Interstitial lung disease (ILD) is one of the most serious pulmonary complications associated with connective tissue diseases (CTDs), resulting in significant morbidity and mortality. Although the ...various CTDs associated with ILD often are considered together because of their shared autoimmune nature, there are substantial differences in the clinical presentations and management of ILD in each specific CTD. This heterogeneity and the cross-disciplinary nature of care have complicated the conduct of prospective multicenter treatment trials and hindered our understanding of the development of ILD in patients with CTD. In this update, we present new information regarding the diagnosis and treatment of patients with ILD secondary to systemic sclerosis, rheumatoid arthritis, dermatomyositis and polymyositis, and Sjögren syndrome. We review information on risk factors for the development of ILD in the setting of CTD. Diagnostic criteria for CTD are presented as well as elements of the clinical evaluation that increase suspicion for CTD-ILD. We review the use of medications in the treatment of CTD-ILD. Although a large, randomized study has examined the impact of immunosuppressive therapy for ILD secondary to systemic sclerosis, additional studies are needed to determine optimal treatment strategies for each distinct form of CTD-ILD. Finally, we review new information regarding the subgroup of patients with ILD who meet some, but not all, diagnostic criteria for a CTD. A careful and systematic approach to diagnosis in patients with ILD may reveal an unrecognized CTD or evidence of autoimmunity in those previously believed to have idiopathic ILD.
In this article, we review the evidence for peripheral blood biomarkers in idiopathic pulmonary fibrosis (IPF), a life-threatening fibrotic lung disease of unknown etiology. We focus on selected ...biomarkers present in peripheral blood, as they are easy to obtain, can be measured longitudinally, and have the greatest likelihood of achieving clinical utility. This article concentrates on biomarkers with mechanistic plausibility that may be directly involved in the development of IPF, including KL-6, surfactant proteins A and D, matrix metalloproteases (MMP) 1 and 7, CCL18, VEGF, YKL-40, osteopontin, circulating fibrocytes, and T cells. After reviewing the evidence base for each, we designate the biomarkers that may have utility as: (1) diagnostic biomarkers to distinguish IPF from other interstitial lung diseases, (2) prognostic biomarkers that are correlated with disease progression or mortality, or (3) biomarkers that can be used as tools for serial monitoring of disease severity. Although there are no validated biomarkers that are currently available, the need for surrogates of diagnosis, prognosis, and monitoring of disease course with emerging therapies is great.
Rheumatoid arthritis-related interstitial lung disease (RA-ILD) is a common connective tissue disease-related ILD (CTD-ILD) associated with high morbidity and mortality. Although rheumatoid factor ...(RF) seropositivity is a risk factor for developing RA-ILD, the relationship between RF seropositivity, mediastinal lymph node (MLN) features, and disease progression is unknown. We aimed to determine if high-titer RF seropositivity predicted MLN features, lung function impairment, and mortality in RA-ILD. In this retrospective cohort study, we identified patients in the University of Chicago ILD registry with RA-ILD. We compared demographic characteristics, serologic data, MLN size, count and location, and pulmonary function over 36 months among patients who had high-titer RF seropositivity (≥ 60 IU/ml) and those who did not. Survival analysis was performed using Cox regression modeling. Amongst 294 patients with CTD-ILD, available chest computed tomography (CT) imaging and serologic data, we identified 70 patients with RA-ILD. Compared to RA-ILD patients with low-titer RF, RA-ILD patients with high-titer RF had lower baseline forced vital capacity (71% vs. 63%; P = 0.045), elevated anti-cyclic citrullinated peptide titer (122 vs. 201; P = 0.001), CT honeycombing (50% vs. 80%; P = 0.008), and higher number of MLN ≥ 10 mm (36% vs. 76%; P = 0.005). Lung function decline over 36 months did not differ between groups. Primary outcomes of death or lung transplant occurred more frequently in the high-titer RF group (HR 2.8; 95% CI 1.1-6.8; P = 0.028). High-titer RF seropositivity was associated with MLN enlargement, CT honeycombing, and decreased transplant-free survival. RF titer may be a useful prognostic marker for stratifying patients by pulmonary disease activity and mortality risk.
Patients with myositis-associated interstitial lung disease (MA-ILD) are often refractory to conventional treatment, and predicting their response to therapy is challenging. Recent case reports and ...small series suggest that tacrolimus may be useful in refractory cases.
A retrospective cohort study of patients with MA-ILD comparing clinical characteristics between those who responded to or failed conventional treatment. In those who failed conventional treatment and received adjunctive tacrolimus, response to tacrolimus was measured by the improvement in myositis, ILD, and change in the dose of glucocorticoids.
Thirty-one of 54 patients (57%) responded to conventional treatment based on the predefined variables of improvement in myositis and/or ILD. Patients with polymyositis (PM)-ILD were more likely to respond to conventional treatment than those with dermatomyositis (DM)-ILD (67% vs 35%, p = 0.013). Twenty-three patients failed conventional treatment, 18 of whom subsequently received adjunctive tacrolimus. Ninety-four percent had improvements in ILD and 72% showed improvement in both myositis and ILD. The mean doses of prednisone decreased from baseline by 65% at 3-6 months (p = 0.002) and 81% at 1 year (p < 0.001).
Patients with PM-ILD were more likely to respond to conventional treatment than patients with DM-ILD, but clinical characteristics and serology did not otherwise predict response to therapy. A majority of patients with MA-ILD refractory to conventional therapy improved while receiving tacrolimus and were able to decrease their dose of both glucocorticoids and other disease-modifying antirheumatic drugs.
Idiopathic pulmonary fibrosis (IPF) is a devastating disease that probably involves several genetic loci. Several rare genetic variants and one common single nucleotide polymorphism (SNP) of MUC5B ...have been associated with the disease. Our aim was to identify additional common variants associated with susceptibility and ultimately mortality in IPF.
First, we did a three-stage genome-wide association study (GWAS): stage one was a discovery GWAS; and stages two and three were independent case-control studies. DNA samples from European-American patients with IPF meeting standard criteria were obtained from several US centres for each stage. Data for European-American control individuals for stage one were gathered from the database of genotypes and phenotypes; additional control individuals were recruited at the University of Pittsburgh to increase the number. For controls in stages two and three, we gathered data for additional sex-matched European-American control individuals who had been recruited in another study. DNA samples from patients and from control individuals were genotyped to identify SNPs associated with IPF. SNPs identified in stage one were carried forward to stage two, and those that achieved genome-wide significance (p<5 × 10(-8)) in a meta-analysis were carried forward to stage three. Three case series with follow-up data were selected from stages one and two of the GWAS using samples with follow-up data. Mortality analyses were done in these case series to assess the SNPs associated with IPF that had achieved genome-wide significance in the meta-analysis of stages one and two. Finally, we obtained gene-expression profiling data for lungs of patients with IPF from the Lung Genomics Research Consortium and analysed correlation with SNP genotypes.
In stage one of the GWAS (542 patients with IPF, 542 control individuals matched one-by-one to cases by genetic ancestry estimates), we identified 20 loci. Six SNPs reached genome-wide significance in stage two (544 patients, 687 control individuals): three TOLLIP SNPs (rs111521887, rs5743894, rs5743890) and one MUC5B SNP (rs35705950) at 11p15.5; one MDGA2 SNP (rs7144383) at 14q21.3; and one SPPL2C SNP (rs17690703) at 17q21.31. Stage three (324 patients, 702 control individuals) confirmed the associations for all these SNPs, except for rs7144383. Linkage disequilibrium between the MUC5B SNP (rs35705950) and TOLLIP SNPs (rs111521887 r(2)=0·07, rs5743894 r(2)=0·16, and rs5743890 r(2)=0·01) was low. 683 patients from the GWAS were included in the mortality analysis. Individuals who developed IPF despite having the protective TOLLIP minor allele of rs5743890 carried an increased mortality risk (meta-analysis with fixed-effect model: hazard ratio 1·72 95% CI 1·24-2·38; p=0·0012). TOLLIP expression was decreased by 20% in individuals carrying the minor allele of rs5743890 (p=0·097), 40% in those with the minor allele of rs111521887 (p=3·0 × 10(-4)), and 50% in those with the minor allele of rs5743894 (p=2·93 × 10(-5)) compared with homozygous carriers of common alleles for these SNPs.
Novel variants in TOLLIP and SPPL2C are associated with IPF susceptibility. One novel variant of TOLLIP, rs5743890, is also associated with mortality. These associations and the reduced expression of TOLLIP in patients with IPF who carry TOLLIP SNPs emphasise the importance of this gene in the disease.
National Institutes of Health; National Heart, Lung, and Blood Institute; Pulmonary Fibrosis Foundation; Coalition for Pulmonary Fibrosis; and Instituto de Salud Carlos III.
Abstract 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 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.
We studied whether African-American race is associated with younger age and decreased survival time at diagnosis of interstitial lung disease (ILD).We performed a multicentre, propensity ...score-matched analysis of patients with an ILD diagnosis followed at five US hospitals between 2006 and 2016. African-Americans were matched with patients of other races based on a time-dependent propensity score calculated from multiple patient, physiological, diagnostic and hospital characteristics. Multivariable logistic regression models were used. All-cause mortality and hospitalisations were compared between race-stratified patient cohorts with ILD, and sensitivity analyses were performed.The study included 1640 patients with ILD, 13% of whom were African-American, followed over 5041 person-years. When compared with patients of other races, African-Americans with ILD were younger at diagnosis (56 years
67 years), but in the propensity-matched analyses had greater survival (hazard ratio 0.46, 95% CI 0.28-0.77; p=0.003) despite similar risk of respiratory hospitalisations (relative risk 1.04, 95% CI 0.83-1.31; p=0.709), and similar GAP-ILD (gender-age-physiology-ILD) scores at study entry. Sensitivity analyses in a separate cohort of 9503 patients with code-based ILD diagnosis demonstrated a similar association of baseline demographic characteristics with all-cause mortality.We conclude that African-Americans demonstrate a unique phenotype associated with younger age at ILD diagnosis and perhaps longer survival time.
Pulmonary fibrosis (PF) is characterized by profound scarring and poor survival. We investigated the association of leukocyte telomere length (LTL) with chronological age and mortality across ...racially diverse PF cohorts. LTL measurements among participants with PF stratified by race/ethnicity were assessed in relation to age and all-cause mortality, and compared to controls. Generalized linear models were used to evaluate the age-LTL relationship, Cox proportional hazards models were used for hazard ratio estimation, and the Cochran-Armitage test was used to assess quartiles of LTL. Standardized LTL shortened with increasing chronological age; this association in controls was strengthened in PF (R = -0.28; P < 0.0001). In PF, age- and sex-adjusted LTL below the median consistently predicted worse mortality across all racial groups (White, HR = 2.21, 95% CI = 1.79-2.72; Black, HR = 2.22, 95% CI = 1.05-4.66; Hispanic, HR = 3.40, 95% CI = 1.88-6.14; and Asian, HR = 2.11, 95% CI = 0.55-8.23). LTL associates uniformly with chronological age and is a biomarker predictive of mortality in PF across racial groups.
Short telomere lengths are found in a subset of patients with idiopathic pulmonary fibrosis, but their clinical significance is unknown. Our aim was to investigate whether patients with various blood ...leucocyte telomere lengths had different overall survival.
In this observational cohort study, we enrolled patients with interstitial lung disease from Dallas, TX (primary cohort), and from Chicago, IL, and San Francisco, CA (replication cohorts). We obtained genomic DNA samples from unrelated healthy controls in Dallas, TX, and spouses of patients were also enrolled as an independent control group. Telomere lengths were measured in genomic DNA samples isolated from peripheral blood obtained at the time of the initial enrolment assessment. The primary endpoint was transplant-free survival (ie, time to death or lung transplantation) in the Dallas cohort. Findings were validated in the two independent idiopathic pulmonary fibrosis cohorts (Chicago and San Francisco).
370 patients were enrolled into the Dallas cohort between June 17, 2003, and Aug 25, 2011. The 149 patients with idiopathic pulmonary fibrosis had shorter telomere lengths than did the 195 healthy controls (mean age-adjusted log-transformed ratio of telomere to single copy gene was -0.16 SD 0.23 vs 0.00 0.18; p<0.0001); however, telomere lengths of the Dallas patients with idiopathic pulmonary fibrosis (1.33 SD 0.25) were similar to the 221 patients with other interstitial lung disease diagnoses (1.46 0.24) after adjusting for age, sex, and ethnicity (p=0.47). Telomere length was independently associated with transplant-free survival time for patients with idiopathic pulmonary fibrosis (HR 0.22 95% CI 0.08-0.63; p=0.0048), but not for patients with interstitial lung disease diagnoses other than idiopathic pulmonary fibrosis (HR 0.73 0.16-3.41; p=0.69). The association between telomere length and survival in patients with idiopathic pulmonary fibrosis was independent of age, sex, forced vital capacity, or diffusing capacity of carbon monoxide, and was replicated in the two independent idiopathic pulmonary fibrosis replication cohorts (Chicago cohort, HR 0.11 0.03-0.39, p=0.00066; San Francisco cohort, HR 0.25 0.07-0.87, p=0.029).
Shorter leucocyte telomere lengths are associated with worse survival in idiopathic pulmonary fibrosis. Additional studies will be needed to establish clinically relevant thresholds for telomere length and how this biomarker might affect risk stratification of patients with idiopathic pulmonary fibrosis.
US National Heart, Lung, and Blood Institute, National Center for Advancing Translational Sciences, Harroun Family Foundation, and Nina Ireland Lung Disease Program.
Objectives
To determine if a quantitative imaging variable (vessel-related structures VRS) could identify subjects with a non-IPF diagnosis CT pattern who were highly likely to have UIP ...histologically.
Methods
Subjects with a multidisciplinary diagnosis of interstitial lung disease including surgical lung biopsy and chest CT within 1 year of each other were included in the study. Non-contrast CT scans were analyzed using the Computer-Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER) program, which quantifies the amount of various abnormal CT patterns on chest CT. Quantitative data were analyzed relative to pathological diagnosis as well as the qualitative CT pattern.
Results
CALIPER-derived volumes of reticulation (
p
= 0.012), honeycombing (
p
= 0.017), and VRS (
p
< 0.001) were associated with a UIP pattern on pathology on univariate analysis but only VRS was associated with a UIP pathology on multivariable analysis (
p
= 0.013). Using a VRS cut-off of 173 cm
3
, the sensitivity and specificity for pathological UIP were similar to those for standard qualitative CT assessment (55.9% and 80.4% compared to 60.6% and 80.4%, respectively). VRS differentiated pathological UIP cases in those with a non-IPF diagnosis CT category (
p
< 0.001) but not in other qualitative CT patterns (typical UIP, probable UIP, and indeterminate for UIP). The rate of pathological UIP in those with VRS greater than 173 cm
3
(84.2%) was nearly identical to those who had a qualitative CT pattern of probable UIP (88.9%).
Conclusions
VRS may be an adjunct to CT in predicting pathology in patients with interstitial lung disease.
Key Points
•
Volume of vessel-related structures (VRS) was associated with usual interstitial pneumonia (UIP) on pathology.
•
This differentiation arose from those with CT scans with a non-IPF diagnosis imaging pattern.
•
Higher VRS has similar diagnostic ramifications for UIP as probable UIP, transitively suggesting in patients with high VRS, pathology may be obviated.