Phenotypic subtypes of fibrotic hypersensitivity pneumonitis identified by machine learning consensus clustering analysis.

BACKGROUND: Patients with fibrotic hypersensitivity pneumonitis (f-HP) have varied clinical and radiologic presentations whose associated phenotypic outcomes have not been previously described. We conducted a study to evaluate mortality and lung transplant (LT) outcomes among clinical clusters of f-HP as characterized by an unsupervised machine learning approach. METHODS: Consensus cluster analysis was performed on a retrospective cohort of f-HP patients diagnosed according to recent international guideline. Demographics, antigen exposure, radiologic, histopathologic, and pulmonary function findings along with comorbidities were included in the cluster analysis. Cox proportional-hazards regression was used to assess mortality or LT risk as a combined outcome for each cluster. RESULTS: Three distinct clusters were identified among 336 f-HP patients. Cluster 1 (n = 158, 47%) was characterized by mild restriction on pulmonary function testing (PFT). Cluster 2 (n = 46, 14%) was characterized by younger age, lower BMI, and a higher proportion of identifiable causative antigens with baseline obstructive physiology. Cluster 3 (n = 132, 39%) was characterized by moderate to severe restriction. When compared to cluster 1, mortality or LT risk was lower in cluster 2 (hazard ratio (HR) of 0.42; 95% CI, 0.21-0.82; P = 0.01) and higher in cluster 3 (HR of 1.76; 95% CI, 1.24-2.48; P = 0.001). CONCLUSIONS: Three distinct phenotypes of f-HP with unique mortality or transplant outcomes were found using unsupervised cluster analysis, highlighting improved mortality in fibrotic patients with obstructive physiology and identifiable antigens.

Genetic Testing Goes Beyond Imaging and Histological Evaluation in Pleuroparenchymal Fibroelastosis.

BACKGROUND: Lung biopsy remains the gold standard in the diagnosis of fibrotic interstitial lung disease (F-ILD), but there is a growing appreciation of the role of pathogenic gene variants in telomere and surfactant protein genes, especially in familial pulmonary fibrosis (FPF). Pleuroparenchymal fibroelastosis (PPFE) is a rare disease that can coexist with different patterns of F-ILD, including FPF. It can be progressive and often leads to respiratory failure and death. This study tested the hypothesis that genetic testing goes beyond radiological and histological findings in PPFE and other F-ILD further informing clinical decision-making for patients and affected family members by identifying pathological gene variants in telomere and surfactant protein genes. METHODS: This is a retrospective review of 70 patients with F-ILD in the setting of FPF or premature lung fibrosis. Six out of 70 patients were diagnosed with PPFE based on radiological or histological characteristics. All patients underwent telomere length evaluation in peripheral blood by Flow-FISH or genetic testing using a customized exome-based panel that included telomere and surfactant protein genes associated with lung fibrosis. RESULTS: Herein, we identified six individuals where radiographic or histopathological analyses of PPFE were linked with telomere biology disorders (TBD) or variants in surfactant protein genes. Each case involved individuals with either personal early-onset lung fibrosis or a family history of the disease. Assessments of telomere length and genetic testing offered insights beyond traditional radiological and histopathological evaluations. CONCLUSION: Detecting anomalies in TBD-related or surfactant protein genes can significantly refine the diagnosis and treatment strategies for individuals with PPFE and other F-ILD.

Diagnosis of renal tumors in Birt-Hogg-Dube syndrome: Clinical presentation and risk factors in a single-center retrospective cohort.

BACKGROUND: Birt-Hogg-Dube (BHD) syndrome is a rare genetic condition associated with the development of renal tumors. This study aims to determine typical age ranges for detecting renal abnormalities, risk factors for tumor development, and long-term outcomes based on current surveillance strategies. METHODS: A single-center multi-site retrospective cohort study was performed on all patients with BHD diagnosed from 2000 to 2023. Baseline demographics, pulmonary function, laboratory, radiologic, and histopathologic findings were collected. Logistic regression was used to assess predictor variables for the development of renal tumors with survival analysis evaluated from the date of BHD diagnosis to date of death or last known follow-up. RESULTS: The study included 149 patients with BHD, 39 (26%) with diagnosed renal tumors, of which 28 had histopathologic confirmation. Mean age at renal tumor detection was 53.61 years. Older age and male sex were predictive of renal tumor development ((odds ratio 1.05; 95% CI, 1.01-1.08, P = 0.002) and (odds ratio 2.59; 95% CI, 1.17-5.73, P = 0.02), respectively). Time to all-cause mortality appeared shorter in those with renal tumors (Log-rank P = 0.02), though no deaths were from cancer or cancer-related complications. CONCLUSIONS: Current screening protocols for renal tumors in BHD suggest the most common presenting age range for presentation is late 40s to early 50s, with older age and male sex as risk factors for tumor development.

Expert consensus on the management of systemic sclerosis-associated interstitial lung disease.

BACKGROUND: Systemic sclerosis (SSc) is a rare, complex, connective tissue disorder. Interstitial lung disease (ILD) is common in SSc, occurring in 35-52% of patients and accounting for 20-40% of mortality. Evolution of therapeutic options has resulted in a lack of consensus on how to manage this condition. This Delphi study was initiated to develop consensus recommendations based on expert physician insights regarding screening, progression, treatment criteria, monitoring of response, and the role of recent therapeutic advances with antifibrotics and immunosuppressants in patients with SSc-ILD. METHODS: A modified Delphi process was completed by pulmonologists (n = 13) and rheumatologists (n = 12) with expertise in the management of patients with SSc-ILD. Panelists rated their agreement with each statement on a Likert scale from - 5 (complete disagreement) to + 5 (complete agreement). Consensus was predefined as a mean Likert scale score of ≤ - 2.5 or ≥ + 2.5 with a standard deviation not crossing zero. RESULTS: Panelists recommended that all patients with SSc be screened for ILD by chest auscultation, spirometry with diffusing capacity of the lungs for carbon monoxide, high-resolution computed tomography (HRCT), and/or autoantibody testing. Treatment decisions were influenced by baseline and changes in pulmonary function tests, extent of ILD on HRCT, duration and degree of dyspnea, presence of pulmonary hypertension, and potential contribution of reflux. Treatment success was defined as stabilization or improvement of signs or symptoms of ILD and functional status. Mycophenolate mofetil was identified as the initial treatment of choice. Experts considered nintedanib a therapeutic option in patients with progressive fibrotic ILD despite immunosuppressive therapy or patients contraindicated/unable to tolerate immunotherapy. Concomitant use of nintedanib with MMF/cyclophosphamide can be considered in patients with advanced disease at initial presentation, aggressive ILD, or significant disease progression. Although limited consensus was achieved on the use of tocilizumab, the experts considered it a therapeutic option for patients with early SSc and ILD with elevated acute-phase reactants. CONCLUSIONS: This modified Delphi study generated consensus recommendations for management of patients with SSc-ILD in a real-world setting. Findings from this study provide a management algorithm that will be helpful for treating patients with SSc-ILD and addresses a significant unmet need.

Antigen identification and avoidance on outcomes in fibrotic hypersensitivity pneumonitis.

BACKGROUND: Suspected causative antigens may be unidentified in 30-50% of patients with fibrotic hypersensitivity pneumonitis (f-HP). It is unclear whether antigen identification and avoidance in this setting offer any additional clinical benefit. We hypothesised that antigen identification and avoidance may improve the clinical course of patients with fibrotic disease. METHODS: Patients meeting recent international practice guidance for f-HP diagnosis evaluated at Mayo Clinic Rochester from January 2005 to December 2018 were included. Causative antigen and antigen avoidance were specifically defined and ascertained through review of the medical records. Cox proportional-hazards regression was performed to assess antigen identification and avoidance as predictors of either all-cause mortality or lung transplantation. RESULTS: 377 patients were included. Of these, suspected causative antigen was identified in 225 (60%). Identification of a suspected antigen (adjusted hazard ratio (HR) 0.69, 95% CI 0.48-0.99; p=0.04) and subsequent antigen avoidance (adjusted HR 0.47, 95% CI 0.31-0.71; p<0.001) were associated with decreased all-cause mortality and transplantation. Both those with suspected antigen identification but nonavoidance and those with unidentifiable antigen had increased risk of all-cause mortality or transplantation (adjusted HR 2.22, 95% CI 1.34-3.69; p=0.002 versus adjusted HR 2.09, 95% CI 1.34-3.26; p=0.001, respectively). Exposure to avian antigen was associated with better outcome compared to other antigen subtypes (adjusted HR 0.63, 95% CI 0.43-0.93; p=0.02). CONCLUSION: Our findings suggest that antigen identification and antigen avoidance remain relevant even in patients with fibrotic disease, where both appear to be associated with improved outcomes.

Nintedanib in progressive interstitial lung diseases: data from the whole INBUILD trial.

BACKGROUND: The primary analysis of the INBUILD trial showed that in subjects with progressive fibrosing interstitial lung diseases (ILDs), nintedanib slowed the decline in forced vital capacity (FVC) over 52 weeks. We report the effects of nintedanib on ILD progression over the whole trial. METHODS: Subjects with fibrosing ILDs other than idiopathic pulmonary fibrosis, who had ILD progression within the 24 months before screening despite management deemed appropriate in clinical practice, were randomised to receive nintedanib or placebo. Subjects continued on blinded randomised treatment until all subjects had completed the trial. Over the whole trial, mean±sd exposure to trial medication was 15.6±7.2 and 16.8±5.8 months in the nintedanib and placebo groups, respectively. RESULTS: In the nintedanib (n=332) and placebo (n=331) groups, respectively, the proportions of subjects who had ILD progression (absolute decline in FVC ≥10% predicted) or died were 40.4% and 54.7% in the overall population (hazard ratio (HR) 0.66, 95% CI 0.53-0.83; p=0.0003) and 43.7% and 55.8% among subjects with a usual interstitial pneumonia (UIP)-like fibrotic pattern on high-resolution computed tomography (HRCT) (HR 0.69, 95% CI 0.53-0.91; p=0.009). In the nintedanib and placebo groups, respectively, the proportions who had an acute exacerbation of ILD or died were 13.9% and 19.6% in the overall population (HR 0.67, 95% CI 0.46-0.98; p=0.04) and 15.0% and 22.8% among subjects with a UIP-like fibrotic pattern on HRCT (HR 0.62, 95% CI 0.39-0.97; p=0.03). CONCLUSION: Based on data from the whole INBUILD trial, nintedanib reduced the risk of events indicating ILD progression.

Effect size of rituximab on pulmonary function in the treatment of connective-tissue disease-related interstitial lung disease: a systematic review and meta-analysis.

BACKGROUND: Rituximab (RTX) has been previously reported as directed treatment in patients with connective-tissue disease-related interstitial lung diseases (CTD-ILD). A systematic assessment of treatment effect size on pulmonary function outcomes and related adverse effects in patients with CTD-ILD has not been previously reported. METHODS: We performed a systematic review and meta-analysis of published reports from PubMed, Embase, and Cochrane Libraries. Randomized and non-randomized controlled trials, case-control, cohort, and case series (with five or more cases) containing individual pulmonary function data and adverse effects were included. Study endpoints were pre- and post-treatment change in percent predicted forced vital capacity (FVC %) and diffusion capacity for carbon monoxide (DLCO%), along with reported drug-related adverse events. RESULTS: Twenty studies totaling 411 patients were identified with 14 included in the meta-analysis of pulmonary function and six in the descriptive review. Random effects meta-analysis of pre- and post-treatment pulmonary function findings demonstrated increases in FVC% (n = 296) (mean difference (MD) 4.57%, [95% CI 2.63-6.51]) and DLCO% (n = 246) (MD 5.0% [95% CI 2.71-7.29]) after RTX treatment. RTX treatment-related adverse effects were reported in 13.6% of the pooled cohort. CONCLUSIONS: A systematic assessment of post-treatment effect size suggests a potential role for RTX in stabilizing or improving lung function in patients with CTD-ILD, with a modest but not insignificant adverse effect profile.

Quantitative CT and machine learning classification of fibrotic interstitial lung diseases.

OBJECTIVES: To evaluate quantitative computed tomography (QCT) features and QCT feature-based machine learning (ML) models in classifying interstitial lung diseases (ILDs). To compare QCT-ML and deep learning (DL) models' performance. METHODS: We retrospectively identified 1085 patients with pathologically proven usual interstitial pneumonitis (UIP), nonspecific interstitial pneumonitis (NSIP), and chronic hypersensitivity pneumonitis (CHP) who underwent peri-biopsy chest CT. Kruskal-Wallis test evaluated QCT feature associations with each ILD. QCT features, patient demographics, and pulmonary function test (PFT) results trained eXtreme Gradient Boosting (training/validation set n = 911) yielding 3 models: M1 = QCT features only; M2 = M1 plus age and sex; M3 = M2 plus PFT results. A DL model was also developed. ML and DL model areas under the receiver operating characteristic curve (AUC) and 95% confidence intervals (CIs) were compared for multiclass (UIP vs. NSIP vs. CHP) and binary (UIP vs. non-UIP) classification performances. RESULTS: The majority (69/78 [88%]) of QCT features successfully differentiated the 3 ILDs (adjusted p ≤ 0.05). All QCT-ML models achieved higher AUC than the DL model (multiclass AUC micro-averages 0.910, 0.910, 0.925, and 0.798 and macro-averages 0.895, 0.893, 0.925, and 0.779 for M1, M2, M3, and DL respectively; binary AUC 0.880, 0.899, 0.898, and 0.869 for M1, M2, M3, and DL respectively). M3 demonstrated statistically significant better performance compared to M2 (∆AUC: 0.015, CI: [0.002, 0.029]) for multiclass prediction. CONCLUSIONS: QCT features successfully differentiated pathologically proven UIP, NSIP, and CHP. While QCT-based ML models outperformed a DL model for classifying ILDs, further investigations are warranted to determine if QCT-ML, DL, or a combination will be superior in ILD classification. KEY POINTS: • Quantitative CT features successfully differentiated pathologically proven UIP, NSIP, and CHP. • Our quantitative CT-based machine learning models demonstrated high performance in classifying UIP, NSIP, and CHP histopathology, outperforming a deep learning model. • While our quantitative CT-based machine learning models performed better than a DL model, additional investigations are needed to determine whether either or a combination of both approaches delivers superior diagnostic performance.

Bronchoalveolar lavage lymphocytosis in hypersensitivity pneumonitis: a retrospective cohort analysis with elimination of incorporation bias.

BACKGROUND: Recent studies support the diagnostic role of bronchoalveolar lavage lymphocytosis (BALL) in patients with suspected hypersensitivity pneumonitis (HP). Our study aim was to determine the spectrum of BALL findings with elimination of incorporation bias in non-fibrotic and fibrotic patients and assess correlates of positive BALL cut-off and BALL association with long-term outcomes in those with fibrotic disease (f-HP). METHODS: A single-center retrospective cohort study was pursued of patients undergoing diagnostic bronchoscopy for interstitial lung disease. Strict study enrollment was based on recent ATS/JRS/ALAT diagnostic guidance meeting 'moderate' or higher diagnostic confidence. BALL findings were assessed in both fibrotic and non-fibrotic HP patients with regression and survival analysis pursued for correlates of positive BALL cut-off and long-term outcome. RESULTS: A total of 148 patients (88 fibrotic and 60 non-fibrotic) meeting moderate or higher diagnostic confidence were included. Median BALL in f-HP was 15% compared to 19% in non-fibrotic patients, with only 28% of f-HP meeting diagnostic cut-off (≥ 30%) compared to 41% of non-fibrotic. For f-HP, centrilobular nodules on computed tomography was positively correlated with a diagnostic BALL (OR 4.07; p = 0.018) while honeycombing was negatively correlated (OR 6.9 × e-8; p = 0.001). Higher BALL was also associated with lower all-cause mortality (HR 0.98; p = 0.015). CONCLUSION: With elimination of incorporation bias, most patients with well-described HP did not meet diagnostic BALL thresholds. Higher BALL was associated with better long-term survival in those with fibrosis, but its diagnostic role may be more additive than characteristic or distinguishing.

Outcomes for hospitalized patients with idiopathic pulmonary fibrosis treated with antifibrotic medications.

BACKGROUND: Idiopathic Pulmonary Fibrosis is a chronic, progressive interstitial lung disease for which there is no cure. However, lung function decline, hospitalizations, and mortality may be reduced with the use of the antifibrotic medications, nintedanib and pirfenidone. Historical outcomes for hospitalized patients with Idiopathic Pulmonary Fibrosis are grim; however there is a paucity of data since the approval of nintedanib and pirfenidone for treatment. In this study, we aimed to determine the effect of nintedanib and pirfenidone on mortality following respiratory-related hospitalizations, intensive care unit (ICU) admission, and mechanical ventilation. METHODS: Using a large U.S. insurance database, we created a one-to-one propensity score matched cohort of patients with idiopathic pulmonary fibrosis treated and untreated with an antifibrotic who underwent respiratory-related hospitalization between January 1, 2015 and December 31, 2018. Mortality was evaluated at 30 days and end of follow-up (up to 2 years). Subgroup analyses were performed for all patients receiving treatment in an ICU and those receiving invasive and non-invasive mechanical ventilation during the index hospitalization. RESULTS: Antifibrotics were not observed to effect utilization of mechanical ventilation or ICU treatment during the index admission or effect mortality at 30-days. If patients survived hospitalization, mortality was reduced in the treated cohort compared to the untreated cohort when followed up to two years (20.1% vs 47.8%). CONCLUSIONS: Treatment with antifibrotic medications does not appear to directly improve 30-day mortality during or after respiratory-related hospitalizations. Post-hospital discharge, however, ongoing antifibrotic treatment was associated with improved long-term survival.

Mechanical Ventilation and Predictors of In-Hospital Mortality in Fibrotic Interstitial Lung Disease With Acute Respiratory Failure: A Cohort Analysis Through the Paradigm of Acute Respiratory Distress Syndrome.

OBJECTIVES: Prior studies report significant mortality in fibrotic interstitial lung disease patients undergoing mechanical ventilation. Little is known about baseline characteristics or ventilator strategies that might improve outcomes. We analyzed the ventilator characteristics of a large cohort of fibrotic interstitial lung disease patients from the perspective of an acute respiratory distress syndrome paradigm to see if any specific mechanical ventilation strategies might improve in-hospital mortality. DESIGN: Retrospective cohort study. SETTING: Single-center, multihospital medical ICUs. PATIENTS: Consecutive fibrotic interstitial lung disease patients who experienced mechanical ventilation for acute respiratory failure. INTERVENTIONS: Interstitial lung disease characteristics, demographics, and ventilator variables were analyzed for univariable and multivariable predictors of in-hospital mortality, adjusted for confounding with an a priori causation model. MEASUREMENTS AND MAIN RESULTS: A total of 111 patients accounted for 114 admissions. Idiopathic pulmonary fibrosis comprised 34% with idiopathic acute exacerbation (65%) being the most common admission type. Ninety-five percent were initiated on mandatory volume-control ventilation with only 50% achieving a low tidal volume strategy (plateau pressure ≤ 30 cm H2O) within 3 hours of intubation. Unadjusted clinical predictors of in-hospital mortality included age (unit odds ratio, 1.05; 1.01-1.10; p = 0.015), time from admission to intubation (hr) (unit odds ratio, 1.01; 1.01-1.03; p = 0.017), and use of paralytics (relative risk, 1.54; 1.26-1.90, p < 0.001). Adjusted mechanical ventilation-related predictors of in-hospital mortality included achieving early targeted plateau pressures (odds ratio, 0.23; 0.07-0.76; p = 0.016), PaO2/FIO2 ratio at 3 (unit odds ratio, 0.98; 0.96-0.99, p = 0.002) and 48 hours (unit odds ratio, 0.98; 0.97-0.99, p = 0.018), initial mean airway pressure (unit odds ratio, 1.13; 1.02-1.28, p = 0.019), and total net fluid status (mL) (unit odds ratio, 1.01; 1.001-1.02, p = 0.0001). CONCLUSIONS: Several factors predict in-hospital mortality in fibrotic interstitial lung disease-associated mechanical ventilation when viewed through an acute respiratory distress syndrome model. Further research is needed to refine strategies that may perhaps improve survival if mechanical ventilation is pursued in this set of patients.

Amyloid in the Lung.

Amyloidosis is the term given to abnormal deposition of misfolded precursor proteins at single or multiple sites, leading to organ dysfunction or clinical signs and symptoms. Pulmonary manifestations are nonspecific and may be associated with several amyloid protein subtypes, commonly AL (light chain) and AA (autoimmune) amyloids. Signs or symptoms of amyloid disease may often involve more of the clinical abnormalities of other affected organs than the lungs themselves. Radiologic pulmonary findings include septal and parenchymal ground glass or nodular infiltrates, multiple nodules, cysts, and focal tracheobronchial abnormalities. Lymphadenopathy with or without calcification and pleural effusions has also been reported. Directed therapy is initiated in response to clinical signs or symptoms often as a result of systemic or secondary diseases or conditions. Long-term prognosis is more dependent on the extent of organ involvement where morbidity is often the highest in those with multisystemic disease.

Spontaneous Pneumomediastinum in Connective Tissue Diseases.

BACKGROUND: Spontaneous pneumomediastinum (SP) is an uncommon disorder but has been described in cases with connective tissue diseases (CTDs), most commonly dermatomyositis and polymyositis. We aimed to explore this relationship by analyzing the characteristics of CTD patients with SP. METHODS: Using a computer-assisted search, we identified 25 patients with CTD and SP evaluated between January 1997 and December 2016 at our institution. Clinicoradiologic characteristics, treatment, and outcomes were extracted and chest computed tomography studies analyzed. RESULTS: We identified 25 patients with CTD and SP. Median (range) age at SP occurrence was 55 (18-82) years, and 60% of the patients were women. Smoking history was present in 37%. Spontaneous pneumomediastinum was symptomatic in 56% of patients. Eighteen patients (72%) had a known CTD diagnosis, and 20 patients (80%) manifested radiologic evidence of interstitial lung disease. Spontaneous pneumomediastinum diagnosis was achieved with chest radiography in 20% of cases and chest computed tomography in the other cases. Spontaneous pneumomediastinum was managed with expectant observation alone in 22 cases (88%). Four patients (16%) had concomitant pneumothorax, 1 of whom required chest tube drainage. There were no deaths attributable to SP during the median (range) follow-up of 13 (0-174) months. Cumulative survival was 52% at 1 year and 40% at 2 years. CONCLUSIONS: Spontaneous pneumomediastinum is an uncommon manifestation of CTD and usually occurs in the presence of interstitial lung disease. Although SP seems to be associated with a relatively benign short-term course, occurrence of SP in CTD patients may be a poor prognostic factor.

Overlap of interstitial pneumonia with autoimmune features with undifferentiated connective tissue disease and contribution of UIP to mortality.

BACKGROUND AND OBJECTIVE: Criteria for interstitial pneumonia with autoimmune features (IPAF) were recently established for research purposes in a joint statement from the European Respiratory Society (ERS) and American Thoracic Society (ATS). We reviewed the utility of these criteria in patients previously diagnosed as broadly defined undifferentiated connective tissue disease (UCTD) and noted overlapping IPAF findings. Additional review was given to IPAF patients with usual interstitial pneumonia (UIP) on histopathology or radiology in terms of survival and outcome. METHODS: Patients with prior UCTD-interstitial lung disease (ILD) were screened by ERS/ATS criteria for IPAF. Clinical data along with all-cause mortality were collated and compared with selected idiopathic pulmonary fibrosis (IPF) patients from the same study period. Survival was compared between IPAF subgroups with and without UIP features. RESULTS: One hundred and one UCTD-ILD subjects (91%) evaluated from 2005 to 2012 also met strict criteria for IPAF. Frequent clinical findings included Raynaud's phenomenon, positive anti-nuclear antibody (ANA) and non-specific interstitial pneumonia (NSIP) pattern on chest computed tomography (CT). Nineteen had features of UIP either on histopathology or CT imaging. As compared with IPF, IPAF patients had overall better survival except in those with UIP features. CONCLUSION: Current IPAF criteria encompassed the majority of broadly defined UCTD-ILD and included those with UIP findings. Survival compared with IPF in those with UIP was similar. Further studies are necessary to refine IPAF definitions for clinical use and guide directed management strategies.

Obliterative bronchiolitis associated with rheumatoid arthritis: analysis of a single-center case series.

BACKGROUND: Rheumatoid arthritis (RA) is a systemic autoimmune condition characterized by erosive inflammation of the joints. One rare pulmonary manifestation is obliterative bronchiolitis (OB), a small airways disease characterized by the destruction of bronchiolar epithelium and airflow obstruction. METHODS: We retrospectively reviewed the clinical data of patients with rheumatoid arthritis-associated obliterative bronchiolitis (RA-OB) from 01/01/2000 to 12/31/2015. Presenting clinical features, longitudinal pulmonary function testing, radiologic findings, and independent predictors of all-cause mortality were assessed. RESULTS: Forty one patients fulfilled criteria for diagnosis of RA-OB. There was notable female predominance (92.7%) with a mean age of 57 ± 15 years. Dyspnea was the most common presenting clinical symptom. Median FEV1 was 40% (IQR 31-52.5) at presentation, with a mean decline of - 1.5% over a follow-up period of thirty-three months. Associated radiologic findings included mosaic attenuation and pulmonary nodules. A majority of patients (78%) received directed therapy including long-acting inhalers, systemic corticosteroids or other immunosuppressive agents, and macrolide antibiotics. All-cause mortality was 27% over a median follow-up of sixty-two months (IQR 32-113). No distinguishable predictors of survival at presentation were found. CONCLUSIONS: RA-OB appears to have a stable clinical course in the majority of patients despite persistent symptoms and severe obstruction based on presenting FEV1.

The use of pretest probability increases the value of high-resolution CT in diagnosing usual interstitial pneumonia.

BACKGROUND: Recent studies have suggested that non-definitive patterns on high-resolution CT (HRCT) scan provide sufficient diagnostic specificity to forgo surgical lung biopsy in the diagnosis of idiopathic pulmonary fibrosis (IPF). The objective of this study was to determine test characteristics of non-definitive HRCT patterns for identifying histopathological usual interstitial pneumonia (UIP). METHODS: Patients with biopsy-proven interstitial lung disease (ILD) and non-definitive HRCT scans were identified from two academic ILD centres. Test characteristics for HRCT patterns as predictors of UIP on surgical lung biopsy were derived and validated in independent cohorts. RESULTS: In the derivation cohort, 64/385 (17%) had possible UIP pattern on HRCT; 321/385 (83%) had inconsistent with UIP pattern. 113/385 (29%) patients had histopathological UIP pattern in the derivation cohort. Possible UIP pattern had a specificity of 91.2% (95% CI 87.2% to 94.3%) and a positive predictive value (PPV) of 62.5% (95% CI 49.5% to 74.3%) for UIP pattern on surgical lung biopsy. The addition of age, sex and total traction bronchiectasis score improved the PPV. Inconsistent with UIP pattern demonstrated poor PPV (22.7%, 95% CI 18.3% to 27.7%). HRCT pattern specificity was nearly identical in the validation cohort (92.7%, 95% CI 82.4% to 98.0%). The substantially higher prevalence of UIP pattern in the validation cohort improved the PPV of HRCT patterns. CONCLUSIONS: A possible UIP pattern on HRCT has high specificity for UIP on surgical lung biopsy, but PPV is highly dependent on underlying prevalence. Adding clinical and radiographic features to possible UIP pattern on HRCT may provide sufficient probability of histopathological UIP across prevalence ranges to change clinical decision-making.

Utility of autoimmune serology testing in the assessment of uncharacterized interstitial lung disease: a large retrospective cohort review.

BACKGROUND: Autoimmune serologies are often obtained in the initial evaluation of uncharacterized interstitial lung disease (ILD). Whether this practice is helpful in delineating connective-tissue disease related ILD (CTD-ILD) is not well known. We assessed the frequency of incident CTD-ILD as detected by autoimmune serology testing and presenting clinical signs and symptoms. METHODS: Consecutive patients seen at our institution over a four year period with newly diagnosed uncharacterized ILD and autoimmune serologic testing were included. Serologic assessment was performed as a standardized order set of 13 laboratory tests. Presenting demographics and clinical signs or symptoms suggestive of autoimmune disease were correlated with the presence or absence of positive serology studies and final CTD-ILD diagnoses. RESULTS: Overall prevalence of newly diagnosed CTD-ILD was 6.9% (42 of 605). Positive serology was seen in 35.2% (213 of 605) of screened ILD. CTD-ILD was diagnosed in 19.2% of those with positive serology, and 52.8% of those with both positive serology and suggestive clinical signs or symptoms. Only 1.4% of those with positive serology and negative review of systems were diagnosed with CTD-ILD. CTD-ILD diagnoses were made more frequently in younger patients ≤60 years with no diagnoses made after the age of 80 (P = 0.009). Positive serology in non-CTD-ILD cases did not appear to confer any survival advantage. CONCLUSIONS: The yield of autoimmune serology testing in uncharacterized ILD appears greatest in those with suggestive clinical signs or symptoms on presentation for CTD-ILD.

Pulmonary mucormycosis: clinical features and outcomes.

PURPOSE: Mucormycosis encompasses a group of opportunistic fungal infections caused by Zygomycetes, order Mucorales. Mucormycosis can manifest as rhino-orbito-cerebral, pulmonary, gastrointestinal, cutaneous, and disseminated infections. Pulmonary mucormycosis is the second most common presentation. This manuscript characterizes the demographics, clinical presentation, diagnostic procedures, radiologic findings, therapeutic interventions, and outcome in pulmonary mucormycosis. METHODS: We retrospectively reviewed clinical data of 35 patients with pulmonary mucormycosis from 2000 to 2015. Microbiologic diagnosis was based on positive culture from a sterile site or findings on histopathology consistent with mucormycosis. Independent predictors of 28-day mortality were assessed using logistic regression. Survival curves were estimated using Kaplan-Meier method. RESULTS: There was male predominance with a mean age of 55 ± 15 years. Analysis of predisposing conditions revealed the prevailing presence of malignancy. Sixty-six percent of patients were receiving immunosuppressive agents. Common presenting clinical findings were fever, neutropenia, dyspnea, and cough. Radiologic findings included pleural effusion and nodules. All patients received medical therapy and 43% underwent additional surgical intervention. Twenty eight day mortality was 29% with concurrent bacteremia found as the sole independent predictor. Similar survival from pulmonary mucormycosis was noted over time. CONCLUSIONS: Pulmonary mucormycosis is an opportunistic angioinvasive fungal infection. Physicians must have a high level of suspicion in immunocompromised patients with fever and respiratory symptoms refractory to antibiotics. A low threshold should be had for performing an invasive procedure to gain reliable diagnosis, as early, aggressive medical and surgical interventions are needed for successful treatment.

Bronchoscopy assessment of acute respiratory failure in interstitial lung disease.

BACKGROUND AND OBJECTIVE: Acute respiratory failure (ARF) in patients with interstitial lung disease (ILD) is associated with significant morbidity and mortality. Recommended assessment for acute exacerbation (AE) of ILD includes exclusion of secondary causes via fibreoptic bronchoscopy. Our aim is to assess the role of bronchoscopy during ARF-ILD. METHODS: Consecutive ILD patients (2002-2014) hospitalized with ARF who underwent bronchoscopy were included. Baseline demographics, underlying ILD diagnoses and presenting clinical features were reviewed. Characteristics of bronchoscopy including diagnostic findings, management and complications were collated. RESULTS: One hundred and six patients accounted for 119 unique bronchoscopies. Sixteen (13%) were abnormal (12 infections and 4 haemorrhages). Baseline presenting clinical features did not differ between those with and without abnormal findings. About half were performed in an intensive care unit (ICU) (53%), with 25% of bronchoscopies performed in a general floor setting resulting in ICU transfer; 71% of whom resulted in immediate mechanical ventilation. Overall management of ARF in those with positive bronchoscopy findings was similar to those without, resulting in similar in-hospital mortality. CONCLUSION: Bronchoscopy in the clinical assessment of ARF-ILD is often performed with only a 13% yield in this large retrospective cohort. As management and in-hospital mortality were similar, routine diagnostic bronchoscopy in ARF-ILD should be further studied given its low yield and high procedural risk.

Mild Cognitive Impairment and Risk of Critical Illness.

OBJECTIVES: Approximately half of ICU admissions are comprised of patients older than 65 years old. Mild cognitive impairment is a common disorder affecting 10-20% of patients in the same age group. A need exists for exploring mild cognitive impairment and risk of critical illness. As mild cognitive impairment may be a contributor to poorer overall health or be a result of it, we sought to determine whether the presence of mild cognitive impairment independently increases the risk of critical illness admissions. DESIGN: Data from the Mayo Clinic Study of Aging were analyzed. All study participants underwent prospective comprehensive cognitive testing and expert panel consensus diagnosis of both cognitive function and clinical state at baseline and subsequent visits. Comparisons were made between those with normal cognitive function and mild cognitive impairment regarding baseline health and frequency of critical illness. SETTING: Single-center population-based cohort out of Olmsted County, MN. PARTICIPANTS: All individuals 70-89 years old were screened for prospective enrollment in the Mayo Clinic Study of Aging. Patients with preexisting dementia and ICU admission within 3 years of entry to the study were excluded from this analysis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 2,425 patients analyzed from the Mayo Clinic Study of Aging, 1,734 patients (71%) were included in the current study. Clinical factors associated with baseline mild cognitive impairment included age, male gender, stroke, and poorer health self-rating. Using a Cox regression model adjusting for these and a priori variables of baseline health, the presence of mild cognitive impairment remained a significant predictor of ICU admission (hazard ratio, 1.50 [1.15-1.96]; p = 0.003). CONCLUSIONS AND RELEVANCE: The presence of mild cognitive impairment is independently associated with increased critical illness admission. Further prospective studies are needed to analyze the impact of critical illness on cognitive function.