospectively. Conclusion: The GAP models use commonly measured clinical and physiologic variables to predict mortality in patients with IPF. Primary Funding Source: University of California, San Francisco Clinical and Translational Science Institute. [ABSTRACT FROM AUTHOR]

Definitive evidence of clinical efficacy in a Phase 3 trial is best shown by a beneficial impact on a clinically meaningful endpoint-that is, an endpoint that directly measures how a patient feels (symptoms), functions (the ability to perform activities in daily life), or survives. In idiopathic pulmonary fibrosis (IPF), we believe the endpoints that best meet these criteria are all-cause mortality and all-cause nonelective hospitalization. There are no validated measures of symptoms or broader constructs such as health status or functional status in IPF. A surrogate endpoint is defined as an indirect measure that is intended to substitute for a clinically meaningful endpoint. Surrogate endpoints can be appropriate outcome measures if validated. However, validation requires substantial evidence that the effect of an intervention on a clinically meaningful endpoint is reliably predicted by the effect of an intervention on the surrogate endpoint. For patients with IPF, there are currently no validated surrogate endpoints. [ABSTRACT FROM AUTHOR]

Rationale: Forced vital capacity (FVC) is an established measure of pulmonary function in idiopathic pulmonary fibrosis (IPF). Evidence regarding its measurement properties and minimal clinically important difference (MCID) in this population is limited. Objectives: To assess the reliability, validity, and responsiveness of FVC and estimate the MCID in patients with IPF. Methods: The study population included all 1,156 randomized patients in two clinical trials of IFN-[gamma]1b. FVC and other measures of functional status were measured at screening or baseline and 24-week intervals thereafter. Reliability was assessed based on two proximal measures of FVC, validity was assessed based on correlations between FVC and other measures of functional status, and responsiveness was assessed based on the relationship between 24-week changes in FVC and other measures of functional status. Distribution-based and anchor-based methods were used to estimate the MCID. Measurements and Main Results: Correlation of percent-predicted FVC between measurements (mean interval, 18 d) was high (r = 0.93; P < 0.001). Correlations between FVC and other parameters were generally weak, with the strongest observed correlation between FVC and carbon monoxide diffusing capacity (r = 0.38; P < 0.001). Correlations between change in FVC and changes in other parameters were slightly stronger (range, r = 0.16-0.37; P < 0.001). Importantly, 1-year risk of death was more than twofold higher (P < 0.001) in patients with a 24-week decline in FVC between 5% and 10%. The estimated MCID was 2-6%. Conclusions: FVC is a reliable, valid, and responsive measure of clinical status in patients with IPF, and a decline of 2-6%, although small, represents a clinically important difference. [ABSTRACT FROM AUTHOR]

Rationale: Gastroesophageal reflux (GER) is highly prevalent in patients with idiopathic pulmonary fibrosis (IPF). Chronic microaspiration secondary to GER may play a role in the pathogenesis and natural history of IPF.Objectives: To investigate the relationship between GER-related variables and survival time in patients with IPF.Methods: Regression analysis was used to investigate the relationship between GER-related variables and survival time in a retrospectively identified cohort of patients with well-characterized IPF from two academic medical centers.Measurements and Main Results: Two hundred four patients were identified for inclusion. GER-related variables were common in this cohort: reported symptoms of GER (34%), a history of GER disease (45%), reported use of GER medications (47%), and Nissen fundoplication (5%). These GER-related variables were significantly associated with longer survival time on unadjusted analysis. After adjustment, the use of GER medications was an independent predictor of longer survival time. In addition, the use of gastroesophageal reflux medications was associated with a lower radiologic fibrosis score. These findings were present regardless of center.Conclusions: The reported use of GER medications is associated with decreased radiologic fibrosis and is an independent predictor of longer survival time in patients with IPF. These findings further support the hypothesis that GER and chronic microaspiration may play important roles in the pathobiology of IPF. [ABSTRACT FROM AUTHOR]

Rationale: A previous trial of bosentan in idiopathic pulmonary fibrosis (IPF) showed a trend to delayed IPF worsening or death. Also, improvements in some measures of dyspnea and health-related quality of life were observed. Objectives: To demonstrate that bosentan delays IPF worsening or death. Methods: Prospective, randomized (2:1), double-blind, placebo-controlled, event-driven, parallel-group, morbidity-mortality trial of bosentan in adults with IPF of less than 3 years' duration, confirmed by surgical lung biopsy, and without extensive honeycombing on high-resolution computed tomography. The primary endpoint was time to IPF worsening (a confirmed decrease from baseline in FVC >= 10% and diffusing capacity of the lung for carbon monoxide >= 15%, or acute exacerbation of IPF) or death up to End of Study. Effects of bosentan on health-related quality of life, dyspnea, and the safety and tolerability of bosentan were investigated. Measurements and Main Results: Six hundred sixteen patients were randomized to bosentan (n = 407) or placebo (n = 209). No significant difference between treatment groups was observed in the primary endpoint analysis (hazard ratio, 0.85; 95% confidence interval, 0.66-1.10; P = 0.2110). No treatment effects were observed on health-related quality of life or dyspnea. Some effects of bosentan treatment were observed in changes from baseline to 1 year in FVC and diffusing capacity of the lung for carbon monoxide. The safety profile for bosentan was similar to that observed in other trials. Conclusions: The primary objective in the Bosentan Use in Interstitial Lung Disease-3 trial was not met. Bosentan was well tolerated. Clinical trial registered with www.clinicaltrials.gov (NCT 00391443). [ABSTRACT FROM AUTHOR]

Rationale: The 6-minute-walk test (6MWT) is a practical and clinically meaningful measure of exercise tolerance with favorable performance characteristics in various cardiac and pulmonary diseases. Performance characteristics in patients with idiopathic pulmonary fibrosis (IPF) have not been systematically evaluated. Objectives: To assess the reliability, validity, and responsiveness of the 6MWT and estimate the minimal clinically important difference (MCID) in patients with IPF. Methods: The study population included all subjects completing a 6MWT in a clinical trial evaluating interferon gamma-1b (n = 822). Six-minute walk distance (6MWD) and other parameters were measured at baseline and at 24-week intervals using a standardized protocol. Parametric and distribution-independent correlation coefficients were used to assess the strength of the relationships between 6MWD and measures of pulmonary function, dyspnea, and health-related quality of life. Both distribution-based and anchor-based methods were used to estimate the MCID. Measurements and Main Results: Comparison of two proximal measures of 6MWD (mean interval, 24 d) demonstrated good reliability (coefficient = 0.83; P < 0.001). 6MWD was weakly correlated with measures of physiologic function and health-related quality of life; however, values were consistently and significantly lower for patients with the poorest functional status, suggesting good construct validity. Importantly, change in 6MWD was highly predictive of mortality; a 24-week decline of greater than 50 m was associated with a fourfold increase in risk of death at 1 year (hazard ratio, 4.27; 95% confidence interval, 2.57- 7.10; P < 0.001). The estimated MCID was 24-45 m. Conclusions: The 6MWT is a reliable, valid, and responsive measure of disease status and a valid endpoint for clinical trials in IPF. [ABSTRACT FROM AUTHOR]

Rationale: The response characteristics of the 6 minute walk test (6MWT) in studies of idiopathic pulmonary fibrosis (IPF) are only poorly understood, and the change in walk distance that constitutes the minimum important difference (MID) over time is unknown.Objectives: To examine changes over time in distance walked (ie, 6MWD) during the 6MWT and to estimate the change in distance that constitutes the MID in patients with IPF.Methods: Data from a recently completed trial that included subjects with IPF who completed the 6MWT, Saint George's Respiratory Questionnaire (SGRQ) and forced vital capacity (FVC) at 6 and 12 months were used to examine longitudinal changes in 6MWD. Both anchor- and distribution-based approaches as well as linear regression analyses were used to determine the MID for 6MWD. The SGRQ Total score and FVC were used as clinical anchors.Main Results: Among 123 subjects alive and able to complete the 6MWT at both follow-up time points, 6MWD did not change significantly over time (378.1 m at baseline vs 376.8 m at 6 months vs 361.3 m at 12 months, p=0.5). The point estimate for the 6MWD MID was 28 m with a range of 10.8-58.5 m.Conclusion: In a group of patients with IPF with moderate physiological impairment, for those alive and able to complete a 6MWT, 6MWD does not change over 12 months. At the population level, the MID for 6MWD appears to be approximately 28 m. Further investigation using other anchors and derivation methods is required to refine estimates of the MID for 6MWD in this patient population. [ABSTRACT FROM AUTHOR]

Rationale: The 2002 American Thoracic Society/European Respiratory Society classification of idiopathic interstitial pneumonias identified nonspecific interstitial pneumonia (NSIP) as a provisional diagnosis. Concern was expressed that NSIP was a "wastebasket" category, difficult to distinguish from other idiopathic interstitial pneumonias. Objectives: The following questions were addressed: (1) Is idiopathic NSIP a distinct entity? 2) If so, what are its clinical, radiologic and pathologic characteristics? (3) What is the role of radiology and pathology in establishing the diagnosis? (4) To make a diagnosis of idiopathic NSIP, what other disorders need to be excluded and how should this be done? Methods: Investigators who had previously reported cases of idiopathic NSIP were invited to submit cases for review (n = 305). After initial review, cases with complete clinical, radiologic, and pathologic information (n = 193) were reviewed in a series of workshops. Measurements and Main Results: Sixty-seven cases were identified as NSIP. Mean age was 52 years, 67% were women, 69% were never-smokers, and 46% were from Asian countries. The most common symptoms were dyspnea (96%) and cough (87%); 69% had restriction. By high-resolution computed tomography, the lower lung zones were predominantly involved in 92% of cases; 46% had a peripheral distribution; 47% were diffuse. Most showed a reticular pattern (87%) with traction bronchiectasis (82%) and volume loss (77%). Lung biopsies showed uniform thickening of alveolar walls with a spectrum of cellular to fibrosing patterns. Five-year survival was 82.3%. Conclusions: Idiopathic NSIP is a distinct clinical entity that occurs mostly in middle-aged women who are never-smokers. The prognosis of NSIP is very good. [ABSTRACT FROM AUTHOR]

Rationale: The American Thoracic Society/European Respiratory Society International Consensus Classification panel identified the clinical entity idiopathic nonspecific interstitial pneumonia (NSIP) as a provisional diagnosis and recommended further study.Objectives: We hypothesized that idiopathic NSIP is an autoimmune disease and the lung manifestation of undifferentiated connective tissue disease (UCTD), a recently described, distinct entity.Methods: We studied 28 consecutive patients with idiopathic interstitial pneumonia (IIP) enrolled in the University of California, San Francisco Interstitial Lung Disease Center who met prespecified criteria for UCTD, as follows: at least one clinical manifestation of connective tissue disease, serologic evidence of systemic inflammation in the absence of clinical infection, and absence of sufficient American College of Rheumatology criteria for another connective tissue disease. Medical record reviews, evaluation of radiographs, and scoring of lung biopsies were performed. The control group consisted of all other patients (n = 47) with IIP who did not meet the UCTD criteria.Measurements and Main Results: The patients with UCTD were more likely to be women, younger, and nonsmokers than the IIP control subjects. Compared with the control group, patients with UCTD-ILD were significantly more likely to have ground-glass opacity on high-resolution computed tomography (HRCT) and NSIP pattern on biopsy, and less likely to have honeycombing on HRCT or usual interstitial pneumonia on biopsy. At our center, the majority of patients classified as idiopathic NSIP (88%) met the criteria for UCTD.Conclusions: Most patients diagnosed with idiopathic NSIP meet the case definition of UCTD. Furthermore, these results show that the clinical entity idiopathic NSIP is different from idiopathic pulmonary fibrosis and appears to be an autoimmune disease. [ABSTRACT FROM AUTHOR]

Rationale: Treatment and prognoses of diffuse parenchymal lung diseases (DPLDs) varies by diagnosis. Obtaining a uniform diagnosis among observers is difficult.Objectives: Evaluate diagnostic agreement between academic and community-based physicians for patients with DPLDs, and determine if an interactive approach between clinicians, radiologists, and pathologists improved diagnostic agreement in community and academic centers.Methods: Retrospective review of 39 patients with DPLD. A total of 19 participants reviewed cases at 2 community locations and 1 academic location. Information from the history, physical examination, pulmonary function testing, high-resolution computed tomography, and surgical lung biopsy was collected. Data were presented in the same sequential fashion to three groups of physicians on separate days.Measurements and Main Results: Each observer's diagnosis was coded into one of eight categories. A kappa statistic allowing for multiple raters was used to assess agreement in diagnosis. Interactions between clinicians, radiologists, and pathologists improved interobserver agreement at both community and academic sites; however, final agreement was better within academic centers (kappa = 0.55-0.71) than within community centers (kappa = 0.32-0.44). Clinically significant disagreement was present between academic and community-based physicians (kappa = 0.11-0.56). Community physicians were more likely to assign a final diagnosis of idiopathic pulmonary fibrosis compared with academic physicians.Conclusions: Significant disagreement exists in the diagnosis of DPLD between physicians based in communities compared with those in academic centers. Wherever possible, patients should be referred to centers with expertise in diffuse parenchymal lung disorders to help clarify the diagnosis and provide suggestions regarding treatment options. [ABSTRACT FROM AUTHOR]

Various reports have demonstrated the importance of small airway inflammation in the development of airflow limitation and progression of COPD. This hypothesis proposes that the pathogenesis of COPD mirrors a chronic inhalational dust-induced disease. The putative inorganic dust in cigarette smoke is aluminum silicate or kaolinite, a common component of clay soils. Kaolinite has been recovered in the alveolar macrophages of smokers and has been reported as a constituent of tobacco products. The origin of kaolinite in tobacco products remains unknown, and possible potential sources are proposed. On inhalation, kaolinite deposition in the distal lung may promote macrophage accumulation within the terminal airways leading to a respiratory bronchiolitis. In the susceptible smoker, important genetic, environmental, immunologic, and mechanical factors interact and modulate this small airway inflammation, ultimately leading to the pathologic lesion of emphysema. Further studies into the effects of kaolinite on macrophage function and the subsequent development of respiratory bronchiolitis could lead to prevention of COPD at its precursor lesion. [ABSTRACT FROM AUTHOR]

Rationale: High-resolution computed tomography (HRCT) is an integral aspect of the evaluation of patients with suspected idiopathic pulmonary fibrosis (IPF). However, few studies have evaluated its use in a large cohort. Objectives: To describe HRCT features in patients with mild to moderate IPF, compare diagnostic evaluations by a radiology core (three thoracic radiologists) with those by study-site radiologists, correlate baseline clinical and physiologic variables with HRCT findings, and evaluate their association with mortality. Methods: We assessed HRCT scans from patients with IPF (n = 315) enrolled in a randomized controlled study evaluating IFN-gamma1b. Measurements and Main Results: There was concordance between study-site and core radiologists regarding the diagnosis of IPF in 86% of cases. Diffusing capacity of carbon monoxide (DLCO) was the physiologic characteristic most highly correlated with HRCT findings. Multivariate analysis identified three independent predictors of mortality: a higher extent of fibrosis score increased the risk of death (p < 0.0001), whereas a higher percent-predicted DLCO (p = 0.004) and treatment assignment to IFN-gamma1b rather than placebo (p = 0.04) reduced the risk of death. Conclusions: A study-site diagnosis of IPF on HRCT was regularly confirmed by core radiologists. Extent of reticulation and honeycombing on HRCT is an important independent predictor of mortality in patients with IPF. [ABSTRACT FROM AUTHOR]

The last century experienced remarkable advances in the classification, diagnosis, and understanding of the pathogenesis of the interstitial lung diseases. Technological advances, particularly physiologic testing, lung imaging studies, bronchoalveolar lavage, surgical lung biopsy, and histopathologic assessment, improved our understanding of these entities. In particular, the advent of high-resolution computed tomography, the narrowed pathologic definition of usual interstitial pneumonia, and recognition of the prognostic importance of separating usual interstitial pneumonia from other idiopathic interstitial pneumonia patterns have profoundly changed the approach to these processes. Most recently, genetic medicine, the use of new technologies (e.g., microarrays, mass spectroscopic analysis of proteins, and laser capture microdissection), and the development of animal models have had a major impact on understanding the pathogenesis and potential molecular targets for interfering with fibrogenesis. This article highlights some of the advances and changes in clinical practice that took place in the management of patients with interstitial lung diseases over the last century. [ABSTRACT FROM AUTHOR]

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a devastating disease, yet validated, reliable criteria for evaluating patient response to therapies in clinical trials are lacking. METHODS: To optimize selection of end point criteria for the study of interferon (IFN)-gamma1b in patients with IPF, we retrospectively analyzed the components of the primary efficacy end point used in a large, controlled study of 330 patients for reliability, validity, and sensitivity to treatment effect. The primary end point components were death, disease progression defined as a > or = 5 mm Hg increase in resting alveolar-arterial oxygen pressure gradient (P[A-a]O2), and disease progression defined as a > or = 10% decrease in percentage of predicted FVC. RESULTS: We found that the P(A-a)O2 criterion was not reliable and was not associated with mortality. In contrast, the FVC criterion was reliable and was associated with a 2.4-fold increase in the risk of death. Of the three measures, only mortality was sensitive to a treatment effect of IFN-gamma1b. Additionally, the tendency for mortality benefit was observed in nearly all patient subgroups defined by baseline physiology. The effect of IFN-gamma1b on mortality was strongest in patients with baseline percentage of predicted FVC > or = 55% (p = 0.004) or percentage of predicted diffusing capacity of the lung for carbon monoxide > or = 30% (p = 0.008). CONCLUSION: We conclude that mortality is the most inclusive end point for future trials of IFN- gamma1b in patients with IPF, and that a > 10% decrement in the percentage of predicted FVC represents a valid measure of disease progression. [ABSTRACT FROM AUTHOR]

Current guidelines recommend that the clinician, radiologist, and pathologist work together to establish a diagnosis of idiopathic interstitial pneumonia. Three clinicians, two radiologists, and two pathologists reviewed 58 consecutive cases of suspected idiopathic interstitial pneumonia. Each participant was provided information in a sequential manner and was asked to record their diagnostic impression and level of confidence at each step. Interobserver agreement improved from the beginning to the end of the review. After the presentation of histopathologic information, radiologists changed their diagnostic impression more often than did clinicians. In general, as more information was provided the confidence level for a given diagnosis improved, and the diagnoses rendered with a high level of confidence were more likely congruent with the final pathologic consensus diagnosis. The final consensus pathologist diagnosis was idiopathic pulmonary fibrosis in 30 cases. Clinicians identified 75% and radiologists identified 48% of these cases before presentation of the histopathologic information. Histopathologic information has the greatest impact on the final diagnosis, especially when the initial clinical/radiographic diagnosis is not idiopathic pulmonary fibrosis. We conclude that dynamic interactions between clinicians, radiologists, and pathologists improve interobserver agreement and diagnostic confidence. [ABSTRACT FROM AUTHOR]

Background: The chronic granulomatous inflammation of sarcoidosis has been hypothesized to depend on the CD4+ T-helper lymphocyte. HIV infection, which depletes these cells, has been reported to attenuate the manifestations of sarcoidosis.Study Objectives: We asked whether the development of symptomatic sarcoidosis in the context of preexisting HIV infection was dependent on the CD4+ lymphocyte count.Design: We performed a retrospective standardized chart review of all patients who developed granulomatous inflammation following HIV infection at an urban academic referral center.Measurements: We identified seven patients with sarcoidosis within this cohort and compared their CD4+ lymphocyte count to that in a cohort of 16 patients in whom similar granulomatous inflammation was found but who did not have sarcoidosis. We then compared our cases to all reported cases using a systematic literature review.Results: The CD4+ lymphocyte count was > 200 cells/ microL in all of our patients with HIV infection when they developed subsequent sarcoidosis. In contrast, specific etiologies for granulomatous inflammation were found in all 10 HIV-infected patients who presented with granulomatous inflammation and a CD4+ lymphocyte count of < 200 cells/ microL, with infectious etiologies found in 8 patients. Similarly, there was relative preservation of the CD4+ lymphocyte count in previously reported cases, with 14 of 19 patients (74%) having an absolute CD4+ lymphocyte count of > 200 cells/ microL.Conclusions: We conclude that the development of the chronic granulomatous inflammation of sarcoidosis appears to depend on the preservation or restoration of the peripheral CD4+ lymphocyte count and that in most cases the CD4+ lymphocyte count exceeds 200 cells/ microL. Furthermore, alternative specific etiologies of granulomatous inflammation are generally identifiable in HIV-infected patients with peripheral CD4+ lymphocyte counts of < 200 cells/ microL. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Two sequential outbreaks of respiratory disease among lifeguards at an indoor swimming pool with water spray features were investigated. METHODS: Questionnaires were administered to recreation center employees following each outbreak. Respondents reporting 2 or more pool-related symptoms were offered clinical evaluation, including bronchoscopy with bronchoalveolar lavage and transbronchial biopsy. Pool air and water were sampled for fungi, bacteria, amoebae, endotoxin, and respirable particulates. RESULTS: Thirty-three lifeguards had noncaseating granulomas on biopsy and/or bronchoalveolar lavage lymphocytosis. Attack rates for the outbreaks were 27% and 65%. Case patients had higher cumulative hours of work and tended to work more hours per week. Analyses indicated increased levels of endotoxin in pool air and water (relative to control pools) and gram-negative bacterial colonization of water sprays. Use of water spray features generated a 5.2-fold increase in the number of respirable particles and up to an 8-fold increase in air endotoxin levels. CONCLUSIONS: Lifeguards in this indoor swimming pool developed granulomatous lung disease associated with endotoxin-containing respirable bioaerosols from water spray features, which ventilation system improvements did not prevent. [ABSTRACT FROM AUTHOR]