Racial and ethnic disparities in idiopathic pulmonary fibrosis: A UNOS/OPTN database analysis

Assessment of the impact of social deprivation, distance to hospital and time to diagnosis on survival in idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive condition associated with a variable prognosis. The relationship between socioeconomic status or distance travelled to respiratory clinics and prognosis is unclear.

RESEARCH QUESTION

To determine whether socioeconomic status, distance to hospital and time to referral affects survival in patients with IPF.

STUDY DESIGN AND METHODS

In this retrospective cohort study, we used data collected from the British Thoracic Society Interstitial Lung Diseases Registry, between 2013 and 2021 (n = 2359) and calculated the quintile of Index of Multiple Deprivation 2019 score, time from initial symptoms to hospital attendance and distance as the linear distance between hospital and home post codes. Survival was assessed using Cox proportional hazards models.

RESULTS

There was a significant association between increasing quintile of deprivation and duration of symptoms prior to hospital presentation, Gender Age Physiology (GAP) index and receipt of supplemental oxygen and antifibrotic therapies at presentation. The most deprived patients had worse overall survival compared to least deprived after adjusting for smoking status, GAP index, distance to hospital and time to referral (HR = 1.39 [1.11, 1.73]; p = 0.003). Patients living furthest from a respiratory clinic also had worse survival compared to those living closest (HR = 1.29 [1.01, 1.64]; p = 0.041).

INTERPRETATION

The most deprived patients with IPF have more severe disease at presentation and worse outcomes. Living far from hospital was also associated with poor outcomes. This suggests inequalities in access to healthcare and requires consideration in delivering effective and equitable care to patients with IPF.

Racial Disparities in Waiting List Outcomes of Patients Listed for Lung Transplantation

BACKGROUND

The Lung Allocation Score, implemented in 2005, prioritized lung transplant candidates by medical urgency rather than waiting list time and was expected to improve racial disparities in transplant allocation. We evaluated whether racial disparities in lung transplant persisted after 2005.

METHODS

We identified all wait-listed adult lung transplant candidates in the United States from 2005 through 2021 using the Scientific Registry of Transplant Recipients. We evaluated the association between race and receipt of a transplant by using a multivariable competing risk regression model adjusted for demographics, socioeconomic status, Lung Allocation Score, clinical measures, and time. We evaluated interactions between race and age, sex, socioeconomic status, and Lung Allocation Score.

RESULTS

We identified 33,158 candidates on the lung transplant waiting list between 2005 and 2021: 27,074 White (82%), 3350 African American (10%), and 2734 Hispanic (8%). White candidates were older, had higher education levels, and had lower Lung Allocation Scores (P < .001). After multivariable adjustment, African American and Hispanic candidates were less likely to receive lung transplants than White candidates (African American: adjusted subhazard ratio, 0.86; 95% CI, 0.82-0.91; Hispanic: adjusted subhazard ratio, 0.82; 95% CI, 0.78-0.87). Lung transplant was significantly less common among Hispanic candidates aged >65 years (P = .003) and non-White candidates from higher-poverty communities (African-American: P = .013; Hispanic: P =.0036).

CONCLUSIONS

Despite implementation of the Lung Allocation Score, racial disparities persisted for wait-listed African American and Hispanic lung transplant candidates and differed by age and poverty status. Targeted interventions are needed to ensure equitable access to this life-saving intervention.

Examining prevalence and predictors of pulmonary hypertension in adults with idiopathic pulmonary fibrosis: a population-based analysis in the United States

Pulmonary hypertension (PH) often complicates idiopathic pulmonary fibrosis (IPF), a progressive parenchymal lung disease. We investigated predictors of PH in IPF hospitalizations in the United States. We identified IPF hospital- izations with or without PH using the National Inpatient Sample (2018) and relevant ICD-10-CM codes. We com- pared demographics, comorbidities, PH prevalence, and its multivariable predictors adjusted for confounders among patients with IPF. In 2018, 30,335 patients from 30,259,863 hospitalizations had IPF, of which 8,075 (26.6%) had PH. Black (41%), Hispanic (21.3%), and female (28.7%) patients had higher rates of PH compared to white patients (25%). The IPF-PH cohort was hospitalized more often in urban teaching (77.7% vs. 72.2%), Midwest, and West hospitals vs. non-PH cohort. Comorbidities including congestive heart failure (2.08 [1.81-2.39]), valvular disease (2.12 [1.74-2.58]), rheumatoid arthritis/collagen vascular disease (1.32 [1.08-1.61]) predicted higher odds of PH. The PH-IPF cohort was less often routinely discharged (35.4%) and more likely to be transferred to intermediate care facilities (22.6%) and home health care (27.1%) (P < 0.001). The PH-IPF group had higher rates of all-cause mortality (12.3% vs. 9.4%), cardiogenic shock (2.4% vs. 1%), dysrhythmia (37.6% vs. 29%), and cardiac arrest (2.7% vs. 1.5%) vs. non-PH cohort (all P < 0.001). Patients with PH-IPF also had longer hospital stays (9 vs. 8) and a higher median cost ($23,054 vs. $19,627, P < 0.001). Nearly 25% of IPF hospitalizations with PH were linked to higher mortality, extended stays, and costs, emphasizing the need to integrate demographic and comorbidity predictors into risk stratification for improved outcomes in patients with IPF-PH.

Supplemental Oxygen Therapy in Interstitial Lung Disease: A Narrative Review

Patients with interstitial lung diseases (ILD) often have hypoxemia at rest and/or with exertion, for which supplemental oxygen is commonly prescribed. The number of patients with ILD who require supplemental oxygen is unknown, although estimates suggest it could be as much as 40%; many of these patients may require high-flow support (>4 L/min). Despite its frequent use, there is limited evidence for the impact of supplemental oxygen on clinical outcomes in ILD, with recommendations for its use primarily based on older studies in patients with chronic obstructive pulmonary disease. Oxygen use in ILD is rarely included as an outcome in clinical trials. Available evidence suggests that supplemental oxygen in ILD may improve quality of life and some exercise parameters in patients whose hypoxemia is a limiting factor; however, oxygen therapy also places new burdens and barriers on some patients that may counter its beneficial effects. The cost of supplemental oxygen in ILD is also unknown but likely represents a significant portion of overall healthcare costs in these patients. Current Centers for Medicare and Medicaid reimbursement policies provide only a modest increase in payment for high oxygen flows, which may negatively impact access to oxygen services and equipment for some patients with ILD. Future studies should examine clinical and quality-of-life outcomes for oxygen use in ILD. In the meantime, given the current limited evidence for supplemental oxygen and considering cost factors and other barriers, providers should take a patient-focused approach when considering supplemental oxygen prescriptions in patients with ILD.

Racial and ethnic disparities in antifibrotic therapy in idiopathic pulmonary fibrosis

BACKGROUND AND OBJECTIVE

Racial disparities have been documented in care of many respiratory diseases but little is known about the impact of race on the treatment of interstitial lung diseases. The purpose of this study was to determine how race and ethnicity influence treatment of idiopathic pulmonary fibrosis.

METHODS

Adults with idiopathic pulmonary fibrosis (>18 years) were identified using TriNetX database and paired-wised comparisons were performed for antifibrotic treatment among White, Black, Hispanic and Asian patients. Mortality of treated and untreated IPF patients was compared after propensity score matching for age, sex, nicotine dependence, oxygen dependence and predicted FVC. Additional comparisons were performed in subgroups of IPF patients older than 65 years of age and with lower lung function.

RESULTS

Of 47,184 IPF patients identified, the majority were White (35,082), followed by Hispanic (6079), Black (5245) and Asian (1221). When subgroups were submitted to matched cohort pair-wise comparisons, anti-fibrotic usage was lower among Black patients compared to White (6.2% vs. 11.4%, p-value <0.0001), Hispanic (10.8% vs. 20.2%, p-value <0.0001) and Asian patients (9.6% vs. 14.7%, p-value = 0.0006). Similar treatment differences were noted in Black individuals older than 65 years and those with lower lung function. Mortality among White patients, but not Hispanic, Black, or Asian patients, was lower in patients on antifibrotic therapy versus not on therapy.

CONCLUSION

This study demonstrated that Black IPF patients had lower antifibrotic use compared to White, Hispanic and Asian patients. Our findings suggest that urgent action is needed to understand the reason why racial disparities exist in the treatment of IPF.

Pulmonary hypertension associated with lung disease: new insights into pathomechanisms, diagnosis, and management

Patients with chronic lung diseases, particularly interstitial lung disease and chronic obstructive pulmonary disease, frequently develop pulmonary hypertension, which results in clinical deterioration, worsening of oxygen uptake, and an increased mortality risk. Pulmonary hypertension can develop and progress independently from the underlying lung disease. The pulmonary vasculopathy is distinct from that of other forms of pulmonary hypertension, with vascular ablation due to loss of small pulmonary vessels being a key feature. Long-term tobacco exposure might contribute to this type of pulmonary vascular remodelling. The distinct pathomechanisms together with the underlying lung disease might explain why treatment options for this condition remain scarce. Most drugs approved for pulmonary arterial hypertension have shown no or sometimes harmful effects in pulmonary hypertension associated with lung disease. An exception is inhaled treprostinil, which improves exercise capacity in patients with interstitial lung disease and pulmonary hypertension. There is a pressing need for safe, effective treatment options and for reliable, non-invasive diagnostic tools to detect and characterise pulmonary hypertension in patients with chronic lung disease.

Disparities in Antifibrotic Medication Utilization Among Veterans With Idiopathic Pulmonary Fibrosis

BACKGROUND

Two antifibrotic medications, pirfenidone and nintedanib, are approved for the treatment of idiopathic pulmonary fibrosis (IPF). Little is known about their real-world adoption.

RESEARCH QUESTION

What are the real-world antifibrotic utilization rates and factors associated with uptake among a national cohort of veterans with IPF?

STUDY DESIGN AND METHODS

This study identified veterans with IPF who received care either provided by the Veterans Affairs (VA) Healthcare System or non-VA care paid for by the VA. Patients who had filled at least one antifibrotic prescription through the VA pharmacy or Medicare Part D between October 15, 2014, and December 31, 2019, were identified. Hierarchical logistic regression models were used to examine factors associated with antifibrotic uptake, accounting for comorbidities, facility clustering, and follow-up time. Fine-Gray models were used to evaluate antifibrotic use by demographic factors, accounting for the competing risk of death.

RESULTS

Among 14,792 veterans with IPF, 17% received antifibrotics. There were significant disparities in adoption, with lower uptake associated with female sex (adjusted OR, 0.41; 95% CI, 0.27-0.63; P < .001), Black race (adjusted OR, 0.60; 95% CI, 0.49-0.73; P < .001), and rural residence (adjusted OR, 0.88; 95% CI, 0.80-0.97; P = .012). Veterans who received their index diagnosis of IPF outside the VA were less likely to receive antifibrotic therapy (adjusted OR, 0.15; 95% CI, 0.10-0.22; P < .001).

INTERPRETATION

This study is the first to evaluate the real-world adoption of antifibrotic medications among veterans with IPF. Overall uptake was low, and there were significant disparities in use. Interventions to address these issues deserve further investigation.

Verbascoside and isoverbascoside ameliorate transforming growth factor β1-induced collagen expression by lung fibroblasts through Smad/non-Smad signaling pathways

AIMS

Pulmonary fibrosis (PF) is a chronic, irreversible, and debilitating lung disease that typically leads to respiratory failure, and is a major cause of morbidity and mortality. Few drugs are effective for the treatment of patients with PF or for reducing the rate of disease progression.

MAIN METHODS

Transforming growth factor-β1 (TGF-β1) is a profibrotic cytokine that signals through Smad and non-Smad pathways. Verbascoside (VB) and isoverbascoside (isoVB) exhibit anti-oxidative and anti-inflammatory activities, however, their anti-fibrotic effects remain unclear. This study evaluated the effects of VB and isoVB on TGF-β1-stimulated murine lung fibroblasts (MLg 2908) and also human lung fibroblasts (confirmed by immunostaining).

KEY FINDINGS

Neither VB nor isoVB had a cytotoxic effect on MLg 2908 fibroblasts. Both compounds (10 μM) reduced intracellular reactive oxygen species and markedly attenuated collagen I expression in TGF-β1 (5 ng/ml)-induced MLg 2908 cells compared to TGF-β1 alone. Both compounds suppressed the TGF-β1-induced phosphorylation of Smad2/3 and ERK/p38 mitogen-activated protein kinases (MAPKs). VB and isoVB, but not pirfenidone and nintedanib, inhibited TGF-β1-induced pSmad2/3, ERK/p38 MAPK, and collagen I expression. VB and isoVB also decreased collagen I deposition in TGF-β1-induced MLg 2908 cells. Only isoVB significantly suppressed collagen I deposition in TGF-β1-induced human pulmonary cells. Our results indicated that VB and isoVB may exert antifibrotic effects by inhibiting TGF-β1-induced collagen I expression via inhibition of oxidative stress and downregulation of the Smad/non-Smad pathway.

SIGNIFICANCE

The present findings suggest that VB or isoVB may be used as a supplement to alleviate PF.

Disparities in Lung Transplant among Patients with Idiopathic Pulmonary Fibrosis: An Analysis of the IPF-PRO Registry

Rationale: Lung transplant offers the potential to extend life for patients with idiopathic pulmonary fibrosis (IPF); yet, this therapeutic modality is only available to a small proportion of patients. Objectives: To identify clinical characteristics and social determinants of health that differentially associate with lung transplant compared with death in patients with IPF. Methods: We evaluated data from the Idiopathic Pulmonary Fibrosis Prospective Outcomes (IPF-PRO) Registry, a multicenter U.S. registry of patients with IPF that was diagnosed or confirmed at the enrolling center in the previous 6 months. Patients were enrolled between June 2014 and October 2018. Patients who were listed for lung transplant were not eligible to enroll in the registry, but patients could be listed for transplant after enrollment. We performed a multivariable time-to-event analysis incorporating competing risks methodology to examine differential associations between prespecified covariates and the risk of lung transplant versus death. Covariates included factors related to lung transplant eligibility, clinical characteristics of IPF, and social determinants of health. Covariates were modeled as time independent or time dependent as appropriate. Results: Among 955 patients with IPF, event rates of lung transplant and death were 7.4% and 16.3%, respectively, at 2 years. Covariates with the strongest differential association were age, median zip code income, and enrollment at a center with a lung transplant program. Lung transplant was less likely (hazard ratio [HR], 0.13 [95% confidence interval (CI), 0.06-0.28] per 5-yr increase) and death more likely (HR, 1.41 [95% CI, 1.22-1.64] per 5-yr increase) among those older than 70 years of age. Higher median zip code income was associated with lung transplant (HR, 1.22 [95% CI, 1.13-1.31] per $10,000 increase) but not death (HR, 0.99 [95% CI, 0.94-1.04] per $10,000 increase). Enrollment at a center with a lung transplant program was associated with lung transplant (HR, 4.31 [95% CI, 1.76-10.54]) but not death (HR, 0.99 [95% CI, 0.69-1.43]). Oxygen use with activity was associated with both lung transplant and death, but more strongly with lung transplant. A higher number of comorbidities was associated with an increased likelihood of death but not lung transplant. Conclusions: For patients in the Idiopathic Pulmonary Fibrosis Prospective Outcomes Registry, median zip code income and access to a lung transplant center differentially impact the risk of lung transplant compared with death, regardless of disease severity measures or other transplant eligibility factors. Interventions are needed to mitigate inequalities in lung transplantation based on socioeconomic status. Clinical trial registered with www.clinicaltrials.gov (NCT01915511).

Research race-specific reference values and lung function impairment, breathlessness and prognosis: Analysis of NHANES 2007-2012

BACKGROUND

Spirometry reference values differ by race/ethnicity, which is controversial. We evaluated the effect of race-specific references on prevalence of lung function impairment and its relation to breathlessness and mortality in the US population.

METHODS

Population-based analysis of the National Health and Nutrition Examination Survey (NHANES) 2007-2012. Race/ethnicity was analyzed as black, white, or other. Reference values for forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) were calculated for each person using the Global Lung Initiative (GLI)-2012 equations for (1) white; (2) black; and (3) other/mixed people. Outcomes were prevalence of lung function impairment (< lower limit of normal [LLN]), moderate/severe impairment (< 50%pred); exertional breathlessness; and mortality until 31 December, 2015.

RESULTS

We studied 14,123 people (50% female). Compared to those for white, black reference values identified markedly fewer cases of lung function impairment (FEV₁) both in black people (9.3% vs. 36.9%) and other non-white (1.5% vs. 9.5%); and prevalence of moderate/severe impairment was approximately halved. Outcomes by impairment differed by reference used: white (best), other/mixed (intermediate), and black (worst outcomes). Black people with FEV₁ ≥ LLN_black but < LLN_white had 48% increased rate of breathlessness and almost doubled mortality, compared to blacks ≥ LLN_white. White references identified people with good outcomes similarly in black and white people. Findings were similar for FEV₁ and FVC.

CONCLUSION

Compared to using a common reference (for white) across the population, race-specific spirometry references did not improve prediction of breathlessness and prognosis, and may misclassify lung function as normal despite worse outcomes in black people.

Prognosis of idiopathic pulmonary fibrosis without anti-fibrotic therapy: a systematic review

In addition to facilitating healthcare delivery planning, reliable information about prognosis is essential for treatment decisions in patients with idiopathic pulmonary fibrosis (IPF). This review aimed to evaluate the prognosis of patients with IPF without anti-fibrotic therapy. We included all cohort studies and the placebo arms of randomised controlled trials (RCTs) in IPF and follow-up of ≥12 months. Two reviewers independently evaluated studies for inclusion, assessed risk of bias and extracted data. A total of 154 cohort studies and 16 RCTs were included. The pooled proportions of mortality were 0.12 (95% CI 0.09–0.14) at 1–2 years, 0.38 (95% CI 0.34–0.42) between 2–5 years, and 0.69 (95% CI 0.59–0.78) at ≥5 years. The pooled mean overall survival was 4 years (95% CI 3.7–4.6) for studies with a follow-up duration of 10 years. At <2 years, forced vital capacity and diffusing capacity of the lung for carbon monoxide declined by a mean of 6.76% predicted (95% CI −8.92 −4.61) and 3% predicted (95% CI −5.14 −1.52), respectively. Although heterogeneity was high, subgroup analyses revealed lower pooled proportions of mortality at 1 year in the RCT participants (0.07 (95% CI 0.05–0.09)) versus cohort study participants (0.14 (95% CI 0.12–0.17)). This review provides comprehensive information on the prognosis of IPF, which can inform treatment discussions with patients and comparisons for future studies with new therapies.

Without anti-fibrotic therapy, patients with IPF have a mortality rate of 31% at ≥5 years, and a mean overall survival of 4 years over 10 years of follow-uphttp://bit.ly/2SDiZSb

Interstitial Lung Diseases in Developing Countries

More than 100 different conditions are grouped under the term interstitial lung disease (ILD). A diagnosis of an ILD primarily relies on a combination of clinical, radiological, and pathological criteria, which should be evaluated by a multidisciplinary team of specialists. Multiple factors, such as environmental and occupational exposures, infections, drugs, radiation, and genetic predisposition have been implicated in the pathogenesis of these conditions. Asbestosis and other pneumoconiosis, hypersensitivity pneumonitis (HP), chronic beryllium disease, and smoking-related ILD are specifically linked to inhalational exposure of environmental agents. The recent Global Burden of Disease Study reported that ILD rank 40th in relation to global years of life lost in 2013, which represents an increase of 86% compared to 1990. Idiopathic pulmonary fibrosis (IPF) is the prototype of fibrotic ILD. A recent study from the United States reported that the incidence and prevalence of IPF are 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively. These data suggests that, in large populated areas such as Brazil, Russia, India, and China (the BRIC region), there may be approximately 2 million people living with IPF. However, studies from South America found much lower rates (0.4–1.2 cases per 100,000 per year). Limited access to high-resolution computed tomography and spirometry or to multidisciplinary teams for accurate diagnosis and optimal treatment are common challenges to the management of ILD in developing countries.

Disparities in pulmonary fibrosis care in the United States: an analysis from the Nationwide Inpatient Sample

Background

Idiopathic pulmonary fibrosis is a disease with high morbidity and mortality. Care for these patients, including lung transplantation, may provide significant benefits, but is resource-intensive and expensive. Disadvantaged patients with IPF may hence be at risk for receiving inferior care.

Methods

We analyzed data from the Nationwide Inpatient Sample, a database consisting of all hospitalizations from a 20% sample of US hospitals. We identified adults hospitalized with IPF between 1998 and 2011 using ICD-9 codes. We assessed the effect of insurance coverage and socioeconomic status (SES) on lung transplantation, a treatment that may improve survival. We also examined the effect of coverage and SES on mortality, as well as discharge to inpatient rehabilitation and receipt of a lung biopsy, two markers of the intensity of care delivered. We used multiple logistic regression to adjust for patient and hospital characteristics.

Results

We identified 148,877 hospitalizations that met our definition of pulmonary fibrosis. In the main adjusted analyses, hospitalizations of patients with Medicaid (OR 0.30, 95% CI 0.16–0.57) or no insurance (OR 0.22, 95% CI 0.07–0.72) were less likely to result in a lung transplantation compared to hospitalizations of those with non-Medicaid insurance. Those of lower SES were also less likely to undergo transplantation, while hospitalized patients with Medicaid and the uninsured were less likely to be discharged to inpatient rehabilitation or to receive a lung biopsy.

Conclusions

Among hospitalized patients with IPF, those with lower SES, Medicaid coverage and without insurance were less likely to receive several clinical interventions.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3407-0) contains supplementary material, which is available to authorized users.

Ethnic differences in idiopathic pulmonary fibrosis: The Japanese perspective

Epidemiologic data suggest that there are ethnic differences between Japanese and other populations with regard to the important clinical aspects of interstitial lung disease (ILD), such as the cause of death and prognostic factors in patients with idiopathic pulmonary fibrosis (IPF). Acute exacerbation (AE) of IPF may be more common in Japan than in the rest of the world, although this suggestion remains controversial. Moreover, AE of ILD induced by gefitinib may also be more common in Japan, indicating that Japanese patients have a genetic vulnerability or susceptibility to AE. Recent large-scale studies are starting to reveal ethnic differences in the genetics of ILD, including the prevalence of the genetic polymorphisms associated with the clinical course of ILD. We anticipate that ongoing and upcoming research regarding ethnic differences will continue to provide valuable insights into the pathogenesis and management of ILD.

Racial and ethnic disparities in lung transplant listing and waitlist outcomes

BACKGROUND

The United States lung transplant registry data demonstrate differences in adult waitlist mortality by race/ethnicity. It is unknown whether these differences persist after risk adjustment or occur secondary to disparities in disease severity at the time of listing.

METHODS

Adult lung transplant waitlist candidates between May 4, 2005 and March 5, 2015 were identified and compared by non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic and Asian race/ethnicity. A competing risk proportional hazards model was used to assess the association of race/ethnicity with the unadjusted and adjusted risk of waitlist death or removal for too sick, transplant, or removal for other reason. Disease illness severity at transplant listing was compared by race/ethnicity.

RESULTS

There were 20,684 lung transplant candidates identified (82% NHW, 9% NHB, 6% Hispanic, 2% Asian and 1% other). Non-white candidates had higher unadjusted waitlist mortality, which was fully mitigated by adjusting for other risk factors (NHB: hazard ratio [HR] 1.05, 95% confidence interval [CI] 0.93 to 1.18; Hispanic: HR 1.02, 95% CI 0.99 to 1.18; Asian: HR 0.90, 95% CI 0.70 to 1.16). Adjusted waitlist access to transplant was lower in non-white candidates (NHB: HR 0.88, 95% CI 0.83 to 0.94; Hispanic: HR 0.87, 95% CI 0.81 to 0.94; Asian: HR 0.83, 95% CI 0.73 to 0.96). NHW candidates with obstructive lung disease and pulmonary fibrosis were older with less illness severity at listing than non-white candidates.

CONCLUSIONS

Within the current lung allocation system, there is no difference in risk-adjusted waitlist mortality by race/ethnicity, but non-white waitlist candidates have lower risk-adjusted access to lung transplant. Non-white candidates are generally younger with greater disease-specific illness severity at the time of lung transplant listing.

Race/ethnicity is associated with ABO-nonidentical liver transplantation in the United States

United Network for Organ Sharing (UNOS) policies allow for ABO-nonidentical liver transplantation (LT) in candidates with Model for End-Stage Liver Disease (MELD) scores greater than 30. Previous studies showed ABO-nonidentical LT resulted in an 18% and 55% net gain in livers for B and AB candidates. These results suggested that the current liver ABO allocation policies may need refinement. There are, however, strong associations between ABO blood groups and race/ethnicity. We hypothesized that race/ethnicity is associated with ABO-nonidentical LT and that this is primarily influenced by recipient ABO status. We examined non-status 1 adult candidates registered between July 1, 2013, and December 31, 2015. There were 27 835 candidates (70% non-Hispanic White, 15% Hispanic, 9% Black, 4% Asian, 1% Other/Multiracial). A total of 11 369 underwent deceased donor LT: 93% ABO identical, 6% ABO compatible, and 1% ABO incompatible. Black and Asian race/ethnicity were associated with increased likelihoods of ABO-nonidentical LT. Adjustment for disease etiology, listing MELD, transplant center volume, and UNOS region did not alter this association. Stepwise inclusion of recipient ABO status did eliminate this significant association of race/ethnicity with ABO-nonidentical LT. Blacks and Asians may be advantaged by ABO-nonidentical LT, and we suspect that changes to the existing policies may disproportionately impact these groups.

A Cost-Effectiveness Analysis of Nintedanib in Idiopathic Pulmonary Fibrosis in the UK

BACKGROUND

International guidelines recommend nintedanib (OFEV^®) as an option for the treatment of idiopathic pulmonary fibrosis (IPF).

OBJECTIVE

The objective of this study was to assess the cost effectiveness of nintedanib versus pirfenidone, N-acetylcysteine and best supportive care (BSC) for the treatment of IPF from a UK payer's perspective.

METHODS

A Markov model was designed to capture the changes in the condition of adults with IPF. Efficacy outcomes included mortality, lung function decline and acute exacerbations. Treatment safety (serious adverse events) and tolerability (overall discontinuation) were also considered. The baseline risk of these events was derived from patient-level data from the placebo arms of nintedanib clinical trials (TOMORROW, INPULSIS-1, INPULSIS-2). A network meta-analysis (NMA) was conducted to estimate the relative effectiveness of the comparator treatments. Quality of life and healthcare resource use data from the clinical trials were also incorporated in the economic model.

RESULTS

Nintedanib showed statistically significant differences against placebo on acute exacerbation events avoided and lung function decline. In the cost-effectiveness analysis, the results were split between two treatments with relative low costs and modest effectiveness (BSC and N-acetylcysteine) and two that showed improved effectiveness (lung function) and higher costs (nintedanib and pirfenidone). All comparators were assumed to have similar projected survival and the difference in quality-adjusted life-years (QALYs) was driven by the acute exacerbations and lung function estimates. In the base-case deterministic pairwise comparison with pirfenidone, nintedanib was found to have fewer acute exacerbations and resulted in less costs and more QALYs gained.

CONCLUSIONS

Compared with BSC (placebo), nintedanib and pirfenidone were the only treatments to show statistical significance in the efficacy parameters. We found substantial uncertainty in the overall cost-effectiveness results between nintedanib and pirfenidone. N-Acetylcysteine was largely similar to BSC but with a worse survival profile. INPULSIS-1 and INPULSIS-2 ClinicalTrials.gov numbers, NCT01335464 and NCT01335477.

Idiopathic Pulmonary Fibrosis and the Elderly: Diagnosis and Management Considerations

Idiopathic pulmonary fibrosis (IPF) is a severe and progressive fibrosing interstitial lung disease, which ultimately results in respiratory failure and death. The median age at diagnosis is 66 years, and the incidence increases with age, making this a disease that predominantly affects the elderly population. IPF can often be difficult to diagnose, as its symptoms--cough, dyspnoea and fatigue--are non-specific and can often be attributed to co-morbidities such as heart failure and chronic obstructive pulmonary disease. Making an accurate diagnosis of IPF is imperative, as new treatments that appear to slow the progression of IPF have recently become available. Pirfenidone and nintedanib are two such treatments, which have shown efficacy in randomised controlled trials. As with all new treatments, caution must be advocated in the elderly, as these patients often lie outside the narrow clinical trial cohorts that are studied, and the benefits of therapy must be weighed against potential toxicities. Both medications, while relatively safe, have been associated with adverse effects, particularly gastrointestinal symptoms such as nausea, diarrhoea and anorexia. In this review, we highlight measures to improve recognition and accurate diagnosis of IPF, as well as co-morbidities that often affect the diagnosis and disease course. The gold standard for IPF diagnosis is a multidisciplinary meeting whereby clinicians, radiologists and histopathologists reach a consensus after interactive discussion. In many cases, a lung biopsy may not be available because of high risk or patient choice, particularly in the elderly. In these cases, there is debate as to whether a biopsy is required, given the high rates of IPF in patients over the age of 70 years with interstitial changes on computed tomography. We also discuss the management of IPF, drawing particular attention to specific issues affecting the elderly population, especially with regard to polypharmacy and end-of-life care. Through this article, we endeavour to improve awareness of this devastating disease and thus improve recognition of the disease and its outcomes in elderly patients.

Epidemiological studies in idiopathic pulmonary fibrosis: pitfalls in methodologies and data interpretation

Data on incidence, prevalence and mortality of idiopathic pulmonary fibrosis (IPF) are sparse and vary across studies. The true incidence and prevalence of the disease are unknown. In general, the overall prevalence and incidence reported in European and Asian countries are lower than those reported in American studies. In recent years, the epidemiological approach to IPF has been difficult for many reasons. First, the diagnostic criteria of the disease have changed over time. Secondly, the coding system used for IPF in administrative databases, the most common data source used to study this aspect of the disease, has been modified in the past few years. Finally, the study design, the methodology and the population selected in each of the studies are very different. All these aspects make comparisons among studies very difficult or impossible. In this review, we list the main issues that might arise when comparing different studies and that should be taken into consideration when describing the state of epidemiological knowledge concerning this pathology.

Short Stature and Access to Lung Transplantation in the United States. A Cohort Study

RATIONALE

Anecdotally, short lung transplant candidates suffer from long waiting times and higher rates of death on the waiting list compared with taller candidates.

OBJECTIVES

To examine the relationship between lung transplant candidate height and waiting list outcomes.

METHODS

We conducted a retrospective cohort study of 13,346 adults placed on the lung transplant waiting list in the United States between 2005 and 2011. Multivariable-adjusted competing risk survival models were used to examine associations between candidate height and outcomes of interest. The primary outcome was the time until lung transplantation censored at 1 year.

MEASUREMENTS AND MAIN RESULTS

The unadjusted rate of lung transplantation was 94.5 per 100 person-years among candidates of short stature (<162 cm) and 202.0 per 100 person-years among candidates of average stature (170-176.5 cm). After controlling for potential confounders, short stature was associated with a 34% (95% confidence interval [CI], 29-39%) lower rate of transplantation compared with average stature. Short stature was also associated with a 62% (95% CI, 24-96%) higher rate of death or removal because of clinical deterioration and a 42% (95% CI, 10-85%) higher rate of respiratory failure while awaiting lung transplantation.

CONCLUSIONS

Short stature is associated with a lower rate of lung transplantation and higher rates of death and respiratory failure while awaiting transplantation. Efforts to ameliorate this disparity could include earlier referral and listing of shorter candidates, surgical downsizing of substantially oversized allografts for shorter candidates, and/or changes to allocation policy that account for candidate height.

Idiopathic Pulmonary Fibrosis in United States Automated Claims. Incidence, Prevalence, and Algorithm Validation

RATIONALE

Estimates of idiopathic pulmonary fibrosis (IPF) incidence and prevalence from electronic databases without case validation may be inaccurate.

OBJECTIVES

Develop claims algorithms to identify IPF and assess their positive predictive value (PPV) to estimate incidence and prevalence in the United States.

METHODS

We developed three algorithms to identify IPF cases in the HealthCore Integrated Research Database. Sensitive and specific algorithms were developed based on literature review and consultation with clinical experts. PPVs were assessed using medical records. A third algorithm used logistic regression modeling to generate an IPF score and was validated using a separate set of medical records. We estimated incidence and prevalence of IPF using the sensitive algorithm corrected for the PPV.

MEASUREMENTS AND MAIN RESULTS

We identified 4,598 patients using the sensitive algorithm and 2,052 patients using the specific algorithm. After medical record review, the PPVs of these algorithms using the treating clinician's diagnosis were 44.4 and 61.7%, respectively. For the IPF score, the PPV was 76.2%. Using the clinical adjudicator's diagnosis, the PPVs were 54 and 57.6%, respectively, and for the IPF score, the PPV was 83.3%. The incidence and period prevalences of IPF, corrected for the PPV, were 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively.

CONCLUSIONS

Sensitive algorithms without correction for false positive errors overestimated incidence and prevalence of IPF. An IPF score offered the greatest PPV, but it requires further validation.

Comorbidities in idiopathic pulmonary fibrosis patients: a systematic literature review

Idiopathic pulmonary fibrosis (IPF) is associated with a fatal prognosis and manifests in patients over 60 years old who may have comorbidities. The prevalence and impact of comorbidities on the clinical course of IPF is unclear.

This systematic literature review examined the prevalence of comorbidities and mortality associated with comorbidities in IPF patients. Relevant observational studies published in English from January 1990 to January 2015 identifiedviaMEDLINE and EMBASE were included; bibliographies of articles were also searched.

Among the 126 studies included, prevalence of pulmonary hypertension (PH) was 3–86%, 6–91% for obstructive sleep apnoea, 3–48% for lung cancer and 6–67% for chronic obstructive pulmonary disease (COPD). Nonrespiratory comorbidities included ischaemic heart disease (IHD) (3–68%) and gastro-oesophageal reflux (GER) (0–94%). Mortality was highest among patients with IPF and lung cancer. Most studies assessed relatively small samples of patients with IPF.

PH, COPD, lung cancer, GER and IHD are significant comorbidities; differences in IPF severity, case definitions and patient characteristics limited the comparability of findings. The identification and prompt treatment of comorbidities may have a clinically significant impact on overall outcome that is meaningful for patients with IPF.

The MUC5B promoter polymorphism is associated with idiopathic pulmonary fibrosis in a Mexican cohort but is rare among Asian ancestries

BACKGROUND

Polymorphisms in the MUC5B promoter, TOLLIP, and nine additional genetic loci have been associated with idiopathic pulmonary fibrosis (IPF) within non-Hispanic white populations. It is unknown whether these variants account for risk of IPF in other racial/ethnic populations. We conducted a candidate single nucleotide polymorphism (SNP) association study in cohorts of Mexican and Korean patients with IPF.

METHODS

We chose 12 SNPs from 11 loci that are associated with IPF among non-Hispanic whites and genotyped these SNPs in cohorts of Mexican (83 patients, 111 control subjects) and Korean (239 patients, 87 control subjects) people. Each SNP was tested for association with IPF, after adjusting for age and sex.

RESULTS

The MUC5B promoter SNP rs35705950 was associated with IPF in the Mexican (OR = 7.36, P = .0001), but not the Korean (P = .99) cohort. The SNP in IVD (chromosome15, rs2034650) was significantly associated with pulmonary fibrosis in both the Mexican (OR = 0.40, P = .01) and Korean (OR = 0.13, P = .0008) cohorts. In the Korean cohort, there were no other variants associated with disease. In the Mexican cohort, SNPs on chromosomes 3, 4, and 11 were also associated with disease.

CONCLUSIONS

The strongest identified genetic risk factor for IPF among the non-Hispanic white population, the MUC5B promoter polymorphism, is also a strong risk factor in a Mexican population, but is very rare in a Korean population. The majority of genetic variants that account for risk of IPF in groups other than non-Hispanic whites are unknown. Hispanic and Asian populations should be studied separately to identify genetic risk loci for IPF.

Idiopathic pulmonary fibrosis--a systematic review on methodology for the collection of epidemiological data

BACKGROUND

Recent studies suggest that the incidence of idiopathic pulmonary fibrosis (IPF) is rising. Accurate epidemiological data on IPF, however, are sparse and the results of previous studies are contradictory. This study was undertaken to gain insight into the various methods used in the epidemiological research of IPF, and to get accurate and comparable data on these different methodologies.

METHODS

A systematic database search was performed in order to identify all epidemiological studies on IPF after the previous guidelines for diagnosis and treatment were published in 2000. Medline (via Pubmed), Science Sitation Index (via Web of Science) and Embase databases were searched for original epidemiological articles published in English in international peer-reviewed journals starting from 2001. After pre-screening and a full-text review, 13 articles were accepted for data abstraction.

RESULTS

Three different methodologies of epidemiological studies were most commonly used, namely: (1) national registry databases, (2) questionnaire-based studies, and (3) analysis of the health care system's own registry databases. The overall prevalence and incidence of IPF varied in these studies between 0.5-27.9/100,000 and 0.22-8.8/100,000, respectively. According to four studies the mortality and incidence of IPF are rising.

CONCLUSIONS

We conclude that there are numerous ways to execute epidemiological research in the field of IPF. This review offers the possibility to compare the different methodologies that have been used, and this information could form a basis for future studies investigating the prevalence and incidence of IPF.

Disparities in lung transplantation before and after introduction of the lung allocation score

BACKGROUND

In May 2005, the Lung Allocation Score (LAS) became the primary method for determining allocation of lungs for organ transplantation for those at least 12 years of age in the United States. During the pre-LAS period, black patients were more likely than white patients to become too sick or die while awaiting transplant. The association between gender and lung transplant outcomes has not been widely studied.

METHODS

Black and white patients aged ≥ 18 years registered on the United Network for Organ Sharing (UNOS) lung transplantation waiting list from January 1, 2000, to May 3, 2005 (pre-LAS, n = 8,765), and from May 4, 2005, to September 4, 2010 (LAS, n = 8,806), were included. Logistic regression analyses were based on smaller cohorts derived from patients listed in the first 2 years of each era (2,350 pre-LAS, and 2,446 LAS) to allow for follow-up time. Lung transplantation was the primary outcome measure. Multivariable analyses were performed within each interval to determine the odds that a patient would die or receive a lung transplant within 3 years of listing.

RESULTS

In the pre-LAS era, black patients were more likely than white patients to become too sick for transplantation or die within 3 years of waiting list registration (43.8% vs 30.8%; odds ratio [OR], 1.84; p < 0.001). Race was not associated with death or becoming too sick while listed for transplantation in the LAS era (14.0% vs 13.3%; OR, 0.93; p = 0.74). Black patients were less likely to undergo transplantation in the pre-LAS era (56.3% vs 69.2%; OR, 0.54; p < 0.001) but not in the LAS era (86.0% vs 86.7%; OR, 1.07; p = 0.74). Women were more likely than men to die or become too sick for transplantation within 3 years of listing in the LAS era (16.1% vs 11.3%; OR, 1.58; p < 0.001) compared with the pre-LAS era (33.4% vs 30.7%; OR, 1.19; p = 0.08).

CONCLUSION

Racial disparities in lung transplantation have decreased with the implementation of LAS as the method of organ allocation; however, gender disparities may have actually increased in the LAS era.

HLA-A and HLA-B gene polymorphism and idiopathic pulmonary fibrosis in a Han Chinese population

Idiopathic pulmonary fibrosis (IPF) is a progressive diffuse interstitial lung disease with poor prognosis of unknown etiology that leading ultimately to death. Predisposing factors are thought to have environmental and genetic inputs.

OBJECTIVE

We investigated the relationship between HLA-A, B gene polymorphism and idiopathic pulmonary fibrosis (IPF) in a Han Chinese population.

PATIENTS AND METHODS

The gene frequency of 36 patients with IPF was detected using a PCR-SSP grouping method. These values were compared with those a Bone Marrow Bank (Shanghai, China) of healthy subjects of identical racial origin as the patient group.

RESULTS

The gene frequency of HLA-A*3 (3.5%), HLA-B*14 (1.4%), -B*15 (10.2%), and -B*40 (5.0%)of the IPF group increased significantly (Pc < 0.05) compared with that in the control group HLA-A*3 (1.0%), HLA-B*14 (0.1%) and -B*15 (1.1%) and -B*40 (0.8%). Investigation of the link between the HLA-A and -B gene showed the gene frequency of HLA-A2B15 to be 5.0% as well as -A2B40 (4.3%), -A11B15 (5.0%), -A24B48 (2.8%) and -A30B40 (2.8%), which were significantly higher than those of the control group (Pc < 0.05).

CONCLUSION

These data suggest that the gene frequency of HLA-A*3, HLA-B*14, -B*15, -B*40, and the linked gene frequency of HLA-A2B15, -A2B40, -A11B15, -A24B58, -A30B40 is associated with IPF pathogenesis.

Delayed access and survival in idiopathic pulmonary fibrosis: a cohort study

RATIONALE

Idiopathic pulmonary fibrosis is often initially misdiagnosed. Delays in accessing subspecialty care could lead to worse outcomes among those with idiopathic pulmonary fibrosis.

OBJECTIVES

To examine the association between delayed access to subspecialty care and survival time in idiopathic pulmonary fibrosis.

METHODS

We performed a prospective cohort study of 129 adults who met American Thoracic Society criteria for idiopathic pulmonary fibrosis evaluated at a tertiary care center. Delay was defined as the time from the onset of dyspnea to the date of initial evaluation at a tertiary care center. We used competing risk survival methods to examine survival time and time to transplantation.

MEASUREMENTS AND MAIN RESULTS

The mean age was 63 years and 76% were men. The median delay was 2.2 years (interquartile range 1.0–3.8 yr), and the median follow-up time was 1.1 years. Age and lung function at the time of evaluation did not vary by delay. A longer delay was associated with an increased risk of death independent of age, sex, forced vital capacity, third-party payer, and educational attainment (adjusted hazard ratio per doubling of delay was 1.3, 95% confidence interval 1.03 to 1.6). Longer delay was not associated with a lower likelihood of undergoing lung transplantation.

CONCLUSIONS

Delayed access to a tertiary care center is associated with a higher mortality rate in idiopathic pulmonary fibrosis independent of disease severity. Early referral to a specialty center should be considered for those with known or suspected interstitial lung disease.

Race and sex differences in response to endothelin receptor antagonists for pulmonary arterial hypertension

BACKGROUND

Recently studied therapies for pulmonary arterial hypertension (PAH) have improved outcomes among populations of patients, but little is known about which patients are most likely to respond to specific treatments. Differences in endothelin-1 biology between sexes and between whites and blacks may lead to differences in patients' responses to treatment with endothelin receptor antagonists (ERAs).

METHODS

We conducted pooled analyses of deidentified, patient-level data from six randomized placebo-controlled trials of ERAs submitted to the US Food and Drug Administration to elucidate heterogeneity in treatment response. We estimated the interaction between treatment assignment (ERA vs placebo) and sex and between treatment and white or black race in terms of the change in 6-min walk distance from baseline to 12 weeks.

RESULTS

Trials included 1,130 participants with a mean age of 49 years; 21% were men, 74% were white, and 6% were black. The placebo-adjusted response to ERAs was 29.7 m (95% CI, 3.7-55.7 m) greater in women than in men (P = .03). The placebo-adjusted response was 42.2 m for whites and -1.4 m for blacks, a difference of 43.6 m (95% CI, -3.5-90.7 m) (P = .07). Similar results were found in sensitivity analyses and in secondary analyses using the outcome of absolute distance walked.

CONCLUSIONS

Women with PAH obtain greater responses to ERAs than do men, and whites may experience a greater treatment benefit than do blacks. This heterogeneity in treatment-response may reflect pathophysiologic differences between sexes and races or distinct disease phenotypes.

Idiopathic pulmonary fibrosis-an epidemiological and pathological review

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease (ILD) affecting the pulmonary interstitium. Other forms of interstitial lung disease exist, and in some cases, an environmental etiology can be delineated. The diagnosis of IPF is typically established by high-resolution CT scan. IPF tends to have a worse prognosis than other forms of ILD. Familial cases of IPF also exist, suggesting a genetic predisposition; telomerase mutations have been observed to occur in familial IPF, which may also explain the increase in IPF with advancing age. Alveolar epithelial cells are believed to be the primary target of environmental agents that have been putatively associated with IPF. These agents may include toxins, viruses, or the autoantibodies found in collagen vascular diseases. The mechanism of disease is still unclear in IPF, but aberrations in fibroblast differentiation, activation, and proliferation may play a role. Epithelial-mesenchymal transition may also be an important factor in the pathogenesis, as it may lead to accumulation of fibroblasts in the lung and a disruption of normal tissue structure. Abnormalities in other components of the immune system, including T cells, B cells, and dendritic cells, as well as the development of ectopic lymphoid tissue, have also been observed to occur in IPF and may play a role in the stimulation of fibrosis that is a hallmark of the disease. It is becoming increasingly clear that the pathogenesis of IPF is indeed a complex and convoluted process that involves numerous cell types and humoral factors.

An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management

This document is an international evidence-based guideline on the diagnosis and management of idiopathic pulmonary fibrosis, and is a collaborative effort of the American Thoracic Society, the European Respiratory Society, the Japanese Respiratory Society, and the Latin American Thoracic Association. It represents the current state of knowledge regarding idiopathic pulmonary fibrosis (IPF), and contains sections on definition and epidemiology, risk factors, diagnosis, natural history, staging and prognosis, treatment, and monitoring disease course. For the diagnosis and treatment sections, pragmatic GRADE evidence-based methodology was applied in a question-based format. For each diagnosis and treatment question, the committee graded the quality of the evidence available (high, moderate, low, or very low), and made a recommendation (yes or no, strong or weak). Recommendations were based on majority vote. It is emphasized that clinicians must spend adequate time with patients to discuss patients' values and preferences and decide on the appropriate course of action.

Racial disparities in survival after lung transplantation

CONTEXT

Racial disparities have not been comprehensively evaluated among recipients of lung transplantation.

OBJECTIVES

To describe the association between race and lung transplant survival and to determine whether racial disparities have changed in the modern (2001-2009) compared with the historical (1987-2000) transplant eras.

DESIGN, SETTING, AND PATIENTS

A retrospective cohort study of 16 875 adults who received primary lung transplants from October 16, 1987, to February 19, 2009, was conducted using data from the United Network of Organ Sharing.

MAIN OUTCOME MEASURES

We measured the risk of death after lung transplant for nonwhites compared with whites using time-to-event analysis.

RESULTS

During the study period, 14 858 white and 2017 nonwhite patients underwent a lung transplant; they differed significantly at baseline. The percentage of nonwhite transplant recipients increased from 8.8% (before 1996) to 15.0% (2005-2009). In the historical era, 5-year survival was lower for nonwhites than whites (40.9% vs 46.9%). Nonwhites were at an increased risk of death independent of age, health and socioeconomic status, diagnosis, geographic region, donor organ characteristics, and operative factors (hazard ratio, 1.15; 95% confidence interval, 1.01-1.30). In subgroup analysis of the historical era, blacks had worsened 5-year survival compared with whites (39.0% vs 46.9%) and black women had worsened survival compared with white women (36.9% vs 48.9%). In the modern transplant era, survival improved for all patients. However, a greater improvement among nonwhites has eliminated the disparities in survival between the races (5-year survival, 52.5% vs 51.6%).

CONCLUSION

In contrast to the historical era, there was no significant difference in lung transplant survival in the modern era between whites and nonwhites.

The use of sildenafil to treat pulmonary hypertension associated with interstitial lung disease

BACKGROUND AND OBJECTIVE

Limited data suggest a benefit following sildenafil treatment in patients with pulmonary hypertension (PH) and interstitial lung disease (ILD). The role of sildenafil in the management of PH in ILD is not clear. We report our experience of ILD patients with PH after 6-month sildenafil therapy.

METHODS

We reviewed 15 patients (mean age 55 ± 15 years; 8 men) with ILD (mean FVC 52.6 ± 15.4%) and PH (mean right ventricular systolic pressure 73.8 ± 17.8 mm Hg). Median brain natriuretic peptide: 37 (5-452) pmol/L; mean 6MWD: 156 ± 101 m.

RESULTS

Following 6-month treatment with sildenafil, brain natriuretic peptide levels were lower (n = 12, P = 0.03), 6MWD was higher (n = 6, P < 0.05), but no change in right ventricular systolic pressure (n = 11) was demonstrated.

CONCLUSIONS

Our observations suggest that sildenafil may be useful in the management of PH in ILD. Controlled trials are warranted before therapeutic recommendations can be made.

Clinical course and prediction of survival in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening, interstitial lung disease of unknown etiology. The median survival of patients with IPF is only 2 to 3 years, yet some patients live much longer. Respiratory failure resulting from disease progression is the most frequent cause of death. To date we have limited information as to predictors of mortality in patients with IPF, and research in this area has failed to yield prediction models that can be reliably used in clinical practice to predict individual risk of mortality. The goal of this concise clinical review is to examine and summarize the current data on the clinical course, individual predictors of survival, and proposed clinical prediction models in IPF. Finally, we will discuss challenges and future directions related to predicting survival in IPF.

Clinical and functional outcomes in Middle Eastern patients with idiopathic pulmonary fibrosis

BACKGROUND

Baseline clinical and physiological variables have been described as relevant predictors of survival among patients with idiopathic pulmonary fibrosis (IPF). However, substantial heterogeneity in both survival time and mortality has been observed with many of these predictive factors. The incidence and mortality rates of IPF vary from country to country, with race potentially contributing to such variations.

OBJECTIVE

We sought to describe baseline clinical features to determine their predictive value among Middle Eastern patients diagnosed with IPF.

METHODS

We retrospectively examined 61 patients diagnosed with IPF at a university hospital in Riyadh, Saudi Arabia.

RESULTS

At presentation, most patients exhibited either dyspnea or cough. The median survival time for all patients was 92 months. Diminished survival was significantly associated with finger clubbing (P = 0.01). Factors not influencing survival were age, gender, percent predicted forced vital capacity, percent predicted forced expiratory volume in 1 s, percent predicted total lung capacity, percent predicted diffusion capacity of the lung for carbon monoxide and resting oxygen saturation.

CONCLUSIONS

Finger clubbing is a significant predictive variable and was associated with a 5-fold increase in mortality. Other baseline demographic characteristics as well as pulmonary function tests were not predictive of prognosis in Middle Eastern patients with IPF. It appears that IPF patients of Middle Eastern descent have a longer median survival curve compared to other races.

Geoepidemiology of COPD and idiopathic pulmonary fibrosis

Progress in improving patient outcomes and advancing therapeutics in chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) is hampered by phenotypic heterogeneity and variable responsiveness to clinical interventions that are not fully explained by currently held disease paradigms for COPD and IPF. Although these chronic lung diseases differ in their geoepidemiology and immunopathogenesis, emerging evidence suggest that organ-specific autoimmunity may underlie subphenotypes of COPD and IPF. In particular, the links to tobacco smoking, diet, gender, and environment are explored in this review. We also highlight potential mechanisms that could guide future investigations in both laboratory and clinical settings. A paradigm shift is needed in how we think about COPD and IPF, based on geoepidemiology and a broader understanding of disease pathogenesis that may ultimately lead to new therapies and improved patient outcomes.

Treatment of idiopathic interstitial pneumonias

The idiopathic interstitial pneumonias can be grouped, for treatment purposes, into primary inflammatory disorders, fibrotic nonspecific interstitial pneumonia (in which inflammation is thought to precede and progress to fibrosis) as well as the most common of the idiopathic interstitial pneumonia subgroups, idiopathic pulmonary fibrosis. Over the past decade, there have been several paradigm shifts in the understanding of idiopathic interstitial pneumonias and their treatment. In particular, we highlight changes in the use of prognostic markers, clinical trial end points and the understanding of pathogenesis of idiopathic pulmonary fibrosis. We outline a practical approach to the treatment of these three patient groups.

Telomere shortening in familial and sporadic pulmonary fibrosis

RATIONALE

Heterozygous mutations in the coding regions of the telomerase genes, TERT and TERC, have been found in familial and sporadic cases of idiopathic interstitial pneumonia. All affected patients with mutations have short telomeres.

OBJECTIVES

To test whether telomere shortening is a frequent mechanism underlying pulmonary fibrosis, we have characterized telomere lengths in subjects with familial or sporadic disease who do not have coding mutations in TERT or TERC.

METHODS

Using a modified Southern blot assay, the telomerase restriction fragment length method, and a quantitative polymerase chain reaction assay we have measured telomere lengths of genomic DNA isolated from circulating leukocytes from normal control subjects and subjects with pulmonary fibrosis.

MEASUREMENTS AND MAIN RESULTS

All affected patients with telomerase mutations, including case subjects heterozygous for newly reported mutations in TERT, have short telomere lengths. A significantly higher proportion of probands with familial pulmonary fibrosis (24%) and sporadic case subjects (23%) in which no coding mutation in TERT or TERC was found had telomere lengths less than the 10th percentile when compared with control subjects (P = 2.6 x 10(-8)). Pulmonary fibrosis affectation status was significantly associated with telomerase restriction fragment lengths, even after controlling for age, sex, and ethnicity (P = 6.1 x 10(-11)). Overall, 25% of sporadic cases and 37% of familial cases of pulmonary fibrosis had telomere lengths less than the 10th percentile.

CONCLUSIONS

A significant fraction of individuals with pulmonary fibrosis have short telomere lengths that cannot be explained by coding mutations in telomerase. Telomere shortening of circulating leukocytes may be a marker for an increased predisposition toward the development of this age-associated disease.

Racial differences in waiting list outcomes in chronic obstructive pulmonary disease

RATIONALE

Blacks with chronic illness have poorer outcomes than whites in the United States. The health outcomes of minorities with chronic obstructive pulmonary disease (COPD) on the lung transplant waiting list have not been studied.

OBJECTIVES

To compare outcomes of black and white patients with COPD after listing for lung transplantation in the United States.

METHODS

Retrospective cohort study of all 280 non-Hispanic black and 5,272 non-Hispanic white adults 40 years and older with COPD listed for lung transplantation in the United States between 1995 and 2004.

MEASUREMENTS AND MAIN RESULTS

Blacks with COPD were more likely to have pulmonary hypertension, obesity, and diabetes; to lack private health insurance; and to live in poorer neighborhoods than whites. Blacks were less likely to undergo transplantation after listing compared with whites, despite adjustment for age, lung function, pulmonary hypertension, cardiovascular risk factors, insurance coverage, and poverty level (adjusted hazard ratio, 0.83; 95% confidence interval, 0.70-0.98; P = 0.03). This was accompanied by a greater risk of dying or being removed from the list among blacks (unadjusted hazard ratio, 1.31; 95% confidence interval, 1.05-1.63; P = 0.02).

CONCLUSIONS

After listing for lung transplantation, black patients with COPD were less likely to undergo transplantation and more likely to die or be removed from the list compared with white patients. Unequal access to care may have contributed to these differences.