Genetic variants associated with susceptibility to idiopathic pulmonary fibrosis in people of European ancestry: a genome-wide association study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with high mortality, uncertain cause, and few treatment options. Studies have identified a significant genetic risk associated with the development of IPF; however, mechanisms by which genetic risk factors promote IPF remain unclear. We aimed to identify genetic variants associated with IPF susceptibility and provide mechanistic insight using gene and protein expression analyses.

METHODS

We used a two-stage approach: a genome-wide association study in patients with IPF of European ancestry recruited from nine different centres in the UK and controls selected from UK Biobank (stage 1) matched for age, sex, and smoking status; and a follow-up of associated genetic variants in independent datasets of patients with IPF and controls from two independent US samples from the Chicago consortium and the Colorado consortium (stage 2). We investigated the effect of novel signals on gene expression in large transcriptomic and genomic data resources, and examined expression using lung tissue samples from patients with IPF and controls.

FINDINGS

602 patients with IPF and 3366 controls were selected for stage 1. For stage 2, 2158 patients with IPF and 5195 controls were selected. We identified a novel genome-wide significant signal of association with IPF susceptibility near A-kinase anchoring protein 13 (AKAP13; rs62025270, odds ratio [OR] 1·27 [95% CI 1·18-1·37], p=1·32 × 10-9) and confirmed previously reported signals, including in mucin 5B (MUC5B; rs35705950, OR 2·89 [2·56-3·26], p=1·12 × 10-66) and desmoplakin (DSP; rs2076295, OR 1·44 [1·35-1·54], p=7·81 × 10-28). For rs62025270, the allele A associated with increased susceptibility to IPF was also associated with increased expression of AKAP13 mRNA in lung tissue from patients who had lung resection procedures (n=1111). We showed that AKAP13 is expressed in the alveolar epithelium and lymphoid follicles from patients with IPF, and AKAP13 mRNA expression was 1·42-times higher in lung tissue from patients with IPF (n=46) than that in lung tissue from controls (n=51).

INTERPRETATION

AKAP13 is a Rho guanine nucleotide exchange factor regulating activation of RhoA, which is known to be involved in profibrotic signalling pathways. The identification of AKAP13 as a susceptibility gene for IPF increases the prospect of successfully targeting RhoA pathway inhibitors in patients with IPF.

FUNDING

UK Medical Research Council, National Heart, Lung, and Blood Institute of the US National Institutes of Health, Agencia Canaria de Investigación, Innovación y Sociedad de la Información, Spain, UK National Institute for Health Research, and the British Lung Foundation.

Autoimmune Hypothyroidism As a Predictor of Mortality in Chronic Hypersensitivity Pneumonitis

Background

Chronic hypersensitivity pneumonitis (CHP) is a fibrotic parenchymal lung disease that occurs when inhalation of environmental antigens leads to immune dysregulation. Autoimmune features have recently been identified as potentially important among patients with CHP. However, the relationship between hypothyroidism (HT) and CHP is unknown. In this study, we investigate the prevalence and impact of HT among patients with CHP.

Methods

We conducted a retrospective, case–control analysis. We identified 121 patients at the University of Chicago Interstitial Lung Disease Center with a multidisciplinary diagnosis of CHP. These patients were matched 3:1 according to age, sex, and race to 363 control subjects with asthma from 2006 to 2015. We analyzed demographics, clinical characteristics, and survival between both groups and assessed the relationship of HT with CHP. Survival analysis was performed using Cox proportional hazards modeling.

Results

Patients with CHP had higher prevalence of HT (25.6%, n = 31) compared to controls (10.7%, n = 39; OR, 2.86; 95% CI, 1.62–4.99; P < 0.0001). Compared to CHP alone, patients with CHP/HT were more likely to be female (80.6 vs 51.1%, P = 0.004), have increased incidence of autoimmune disease (19.4 vs 3.3%, P = 0.009), antinuclear antibody seropositivity (80.6 vs 57.0%, P = 0.019), and higher TSH levels (4.0 vs 1.9 mIU/L, P < 0.0001). HT was a significant independent predictor of mortality among CHP patients with seropositive ANA (HR, 3.39; 95% CI, 1.31–8.80; P = 0.012).

Conclusion

HT is common in patients with CHP and may carry prognostic significance in patients with features of autoimmunity. Further research exploring common pathogenic pathways between autoimmune HT and CHP may illuminate the association of HT with survival.

Phenotypic Clusters Predict Outcomes in a Longitudinal Interstitial Lung Disease Cohort

BACKGROUND

The current interstitial lung disease (ILD) classification has overlapping clinical presentations and outcomes. Cluster analysis modeling is a valuable tool in identifying distinct clinical phenotypes in heterogeneous diseases. However, this approach has yet to be implemented in ILD.

METHODS

Using cluster analysis, novel ILD phenotypes were identified among subjects from a longitudinal ILD cohort, and outcomes were stratified according to phenotypic clusters compared with subgroups according to current American Thoracic Society/European Respiratory Society ILD classification criteria.

RESULTS

Among subjects with complete data for baseline variables (N = 770), four clusters were identified. Cluster 1 (ie, younger white obese female subjects) had the highest baseline FVC and diffusion capacity of the lung for carbon monoxide (Dlco). Cluster 2 (ie, younger African-American female subjects with elevated antinuclear antibody titers) had the lowest baseline FVC. Cluster 3 (ie, elderly white male smokers with coexistent emphysema) had intermediate FVC and Dlco. Cluster 4 (ie, elderly white male smokers with severe honeycombing) had the lowest baseline Dlco. Compared with classification according to ILD subgroup, stratification according to phenotypic clusters was associated with significant differences in monthly FVC decline (Cluster 4, -0.30% vs Cluster 2, 0.01%; P < .0001). Stratification by using clusters also independently predicted progression-free survival (P < .001) and transplant-free survival (P < .001).

CONCLUSIONS

Among adults with diverse chronic ILDs, cluster analysis using baseline characteristics identified four distinct clinical phenotypes that might better predict meaningful clinical outcomes than current ILD diagnostic criteria.

Outcomes of immunosuppressive therapy in chronic hypersensitivity pneumonitis

In chronic hypersensitivity pneumonitis (CHP), lack of improvement or declining lung function may prompt use of immunosuppressive therapy. We hypothesised that use of azathioprine or mycophenolate mofetil with prednisone reduces adverse events and lung function decline, and improves transplant-free survival.

Patients with CHP were identified. Demographic features, pulmonary function tests, incidence of treatment-emergent adverse events (TEAEs) and transplant-free survival were characterised, compared and analysed between patients stratified by immunosuppressive therapy. A multicentre comparison was performed across four independent tertiary medical centres.

Among 131 CHP patients at the University of Chicago medical centre (Chicago, IL, USA), 93 (71%) received immunosuppressive therapy, and had worse baseline forced vital capacity (FVC) and diffusing capacity, and increased mortality compared with those who did not. Compared to patients treated with prednisone alone, TEAEs were 54% less frequent with azathioprine therapy (p=0.04) and 66% less frequent with mycophenolate mofetil (p=0.002). FVC decline and survival were similar between treatment groups. Analyses of datasets from four external tertiary medical centres confirmed these findings.

CHP patients who did not receive immunosuppressive therapy had better survival than those who did. Use of mycophenolate mofetil or azathioprine was associated with a decreased incidence of TEAEs, and no difference in lung function decline or survival when compared with prednisone alone. Early transition to mycophenolate mofetil or azathioprine may be an appropriate therapeutic approach in CHP, but more studies are needed.

Early transition to mycophenolate mofetil or azathioprine may be an appropriate therapeutic approach in CHPhttp://ow.ly/kAN130dRIX8

Comorbid Conditions in Idiopathic Pulmonary Fibrosis: Recognition and Management

Idiopathic pulmonary fibrosis (IPF), a fibrosing interstitial pneumonia of unknown etiology, primarily affects older adults and leads to a progressive decline in lung function and quality of life. With a median survival of 3-5 years, IPF is the most common and deadly of the idiopathic interstitial pneumonias. Despite the poor survivorship, there exists substantial variation in disease progression, making accurate prognostication difficult. Lung transplantation remains the sole curative intervention in IPF, but two anti-fibrotic therapies were recently shown to slow pulmonary function decline and are now approved for the treatment of IPF in many countries around the world. While the approval of these therapies represents an important first step in combatting of this devastating disease, a comprehensive approach to diagnosing and treating patients with IPF remains critically important. Included in this comprehensive assessment is the recognition and appropriate management of comorbid conditions. Though IPF is characterized by single organ involvement, many comorbid conditions occur within other organ systems. Common cardiovascular processes include coronary artery disease and pulmonary hypertension (PH), while gastroesophageal reflux and hiatal hernia are the most commonly encountered gastrointestinal disorders. Hematologic abnormalities appear to place patients with IPF at increased risk of venous thromboembolism, while diabetes mellitus (DM) and hypothyroidism are prevalent metabolic disorders. Several pulmonary comorbidities have also been linked to IPF, and include emphysema, lung cancer, and obstructive sleep apnea. While the treatment of some comorbid conditions, such as CAD, DM, and hypothyroidism is recommended irrespective of IPF, the benefit of treating others, such as gastroesophageal reflux and PH, remains unclear. In this review, we highlight common comorbid conditions encountered in IPF, discuss disease-specific diagnostic modalities, and review the current state of treatment data for several key comorbidities.

Microbes Are Associated with Host Innate Immune Response in Idiopathic Pulmonary Fibrosis

RATIONALE

Differences in the lung microbial community influence idiopathic pulmonary fibrosis (IPF) progression. Whether the lung microbiome influences IPF host defense remains unknown.

OBJECTIVES

To explore the host immune response and microbial interaction in IPF as they relate to progression-free survival (PFS), fibroblast function, and leukocyte phenotypes.

METHODS

Paired microarray gene expression data derived from peripheral blood mononuclear cells as well as 16S ribosomal RNA sequencing data from bronchoalveolar lavage obtained as part of the COMET-IPF (Correlating Outcomes with Biochemical Markers to Estimate Time-Progression in Idiopathic Pulmonary Fibrosis) study were used to conduct association pathway analyses. The responsiveness of paired lung fibroblasts to Toll-like receptor 9 (TLR9) stimulation by CpG-oligodeoxynucleotide (CpG-ODN) was integrated into microbiome-gene expression association analyses for a subset of individuals. The relationship between associated pathways and circulating leukocyte phenotypes was explored by flow cytometry.

MEASUREMENTS AND MAIN RESULTS

Down-regulation of immune response pathways, including nucleotide-binding oligomerization domain (NOD)-, Toll-, and RIG1-like receptor pathways, was associated with worse PFS. Ten of the 11 PFS-associated pathways correlated with microbial diversity and individual genus, with species accumulation curve richness as a hub. Higher species accumulation curve richness was significantly associated with inhibition of NODs and TLRs, whereas increased abundance of Streptococcus correlated with increased NOD-like receptor signaling. In a network analysis, expression of up-regulated signaling pathways was strongly associated with decreased abundance of operational taxonomic unit 1341 (OTU1341; Prevotella) among individuals with fibroblasts responsive to CpG-ODN stimulation. The expression of TLR signaling pathways was also linked to CpG-ODN responsive fibroblasts, OTU1341 (Prevotella), and Shannon index of microbial diversity in a network analysis. Lymphocytes expressing C-X-C chemokine receptor 3 CD8 significantly correlated with OTU1348 (Staphylococcus).

CONCLUSIONS

These findings suggest that host-microbiome interactions influence PFS and fibroblast responsiveness.

Interstitial Pneumonia With Autoimmune Features: Value of Histopathology

CONTEXT

- Patients with idiopathic interstitial pneumonia may display evidence of autoimmunity without meeting criteria for a defined connective tissue disease. A recent European Respiratory Society/American Thoracic Society statement proposed research criteria for interstitial pneumonia with autoimmune features (IPAF), which includes findings from the clinical, serologic, and morphologic domains.

OBJECTIVES

- To investigate the importance of histopathologic criteria within the morphologic domain and to report our methodology for identifying these features.

DESIGN

- Patients with idiopathic interstitial pneumonia at the University of Chicago who underwent surgical lung biopsy or lung transplantation were assessed for IPAF histopathologic features, using the initial pathology interpretation in the electronic records. A focused rereview of available slides by a pulmonary pathologist was then performed for patients who failed to meet IPAF criteria on initial pathology assessment.

RESULTS

- Of 422 patients with idiopathic interstitial pneumonia, 176 (41.7%) underwent surgical lung biopsy or lung transplant. Forty-six of those 176 patients (26.1%) met IPAF criteria by initial pathology interpretation and a positive clinical or serologic feature. Of the remaining 130 patients, 73 (56.2%) met either the clinical or serologic domains without meeting the morphologic domain, whereas 36 (27.7%) had slides available for pathology rereview. This rereview demonstrated nonspecific interstitial pneumonia in 8 of 36 patients (22.2%) and lymphoplasmacytic infiltrates in 6 of 36 patients (16.7%), resulting in an additional 7 of 36 patients (19.4%) with idiopathic interstitial pneumonia that met the IPAF criteria. In IPAF, pulmonary vasculopathy was the most prevalent finding (45 of 84; 53.6%) and predicted increased mortality (hazard ratio, 2.5; P = .04).

CONCLUSIONS

- Using a methodological approach to identifying IPAF pathology, we demonstrate a significant increase in the number of patients meeting IPAF criteria because of focused pathologic review and highlight the prognostic value of the IPAF pathologic findings.

Azathioprine response in patients with fibrotic connective tissue disease-associated interstitial lung disease

BACKGROUND

Azathioprine is a commonly prescribed therapy for connective tissue disease-associated interstitial lung disease (CTD-ILD). Combination therapy that included azathioprine was recently shown to increase the risk of death and hospitalization in patients with idiopathic pulmonary fibrosis. Whether azathioprine increases the risk of adverse outcomes in patients with fibrotic CTD-ILD, including those with CTD-associated usual interstitial pneumonia (UIP), remains unknown.

METHODS

A retrospective cohort analysis was performed to determine the combined incidence rate of death, transplant and respiratory hospitalization associated with azathioprine exposure. A fibrotic CTD-ILD cohort treated with mycophenolate mofetil served as a comparator group. Incidence rates were compared with an incidence rate ratio (IRR) generated by negative binomial regression. Longitudinal pulmonary function response was then assessed using mixed effects linear regression models.

RESULTS

Fifty-four patients were treated with azathioprine and forty-three with mycophenolate. Medication discontinuation due to non-respiratory side effects occurred in 27% and 5% of the azathioprine and mycophenolate cohorts, respectively. The combined incidence rate of adverse outcomes was 0.015 and 0.013 for azathioprine and mycophenolate, respectively (IRR 1.23; 95% CI 0.49-3.12; p = 0.66). Similar incidence rates were observed among those with CTD-UIP (IRR 0.83; 95% CI 0.21-3.31; p = 0.79). Both groups demonstrated pulmonary function stability over time, with the azathioprine group demonstrating a marginal improvement.

CONCLUSIONS

A significant minority of patients could not tolerate azathioprine due to non-respiratory side effects. Of those who did tolerate azathioprine, a similar incidence of adverse outcomes was observed as those treated with mycophenolate. Both therapies were associated with stability in pulmonary function.

Characterisation of patients with interstitial pneumonia with autoimmune features

Patients with interstitial lung disease (ILD) may have features of connective tissue disease (CTD), but lack findings diagnostic of a specific CTD. A recent European Respiratory Society/American Thoracic Society research statement proposed criteria for patients with interstitial pneumonia with autoimmune features (IPAF).We applied IPAF criteria to patients with idiopathic interstitial pneumonia and undifferentiated CTD-ILD (UCTD). We then characterised the clinical, serological and morphological features of the IPAF cohort, compared outcomes to other ILD cohorts and validated individual IPAF domains using survival as an endpoint.Of 422 patients, 144 met IPAF criteria. Mean age was 63.2 years with a slight female predominance. IPAF cohort survival was marginally better than patients with idiopathic pulmonary fibrosis, but worse than CTD-ILD. A non-usual interstitial pneumonia pattern was associated with improved survival, as was presence of the clinical domain. A modified IPAF cohort of those meeting the clinical domain and a radiographic or histological feature within the morphological domain displayed survival similar to those with CTD-ILD.IPAF is common among patients with idiopathic interstitial pneumonia and UCTD. Specific IPAF features can identify subgroups with differential survival. Further research is needed to replicate these findings and determine whether patients meeting IPAF criteria benefit from immunosuppressive therapy.

TOLLIP, MUC5B, and the Response to N-Acetylcysteine among Individuals with Idiopathic Pulmonary Fibrosis

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease of unknown etiology. The genes TOLLIP and MUC5B play important roles in lung host defense, which is an immune process influenced by oxidative signaling. Whether polymorphisms in TOLLIP and MUC5B modify the effect of immunosuppressive and antioxidant therapy in individuals with IPF is unknown.

OBJECTIVES

To determine whether single-nucleotide polymorphisms (SNPs) within TOLLIP and MUC5B modify the effect of interventions in subjects participating in the Evaluating the Effectiveness of Prednisone, Azathioprine, and N-Acetylcysteine in Patients with Idiopathic Pulmonary Fibrosis (PANTHER-IPF) clinical trial.

METHODS

SNPs within TOLLIP (rs5743890/rs5743894/rs5743854/rs3750920) and MUC5B (rs35705950) were genotyped. Interaction modeling was conducted with multivariable Cox regression followed by genotype-stratified survival analysis using a composite endpoint of death, transplantation, hospitalization, or a decline of ≥ 10% in FVC.

MEASUREMENTS AND MAIN RESULTS

Significant interaction was observed between N-acetylcysteine (NAC) therapy and rs3750920 within TOLLIP (P interaction = 0.001). After stratifying by rs3750920 genotype, NAC therapy was associated with a significant reduction in composite endpoint risk (hazard ratio, 0.14; 95% confidence interval, 0.02-0.83; P = 0.03) in those with a TT genotype, but a nonsignificant increase in composite endpoint risk (hazard ratio, 3.23; 95% confidence interval, 0.79-13.16; P = 0.10) was seen in those with a CC genotype. These findings were then replicated in an independent IPF cohort.

CONCLUSIONS

NAC may be an efficacious therapy for individuals with IPF with an rs3750920 (TOLLIP) TT genotype, but it was associated with a trend toward harm in those with a CC genotype. A genotype-stratified prospective clinical trial should be conducted before any recommendation regarding the use of off-label NAC to treat IPF.

Predictors of survival in coexistent hypersensitivity pneumonitis with autoimmune features

BACKGROUND

Hypersensitivity pneumonitis (HP), an immune-mediated inflammatory interstitial lung disease (ILD), can result from exposure to several well-recognized antigens. Despite antigen avoidance, progressive pulmonary fibrosis and death can occur, suggesting that additional factors may contribute to disease activity. We hypothesized that the presence of autoimmunity might impact clinical course in patients with HP. In this study, we examined an HP cohort to identify those with HP and autoimmune features (HPAF), and determine its prevalence and outcomes.

METHODS

The University of Chicago ILD registry was screened to identify patients with HP. Patients were characterized as HPAF if they had an autoimmune disease or features of autoimmunity, defined as the presence of specific connective tissue disease (CTD) symptoms and serologies. Demographics, clinical characteristics, and outcomes were compared between groups. Survival analysis was performed using Cox regression to identify predictors of transplant-free survival in this cohort.

RESULTS

One hundred twenty patients with chronic, fibrotic HP were identified. Of these, 18/120 (15%) were characterized as HPAF. Compared to those without evidence of autoimmunity, patients with HPAF had a higher proportion of females (54% vs. 83%, respectively; p = 0.02) but were otherwise similar with regard to clinical characteristics. The presence of autoimmunity was an independent predictor of increased mortality (HR 4.45; 95% CI 1.43-13.88; p = 0.01) after multivariable adjustment.

CONCLUSIONS

Fifteen percent of patients with chronic, fibrotic HP displayed evidence of a concurrent defined autoimmune disease or autoimmune features suggestive of CTD. The presence of autoimmunity in patients with chronic, fibrotic HP may portend a poorer prognosis. Future studies are needed to validate these findings and determine the impact of immunosuppressive treatment.

A functional genomic model for predicting prognosis in idiopathic pulmonary fibrosis

Background

The course of disease for patients with idiopathic pulmonary fibrosis (IPF) is highly heterogeneous. Prognostic models rely on demographic and clinical characteristics and are not reproducible. Integrating data from genomic analyses may identify novel prognostic models and provide mechanistic insights into IPF.

Methods

Total RNA of peripheral blood mononuclear cells was subjected to microarray profiling in a training (45 IPF individuals) and two independent validation cohorts (21 IPF/10 controls, and 75 IPF individuals, respectively). To identify a gene set predictive of IPF prognosis, we incorporated genomic, clinical, and outcome data from the training cohort. Predictor genes were selected if all the following criteria were met: 1) Present in a gene co-expression module from Weighted Gene Co-expression Network Analysis (WGCNA) that correlated with pulmonary function (p < 0.05); 2) Differentially expressed between observed “good” vs. “poor” prognosis with fold change (FC) >1.5 and false discovery rate (FDR) < 2 %; and 3) Predictive of mortality (p < 0.05) in univariate Cox regression analysis. “Survival risk group prediction” was adopted to construct a functional genomic model that used the IPF prognostic predictor gene set to derive a prognostic index (PI) for each patient into either high or low risk for survival outcomes. Prediction accuracy was assessed with a repeated 10-fold cross-validation algorithm and independently assessed in two validation cohorts through multivariate Cox regression survival analysis.

Results

A set of 118 IPF prognostic predictor genes was used to derive the functional genomic model and PI. In the training cohort, high-risk IPF patients predicted by PI had significantly shorter survival compared to those labeled as low-risk patients (log rank p < 0.001). The prediction accuracy was further validated in two independent cohorts (log rank p < 0.001 and 0.002). Functional pathway analysis revealed that the canonical pathways enriched with the IPF prognostic predictor gene set were involved in T-cell biology, including iCOS, T-cell receptor, and CD28 signaling.

Conclusions

Using supervised and unsupervised analyses, we identified a set of IPF prognostic predictor genes and derived a functional genomic model that predicted high and low-risk IPF patients with high accuracy. This genomic model may complement current prognostic tools to deliver more personalized care for IPF patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0142-8) contains supplementary material, which is available to authorized users.

Prostacyclin and oral vasodilator therapy in sarcoidosis-associated pulmonary hypertension: a retrospective case series

BACKGROUND

It is unclear whether recent advances in pulmonary arterial hypertension therapy can be safely applied to sarcoidosis-associated pulmonary hypertension (SAPH). Evidence for prostacyclin (PG) therapy in SAPH is limited.

METHODS

We conducted a single-center, retrospective review of 46 patients with sarcoidosis, 26 of whom had SAPH. Thirteen received PG as monotherapy or in combination with oral vasodilators.

RESULTS

Follow-up right-sided heart catheterization at a mean of 12.7 months revealed improved cardiac output, cardiac index, and pulmonary vascular resistance. Functional class and N-terminal pro-brain natriuretic peptide levels also improved in patients treated with PG. No significant change in oxygen requirement was seen with vasodilator therapy initiation. At 2 years, 15 patients with SAPH survived, including eight on PG, and at 5 years, seven survived, including five on PG. Survival was significantly reduced in patients with SAPH compared with patients who had sarcoidosis without pulmonary hypertension. Multivariate analysis demonstrated that the use of PG therapy in SAPH is not associated with increased mortality.

CONCLUSIONS

Many patients with severe SAPH showed significant hemodynamic and clinical improvement on long-term IV or subcutaneous PG therapy and had survival outcomes similar to patients with moderate SAPH on oral vasodilator therapy.

Thyroid Disease Is Prevalent and Predicts Survival in Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND

A significant minority of patients with idiopathic pulmonary fibrosis (IPF) display features of autoimmunity without meeting the criteria for overt connective tissue disease. A link between IPF and other immune-mediated processes, such as hypothyroidism (HT), has not been reported. In this investigation, we aimed to determine whether HT is associated with IPF and if outcomes differ between patients with IPF with and without HT.

METHODS

A retrospective case-control analysis was conducted. Of 311 patients referred to the University of Chicago Interstitial Lung Disease Center with an initial diagnosis of IPF, 196 met the inclusion criteria and were included in the final analysis. Each case was matched 1:1 by age, sex, and race to a control subject with COPD.

RESULTS

HT was identified in 16.8% of cases and 7.1% of control subjects (OR, 2.7; 95% CI, 1.31-5.54; P = .01). Among patients with IPF, HT was associated with reduced survival time (P < .001) and was found to be an independent predictor of mortality in multivariable Cox regression analysis (hazard ratio, 2.12; 95% CI, 1.31-3.43; P = .002). A secondary analysis of two IPF clinical trial datasets supports these findings.

CONCLUSIONS

HT is common among patients with IPF, with a higher prevalence than in those with COPD and the general population. The presence of HT also predicts mortality in IPF, a finding that may improve future prognostication models. More research is needed to determine the biologic link between IPF and HT and how the presence of thyroid disease may influence disease progression.

Undernutrition regulates the expression of a novel splice variant of myostatin and insulin-like growth factor 1 in ovine skeletal muscle

Undernutrition suppresses the growth of skeletal muscles and alters the expression of insulin-like growth factor 1 (IGF1), a key mitogen, and myostatin, a potent inhibitor of myogenesis. These changes can explain, at least in part, the reduced growth of skeletal muscles in underfed lambs. We have recently identified a myostatin splice variant (MSV) that binds to and antagonizes the canonical signaling of myostatin. In the present study, we hypothesized that the expression of MSV would be reduced in conjunction with myostatin and IGF1 in response to underfeeding in skeletal muscles of sheep. Young growing ewes were fed either ad libitum or an energy-restricted diet (30% of maintenance requirements) for 28 d. This regime of underfeeding resulted in a 24% reduction in body mass (P < 0.001) and a 36% reduction in the mass of the semitendinosus muscles relative to controls (P < 0.001) by day 28. The concentrations of MSV and IGF1 messenger RNA (mRNA) were reduced (both P < 0.001), but myostatin mRNA was not altered in semitendinosus muscles. Unlike the reduced expression of mRNA, the abundance of MSV protein was increased (P < 0.05) and there was no change in the abundance of myostatin protein. Our results suggest that undernutrition for 28 d decreases the signaling of myostatin by increasing the abundance of MSV protein. Although this action may reduce the growth inhibitory activity of myostatin, it cannot prevent the loss of growth of skeletal muscles during undernutrition.

Idiopathic pulmonary fibrosis: early detection and referral

Idiopathic pulmonary fibrosis (IPF), a devastating progressive interstitial lung disease (ILD) with no known cause or cure, is the most common and deadly of the idiopathic interstitial pneumonias. With a median survival of 3-5 years following diagnosis, IPF is characterized by a progressive decline in lung function and quality of life in most patients. Vigilance among clinicians in recognizing IPF early in the disease course remains critical to properly caring for these patients, as this provides the widest range of management options. When IPF is suspected, a multidisciplinary evaluation (MDE) by a clinician, radiologist and pathologist with ILD expertise should occur, as this improves diagnostic agreement in both community and academic settings. When community MDE is not possible, or diagnostic doubt exists, referral to an ILD center should be considered. ILD center referral may also provide access specialized care, including clinical trials and lung transplantation, and should be considered for any patient with an established diagnosis of IPF.

Excessive daytime sleepiness and obstructive sleep apnea in patients with sarcoidosis

BACKGROUND

Systemic symptoms are common in sarcoidosis and are associated with a decreased quality of life. Excessive daytime sleepiness (EDS) often is associated with obstructive sleep apnea (OSA) but may be a systemic symptom independently associated with sarcoidosis. The aim of this study was to assess the relationship between sarcoidosis and EDS.

METHODS

In a retrospective analysis, we used Epworth Sleepiness Scale scores to compare sleepiness in 62 patients with sarcoidosis with 1,005 adults without sarcoidosis referred for polysomnography for suspicion of OSA. Linear regression models controlled for covariates. In a subgroup analysis of patients with sarcoidosis, sleepiness scores and polysomnograms were compared between those with normal and those with abnormal pulmonary function based on total lung capacity.

RESULTS

EDS was more common in patients with sarcoidosis than in those without, and sarcoidosis remained an independent predictor of increased sleepiness after controlling for covariates. Compared with control patients referred for polysomnography, fewer patients with sarcoidosis had clinically significant OSA. However, among patients with sarcoidosis, OSA was more severe in those with abnormal lung function.

CONCLUSIONS

Sarcoidosis is independently associated with EDS. Sleepiness may contribute to the morbidity of sarcoidosis and should be followed even after treating for potentially coexisting OSA or depression. Abnormal lung function in sarcoidosis may contribute to OSA, although the mechanisms for this are not known.

Comorbid personality disorder and treatment use in a community sample of youths: a 20-year follow-up

OBJECTIVE

The impact of comorbid personality disorder (PD) on subsequent treatment and psychotropic drug use was examined in a representative sample of over 700 individuals.

METHOD

Axis I disorders and PD were assessed by self- and mother-report at mean ages 13 and 22 years, and by self-report at mean age 33. Mothers reported treatment use by participants before mean age 33; participants reported treatment and psychotropic drug use at mean age 33.

RESULTS

Individuals with multiple axis I disorders without PD, axis I disorder-PD comorbidity, and single disorders were compared simultaneously to individuals not diagnosed. Overall, odds of subsequent and past year treatment or psychotropic drug use or both were highest when PD co-occurred with a mood, an anxiety, a disruptive, or a substance use disorder.

CONCLUSION

Co-occurring personality pathology may contribute to elevated mental health service use, including use of psychotropic drugs, among young adults in the community.

Prolonged underfeeding of sheep increases myostatin and myogenic regulatory factor Myf-5 in skeletal muscle while IGF-I and myogenin are repressed

The IGF axis is nutritionally sensitive in vivo and IGFs stimulate myoblast proliferation and differentiation in vitro, while myostatin inhibits these processes in vitro. We hypothesised that underfeeding would reversibly inhibit the myogenic activity of satellite cells in vivo together with decreased IGF-I and increased myostatin in muscle. Satellite cell activity was measured indirectly from the expression of proliferating cell nuclear antigen (PCNA) and the myogenic regulatory factors (MRFs), MyoD, Myf-5 and myogenin. Young sheep were underfed (30% of maintenance) and some killed after 1, 4, 12, 17, 21 and 22 weeks. Remaining underfed animals were then re-fed a control ration of pellets and killed after 2 days, and 1, 6 and 30 weeks. Expression of PCNA and MRFs decreased during the first week of underfeeding. This coincided with reduced IGF-I and myostatin mRNA, and processed myostatin. Subsequently, Myf-5, MyoD, myostatin mRNA and processed myostatin increased, suggesting that satellite cells may have become progressively quiescent. Long-term underfeeding caused muscle necrosis in some animals and IGF-I and MRF expression was increased in these, indicating the activation of satellite cells for muscle repair. Re-feeding initiated rapid muscle growth and increased expression of PCNA, IGF-I and the MRFs concurrently with decreased myostatin proteins. In conclusion, these data indicate that IGF-I and myostatin may work in a coordinated manner to regulate the proliferation, differentiation and quiescence of satellite cells in vivo.

Internal consistency, intercriterion overlap and diagnostic efficiency of criteria sets for DSM-IV schizotypal, borderline, avoidant and obsessive-compulsive personality disorders

OBJECTIVE

To evaluate performance characteristics of DSM-IV Personality Disorders (PDs) criteria.

METHOD

Six hundred and sixty-eight adults recruited for the Collaborative Longitudinal Personality Disorders Study (CLPS) were assessed with diagnostic interviews.

RESULTS

Within-category inter-relatedness was evaluated by Cronbach's alpha and median intercriterion correlations (MIC). Cronbach's alpha ranged from 0.47 to 0.87 (median=0.71); seven of the 10 PDs had alphas greater than 0.70. Between-category criterion overlap was evaluated by "inter-category" intercriterion correlations between all PD pairs (ICMIC). ICMIC values (median=0.08) were lower than MIC values (median=0.23). Diagnostic efficiency statistics (sensitivity, specificity, positive predictive power and negative predictive power were calculated for schizotypal, borderline, avoidant and obsessive-compulsive PDs.

CONCLUSION

DSM-IV PD criteria sets have some convergent validity and discriminant validity: criteria for individual PDs correlate better with each other than with criteria for other PDs. Diagnostic efficiency statistics provide guidance regarding usefulness of criteria for inclusion or exclusion.

Molecular expression of myostatin and MyoD is greater in double-muscled than normal-muscled cattle fetuses

Excessive muscling in double-muscled cattle arises from mutations in the myostatin gene, but the role of myostatin in normal muscle development is unclear. The aim of this study was to measure the temporal relationship of myostatin and myogenic regulatory factors during muscle development in normal (NM)- and double-muscled (DM) cattle to determine the timing and possible targets of myostatin action in vivo. Myostatin mRNA peaked at the onset of secondary fiber formation (P < 0.001) and was greater in DM (P < 0.001) than in NM. MyoD expression was also elevated throughout primary and secondary fiber formation (P < 0.001) and greater in DM (P < 0.05). Expression of myogenin peaked later than MyoD (P < 0.05); however, it did not differ between NM and DM. These data show that myostatin and MyoD increase coincidentally during formation of muscle fibers, indicating a coordinated role in the terminal differentiation and/or fusion of myoblasts. Myostatin mRNA is also consistently higher in DM than NM, suggesting that a feedback loop of regulation is also disrupted in the myostatin-deficient condition.

The Collaborative Longitudinal Personality Disorders Study: development, aims, design, and sample characteristics

This paper describes the aims, background, design, and methods used in a collaborative longitudinal study of Axis II personality disorders (PDs). This study examines the putative stability of selected PD diagnoses and criteria, what factors affect their course, and whether their stability and course distinguishes them from a representative Axis I disorder. This article also describes the acquisition and demographics of the sample on whom the study is being done. A prospective, repeated measures investigation of the stability of PDs is now underway at multiple clinical settings in four collaborating urban sites in Boston. New Haven, New York, and Providence. Diagnostic assignments are based on semistructured interview assessments (by clinically trained raters) and confirmed by at least one additional contrasting diagnostic method. The sample consists of 668 treatment seeking and reliably diagnosed adults recruited from a broad range of clinical sites. By design, patients in the sample met standards for one of five diagnostic subgroups: (a) schizotypal (N = 86); (b) borderline (N = 175); (c) avoidant (N = 157); (d) obsessive-compulsive (N = 153) personality disorders or a control group having (e) major depressive disorder without personality disorder (N = 97).

Treatment utilization by patients with personality disorders

OBJECTIVE

Utilization of mental health treatment was compared in patients with personality disorders and patients with major depressive disorder without personality disorder.

METHOD

Semistructured interviews were used to assess diagnosis and treatment history of 664 patients in four representative personality disorder groups-schizotypal, borderline, avoidant, and obsessive-compulsive-and in a comparison group of patients with major depressive disorder.

RESULTS

Patients with personality disorders had more extensive histories of psychiatric outpatient, inpatient, and psychopharmacologic treatment than patients with major depressive disorder. Compared to the depression group, patients with borderline personality disorder were significantly more likely to have received every type of psychosocial treatment except self-help groups, and patients with obsessive-compulsive personality disorder reported greater utilization of individual psychotherapy. Patients with borderline personality disorder were also more likely to have used antianxiety, antidepressant, and mood stabilizer medications, and those with borderline or schizotypal personality disorder had a greater likelihood of having received antipsychotic medications. Patients with borderline personality disorder had received greater amounts of treatment, except for family/couples therapy and self-help, than the depressed patients and patients with other personality disorders.

CONCLUSIONS

These results underscore the importance of considering personality disorders in diagnosis and treatment of psychiatric patients. Borderline and schizotypal personality disorder are associated with extensive use of mental health resources, and other, less severe personality disorders may not be addressed sufficiently in treatment planning. More work is needed to determine whether patients with personality disorders are receiving adequate and appropriate mental health treatments.

Childhood verbal abuse and risk for personality disorders during adolescence and early adulthood

Data from a community-based longitudinal study were used to investigate whether childhood verbal abuse increases risk for personality disorders (PDs) during adolescence and early adulthood. Psychiatric and psychosocial interviews were administered to a representative community sample of 793 mothers and their offspring from two New York State counties in 1975, 1983, 1985 to 1986, and 1991 to 1993, when the mean ages of the offspring were 5, 14, 16, and 22 years, respectively. Data regarding childhood abuse and neglect were obtained from the psychosocial interviews and from official New York State records. Offspring who experienced maternal verbal abuse during childhood were more than three times as likely as those who did not experience verbal abuse to have borderline, narcissistic, obsessive-compulsive, and paranoid PDs during adolescence or early adulthood. These associations remained significant after offspring temperament, childhood physical abuse, sexual abuse, neglect, physical punishment during childhood, parental education, parental psychopathology, and co-occurring psychiatric disorders were controlled statistically. In addition, youths who experienced childhood verbal abuse had elevated borderline, narcissistic, paranoid, schizoid, and schizotypal PD symptom levels during adolescence and early adulthood after the covariates were accounted for. These findings suggest that childhood verbal abuse may contribute to the development of some types of PDs, independent of offspring temperament, childhood physical abuse, sexual abuse, neglect, physical punishment during childhood, parental education, parental psychopathology, and co-occurring psychiatric disorders.