Deregulated immune cell recruitment orchestrated by c-MET impairs pulmonary inflammation and fibrosis.

BACKGROUND: Pulmonary fibrosis (PF) represents the pathologic end stage of several interstitial lung diseases (ILDs) associated with high morbidity and mortality rates. However, current treatments can only delay disease progression rather than provide a cure. The role of inflammation in PF progression is well-established, but new insights into immune regulation are fundamental for developing more efficient therapies. c-MET signaling has been implicated in the migratory capacity and effector functions of immune cells. Nevertheless, the role of this signaling pathway in the context of PF-associated lung diseases remains unexplored. METHODS: To determine the influence of c-MET in immune cells in the progression of pulmonary fibrosis, we used a conditional deletion of c-Met in immune cells. To induce pulmonary fibrosis mice were administered with bleomycin (BLM) intratracheally. Over the course of 21 days, mice were assessed for weight change, and after euthanasia at different timepoints, bronchoalveolar lavage fluid cells and lung tissue were assessed for inflammation and fibrosis. Furthermore, c-MET expression was assessed in cryobiopsy sections, bronchoalveolar lavage fluid cells samples and single cell RNA-sequencing dataset from human patients with distinct interstitial lung diseases. RESULTS: c-MET expression was induced in lung immune cells, specifically in T cells, interstitial macrophages, and neutrophils, during the inflammatory phase of BLM-induced PF mouse model. Deletion of c-Met in immune cells correlated with earlier weight recovery and improved survival of BLM-treated mice. Moreover, the deletion of c-Met in immune cells was associated with early recruitment of the immune cell populations, normally found to express c-MET, leading to a subsequent attenuation of the cytotoxic and proinflammatory environment. Consequently, the less extensive inflammatory response, possibly coupled with tissue repair, culminated in less exacerbated fibrotic lesions. Furthermore, c-MET expression was up-regulated in lung T cells from patients with fibrosing ILD, suggesting a potential involvement of c-MET in the development of fibrosing disease. CONCLUSIONS: These results highlight the critical contribution of c-MET signaling in immune cells to their enhanced uncontrolled recruitment and activation toward a proinflammatory and profibrotic phenotype, leading to the exacerbation of lung injury and consequent development of fibrosis.

Syncytiotrophoblast Markers Are Downregulated in Placentas from Idiopathic Stillbirths.

The trophoblast cells are responsible for the transfer of nutrients between the mother and the foetus and play a major role in placental endocrine function by producing and releasing large amounts of hormones and growth factors. Syncytiotrophoblast cells (STB), formed by the fusion of mononuclear cytotrophoblasts (CTB), constitute the interface between the foetus and the mother and are essential for all of these functions. We performed transcriptome analysis of human placental samples from two control groups-live births (LB), and stillbirths (SB) with a clinically recognised cause-and from our study group, idiopathic stillbirths (iSB). We identified 1172 DEGs in iSB, when comparing with the LB group; however, when we compared iSB with the SB group, only 15 and 12 genes were down- and upregulated in iSB, respectively. An assessment of these DEGs identified 15 commonly downregulated genes in iSB. Among these, several syncytiotrophoblast markers, like genes from the PSG and CSH families, as well as ALPP, KISS1, and CRH, were significantly downregulated in placental samples from iSB. The transcriptome analysis revealed underlying differences at a molecular level involving the syncytiotrophoblast. This suggests that defects in the syncytial layer may underlie unexplained stillbirths, therefore offering insights to improve clinical obstetrics practice.

The impact of nintedanib and pirfenidone on lung function and survival in patients with idiopathic pulmonary fibrosis in real-life setting.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic, fibrosing interstitial pneumonia of unknown cause that is associated with radiological and/or histological features of usual interstitial pneumonia (UIP). A mean survival of 2-5 years was reported previously to the advent of antifibrotics. According to clinical trials, nintedanib and pirfenidone induce a significant delay in functional decline, with a favorable impact on survival. METHODS: A real-life retrospective and longitudinal study was conducted to assess the efficacy and tolerability of antifibrotics in IPF patients, between January 2014 and December 2020. Two groups (under nintedanib or pirfenidone) were analyzed at diagnosis through their clinical features and radiological patterns. Lung function was assessed at diagnosis (time 0) and after 6, 12 and 24 months of treatment. We also compared this antifibrotic cohort with an older naïve antifibrotic cohort, mainly treated with immunosuppressive drugs and/or N- acetylcysteine. Survival was analyzed and prognostic features were also studied. Statistical analysis was performed with IBM® SPSS®. RESULTS: A cohort of 108 patients under antifibrotics (nintedanib n = 54; pirfenidone n = 54) was assessed. Lung function analysis showed an overall stabilization in FVC and DLCO mean predicted percentages at 6, 12 and 24 months of treatment. The mean decline in FVC and DLCO, at 12 months, was -40.95 ± 438.26 mL and -0.626 ± 1.31 mL/min/mmHg, respectively. However, during this period, 34.2% of the patients died mostly due to acute exacerbation associated with a poorer lung function at diagnosis. Mean survival in the naïve antifibrotic cohort was significantly lower than in the antifibrotic cohort (39.9 months versus 58.2 months; p < 0.005). Regarding lung function evolution and survival, we found no differences between definitive or probable UIP radiological patterns, both on patients under nintedanib and pirfenidone (p = 0.656). CONCLUSIONS: In this real-life observational study, the positive impact of antifibrotic therapy on the IPF clinical course and on survival was corroborated. Regarding efficacy, there was no difference between patients taking nintedanib or pirfenidone. The need for an early treatment was also demonstrated, since a worse outcome is clearly associated with lower lung volumes and lower diffusing capacity at diagnosis.

The Role of Ultrasonography in the Diagnosis and Decision Algorithm for the Management of Pneumothorax after Transbronchial Lung Cryobiopsy.

BACKGROUND: Pneumothorax is one of the main complications of transbronchial lung cryobiopsy (TBLC). Chest ultrasound (CUS) is a radiation-free alternative method for pneumothorax detection. OBJECTIVE: We tested CUS diagnostic accuracy for pneumothorax and assessed its role in the decision algorithm for pneumothorax management. Secondary objectives were to evaluate the post-procedure pneumothorax occurrence and risk factors. METHODS: Eligible patients underwent TBLC, followed by chest X-ray (CXR) evaluation 2 h after the procedure, as our standard protocol. Bedside CUS was performed within 30 min and 2 h after TBLC. Pneumothorax by CUS was defined by the absence of lung sliding and comet-tail artefacts and confirmed with the stratosphere sign on M-mode. Pneumothorax size was determined through lung point projection on CUS and interpleural distance on CXR and properly managed according to clinical status. RESULTS: Sixty-seven patients were included. Nineteen pneumothoraces were detected at 2 h after the procedure, of which 8 (42.1%) were already present at the first CUS evaluation. All CXR-detected pneumothoraces had a positive CUS detection. There were 3 discordant cases (κ = 0.88, 95% CI: 0.76-1.00, p < 0.001), which were detected by CUS but not by inspiration CXR. We calculated a specificity of 97.5% (95% CI: 86.8-99.9) and a sensitivity of 100% (95% CI: 87.2-100) for CUS. Pneumothorax rate was higher when biopsies were taken in 2 lobes and if histology had pleural representation. Final diagnosis was achieved in 79.1% of patients, with the most frequent diagnosis being hypersensitivity pneumonitis. Regarding patients with large-volume pneumothorax needing drainage, the rate of detection was similar between CUS and CRX. CONCLUSION: CUS can replace CXR in detecting the presence of pneumothorax after TBLC, and the lung point site can reliably indicate its size. This useful method optimizes time spent at the bronchology unit and allows immediate response in symptomatic patients, helping to choose optimal treatment strategies, while preventing ionizing radiation exposure.

Early Gestational Diagnosis of Lethal Skeletal Dysplasias: A 15 Year Retrospective Cohort Reviewing Concordance between Ultrasonographic, Genetic and Morphological Features.

Aim: We evaluated the diagnostic accuracy of ultrasound, postmortem and genetic studies in classifying skeletal dysplasias in the first vs second trimester of pregnancy. Methods: We retrospectively gathered data from a 15 year period of all the prenatal ultrasounds, autopsies, and available genetic studies on fetuses with skeletal dysplasias from our institution. Results: Five (23%) and 17 (77%) fetuses were diagnosed during the first and second trimester of pregnancy respectively. Only partial characterization was possible with ultrasound in the first trimester. Complete characterization was established in five cases (30%) in the second trimester with ultrasound alone. Pathology provided an additional diagnostic yield of 40% and 47% and genetics an additional 40% and 11% in the first and second trimesters respectively. Conclusion: Ultrasound is an effective screening but not a diagnostic tool. Complete characterizations of dysplasia increased from 22% by ultrasound alone to 86% with pathology and genetics.

Enlightening clinical and therapeutic heterogeneity in thoracic actinomycosis: A review in bronchiectasis and non-bronchiectasis patients.

Actinomycosis is a rare chronic infection triggered by species of Actinomyces. Although thoracic involvement represents about 15% of human actinomycosis, its true incidence may be underestimated, not only because of its challenging diagnosis, but also because it can be treated unintentionally with antibiotics for other diseases. In this sense, this work aims at providing an up-to-date literature review on thoracic actinomycoses, with particular emphasis on presentation, diagnostic and therapeutic approaches, also paving upcoming clinical interventions from findings obtained of a presentation of a case series. Data discussed here clearly denote the rarity, non-specificity and heterogeneity of clinical presentations of the disease, reinforcing the need for individualized therapeutic approaches.

Sporadic Creutzfeldt-Jakob disease presenting as epilepsia partialis continua and non-ictal nystagmus.

BACKGROUND AND PURPOSE: Creutzfeldt-Jakob disease (CJD) is a rare form of rapidly progressive neurodegenerative disorder. Seizures are uncommon in the early stage of CJD, increasing diagnostic difficulty. METHODS: An autopsy-proven case of CJD presenting initially as an epilepsia partialis continua is reported, in which the initial workup was unremarkable. Retrospectively, the presence of nystagmus, which proved to be non-epileptic, pointed to a cerebellar lesion before a diagnosis of clinically probable CJD was made. RESULTS: A 70-year-old man presented with a 3-week history of intermittent rhythmic jerking tremors in his left limbs, interfering with his gait. Examination showed left body clonic movements. Electroencephalography revealed an ictal right centroparietal pattern of focal status epilepticus. Video-oculography revealed right-beating nystagmus (mean slow phase velocity [SPV] 3.4º/s) in the dark and left-beating nystagmus (SPV 2.6º/s) in the light, left-beating nystagmus after head shaking (SPV 4º/s) and during mastoid vibration (SPV 11º/s) and mildly hypoactive horizontal head impulses. Search for occult malignancy, serologies, cerebrospinal fluid analyses, anti-onconeural antigen, auto-immune panel and brain magnetic resonance imaging were unrevealing. Rapid neurological decline was observed. Three weeks later, cerebrospinal fluid was positive for 14.3.3 protein, electroencephalography showed generalized periodic sharp wave complexes and brain magnetic resonance imaging revealed diffusion restriction and T2/fluid-attenuated inversion recovery hyperintensities in the cerebellum, basal ganglia, thalamus and cortex. He died 1 month later. Neuropathological study confirmed the diagnosis of CJD. CONCLUSION: This case highlights that CJD should be considered in the differential diagnosis of new onset epilepsia partialis continua and that neuro-ophthalmological examination can be helpful in pointing to early asymmetric cerebellar involvement.

Mother-reported pain experience between ages 7 and 10: A prospective study in a population-based birth cohort.

BACKGROUND: Trajectory studies suggest considerable stability of persistent or recurrent pain in adolescence. This points to the first decade of life as an important aetiologic window for shaping future pain, where the potential for prevention may be optimised. OBJECTIVES: We aimed to quantify changes in mother-reported pain experience in children between ages 7 and 10 and describe clusters of different pain experiences defined by complementary pain features. METHODS: We conducted a prospective study using data from 4036 Generation XXI birth cohort participants recruited in 2005-06. Pain history was reported by mothers at ages 7 and 10 using the Luebeck pain screening questionnaire. We tracked changes in six pain features over time using relative risks (RRs) and their 95% confidence intervals (95% CIs). Clusters were obtained using the k-medoids algorithm. RESULTS: The risk of severe pain at age 10 increased with increasing severity at age 7, with RRs ranging from 2.18 (95% CI 1.90, 2.50) for multisite to 4.43 (95% CI 3.19, 6.15) for high frequency pain at age 7. A majority of children (59.4%) had transient or no pain but two clusters included children with stable recurrent pain (n = 404, 10.2% of the sample). One of those (n = 177) was characterised by higher probabilities of multisite pain (74.6% and 66.7% at ages 7 and 10, respectively), with psychosocial triggers/contexts (59.3% and 61.0%) and daily-living restrictions (72.2% and 84.6%). Most children in that cluster (58.3%) also self-reported recent pain at age 10 and had more frequent family history of chronic pain (60.5%). CONCLUSIONS: All pain features assessed tracked with a positive gradient between ages 7 and 10, arguing for the significance of the first decade of life in the escalation of the pain experience. Multisite pain and psychosocial attributions appeared to be early markers of more adverse pain experiences.

Impact of Azathioprine use in chronic hypersensitivity pneumonitis patients.

INTRODUCTION: Systemic corticosteroids are widely used in chronic hypersensitivity pneumonitis (CHP); however, there is not much evidence to support their use, besides being associated with significant side effects. Azathioprine (AZA) use is common in CHP, although not prospectively tested in randomized controlled trials. Our objective was to evaluate the lung function trajectory of CHP patients after AZA initiation, as well as to assess the safety profile of this drug. METHODS: Retrospective analysis of patients initiated on AZA following a multidisciplinary team diagnosis of CHP. The longitudinal trajectory of lung function in the first 2 years of treatment was assessed. RESULTS: Thirty-five out of 62 patients (56.5%) remained on treatment after 2 years. AZA treatment was associated with a significant improvement in forced vital capacity (FVC) at 12 and 24 months (p = 0.015 and p < 0.001, respectively). A slight increase in total lung capacity (TLC) and 6-min walking test (6MWT) were also reported, although it did not reach statistical differences at the end of 2 years. No changes in diffusion capacity for carbon monoxide (DLCO) were observed. CONCLUSIONS: This is the first study identifying an improvement in lung function (FVC) of CHP patients on AZA treatment for 2 years. Prospective studies are needed to confirm these results and to more adequately select CHP patients who may benefit from AZA.

Diagnostic Yield of Computed Tomography-Guided Transthoracic Lung Biopsy in Diffuse Lung Diseases.

BACKGROUND: Accurate diagnosis is essential for successful management of diffuse lung disease (DLD). Histopathology may sometimes be necessary. Surgical lung biopsy, the gold standard, carries a risk of morbidity and mortality. Computed tomography (CT) guided transthoracic lung biopsy (CT-TLB) is a minimally invasive method for obtaining lung tissue. However, its diagnostic yield is unknown in DLD. OBJECTIVE: To assess the diagnostic yield of CT-TLB in DLD according to the predominant high-resolution CT (HRCT) patterns. METHODS: Between January 2009 and December 2016, we enrolled all consecutive adult patients with suspicion of DLD who underwent CT-guided transthoracic lung biopsy during the diagnostic work-up. All biopsies were performed by a senior interventional radiologist using CT fluoroscopy. RESULTS: The study included 169 patients (50.3% men) with a mean (±SD) age of 58.3 ± 14 years. Consolidation was the predominant HRCT pattern. A definitive or probable diagnosis was made in 66.3%. The most frequent diagnosis was organizing pneumonia (36.2%). Diagnostic yield was higher when the predominant HRCT pattern was consolidation or nodular. The most common complication was pneumothorax (17.8%); other complications included mild hemoptysis (7.7%), hemothorax (1.2%), and death (0.59%). No acute exacerbation of the underlying condition was observed. CONCLUSIONS: CT-TLB proved to be accurate and safe for the diagnosis of DLD. The overall diagnostic yield of the procedure was 66.3%. Given its low complication rates, CT-TLB can be an option in patients whose respiratory function is seriously impaired and in those with substantial comorbidities, where more invasive procedures cannot be performed for reasons of safety.

Pigmented hepatocellular adenoma with ß-catenin activation: case report and literature review.

 Hepatocellular adenomas (HCAs) are benign liver tumors recently characterized into 4 different types according to genetic, pathological and clinical features. The prognosis is not well established yet and malignant transformation has been recently associated with ß-catenin activation. We aimed to describe a case of a pigmented HCA with ß-catenin nuclear expression and inflammatory features and to review the cases of pigmented HCAs in the literature. We report a case of a young female patient without contraceptive use, with a liver tumor diagnosis. Liver biopsy revealed diffuse expression of ß-catenin and a partial hepatic resection was performed. The histologic analysis revealed a hepatocellular tumor composed of uniform trabeculae of hepatocytes and solid areas, the later with a significant amount of black pigment highlighted by Masson-Fontana stain. Immunohistochemistry showed co-expression of C-reactive protein and serum amyloid A in the tumor. Literature review revealed that pigmented HCAs, previously reported as dark adenomas, are rare tumors. In HCAs, the presence of ß-catenin activation should be searched for due to the higher risk of malignant transformation in hepatocarcinoma. We describe a pigmented HCA with ß-catenin nuclear expression and inflammatory features being the fifth case reported so far.

Primary diffuse large B-cell lymphoma of the heart: A rare case of heart failure.

A 65-year-old man with previous history of smoking, controlled HIV infection, treated hepatitis B infection, and type III cryoglobulinemia, was admitted due to right heart failure symptoms and significant weight loss. Despite being haemodynamically stable, he had periods of 1:1 conduction atrial flutter and presented with respiratory alkalosis and metabolic acidosis, as well as acute kidney and hepatic dysfunction, elevated D-dimer and cardiac markers. He underwent imaging with chest computed tomography and echocardiogram that confirmed pulmonary embolism and most notably revealed a significant sized cardiac mass causing almost complete obstruction of the right chambers, with no cleavage plane with the myocardial walls and tricuspid valve. Cardiac magnetic resonance was highly suggestive of malignancy. Cardiac surgery for mass excision and endomyocardial biopsy for diagnosis were considered, but the patient died with obstructive shock unresponsive to medical treatment. The autopsy revealed a primary unspecified diffuse large B-cell lymphoma.

Creutzfeldt-Jakob Disease: A Rare Case of Dementia.

Prion diseases are rare neurodegenerative diseases that have a rapid evolution. Creutzfeldt-Jakob disease (CJD) is the most common and its sporadic form the most frequent. Definitive diagnosis is only obtained through autopsy, and there are currently no available treatments. Here, we present a case of an 84-year-old woman presenting with resting tremor, abnormal gait, frequent falls, apraxia, visual hallucinations, and delirium. There were no signs of relevant metabolic, infectious, or nutritional alterations, and brain computed tomography (CT) scan and magnetic resonance imaging (MRI) had no significant findings. Two months later, the patient was completely immobile with mutism, seizures, and myoclonus. In the presence of a rapidly progressive dementia associated with myoclonus, it was hypothesized that the patient had CJD. The patient's clinical state deteriorated, she died, and autopsy confirmed sporadic CJD. The purpose of this case is to highlight a rare disease that can go undiagnosed because of low awareness and clinical suspicion and the importance of the differential diagnosis of dementia, a common disease at this age.

Recurrent Wells' syndrome associated with allergic asthma exacerbation.

Wells syndrome is an inflammatory eosinophilic dermatosis of unknown pathogenesis characterized by clinical polymorphism, a suggestive but nonspecific histopathologic traits, usually with a recurrent course and inconstant response to therapy. It seems to be an unspecific hypersensitivity reaction in response to various exogenous and endogenous stimuli, such as insect bites, infections, drug eruption or underlying internal disorders. We present a patient with allergic asthma and atopic dermatitis in whom a skin eruption developed in the sequence of allergic asthma exacerbation, which was clinically and histologically consistent with the diagnosis of eosinophilic cellulitis. The authors discuss the probability of a common pathogenesis and the role of IL-5. To our best knowledge this is the first pediatric case where this association is reported.

A 30-Year-Old Man With Cough, Dyspnea, and Upper Lobe Opacities.

CASE PRESENTATION: A 30-year-old man presents with dry cough and dyspnea on exertion (modified Medical Research Council dyspnea scale of 3), with progressive worsening over several months. He denies other respiratory or cardiac symptoms such as wheezing, hemoptysis, thoracalgia, palpitations, or leg swelling. He also denies constitutional symptoms, namely fever, sweating, anorexia, or weight loss. The patient is a current smoker (five cigarettes per day), with no other significant exposures, diseases, or medications. He had no personal history of respiratory diseases or TB. Relevant family history included an aunt with nonspecified interstitial lung disease and lung transplant.

Mortality risk prediction with ILD-GAP index in a fibrotic hypersensitivity pneumonitis cohort.

BACKGROUND: Fibrotic hypersensitivity pneumonitis (fHP) is associated with significant morbidity and mortality. Interstitial lung disease-gender-age-physiology (ILD-GAP) performance in fHP outside the initial cohort was never performed. AIM: To assess the ILD-GAP index's ability to predict mortality in a Portuguese cohort of patients with fHP and analyse whether other clinical variables add value. METHODS: Retrospective analysis of fHP cohort in two Portuguese ILD centres. The baseline ILD-GAP index was calculated. Survival was analysed in months; mortality was the primary outcome. Univariate and multivariate analyses to identify mortality risk factors were performed. RESULTS: A total of 141 patients were included. Fifty-three patients (37.6%) died during the follow-up. The usual interstitial pneumonia (UIP) pattern was found in 49.6%, and their survival was inferior to non-UIP [32 months (interquartile range, IQR = 19, 60) versus 52 months (IQR = 28, 98), p = 0.048]. Patients with an ILD-GAP index higher than three double their risk of mortality [hazard ratio (HR) = 6.48, 95% confidence interval (CI) = (3.03-13.96)] when compared with the patients with an index between 2 and 3 [HR = 3.04, 95% CI = (1.62-5.71)] adjusting for acute exacerbation history. Even though UIP patients had worse survival, it did not reach statistical significance when UIP pattern was added to this model. Acute exacerbation history was an independent risk factor for mortality; however, ILD-GAP still predicted mortality after adjusting for this factor. PaO2 and 6-minute walk test desaturation were not significant risk factors. CONCLUSION: ILD-GAP index is a good predictor for mortality in fHP, even after adjusting for other mortality risk factors.

Detection of SARS-CoV-2 infection in thyroid follicular cells from a COVID-19 autopsy series.

Objective: To understand whether thyroid cells can be directly infected by the SARS-CoV-2 virus and to establish a putative correlation with the expression of the host entry machinery: ACE-2, TMPRSS2, and furin. Methods: We assessed the presence of SARS-CoV-2 virus at the gene level by RT-PCR, viral RNA transcripts localization by in situ hybridization, and by detecting viral proteins by immunohistochemistry for the nucleocapsid and the spike proteins. Furthermore, we also described the immunoexpression of key host factors for virus entry in the COVID-19 thyroid samples. Results: We performed RT-PCR for SARS-CoV-2 in all autopsy specimens and detected viral genome positivity in 13 of 15 thyroid tissues and in a lung specimen. In 9 of the 14 positive samples, we were also able to confirm SARS-CoV-2 signal by in situ hybridization. Immunohistochemistry for the viral nucleocapsid and spike protein was also positive for ten and nine of the RT-PCR-positive cases, respectively, but revealed a lower sensitivity. We also described, for the first time in a COVID-19 series, the immunohistochemical expression of ACE-2, TMPRSS2, and furin in the thyroid. Conclusions: Our results obtained in thyroid specimens from deceased COVID-19 patients indicate that thyrocytes can be directly infected by SARS-CoV-2 since we detected the presence of SARS-CoV-2 genome in follicular cells. Nevertheless, we did not find a clear correlation between the presence of viral genome and the expression of the host factors for virus entry, namely ACE-2, TMPRSS2, and furin.

Predictive value of common genetic variants in idiopathic pulmonary fibrosis survival.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial pneumonia of unknown etiology. The role of genetic risk factors has been the focus of numerous studies probing for associations of genetic variants with IPF. We aimed to determine whether single-nucleotide polymorphisms (SNPs) of four candidate genes are associated with IPF susceptibility and survival in a Portuguese population. A retrospective case-control study was performed with 64 IPF patients and 74 healthy controls. Ten single-nucleotide variants residing in the MUC5B, TOLLIP, SERPINB1, and PLAU genes were analyzed. Single- and multi-locus analyses were performed to investigate the predictive potential of specific variants in IPF susceptibility and survival. Multifactor dimensionality reduction (MDR) was employed to uncover predictive multi-locus interactions underlying IPF susceptibility. The MUC5B rs35705950 SNP was significantly associated with IPF: T allele carriers were significantly more frequent among IPF patients (75.0% vs 20.3%, P < 1.0 × 10-6). Genotypic and allelic distributions of TOLLIP, PLAU, and SERPINB1 SNPs did not differ significantly between groups. However, the MUC5B-TOLLIP T-C-T-C haplotype, defined by the rs35705950-rs111521887-rs5743894-rs5743854 block, emerged as an independent protective factor in IPF survival (HR = 0.37, 95% CI 0.17-0.78, P = 0.009, after adjustment for FVC). No significant multi-locus interactions correlating with disease susceptibility were detected. MUC5B rs35705950 was linked to an increased risk for IPF, as reported for other populations, but not to disease survival. A haplotype incorporating SNPs of the MUC5B-TOLLIP locus at 11p15.5 seems to predict better survival and could prove useful for prognostic purposes and IPF patient stratification. KEY MESSAGES : The MUC5B rs35705950 minor allele is associated with IPF risk in the Portuguese. No predictive multi-locus interactions of IPF susceptibility were identified by MDR. A haplotype defined by MUC5B and TOLLIP SNPs is a protective factor in IPF survival. The haplotype may be used as a prognostic tool for IPF patient stratification.