High risk of lung cancer in surfactant-related gene variant carriers.

BACKGROUND: Several rare surfactant-related gene (SRG) variants associated with interstitial lung disease are suspected to be associated with lung cancer, but data are missing. We aimed to study the epidemiology and phenotype of lung cancer in an international cohort of SRG variant carriers. METHODS: We conducted a cross-sectional study of all adults with SRG variants in the OrphaLung network and compared lung cancer risk with telomere-related gene (TRG) variant carriers. RESULTS: We identified 99 SRG adult variant carriers (SFTPA1 (n=18), SFTPA2 (n=31), SFTPC (n=24), ABCA3 (n=14) and NKX2-1 (n=12)), including 20 (20.2%) with lung cancer (SFTPA1 (n=7), SFTPA2 (n=8), SFTPC (n=3), NKX2-1 (n=2) and ABCA3 (n=0)). Among SRG variant carriers, the odds of lung cancer was associated with age (OR 1.04, 95% CI 1.01-1.08), smoking (OR 20.7, 95% CI 6.60-76.2) and SFTPA1/SFTPA2 variants (OR 3.97, 95% CI 1.39-13.2). Adenocarcinoma was the only histological type reported, with programmed death ligand-1 expression ≥1% in tumour cells in three samples. Cancer staging was localised (I/II) in eight (40%) individuals, locally advanced (III) in two (10%) and metastatic (IV) in 10 (50%). We found no somatic variant eligible for targeted therapy. Seven cancers were surgically removed, 10 received systemic therapy, and three received the best supportive care according to their stage and performance status. The median overall survival was 24 months, with stage I/II cancers showing better survival. We identified 233 TRG variant carriers. The comparative risk (subdistribution hazard ratio) for lung cancer in SRG patients versus TRG patients was 18.1 (95% CI 7.1-44.7). CONCLUSIONS: The high risk of lung cancer among SRG variant carriers suggests specific screening and diagnostic and therapeutic challenges. The benefit of regular computed tomography scan follow-up should be evaluated.

CSF2RB mutation-related hereditary pulmonary alveolar proteinosis: the "long and winding road" into adulthood.

Genetic analysis pre-lung transplantation diagnosed a case of hereditary pulmonary alveolar proteinosis (PAP) complicated by fibrosis in adulthood. The need for genetic testing in GM-CSF autoantibody negative and unclassifiable PAP is highlighted. https://bit.ly/3QcsYwM.

Pleuropulmonary Manifestations of Vacuoles, E1 Enzyme, X-Linked, Autoinflammatory, Somatic (VEXAS) Syndrome.

BACKGROUND: The vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a newly identified autoinflammatory disorder related to somatic UBA1 mutations. Up to 72% of patients may show lung involvement. RESEARCH QUESTION: What are the pleuropulmonary manifestations in VEXAS syndrome? STUDY DESIGN AND METHODS: One hundred fourteen patients were included in the French cohort of VEXAS syndrome between November 2020 and May 2021. Each patient included in the study who had an available chest CT scan was discussed in an adjudication multidisciplinary team and classified as showing potentially pleuropulmonary-specific involvement of VEXAS syndrome or others. RESULTS: Fifty-one patients had a CT scan available for review and 45 patients (39%) showed pleuropulmonary abnormalities on chest CT scan that were considered related to VEXAS syndrome after adjudication. Most patients were men (95%) with a median age 67.0 years at the onset of symptoms. Among these 45 patients, 44% reported dyspnea and 40% reported cough. All 45 patients showed lung opacities on chest CT scan (including ground-glass opacities [87%], consolidations [49%], reticulation [38%], and septal lines [51%]) and 53% of patients showed pleural effusion. Most patients showed improvement with prednisone, but usually required > 20 mg/d. The main clinical and biological features as well the median survival did not differ between the 45 patients with pleuropulmonary involvement and the rest of the cohort, suggesting that the prevalence of pleuropulmonary involvement might have been underdiagnosed in the rest of the cohort. INTERPRETATION: Pulmonary manifestations are frequent in VEXAS syndrome, but rarely are at the forefront. The initial outcome is favorable with prednisone and does not seem to lead to pulmonary fibrosis.

Anti-mutated citrullinated vimentin antibodies are increased in IPF patients.

INTRO: An increased prevalence of serum anti-MCV antibody is observed in the serum of patients with idiopathic pulmonary fibrosis (IPF) but the clinical relevance of these antibodies is unknown. METHODS: Patients from our center with a diagnosis of IPF according to the 2018 ATS/ERS/JRS/ALAT guidelines and at least one anti-MCV assay available were selected. All patients were part of the prospective cohort European IPF registry and selected between 03/2010 and 03/2018. We constituted two groups of patients according to the anti-MCV status at baseline to compare their characteristics at baseline and the evolution of lung function, survival and/or transplantation status. RESULTS: Anti-MCV data were available for 101 patients, of whom 86 had complete clinical data available. Twenty-nine (34 %) patients had a positive anti-MCV assay (MCV+), at a low level in most patients (29 UI/mL [IQR 25-40]), and 57 (66 %) patients a negative assay (MCV-). MCV+ patients were 20 men and 9 women, with a median age of 73 years [IQR 67-78]. MCV- patients were 49 men and 8 women with a median age of 72 years [IQR 64-77]. Sixty-two (75 %) patients were ex-smokers and 5 (6 %) were active smokers. Median cumulative tobacco smoke exposure was 22.5 (15.0-38.6) and was similar in both groups. Lung function test results and HRCT pattern distribution was similar in both groups at baseline. The median duration of follow-up was 3.5 years [IQR 2.1-5.0]. Lung function decline was similar in both groups. During the study period, 31 (36 %) patients died or have been transplanted with no difference in transplant-free survival status between the two groups. CONCLUSION: Low level anti-MCV autoimmunity was prevalent in IPF patients.

Acute worsening of native lung fibrosis after single lung transplantation for pulmonary fibrosis: two case reports.

BACKGROUND: In patients receiving single lung transplantation for idiopathic pulmonary fibrosis, worsening of fibrosis of the native lung is usually progressive over time, with no significant effects on gas exchange. CASE PRESENTATION: Here, we describe the cases of two Caucasian male recipients of single lung transplants for idiopathic pulmonary fibrosis, 65 and 62 years of age, who exhibited acute worsening of lung fibrosis after an episode of serious viral infection (cytomegalovirus primo-infection in one case and COVID-19 in the other). In both cases, along with opacification of the native lung over several days, the patients presented acute respiratory failure that required the use of high-flow nasal oxygen therapy. Eventually, hypoxemic respiratory failure resolved, but with rapid progression of fibrosis of the native lung. CONCLUSION: We conclude that acute worsening of fibrosis on the native lung secondary to a severe viral infection should be added to the list of potential complications developing on the native lung after single lung transplantation for idiopathic pulmonary fibrosis.

Interstitial lung diseases associated with mutations of poly(A)-specific ribonuclease: A multicentre retrospective study.

BACKGROUND AND OBJECTIVE: Poly(A)-specific ribonuclease (PARN) mutations have been associated with familial pulmonary fibrosis. This study aims to describe the phenotype of patients with interstitial lung disease (ILD) and heterozygous PARN mutations. METHODS: We performed a retrospective, observational, non-interventional study of patients with an ILD diagnosis and a pathogenic heterozygous PARN mutation followed up in a centre of the OrphaLung network. RESULTS: We included 31 patients (29 from 16 kindreds and two sporadic patients). The median age at ILD diagnosis was 59 years (range 54 to 63). In total, 23 (74%) patients had a smoking history and/or fibrogenic exposure. The pulmonary phenotypes were heterogenous, but the most frequent diagnosis was idiopathic pulmonary fibrosis (n = 12, 39%). Haematological abnormalities were identified in three patients and liver disease in two. In total, 21 patients received a specific treatment for ILD: steroids (n = 13), antifibrotic agents (n = 11), immunosuppressants (n = 5) and N-acetyl cysteine (n = 2). The median forced vital capacity decline for the whole sample was 256 ml/year (range -363 to -148). After a median follow-up of 32 months (range 18 to 66), 10 patients had died and six had undergone lung transplantation. The median transplantation-free survival was 54 months (95% CI 29 to ∞). Extra-pulmonary features were less frequent with PARN mutation than telomerase reverse transcriptase (TERT) or telomerase RNA component (TERC) mutation. CONCLUSION: IPF is common among individuals with PARN mutation, but other ILD subtypes may be observed.

Transthoracic lung biopsy for pulmonary nodules ≤20†mm in routine clinical care.

BACKGROUND: Computed tomography (CT) screening has improved lung cancer survival, yet increasingly detects small lung lesions. Thus, the number of transthoracic lung biopsies (TTLB) for small nodules is expected to rise significantly. The aim of the present study was to evaluate the diagnostic accuracy and safety of CT-guided TTLB for nodules ≤20 mm versus nodules >20 mm. STUDY DESIGN AND METHODS: Data for CT-guided TTLBs from 474 consecutive patients were prospectively collected over a 3-year period (198 lesions ≤20 mm and 276 lesions >20 mm) in a teaching hospital and analysed in terms of diagnostic performance and complications. RESULTS: There were more conclusive biopsies in the >20 mm lesion group (n=236, 85.5%) than in ≤20 mm lesion group (n=140, 70.7%; p<0.001). The overall accuracy, sensitivity, specificity and negative predictive value for diagnosing malignant lesions after first TTLB were 88.4%, 84%, 100% and 70.1%, respectively, for ≤20 mm lesions, and 94.2%, 93%, 100% and 74.6%, respectively, for >20 mm lesions. Pneumothorax requiring drainage was significantly more common for ≤20 mm lesions, compared to TTLB of larger lesions (9.6% versus 4.3%; p=0.02). Prolonged hospital stay due to pneumothorax occurred in 27 (17.4%) TTLBs of ≤20 mm lesions and 15 (7%) TTLBs of >20 mm lesions (p=0.002). There were no deaths. The only variable significantly associated with diagnostic failure in the ≤20 mm lesion group was the radiologist's experience. INTERPRETATION: TTLBs for lesions ≤20 mm were associated with slightly lower diagnostic performance, whereas the higher rate of major complications was still inferior to that extrapolated from United States insurance databases.

Cyclophosphamide added to glucocorticoids in acute exacerbation of idiopathic pulmonary fibrosis (EXAFIP): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: The use of cyclophosphamide in patients with acute exacerbation of idiopathic pulmonary fibrosis (IPF) is unknown. Our study was designed to evaluate the efficacy and safety of four cyclophosphamide pulses in addition to high-dose methylprednisolone in this population. METHODS: In this double-blind, placebo-controlled trial done in 35 departments across 31 hospitals in France, adult patients (≥18 years) with acute exacerbation of IPF and those with suspected acute exacerbation of IPF were randomly assigned in a 1:1 ratio using a web-based system to receive either intravenous pulses of cyclophosphamide (600 mg/m2) plus uromitexan as haemorrhagic cystitis prophylaxis (200 mg/m2) at the time of cyclophosphamide administration and then again, 4 h later, or placebo at days 0, 15, 30, and 60. Random assignment was stratified according to the severity of IPF and was block-balanced with variable block sizes of four or six patients. Patients receiving mechanical ventilation, with active infection, with active cancer, or who were registered on the lung transplant waiting list were excluded. All patients received standardised high-dose glucocorticoids. The investigators, patients, and the sponsor were masked to the treatment assignments. The primary endpoint was 3-month all-cause mortality, analysed by a χ2 test adhering to an intention-to-treat principle. The trial is now complete and registered with ClinicalTrials.gov, NCT02460588. FINDINGS: Between Jan 22, 2016, and July 19, 2018, 183 patients were assessed for eligibility, of whom 120 patients were randomly assigned and 119 patients (62 [52%] with severe IPF) received at least one dose of cyclophosphamide (n=60) or placebo (n=59), all of whom were included in the intention-to-treat analysis. The 3-month all-cause mortality was 45% (27/60) in patients given cyclophosphamide compared with 31% (18/59) in the placebo group (difference 14·5% [95% CI -3·1 to 31·6]; p=0·10). Similar results were found after adjustment by IPF severity (odds ratio [OR] 1·89 [95% CI 0·89-4·04]). The risk of death at 3 months, independent of the treatment received, was higher with severe than non-severe IPF (OR 2·62 [1·12-6·12]) and was lower with the use of antifibrotic therapy (OR 0·33 [0·13-0·82]). Adverse events were similar between groups by 6 months (25 [42%] in the cyclophosphamide group vs 30 [51%] in the placebo group) and their proportion, including infections, did not differ. Overall infection was the main adverse event and occurred in 20 (33%) of 60 patients in the cyclophosphamide group versus 21 (36%) of 59 patients in the placebo group. INTERPRETATION: In patients with acute exacerbation of IPF, adding intravenous cyclophosphamide pulses to glucocorticoids increased 3-month mortality. These findings provide evidence against the use of intravenous cyclophosphamide in such patients. FUNDING: Programme Hospitalier de Recherche Clinique of the French Ministry of Health (PHRC 2014-502), Roche Pharmaceuticals.

Clinical Impact of Surgical Lung Biopsy for Interstitial Lung Disease in a Reference Center.

BACKGROUND: Diagnosis of interstitial lung disease is based on the analysis of clinical, biological, radiological, and pathological findings during a multidisciplinary discussion (MDD). When a definitive diagnosis is not possible, guidelines recommend obtaining lung samples through surgical lung biopsy (SLB). We sought to determine morbidity, mortality, diagnostic yield, and therapeutic impact of SLB in the management of patients with interstitial lung disease. METHODS: We retrospectively analyzed morbidity, mortality, diagnostic yield, and therapeutic changes after SLB for interstitial lung disease performed electively from January 2015 to May 2019 in a reference center. Each case was reviewed during 2 MDDs, first without and then with the result of the SLB. RESULTS: The study group included 73 patients (56% male, age 66 [interquartile range (IQR), 57-70] years, forced vital capacity 79% [IQR, 69%-91%], diffusing capacity of the lungs for carbon monoxide 52% [IQR, 46%-63%]). Median postoperative hospital length of stay was 2 (IQR, 0-11) days. Thirteen (17%) patients experienced at least 1 complication, including pain at 1 month (n = 8) and residual pneumothorax (n = 6). No serious complication or postoperative death was noticed. After the first retrospective MDD, the working diagnosis was idiopathic nonspecific interstitial pneumonia in 20 (27%), idiopathic pulmonary fibrosis in 18 (25%), fibrotic hypersensitivity pneumonitis in 15 (21%), unclassifiable interstitial lung disease in 5 (7%), and other diagnosis in 15 (21%) patients. After SLB and second retrospective MDD, the final diagnosis was modified in 35 (48%) patients and led to therapeutic changes in 33 (45%) patients. CONCLUSIONS: SLB is associated with no serious complication or death and notably changes the diagnosis and treatment of interstitial lung disease.

Diagnosis Yield and Safety of Surgical Biopsy in Interstitial Lung Diseases: A Prospective Study.

BACKGROUND: Surgical lung biopsy is essential in the diagnostic algorithm of interstitial lung disease (ILD) of unknown cause. Safety concerns have been recently reiterated. This study prospectively assessed the yield of diagnosis and safety of video-assisted thoracoscopic surgical lung biopsy (VATS-LB) for ILD diagnosis. METHODS: This prospective study, conducted in 6 ILD-referral Paris hospitals, included 103 patients with ILD. VATS-LB was proposed after initial multidisciplinary discussion. A final diagnosis was made after the procedure, during a second multidisciplinary discussion. The main outcome was to determine the final diagnoses and their proportion after VATS-LB. Other outcomes were the percentage of change in diagnosis and treatment propositions after VATS-LB and adverse events during 3 months after the operation, postoperative pulmonary function, quality of life, and pain. RESULTS: A definite diagnosis was reached in 87 patients (84.4%), and 16 remained unclassifiable (15.6%). After VATS-LB, the hypothesized diagnosis changed in 65 patients (63.1%) and treatment changed in 41 patients (39.8%). One patient died of acute exacerbation. In-hospital complications were predicted by a shorter preoperative 6-minute walking test distance and by forced vital capacity lower than 77%. Postoperative quality of life was not modified at 3 months, whereas forced vital capacity decreased slightly. Postoperative neuropathic pain was revealed in 5% of patients at 1 month and in 2% at 3 months. CONCLUSIONS: VATS-LB dramatically changed preoperative hypothetical diagnoses and treatment in ILD of unknown cause, with good patient survival in ILD referral centers.

NKX2.1 (TTF1) germline mutation associated with pulmonary fibrosis and lung cancer.

Germline surfactant-associated genes mutations are associated with ILD and increased risk of lung cancer https://bit.ly/3CkkXgD.

MUC5B promoter variant rs35705950 and rheumatoid arthritis associated interstitial lung disease survival and progression.

BACKGROUND: The major risk factor for idiopathic pulmonary fibrosis (IPF), MUC5B rs35705950, was found to be associated with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Whilst the MUC5B rs35705950 T risk allele has been associated with better survival in IPF, its impact on RA-ILD prognosis remains to be determined. Our objective was to explore the influence of MUC5B rs35705950 on survival and progression in RA-ILD. METHODS: Through an international retrospective observational study, patients with RA-ILD were genotyped for the MUC5B rs35705950 variant and consecutive pulmonary function tests (PFTs) findings were collected. Longitudinal data up to a 10-year follow-up were considered and analyzed using mixed regression models. Proportional hazards and joint proportional hazards models were used to analyze the association of baseline and longitudinal variables with lung transplant-free survival. Significant progression of RA-ILD was defined as at least an absolute or relative 10% decline of forced vital capacity at 2 years from baseline. RESULTS: Out of 321 registered patients, 261 were included in the study: 139 women (53.3%), median age at RA-ILD diagnosis 65 years (interquartile range [IQR] 57 to 71), 151 ever smokers (59.2%). Median follow-up was 3.5 years (IQR 1.3 to 6.6). Mortality rate was 32% (95%CI 19 to 42) at 10 years. The MUC5B rs35705950 variant did not impact lung transplant-free survival (HR for the T risk allele carriers=1.26; 95%CI 0.61 to 2.62; P=0.53). Decline in pulmonary function at 2 years was not influenced by MUC5B rs35705950 (OR=0.95; 95%CI 0.44 to 2.05; P=0.89), irrespective of the HRCT pattern. CONCLUSION: In this study, the MUC5B rs35705950 promoter variant did not influence transplant- free survival or decline in pulmonary function in patients with RA-ILD.

Radiation dose reduction with the wide-volume scan mode for interstitial lung diseases.

OBJECTIVES: The wide-volume mode, available on wide-area detector row CTs, has the advantage of reducing exposure time and radiation dose. It is infrequently used for lung diseases. The purpose of this study is to compare image quality and radiation dose of wide-volume chest CT to those of standard helical CT in the setting of interstitial lung diseases. METHODS: Retrospective monocentric study including 50 consecutive patients referred for follow-up or screening of interstitial lung diseases, requiring prone scan, acquired with the wide-volume mode, in addition to the routine supine scan, acquired with the helical mode. The optimal collimation in wide-volume mode (320 × 0.5mm or 240 × 0.5mm) was chosen according to the length of the thorax. Wide-volume acquisitions were compared to helical acquisitions for radiation dose (CTDIvol, DLP) and image quality, including analysis of normal structures, lesions, overall image quality, and artifacts (Wilcoxon signed-rank test). RESULTS: Median CTDIvol and DLP with wide volumes (3.1 mGy and 94.6 mGy·cm) were significantly reduced (p < 0.0001) as compared to helical mode (3.7mGy and 122.1 mGy·cm), leading to a median 21% and 32% relative reduction of CTDIvol and DLP, respectively. Image noise and quality were not significantly different between the two modes. Misalignment artifact at the junction of two volumes was occasionally seen in the wide-volume scans and, when present, did not impair the diagnostic quality in the majority of cases. CONCLUSIONS: Wide-volume mode allows 32% radiation dose reduction compared to the standard helical mode and could be used routinely for diagnosis and follow-up of interstitial lung diseases. KEY POINTS: • Retrospective monocentric study showed that wide-volume scan mode reduces radiation dose by 32% in comparison to helical mode for chest CT in the setting of interstitial lung diseases. • Mild misalignment may be observed at the junction between volumes with the wide-volume mode, without decrease of image quality in the majority of cases and without impairing diagnostic quality. • Wide-volume mode could be used routinely for the diagnosis and follow-up of interstitial lung diseases.

A 29-Year-Old Man With an Osteolytic Rib Lesion.

CASE PRESENTATION: A 29-year-old man with no significant medical history presented to the ED with a 4-week history of chest pain. The pain was insidious, located on the right side of the chest, increased by deep breathing, and incompletely alleviated by acetaminophen. The patient had never smoked tobacco. He denied any recent fevers, chills, dyspnea, cough, night sweats, hemoptysis, or history of trauma but had lost at least 8 kg in the past 6 months. The patient was from Morocco and had lived in France for 1 year.

Functional assessment and phenotypic heterogeneity of SFTPA1 and SFTPA2 mutations in interstitial lung diseases and lung cancer.

INTRODUCTION: Interstitial lung diseases (ILDs) can be caused by mutations in the SFTPA1 and SFTPA2 genes, which encode the surfactant protein (SP) complex SP-A. Only 11 SFTPA1 or SFTPA2 mutations have so far been reported worldwide, of which five have been functionally assessed. In the framework of ILD molecular diagnosis, we identified 14 independent patients with pathogenic SFTPA1 or SFTPA2 mutations. The present study aimed to functionally assess the 11 different mutations identified and to accurately describe the disease phenotype of the patients and their affected relatives. METHODS: The consequences of the 11 SFTPA1 or SFTPA2 mutations were analysed both in vitro, by studying the production and secretion of the corresponding mutated proteins and ex vivo, by analysing SP-A expression in lung tissue samples. The associated disease phenotypes were documented. RESULTS: For the 11 identified mutations, protein production was preserved but secretion was abolished. The expression pattern of lung SP-A available in six patients was altered and the family history reported ILD and/or lung adenocarcinoma in 13 out of 14 families (93%). Among the 28 SFTPA1 or SFTPA2 mutation carriers, the mean age at ILD onset was 45 years (range 0.6-65 years) and 48% underwent lung transplantation (mean age 51 years). Seven carriers were asymptomatic. DISCUSSION: This study, which expands the molecular and clinical spectrum of SP-A disorders, shows that pathogenic SFTPA1 or SFTPA2 mutations share similar consequences for SP-A secretion in cell models and in lung tissue immunostaining, whereas they are associated with a highly variable phenotypic expression of disease, ranging from severe forms requiring lung transplantation to incomplete penetrance.

Impact of genetic factors on fibrosing interstitial lung diseases. Incidence and clinical presentation in adults.

At least 10% of patients with pulmonary fibrosis, whether idiopathic or secondary, present heritable pulmonary fibrosis suspected on familial aggregation of pulmonary fibrosis, specific syndromes or early age of diagnosis. Approximately 30% of those patients have an identified mutation mostly in telomere related genes (TRG) more rarely in surfactant homeostasis or other genes. TRG mutation may be associated with hematological and hepatic diseases that may worsen after lung transplantation requiring a specific care and adapted immunosuppression. Surfactant genes mutations are usually associated with ground-glass opacities and cysts on CT scan and may improve with steroids, hydroxychloroquine or azithromycin. Moreover relatives should benefit from a genetic analysis associated with a clinical evaluation according to the gene involved. Genetics of pulmonary fibrosis raise specific problems from diagnosis, therapy or genetic counseling varying from one gene to another.

Thoracic involvement of diffuse lymphangiomatosis successfully treated with sildenafil.

General lymphatic anomaly (GLA) is a very rare disorder, characterised by multifocal lymphatic malformations into various tissues that is due to congenital abnormalities of lymphatic development. No treatment has ever proved its efficiency.We report a 22-year-old man with recurrent bronchial casts due to thoracic involvement of GLA. After a 6-month treatment with sildenafil (20 mg three times a day), a phosphodiesterase 5 inhibitor, chest CT scan showed a complete regression of ground-glass opacities and lung function test results improved substantially and remained stable for 1 year. The treatment was well tolerated.This observation suggests that sildenafil may be a therapeutic approach to be tested in thoracic involvement of GLA.

Anti-parietal cell autoimmunity is associated with an accelerated decline of lung function in IPF patients.

BACKGROUND: Autoantibodies against lung epithelial antigens are often detected in patients with Idiopathic Pulmonary Fibrosis (IPF). Anti-Parietal Cell Antibodies (APCA) target the H+/K+ATPase (proton pump). APCA prevalence and lung H+/K+ATPase expression was never studied in IPF patients. METHODS: We retrospectively collected clinical, lung function and imaging data from APCA positive patients (APCA+IPF) and compared them with APCA negative IPF patients matched on the date of diagnostic assessment. H+/K+ATPase expression was assessed with immunohistochemistry and PCR. RESULTS: Among 138 IPF patients diagnosed between 2007 and 2014 and tested for APCA, 19 (13.7%) APCA+ patients were identified. APCA+IPF patients were 16 men and 3 women, mean age 71 years. The median titer of APCA was 1:160. A pernicious anemia was present in 5 patients and preceded the fibrosis in 3 cases. With a mean follow up of 31 months, 2 patients had an exacerbation and 7 patients died. As compared with 19 APCA- IPF patients, APCA+IPF patients had a less severe disease with better DLCO (57% vs 43% predicted), preserved PaO2 (85 ± 8 mmHg vs 74 ± 11 mmHg), a lower rate of honeycombing on HRCT (58% vs 89%), but they experienced an accelerated decline of FVC (difference 61.4 ml/year; p = .0002). The H+/K+ATPase was strongly expressed by hyperplastic alveolar epithelial cells in the fibrotic lung. CONCLUSION: Anti-parietal cell autoimmunity is detected in some IPF patients and is associated with an accelerated decline of lung function. Anti-parietal cell autoimmunity may promote lung fibrosis progression.