Serum C-reactive protein is associated with earlier mortality across different interstitial lung diseases

BACKGROUND AND OBJECTIVE

The acute-phase protein C-reactive protein (CRP) is known to be associated with poor outcomes in cancer and cardiovascular disease, but there is limited evidence of its prognostic implications in interstitial lung diseases (ILDs). We therefore set out to test whether baseline serum CRP levels are associated with mortality in four different ILDs.

METHODS

In this retrospective study, clinically measured CRP levels, as well as baseline demographics and lung function measures, were collected for ILD patients first presenting to the Royal Brompton Hospital between January 2010 and December 2019. Cox regression analysis was used to determine the relationship with 5-year mortality.

RESULTS

Patients included in the study were: idiopathic pulmonary fibrosis (IPF) n = 422, fibrotic hypersensitivity pneumonitis (fHP) n = 233, rheumatoid arthritis associated ILD (RA-ILD) n = 111 and Systemic Sclerosis associated ILD (SSc-ILD) n = 86. Patients with a recent history of infection were excluded. Higher CRP levels were associated with shorter 5-year survival in all four disease groups on both univariable analyses, and after adjusting for age, gender, smoking history, immunosuppressive therapy and baseline disease severity (IPF: HR (95% CI): 1.3 (1.1-1.5), p = 0.003, fHP: 1.5 (1.2-1.9), p = 0.001, RA-ILD: 1.4 (1.1-1.84), p = 0.01 and SSc-ILD: 2.7 (1.6-4.5), p < 0.001).

CONCLUSION

Higher CRP levels are independently associated with reduced 5-year survival in IPF, fHP, RA-ILD and SSc-ILD.

Transcriptomic and network analysis identifies shared and unique pathways and immune changes across fibrotic interstitial lung diseases

BACKGROUND

Interstitial lung disease (ILD) encompasses a diverse group of disorders characterized by chronic inflammation and fibrosis of the pulmonary interstitium. Three ILDs, namely idiopathic pulmonary fibrosis (IPF), fibrotic hypersensitivity pneumonitis (fHP), and connective tissue disease-associated ILD (CTD-ILD), exhibit similar progressive fibrosis phenotypes, yet possess distinct etiologies, encouraging us to explore their different underlying mechanisms.

METHODS

Transcriptome data of fibrotic lung tissues from patients with IPF, fHP, and CTD-ILD were subjected to functional annotation, network, and pathway analyses. Additionally, we employed the xCell deconvolution algorithm to predict immune cell infiltration in patients with fibrotic ILDs and healthy controls.

RESULTS

We identified a shared progressive fibrosis-related module in these diseases which was related to extracellular matrix (ECM) degradation and production and potentially regulated by the p53 family transcription factors. In IPF, neuron-related processes emerged as a critical specific mechanism in functional enrichment. In fHP, we observed that B cell signaling and immunoglobulin A (IgA) production may act as predominant processes, which was further verified by B cell infiltration and the central role of CD19 gene. In CTD-ILD, active chemokine processes were enriched, and active dendritic cells (aDCs) were predicted to infiltrate the lung tissues.

CONCLUSIONS

This study revealed shared and specific molecular and cellular pathways among IPF, fHP, and CTD-ILD, providing a basis for understanding their pathogenesis and identifying potential therapeutic targets.

Serum Specific Antibodies Do Not Seem to Have an Additional Role in the Diagnosis of Hypersensitivity Pneumonitis

BACKGROUND

We aimed to investigate the contribution of serum IgG testing to the history of exposure in the diagnosis of fibrotic hypersensitivity pneumonitis.

METHODS

A single-center, retrospective, cross-sectional study including 63 patients pathologically diagnosed with fibrotic hypersensitivity pneumonitis in line with the guidelines of the American Thoracic Society. Descriptive statistics were presented and Kappa statistic was performed to evaluate the compatibility between panel and the history of exposure.

RESULTS

The median age was 63 (22-81) years and 34 (54%) were male. Forty-six patients (73%) had a positive history of exposure. Thirty-nine patients (61.9%) had a positive HP/Avian panel. The most common exposure agent was mold (34.9%), followed by parakeet (31.7%). The antibody detected the most was penicillium chrysogenum lgG (36.5%), followed by aspergillus fumigatus (31.8%). There was no compatibility between HP/Avian panel and history of exposure (kappa coefficient= 0.18, p= 0.14). When the exposure was only assessed based on the history, 4 (6.35%) patients were diagnosed as fibrotic hypersensitivity pneumonitis with low confidence, 6 (9.52%) with moderate confidence, 11 (17.46%) with high confidence and 42 (66.67%) with definite confidence; whereas 4 (6.35%) patients were diagnosed as fibrotic hypersensitivity pneumonitis with low confidence, 6 (9.52%) with moderate confidence, 9 (14.29%) patients with high confidence and 44 (69.84%) patients with definite confidence if exposure was evaluated with history and/or panel.

CONCLUSIONS

Serum specific precipitating antibody panel does not seem to provide additional value to the history of exposure in the diagnosis of fibrotic hypersensitivity pneumonitis.

Pathologic Criteria for the Diagnosis of Usual Interstitial Pneumonia vs Fibrotic Hypersensitivity Pneumonitis in Transbronchial Cryobiopsies

Transbronchial cryobiopsy (TBCB) is increasingly used for the diagnosis of fibrosing interstitial pneumonias, but there are few detailed descriptions of the pathologic findings in such cases. It has been proposed that a combination of patchy fibrosis and fibroblast foci with an absence of alternative features is diagnostic of usual interstitial pneumonia (UIP; ie, idiopathic pulmonary fibrosis [IPF]) in TBCB. In this study, we reviewed 121 TBCB in which a diagnosis of fibrotic hypersensitivity pneumonitis (FHP; n = 83) or IPF (n = 38) was made by multidisciplinary discussion and evaluated a range of pathologic features. Patchy fibrosis was found in 65 of 83 (78%) biopsies from FHP and 32of 38 (84%) biopsies from UIP/IPF cases. Fibroblast foci were present in 47 of 83 (57%) FHP and 27 of 38 (71%) UIP/IPF cases. Fibroblast foci/patchy fibrosis combined did not favor either diagnosis. Architectural distortion was seen in 54 of 83 (65%) FHP and 32 of 38 (84%) UIP/IPF cases (odds ratio [OR] for FHP, 0.35; P = .036) and honeycombing in 18 of 83 (22%) and 17 of 38 (45%), respectively (OR, 0.37; P = .014). Airspace giant cells/granulomas were present in 13 of 83 (20%) FHP and 1 of 38 (2.6%) UIP/IPF cases (OR for FHP, 6.87; P = .068), and interstitial giant cells/granulomas in 20 of 83 (24%) FHP and 0 of 38 (0%) UIP/IPF (OR, 6.7 x 106; P = .000). We conclude that patchy fibrosis plus fibroblast foci can be found in TBCB from both FHP and UIP/IPF. The complete absence of architectural distortion/honeycombing favors a diagnosis of FHP, as does the presence of airspace or interstitial giant cells/granulomas, but these measures are insensitive, and many cases of FHP cannot be separated from UIP/IPF on TBCB.

Bronchoalveolar Lavage Cell Count and Lymphocytosis Are the Important Discriminators between Fibrotic Hypersensitivity Pneumonitis and Idiopathic Pulmonary Fibrosis

BACKGROUND

Fibrotic hypersensitivity pneumonitis (fHP) shares many features with other fibrotic interstitial lung diseases (ILD), and as a result it can be misdiagnosed as idiopathic pulmonary fibrosis (IPF). We aimed to determine the value of bronchoalveolar lavage (BAL) total cell count (TCC) and lymphocytosis in distinguishing fHP and IPF and to evaluate the best cut-off points discriminating these two fibrotic ILD.

METHODS

A retrospective cohort study of fHP and IPF patients diagnosed between 2005 and 2018 was conducted. Logistic regression was used to evaluate the diagnostic utility of clinical parameters in differentiating between fHP and IPF. Based on the ROC analysis, BAL parameters were evaluated for their diagnostic performance, and optimal diagnostic cut-offs were established.

RESULTS

A total of 136 patients (65 fHP and 71 IPF) were included (mean age 54.97 ± 10.87 vs. 64.00 ± 7.18 years, respectively). BAL TCC and the percentage of lymphocytes were significantly higher in fHP compared to IPF (p < 0.001). BAL lymphocytosis >30% was found in 60% of fHP patients and none of the patients with IPF. The logistic regression revealed that younger age, never smoker status, identified exposure, lower FEV₁, higher BAL TCC and higher BAL lymphocytosis increased the probability of fibrotic HP diagnosis. The lymphocytosis >20% increased by 25 times the odds of fibrotic HP diagnosis. The optimal cut-off values to differentiate fibrotic HP from IPF were 15 × 10⁶ for TCC and 21% for BAL lymphocytosis with AUC 0.69 and 0.84, respectively.

CONCLUSIONS

Increased cellularity and lymphocytosis in BAL persist despite lung fibrosis in HP patients and may be used as important discriminators between IPF and fHP.

Fibrotic Hypersensitivity Pneumonitis Diagnosed by a Re-evaluation with Bronchoalveolar Lavage at Disease Deterioration

A 79-year-old man was admitted with worsening cough, dyspnea, and increased ground-glass opacity on chest computed tomography (CT). He had been diagnosed with idiopathic pulmonary fibrosis given the absence of an identifiable cause of interstitial pneumonia, chest CT findings, and absence of lymphocytosis in bronchoalveolar lavage (BAL) fluid. Meticulous history taking revealed extensive exposure to inciting antigens contained in chicken fertilizer before symptom worsening. A re-evaluation with BAL showed lymphocytosis, and clinical improvement with antigen avoidance confirmed the diagnosis of fibrotic hypersensitivity pneumonitis (fHP). A re-evaluation with BAL at disease deterioration after possible exposure to inciting antigen can facilitate a correct fHP diagnosis.

Features of transbronchial lung cryobiopsy-diagnosed fibrotic hypersensitivity pneumonitis

BACKGROUND

Hypersensitivity pneumonitis (HP) is a common type among all the interstitial lung diseases, and transbronchial lung cryobiopsy is an alternative diagnostic technique for interstitial lung diseases. In this study, we describe the clinical and pathological features of fibrotic hypersensitivity pneumonitis diagnosed with transbronchial lung cryobiopsy (TBLC).

METHODS

A total of 46 diffused parenchyma lung disease (DPLD) patients received TBLC were included in this study. Medical records including medical history spirometry examinations, 6-min walk test (6MWT) results, high resolution computed tomographic (HRCT) scans, BAL, and histopathology were collected. Results of HRCT and histopathology were compared and classified, especially.

RESULTS

Sixteen patients were diagnosed with fibrotic HP, the mean age of whom was 56.3 ± 12.1 years, and 62.5% of them were male. Three of the 16 patients had been misdiagnosed as tuberculosis and received antituberculosis medications, five patients had been diagnosed as unclassifiable pulmonary fibrosis, and five patients had been diagnosed as idiopathic pulmonary fibrosis (IPF). Thirteen (81.3%) patients had a normal lymphocyte count in BAL. The pathological features of usual interstitial pneumonia (UIP) were detected in 11 (68.8%) of the cases, poor defined granulomatous was detected in nine (56.3%) of the cases, and bronchiolocentric fibrosis was detected in two (12.5%) of the 16 cases.

CONCLUSIONS

Fibrotic hypersensitivity pneumonitis should be included in differential diagnosis of pulmonary fibrosis. Pathological characteristics of fibrotic hypersensitivity pneumonitis could be demonstrated from cryobiopsy lung tissue. TBLC is recommended as an alternative diagnostic technique, which may improve the specificity of hypersensitivity pneumonia detection, and UIP is the most frequent pathological finding.

Short-term lung function changes predict mortality in patients with fibrotic hypersensitivity pneumonitis

Background and objective

A proportion of patients with fibrotic hypersensitivity pneumonitis (fHP) follow a progressive disease course despite immunosuppressive treatment. Little is known about predictors of mortality in fHP. We aimed to investigate the impact of short‐term lung function changes in fHP on mortality.

Methods

Baseline demographics for 145 consecutive patients with a multi‐disciplinary team diagnosis of fHP, as well as baseline and 1‐year follow‐up of lung function, baseline echocardiographic findings, bronchoalveolar lavage (BAL) cellularity and all‐cause mortality were recorded. Changes in forced vital capacity (FVC) ≥ 5% and ≥10%, and diffusion capacity of the lung for carbon monoxide (DLCO) ≥ 10% and ≥15% at 1 year were calculated. Cox proportional hazards analysis was performed to test for associations with mortality.

Results

Baseline lung function severity, age, presence of honeycombing on computed tomography (CT) and echocardiographic pulmonary arterial systolic pressure (PASP) ≥ 40 mm Hg were associated with early mortality, while BAL lymphocytosis was associated with improved survival. A decline in FVC ≥ 5% (hazard ratio [HR]: 3.10, 95% CI: 2.00–4.81, p < 0.001), FVC ≥ 10% (HR: 3.11, 95% CI: 1.94–4.99, p < 0.001), DLCO ≥ 10% (HR: 2.80, 95% CI: 1.78–4.42, p < 0.001) and DLCO ≥ 15% (HR: 2.92, 95% CI: 1.18–4.72, p < 0.001) at 1 year was associated with markedly reduced survival on univariable and multivariable analyses after correcting for demographic variables, disease severity, honeycombing on CT and treatment, as well as BAL lymphocytosis and PASP ≥ 40 mm Hg on echocardiography, in separate models.

Conclusion

Worsening in FVC and DLCO at 1 year, including a marginal decline in FVC ≥ 5% and DLCO ≥ 10%, is predictive of markedly reduced survival in fHP.

[Comparative pathomorphological characteristics of idiopathic pulmonary fibrosis and fibrotic hypersensitivity pneumonitis]

The paper presents an X-ray morphological differential diagnosis of idiopathic pulmonary fibrosis (IPF) and fibrotic hypersensitivity pneumonitis (FHP). It describes the etiology, pathogenesis, radiological signs, and pathoanatomy of IPF and FHP. For differential diagnosis, radiological and morphological signs were studied in 105 patients with IPF and in 111 patients with FHP. The mean ages of patients with IPF or FHP were 65.0±8.9 and 48.9±12.3 years, respectively. The history of IPF to the moment of its diagnosis ranged from 1 to 18 months, while that of FHP was 35 to 79 days. The authors describe the additional morphological signs of FHP: delicate collagen fibrosis; smooth muscle metaplasia in the interalveolar septa and fibrotic areas; fibroblastic foci mainly in the walls of bronchioles; plasma cell infiltration of interalveolar septa with a touch of neutrophils and eosinophils. A table has been compiled for differential diagnosis according to the morphological signs of IPF and FHP.

Advances with pharmacotherapy for the treatment of interstitial lung disease

INTRODUCTION

In recent decades, the primary focus of pharmaceutical research in interstitial lung diseases (ILD) has been on idiopathic pulmonary fibrosis (IPF). Recently, pharmaceutical development has also focused on other forms of ILDs, including connective tissue diseases associated ILD, fibrotic hypersensitivity pneumonitis, and sarcoidosis.

AREAS COVERED

The authors summarize the advances in pharmacotherapy for the treatment of ILD. Specifically, the authors review the most recent studies and discuss the most recent research findings and future prospects.

EXPERT OPINION

Data collected over the past years have confirmed the efficacy of antifibrotic drugs on slowing disease progression in IPF. The usual strategy for CTD-ILD management is represented by the combined use of corticosteroids and immunosuppressive agents. There is an urgent need for new target therapies. The concept of progressive fibrosing ILD has emerged in the ILD community in recent years, which has led to grouping several diseases with a common disease behavior to find an effective treatment . At present, selecting the best therapy in ILDs should be reasonably performed on a case-by-case basis through a multidisciplinary team discussion in tertiary ILD centers, taking into consideration patients' symptoms, lung functional trends, and radiological changes.

Effect of Oral Methyl Prednisolone on Different Radiological Patterns of Hypersensitivity Pneumonitis

Background

Hypersensitivity pneumonitis (HP) is an immune-mediated disorder that causes inflammation of interstitial lung, bronchioles, and alveoli. Although corticosteroids have been used as first line treatment for HP for many years, it does not provide satisfactory results in all patients. The aim of this study is to compare the effect of oral methylprednisolone on different radiological patterns of HP to identify the most adequate candidates for corticosteroids.

Patients and Methods

Fifty-three patients with confirmed diagnosis of HP were divided into two groups according to their radiological patterns based on high resolution computed tomography (HRCT) findings. The first group included 21 patients with fibrotic HP (fHP), the second group included 32 patients without fibrosis; non-fibrotic HP patients (nfHP). The second group is divided into 3 subgroups: mosaic, attenuation, centrilobular nodules and finally, ground-glass opacities. All patients were administered methylprednisolone by dose 0.5mg/kg/day for eight consecutive weeks. HRCT was performed at the beginning of the study. Spirometry, six-minute walk and oximetry were performed periodically to assess the patients' progress.

Results

Upon finalizing the treatment process, a significant improvement was noticed in FEV1 (p < 0.001), FVC (p <0.001), six-minute walk test (p =0.001) and oximetry (p <0.05) in nfHP compared to the fHP patients. However, there was a significant improvement in (p <0.01), FVC (p <0.01), oximetry (p <0.01) and six-minute walk test (p <0.01) in fibrotic patients after receiving the treatment. There was no significant difference in the response of FEV1 (p =0.82), FVC (p =0.15), six-minute walk test (p =0.36) and oximetry (p =0.27) among the subgroups of nfHP patients.

Conclusion

It was accordingly concluded that corticosteroid treatment is more effective in treatment of nfHP than fHP patients but still has effect on fibrotic patients. There is no significant difference in the response to corticosteroids among nfHP patients' subgroups.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

Fibrotic Hypersensitivity Pneumonitis: Key Issues in Diagnosis and Management

The diagnosis of hypersensitivity pneumonitis (HP) relies on the clinical evaluation of a number of features, including a history of significant exposure to potentially causative antigens, physical examination, chest CT scan appearances, bronchoalveolar lavage lymphocytosis, and, in selected cases, histology. The presence of fibrosis is associated with higher morbidity and mortality. Differentiating fibrotic HP from the idiopathic interstitial pneumonias can be a challenge. Furthermore, even in the context of a clear diagnosis of fibrotic HP, the disease behaviour can parallel that of idiopathic pulmonary fibrosis in a subgroup, with inexorable progression despite treatment. We review the current knowledge on the diagnosis, management, and prognosis of HP with particular focus on the fibrotic phenotype.