Circulating biomarker analyses in a longitudinal cohort of patients with IPF.

Idiopathic pulmonary fibrosis (IPF) is an incurable interstitial lung disease characterized by fibrosis. Two FDA-approved drugs, pirfenidone and nintedanib, only modestly prolong survival. In this study, we asked whether levels of select circulating biomarkers in patients with IPF demonstrated changes in response to treatment over time and whether treatment with pirfenidone and nintedanib led to differential biomarker expression. Serial plasma samples from 48 patients with IPF on usual treatment and six healthy volunteers were analyzed to identify differentially expressed blood protein. Hypothesis-driven potential biomarker selection was based on recent literature, internal preclinical data, and the PROLIFIC Consortium (Schafer P. 6th Annual IPF Summit. Boston, MA, 2022) proposed biomarkers of pulmonary fibrosis. We compared our findings to public databases to provide insights into relevant signaling pathways in IPF. Of the 26 proteins measured, we found that 11 (SP-D, TIMP1, MMP7, CYFRA21-1, YKL40, CA125, sICAM, IP-10, MDC, CXCL13) were significantly elevated in patients with IPF compared with healthy volunteers but their levels did not significantly change over time. In the IPF samples, seven proteins were elevated in the treatment group compared with the no-treatment group. However, protein profiles were not distinguishable between patients on pirfenidone versus nintedanib. We demonstrated that most proteins differentially detected in our samples were predicted to be secreted from the lung epithelial or interstitial compartments. However, a significant minority of the proteins are not known to be transcriptionally expressed by lung cells, suggesting an ongoing systemic response. Understanding the contributions of the systemic response in IPF may be important as new therapeutics are developed.NEW & NOTEWORTHY In this study, we confirmed protein expression differences in only a subset of predicted biomarkers from IPF and control subjects. Most differentially expressed proteins were predicted to be secreted from lung cells. However, a significant minority of the proteins are not known to be transcriptionally expressed by lung cells, suggesting an ongoing systemic response. The contributions of the systemic response in IPF may be important as new therapeutics are developed.

External Control Arms in Idiopathic Pulmonary Fibrosis Using Clinical Trial and Real-World Data Sources.

Rationale: Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease for which novel therapies are needed. External controls (ECs) could enhance IPF trial efficiency, but the direct comparability of ECs versus concurrent controls is unknown. Objectives: To develop IPF ECs by fit-for-purpose data standards to historical randomized clinical trial (RCT), multicenter registry (Pulmonary Fibrosis Foundation Patient Registry), and electronic health record (EHR) data and to evaluate endpoint comparability among ECs and the phase II RCT of BMS-986020. Methods: After data curation, the rate of change in FVC from baseline to 26 weeks among participants receiving BMS-986020 600 mg twice daily was compared with the BMS-placebo arm and ECs using mixed-effects models with inverse probability weights. Measurements and Main Results: At 26 weeks, the rates of change in FVC were -32.71 ml for BMS-986020 and -130.09 ml for BMS-placebo (difference, 97.4 ml; 95% confidence interval [CI], 24.6-170.2), replicating the original BMS-986020 RCT. RCT ECs showed treatment effect point estimates within the 95% CI of the original BMS-986020 RCT. Pulmonary Fibrosis Foundation Patient Registry ECs and EHR ECs experienced a slower rate of FVC decline compared with the BMS-placebo arm, resulting in treatment-effect point estimates outside of the 95% CI of the original BMS-986020 RCT. Conclusions: IPF ECs generated from historical RCT placebo arms result in comparable primary treatment effects to that of the original clinical trial, whereas ECs from real-world data sources, including registry or EHR data, do not. RCT ECs may serve as a potentially useful supplement to future IPF RCTs.

Nintedanib for Systemic Sclerosis-Associated Interstitial Lung Disease.

BACKGROUND: Interstitial lung disease (ILD) is a common manifestation of systemic sclerosis and a leading cause of systemic sclerosis-related death. Nintedanib, a tyrosine kinase inhibitor, has been shown to have antifibrotic and antiinflammatory effects in preclinical models of systemic sclerosis and ILD. METHODS: We conducted a randomized, double-blind, placebo-controlled trial to investigate the efficacy and safety of nintedanib in patients with ILD associated with systemic sclerosis. Patients who had systemic sclerosis with an onset of the first non-Raynaud's symptom within the past 7 years and a high-resolution computed tomographic scan that showed fibrosis affecting at least 10% of the lungs were randomly assigned, in a 1:1 ratio, to receive 150 mg of nintedanib, administered orally twice daily, or placebo. The primary end point was the annual rate of decline in forced vital capacity (FVC), assessed over a 52-week period. Key secondary end points were absolute changes from baseline in the modified Rodnan skin score and in the total score on the St. George's Respiratory Questionnaire (SGRQ) at week 52. RESULTS: A total of 576 patients received at least one dose of nintedanib or placebo; 51.9% had diffuse cutaneous systemic sclerosis, and 48.4% were receiving mycophenolate at baseline. In the primary end-point analysis, the adjusted annual rate of change in FVC was -52.4 ml per year in the nintedanib group and -93.3 ml per year in the placebo group (difference, 41.0 ml per year; 95% confidence interval [CI], 2.9 to 79.0; P = 0.04). Sensitivity analyses based on multiple imputation for missing data yielded P values for the primary end point ranging from 0.06 to 0.10. The change from baseline in the modified Rodnan skin score and the total score on the SGRQ at week 52 did not differ significantly between the trial groups, with differences of -0.21 (95% CI, -0.94 to 0.53; P = 0.58) and 1.69 (95% CI, -0.73 to 4.12 [not adjusted for multiple comparisons]), respectively. Diarrhea, the most common adverse event, was reported in 75.7% of the patients in the nintedanib group and in 31.6% of those in the placebo group. CONCLUSIONS: Among patients with ILD associated with systemic sclerosis, the annual rate of decline in FVC was lower with nintedanib than with placebo; no clinical benefit of nintedanib was observed for other manifestations of systemic sclerosis. The adverse-event profile of nintedanib observed in this trial was similar to that observed in patients with idiopathic pulmonary fibrosis; gastrointestinal adverse events, including diarrhea, were more common with nintedanib than with placebo. (Funded by Boehringer Ingelheim; SENSCIS ClinicalTrials.gov number, NCT02597933.).

LPA1 antagonist BMS-986020 changes collagen dynamics and exerts antifibrotic effects in vitro and in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a debilitating lung disease with limited treatment options. A phase 2 trial (NCT01766817) showed that twice-daily treatment with BMS-986020, a lysophosphatidic acid receptor 1 (LPA1) antagonist, significantly decreased the slope of forced vital capacity (FVC) decline over 26 weeks compared with placebo in patients with IPF. This analysis aimed to better understand the impact of LPA1 antagonism on extracellular matrix (ECM)-neoepitope biomarkers and lung function through a post hoc analysis of the phase 2 study, along with an in vitro fibrogenesis model. METHODS: Serum levels of nine ECM-neoepitope biomarkers were measured in patients with IPF. The association of biomarkers with baseline and change from baseline FVC and quantitative lung fibrosis as measured with high-resolution computed tomography, and differences between treatment arms using linear mixed models, were assessed. The Scar-in-a-Jar in vitro fibrogenesis model was used to further elucidate the antifibrotic mechanism of BMS-986020. RESULTS: In 140 patients with IPF, baseline ECM-neoepitope biomarker levels did not predict FVC progression but was significantly correlated with baseline FVC and lung fibrosis measurements. Most serum ECM-neoepitope biomarker levels were significantly reduced following BMS-986020 treatment compared with placebo, and several of the reductions correlated with FVC and/or lung fibrosis improvement. In the Scar-in-a-Jar in vitro model, BMS-986020 potently inhibited LPA1-induced fibrogenesis. CONCLUSIONS: BMS-986020 reduced serum ECM-neoepitope biomarkers, which were previously associated with IPF prognosis. In vitro, LPA promoted fibrogenesis, which was LPA1 dependent and inhibited by BMS-986020. Together these data elucidate a novel antifibrotic mechanism of action for pharmacological LPA1 blockade. Trial registration ClinicalTrials.gov identifier: NCT01766817; First posted: January 11, 2013; https://clinicaltrials.gov/ct2/show/NCT01766817 .

Incidence Rates of Interstitial Lung Disease Events in Tofacitinib-Treated Rheumatoid Arthritis Patients: Post Hoc Analysis From 21 Clinical Trials.

BACKGROUND/OBJECTIVE: Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). Interstitial lung disease (ILD) is an extra-articular manifestation of RA. We investigated incidence rates of ILD in patients with RA, receiving tofacitinib 5 or 10 mg twice daily, and identified potential risk factors for ILD. METHODS: This post hoc analysis comprised a pooled analysis of patients receiving tofacitinib 5 or 10 mg twice daily or placebo from 2 phase (P)1, 10 P2, 6 P3, 1 P3b/4, and 2 long-term extension studies. Interstitial lung disease events were adjudicated as "probable" (supportive clinical evidence) or "possible" (no supportive clinical evidence) compatible adverse events. Incidence rates (patients with events per 100 patient-years) were calculated for ILD events. RESULTS: Of 7061 patients (patient-years of exposure = 23,393.7), 42 (0.6%) had an ILD event; median time to ILD event was 1144 days. Incidence rates for ILD with both tofacitinib doses were 0.18 per 100 patient-years. Incidence rates generally remained stable over time. There were 17 of 42 serious adverse events (40.5%) of ILD; for all ILD events (serious and nonserious), 35 of 42 events (83.3%) were mild to moderate in severity. A multivariable Cox regression analysis identified age 65 years or older (hazard ratio 2.43 [95% confidence interval, 1.13-5.21]), current smokers (2.89 [1.33-6.26]), and Disease Activity Score in 28 joints-erythrocyte sedimentation rate score (1.30 [1.04-1.61]) as significant risk factors for ILD events. CONCLUSIONS: Across P1/2/3/4/long-term extension studies, incidence rates for ILD events were 0.18 following tofacitinib treatment, and ILD events were associated with known risk factors for ILD in RA.

Clinical Characteristics and Natural History of Autoimmune Forms of Interstitial Lung Disease: A Single-Center Experience.

OBJECTIVE: To describe the phenotypic characteristics and natural history of patients with autoimmune forms of interstitial lung disease (ILD). METHODS: Retrospective, descriptive, single-center study of patients with autoimmune forms of ILD evaluated between February 2008 and August 2014. All data were extracted from the electronic medical record. Longitudinal changes in forced vital capacity (FVC%) and diffusion capacity for carbon monoxide (DLco%) in percent predicted were analyzed and time-to-event analyses for death were performed using Cox regression. RESULTS: Of the entire cohort (n = 243), systemic sclerosis (SSc)-associated ILD (n = 88, 36%), interstitial pneumonia with autoimmune features (IPAF, n = 56, 23%), rheumatoid arthritis (RA)-associated ILD (n = 42, 17%), and idiopathic inflammatory myopathy (IIM)-associated ILD (n = 26, 11%) were the most common phenotypes. The SSc-ILD, IIM-ILD, and IPAF groups had similar features: average age in the mid-50s, strongly female predominant and more likely to have nonspecific interstitial pneumonia (NSIP). In contrast, RA-ILD patients were older, gender balanced, more likely to be past smokers and were UIP predominant. Adjusted longitudinal lung function was stable during a median follow-up period of nearly 4 years and the independent predictors for death were older age (p = 0.003), male sex (p = 0.019), and lower FVC (p = < 0.001). CONCLUSIONS: The predominant phenotypes of autoimmune ILD were SSc-ILD, IPAF, RA-ILD, and IIM-ILD. In contrast to the other subsets, those with RA-ILD may be older, gender balanced, with more smoking history, and higher proportion of UIP. Longitudinal lung function was stable among the groups and younger age, female gender, and better lung function were associated with improved survival.

Utility of B-type natriuretic peptides in the assessment of patients with systemic sclerosis-associated pulmonary hypertension in the PHAROS registry.

OBJECTIVES: To assess the utility of B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) in detecting and monitoring pulmonary hypertension (PH) in systemic sclerosis (SSc). METHODS: PHAROS is a multicenter prospective cohort of SSc patients at high risk for developing pulmonary arterial hypertension (SSc-AR-PAH) or with a definitive diagnosis of SSc-PH. We evaluated 1) the sensitivity and specificity of BNP≥64 and NT-proBNP≥210 pg/mL for the detection of SSc-PAH and/ or SSc-PH in the SSc-AR-PAH population; 2) baseline and longitudinal BNP and NT-proBNP levels as predictors of progression to SSc-PAH and/or SSc-PH; 3) baseline BNP≥180, NT-proBNP≥553 pg/mL, and longitudinal changes in BNP and NT-proBNP as predictors of mortality in SSc-PH diagnosed patients. RESULTS: 172 SSc-PH and 157 SSc-AR- PAH patients had natriuretic peptide levels available. Median BNP and NT-proBNP were significantly higher in the SSc-PH versus SSc-AR-PAH group. The sensitivity and specificity for SSc-PAH detection using baseline BNP≥64 pg/mL was 71% and 59%; and for NT-proBNP≥210 pg/mL, 73% and 78%. NT-proBNP showed stronger correlations with haemodynamic indicators of right ventricular dysfunction than BNP. Baseline creatinine, RVSP > 40 mmHg, and FVC%:DLco% ratio ≥1.8 were associated with progression from SSc-AR-PAH to SSc-PH but no association with individual or combined baseline BNP and NT-proBNP levels was observed. Baseline and follow-up BNP or NT-proBNP levels were not predictive of death, however, a composite BNP/NT-proBNP group predicted mortality (HR 3.81 (2.08-6.99), p<.0001). CONCLUSIONS: NT-proBNP may be more useful than BNP in the detection and monitoring of PAH in SSc patients, but additional studies are necessary.

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.

Predictors of mortality in rheumatoid arthritis-associated interstitial lung disease.

Interstitial lung disease (ILD) is a common pulmonary manifestation of rheumatoid arthritis. There is lack of clarity around predictors of mortality and disease behaviour over time in these patients.We identified rheumatoid arthritis-related interstitial lung disease (RA-ILD) patients evaluated at National Jewish Health (Denver, CO, USA) from 1995 to 2013 whose baseline high-resolution computed tomography (HRCT) scans showed either a nonspecific interstitial pneumonia (NSIP) or a "definite" or "possible" usual interstitial pneumonia (UIP) pattern. We used univariate, multivariate and longitudinal analytical methods to identify clinical predictors of mortality and to model disease behaviour over time.The cohort included 137 subjects; 108 had UIP on HRCT (RA-UIP) and 29 had NSIP on HRCT (RA-NSIP). Those with RA-UIP had a shorter survival time than those with RA-NSIP (log rank p=0.02). In a model controlling for age, sex, smoking and HRCT pattern, a lower baseline % predicted forced vital capacity (FVC % pred) (HR 1.46; p<0.0001) and a 10% decline in FVC % pred from baseline to any time during follow up (HR 2.57; p<0.0001) were independently associated with an increased risk of death.Data from this study suggest that in RA-ILD, disease progression and survival differ between subgroups defined by HRCT pattern; however, when controlling for potentially influential variables, pulmonary physiology, but not HRCT pattern, independently predicts mortality.

An official European Respiratory Society/American Thoracic Society research statement: interstitial pneumonia with autoimmune features.

Many patients with an idiopathic interstitial pneumonia (IIP) have clinical features that suggest an underlying autoimmune process but do not meet established criteria for a connective tissue disease (CTD). Researchers have proposed differing criteria and terms to describe these patients, and lack of consensus over nomenclature and classification limits the ability to conduct prospective studies of a uniform cohort.The "European Respiratory Society/American Thoracic Society Task Force on Undifferentiated Forms of Connective Tissue Disease-associated Interstitial Lung Disease" was formed to create consensus regarding the nomenclature and classification criteria for patients with IIP and features of autoimmunity.The task force proposes the term "interstitial pneumonia with autoimmune features" (IPAF) and offers classification criteria organised around the presence of a combination of features from three domains: a clinical domain consisting of specific extra-thoracic features, a serologic domain consisting of specific autoantibodies, and a morphologic domain consisting of specific chest imaging, histopathologic or pulmonary physiologic features.A designation of IPAF should be used to identify individuals with IIP and features suggestive of, but not definitive for, a CTD. With IPAF, a sound platform has been provided from which to launch the requisite future research investigations of a more uniform cohort.

Connective Tissue Disease-Associated Interstitial Lung Disease: A Focused Review.

The connective tissue diseases (CTDs) are a group of systemic disorders characterized by autoimmunity and autoimmune-mediated organ damage. The lung is a frequent target and all components of the respiratory system are at risk. Interstitial lung disease (ILD) represents a broad group of diffuse parenchymal lung injury patterns characterized by varying degrees of inflammation and fibrosis, is a common manifestation of CTD particularly common in systemic sclerosis, polymyositis/dermatomyositis, and rheumatoid arthritis, and is a leading cause of significant morbidity and mortality. The lung injury patterns of CTD-associated ILD (CTD-ILD) mirror those of idiopathic interstitial pneumonia and may arise at any time during the course of the CTD or may be the first manifestation of CTD. Patients with CTD that present with respiratory failure often present significant diagnostic dilemmas. Thorough and comprehensive assessments to exclude respiratory *infection, acute interstitial pneumonia, medication toxicity, pulmonary embolism, cardiac dysfunction, and diffuse alveolar hemorrhage are the fundamental components for the evaluation of such patients. Furthermore, patients with CTD are also at risk of acute exacerbations of underlying ILD. Acute exacerbations are manifested by subacute respiratory deterioration with worsening hypoxemia in the setting of new radiographic abnormalities. The prognosis of patients with CTD having respiratory failure is often quite poor, highlighting the need for prompt and thorough clinical assessments to determine the underlying etiology and implementation of appropriate therapeutic strategies.

Interstitial lung disease evaluation: detecting connective tissue disease.

Interstitial lung disease (ILD) is a common manifestation of connective tissue disease (CTD) and is often associated with significant morbidity and mortality. The evaluation of ILD in patients with CTD is complex because of the heterogeneity of the CTD spectrum, the various patterns and degrees of severity of ILD encountered, and because ILD can be identified at any point in time in these patients. A thorough - and optimally multidisciplinary - evaluation is needed when CTD patients develop ILD or when evaluating ILD patients for the presence of occult CTD. Determining whether ILD is associated with a preexisting CTD requires the exclusion of alternative etiologies, and thorough assessments of the clinical features of both the CTD and ILD. The detection of occult CTD in patients with presumed idiopathic interstitial pneumonia requires careful integration of clinical, serologic, and thoracic imaging and histopathologic features.

Rituximab as successful adjunct treatment in a patient with disseminated nontuberculous mycobacterial infection due to acquired anti-interferon-γ autoantibody.

An acquired immune deficiency due to interferon gamma (IFN-γ) autoantibodies was diagnosed in a 78-year-old Japanese man with treatment-refractory disseminated nontuberculous mycobacterial infection. In addition to standard antimycobacterial therapy, he was successfully treated with rituximab to eliminate B cells and thereby the autoantibody. Subsequently, he obtained a sustained remission from infection.

Connective tissue disease related interstitial lung diseases and idiopathic pulmonary fibrosis: provisional core sets of domains and instruments for use in clinical trials.

RATIONALE: Clinical trial design in interstitial lung diseases (ILDs) has been hampered by lack of consensus on appropriate outcome measures for reliably assessing treatment response. In the setting of connective tissue diseases (CTDs), some measures of ILD disease activity and severity may be confounded by non-pulmonary comorbidities. METHODS: The Connective Tissue Disease associated Interstitial Lung Disease (CTD-ILD) working group of Outcome Measures in Rheumatology-a non-profit international organisation dedicated to consensus methodology in identification of outcome measures-conducted a series of investigations which included a Delphi process including >248 ILD medical experts as well as patient focus groups culminating in a nominal group panel of ILD experts and patients. The goal was to define and develop a consensus on the status of outcome measure candidates for use in randomised controlled trials in CTD-ILD and idiopathic pulmonary fibrosis (IPF). RESULTS: A core set comprising specific measures in the domains of lung physiology, lung imaging, survival, dyspnoea, cough and health-related quality of life is proposed as appropriate for consideration for use in a hypothetical 1-year multicentre clinical trial for either CTD-ILD or IPF. As many widely used instruments were found to lack full validation, an agenda for future research is proposed. CONCLUSION: Identification of consensus preliminary domains and instruments to measure them was attained and is a major advance anticipated to facilitate multicentre RCTs in the field.

Current approach to connective tissue disease-associated interstitial lung disease.

PURPOSE OF REVIEW: To review current approaches to the complex intersection of interstitial lung disease (ILD) with the spectrum of connective tissue disease (CTD). RECENT FINDINGS: There is a growing appreciation that the approach to CTD-associated ILD (CTD-ILD) can be enhanced by a multidisciplinary evaluation that often incorporates the rheumatologist. Determining that ILD is associated with an established CTD requires the exclusion of alternative causes and thorough assessments of the clinical features of both the CTD and ILD. The detection of occult CTD in patients with presumed 'idiopathic' disease requires careful attention to the demographic profile, historical clues, subtle physical examination findings, specific autoantibody positivity, radiologic, and histopathologic features. A comprehensive treatment program for CTD-ILD should address comorbid conditions and consider implementation of adjunctive therapeutic strategies. Pharmacologic intervention for CTD-ILD is reserved for those with progressive, clinically significant disease and typically involves use of immunosuppressive therapies. SUMMARY: A multidisciplinary approach can be helpful for CTD-ILD. Further research and controlled trials are needed to determine how to best manage the diverse spectrum of CTD-ILD.

Cross-disciplinary collaboration in connective tissue disease-related lung disease.

Lung disease is a common manifestation of connective tissue disease (CTD) and is associated with significant morbidity and mortality. The evaluation of lung disease, and interstitial lung disease (ILD) in particular, in patients with CTD is complex because of the heterogeneity of the CTDs, the varied types and degrees of severity of ILD encountered, and because ILD can be identified at any point in time in these patients. Cross-disciplinary, thorough evaluations are needed when CTD patients develop ILD or when evaluating ILD patients for the presence of occult CTD. Determining that ILD is associated with an established CTD requires the exclusion of alternative etiologies, and thorough assessments of the clinical features of both the CTD and ILD. The detection of occult CTD in patients with "idiopathic" ILD requires careful attention to the demographic profile, historical clues, subtle physical examination findings, specific autoantibody positivity, radiological and histopathological features, and can be optimized by a multidisciplinary approach that includes rheumatological collaboration. Not all patients with CTD-associated ILD require pharmacological therapy, and management decisions should consider pace and severity of the disease, intra- and extrathoracic features of activity and can be optimized by cross-disciplinary collaboration.

Interstitial lung disease in connective tissue disorders.

Some of the most pressing challenges associated with interstitial lung disease (ILD) are how best to define, diagnose, and treat connective tissue disease-associated ILD (CTD-ILD)--disorders with potentially substantial morbidity and mortality. In this focused review, we address aspects of prognosis for CTD-ILD and what indices might predict outcome, together with lessons that can be learnt from clinical trials of systemic sclerosis-associated ILD and idiopathic pulmonary fibrosis and how these lessons might be applied to future studies of CTD-ILD.

Toll-like receptor 7 (TLR7)-driven accumulation of a novel CD11c⁺ B-cell population is important for the development of autoimmunity.

Females are more susceptible than males to many autoimmune diseases. The processes causing this phenomenon are incompletely understood. Here, we demonstrate that aged female mice acquire a previously uncharacterized population of B cells that we call age-associated B cells (ABCs) and that these cells express integrin α(X) chain (CD11c). This unexpected population also appears in young lupus-prone mice. On stimulation, CD11c(+) B cells, both from autoimmune-prone and healthy strains of mice, secrete autoantibodies, and depletion of these cells in vivo leads to reduction of autoreactive antibodies, suggesting that the cells might have a direct role in the development of autoimmunity. We have explored factors that contribute to appearance of ABCs and demonstrated that signaling through Toll-like receptor 7 is crucial for development of this B cell population. We were able to detect a similar population of B cells in the peripheral blood of some elderly women with autoimmune disease, suggesting that there may be parallels between the creation of ABC-like cells between mice and humans.

Baseline characteristics and follow-up in patients with normal haemodynamics versus borderline mean pulmonary arterial pressure in systemic sclerosis: results from the PHAROS registry.

BACKGROUND: Patients with normal (mean pulmonary arterial pressure (mPAP) ≤20 mm Hg) and borderline mean pulmonary pressures (21-24 mm Hg) are "at risk" of developing pulmonary hypertension (PH). The objectives of this analysis were to examine the baseline characteristics in systemic sclerosis (SSc) with normal and borderline mPAP and to explore long-term outcomes in SSc patients with borderline mPAP versus normal haemodynamics. METHODS: PHAROS is a multicentre prospective longitudinal cohort of patients with SSc "at risk" or recently diagnosed with resting PH on right heart catheterisation (RHC). Baseline clinical characteristics, pulmonary function tests, high-resolution CT, 2-dimensional echocardiogram and RHC results were analysed in normal and borderline mPAP groups. RESULTS: 206 patients underwent RHC (results showed 35 normal, 28 borderline mPAP, 143 resting PH). There were no differences in the baseline demographics. Patients in the borderline mPAP group were more likely to have restrictive lung disease (67% vs 30%), fibrosis on high-resolution CT and a higher estimated right ventricular systolic pressure on echocardiogram (46.3 vs 36.2 mm Hg; p<0.05) than patients with normal haemodynamics. RHC revealed higher pulmonary vascular resistance and more elevated mPAP on exercise (≥30; 88% vs 56%) in the borderline mPAP group (p<0.05 for both). Patients were followed for a mean of 25.7 months and 24 patients had a repeat RHC during this period. During follow-up, 55% of the borderline mPAP group and 32% of the normal group developed resting PH (p=NS). CONCLUSIONS: Patients with borderline mPAP have a greater prevalence of abnormal lung physiology, pulmonary fibrosis and the presence of exercise mPAP ≥30 mm Hg.