IPF: New insight in diagnosis and prognosis

Air pollution and hospitalization of patients with idiopathic pulmonary fibrosis in Beijing: a time-series study

Background

A small number of studies suggested that air pollution was associated with idiopathic pulmonary fibrosis (IPF) exacerbation, incidence and mortality. However, no studies to date were conducted in regions where air pollution is substantial. We aimed to investigate whether there are associations between acute increases in air pollution and hospitalization of patients with a confirmed primary diagnosis of IPF in Beijing.

Methods

Daily count of IPF hospitalizations (International Classification of Disease-10th Revision, J84.1) was obtained from an administrative database for 2013–2017 while daily city-wide average concentrations of PM₁₀, PM_2.5, NO₂, Ozone, SO₂ were obtained from 35 municipal monitoring stations for the same period. The association between daily IPF hospitalization and average concentration of each pollutant was analyzed with a generalized additive model estimating Poisson distribution.

Results

Daily 24-h mean PM_2.5 concentration during 2013–2017 was 76.7 μg/m³. The relative risk (RR) of IPF hospitalization per interquartile range (IQR) higher (72 μg/m³) in PM_2.5 was 1.049 (95% CI 1.024–1.074) and 1.031 (95% CI 1.007–1.056) for lag0 and moving averages 0–1 days respectively. No significant associations were observed for other lags. Statistically significant positive associations were also observed at lag0 with SO₂, Ozone and NO₂ (in men only). Positive associations were seen at moving averages 0–30 days for PM₁₀ (RR per 86 μg/m³: 1.021, 95% CI 0.994–1.049), NO₂ (RR per 30 μg/m³: 1.029, 95% CI 0.999–1.060), and SO₂ (RR per 15 μg/m³: 1.060 (95% CI 1.025–1.097), but not with PM_2.5 or Ozone.

Conclusions

Despite improvement in air quality since the implementation of clean air policy in 2013, acute exposure to higher levels of air pollution is significantly associated with IPF hospitalization in Beijing. Air quality policy should be continuously enforced to protect vulnerable IPF populations as well as the general public.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01998-8.

Pathological Roles and Clinical Usefulness of Periostin in Type 2 Inflammation and Pulmonary Fibrosis

Periostin is known to be a useful biomarker for various diseases. In this article, we focus on allergic diseases and pulmonary fibrosis, for which we and others are now developing detection systems for periostin as a biomarker. Biomarker-based precision medicine in the management of type 2 inflammation and fibrotic diseases since heterogeneity is of utmost importance. Periostin expression is induced by type 2 cytokines (interleukin-4/-13) or transforming growth factor-β, and plays a vital role in the pathogenesis of allergic inflammation or interstitial lung disease, respectively, andits serum levels are correlated disease severity, prognosis and responsiveness to the treatment. We first summarise the importance of type 2 biomarker and then describe the pathological role of periostin in the development and progression of type 2 allergic inflammation and pulmonary fibrosis. In addition, then, we summarise the recent development of assay methods for periostin detection, and analyse the diseases in which periostin concentration is elevated in serum and local biological fluids and its usefulness as a biomarker. Furthermore, we describe recent findings of periostin as a biomarker in the use of biologics or anti-fibrotic therapy. Finally, we describe the factors that influence the change in periostin concentration under the healthy conditions.

Study of cognitive functions in major idiopathic interstitial pneumonias

Background

Cognitive dysfunction in idiopathic interstitial pneumonia (IIP) is an important clinical co-morbidity that is associated with impaired lung function. The aim of the work is to assess cognitive function in major IIP and to find out the relation between cognitive dysfunction and the oxygenation parameters.

Results

Fifty individuals were involved in the study; 30 patients with major IIP and 20 healthy individuals. Patients with IIP had significantly lower mini mental state examination (MMSE) score compared to the control group (P < 0.001). Wechsler Deterioration Index (WDI) revealed that 33.3% (n = 10) of the patients with IIP had sure cognitive impairment and 26.6% (n = 8) had ongoing cognitive deterioration. Patients with idiopathic pulmonary fibrosis (IPF) had lower cognitive function than other IIP.

Conclusion

There is an impairment of cognitive function in patients with major IIP, particularly in IPF, as measured by WDI and MMSE. Further large studies are needed to assess the possible predictors of cognitive impairment and their effects on the patients’ outcome.

Epidemiology of idiopathic pulmonary fibrosis: a population-based study in primary care

Idiopathic pulmonary fibrosis (IPF) is a chronic disease with unknown etiology and poor prognosis. Little is known about the epidemiology of this disease; most of the studies are limited by small and restricted cohort studies. We aim to investigate the epidemiology of IPF in the Italian primary care setting using the Health Search Database (HSD) between January 2002 and June 2017. In an attempt to define cases of IPF we adopted iterative combinations of International Classification of Diseases Ninth Revision (ICD-9-CM) and other clinical investigations according to three different operational Algorithms. Incidence and prevalence rate, according to the three Algorithms defining IPF, were calculated and the association with candidate determinants [sex, age, gastro-esophageal reflux (GERD) and smoking status] was evaluated. We identified 1,104,307 eligible patients. The prevalence rate of IPF varies between 2.6 to 24.3 per 100.000 person-year, using algorithm 1 and from 0.8 to 7 using algorithm 3. The incidence rate of IPF varies between 1.25 and 3.77 per 100.000 person-years, using algorithm 1 and from 0.10 to 1.61 using algorithm 3. The mean adjusted incidence rate ratio of IPF, using algorithm 1, is 2.33 (95% CI 2.11-2.57) per 100.000 person-years. Over the study years, the trend of prevalence was statistically significantly increasing while the incidence rate started to increase in the last 3 years. The analyses on candidate determinants showed that patients aged 61 years or older, those suffering from GERD, and former smokers were statistically significantly at greater risk of incurring IPF. To our knowledge, this is one of the first European IPF epidemiological studies conducted in primary care. The increase of the incidence rates is likely due to a growing awareness for IPF among General Practitioners, while the increase of prevalence rates may be due to an increase of survival, a result of recent advances in the diagnosis, management and therapies for the disease.

Validation of 4-meter-gait-speed test and 5-repetitions-sit-to-stand test in patients with pulmonary fibrosis: a clinimetric validation study

Background and objective: Patients with pulmonary fibrosis (PF) have a clear exercise intolerance. The 4-meter-gait-speed (4MGS) test and the 5-repetitions-sit-to-stand (5STS) test are easy, inexpensive and reliable measures of functional performance. Both tests have been validated in healthy adults and patients with chronic obstructive pulmonary disease. 4MGS test and 5STS test have not been studied in patients with PF. Methods: In this cross-sectional clinimetric validation study 51 PF patients conducted in random order the 4MGS test, 5STS test and the 6-min walk test (6MWT) on a single day. Additionally, body weight, height, lean body mass, health-related quality of life, disease severity, handgrip strength, dyspnoea and leg fatigue were assessed. The setting was a tertiary referral center for Interstitial Lung Diseases. Results: Patients had a diagnosis of idiopathic pulmonary fibrosis (IPF, 37%), PF other than IPF (47%), or unclassified (16%). Patients walked 453±111m in six minutes. Moreover, it took the patients 2.0±0.5s to walk 4 m, and 12.0±3.8s for the 5STS test. The 4MGS test (r = 0.77; p<0.01) and the 5STS test (r = -0.41; p<0.01) correlated significantly with the distance walked in 6MWT. Indeed, 4MGS combined with handgrip strength and Medical Research Council dyspnoea grade could explain 75% of the variance in 6MWD. Conclusions: 4-meter-gait-speed and 5-repetitions sit-to-stand are significantly and independently correlated with the 6-minute walk distance in patients with pulmonary fibrosis. Indeed, 4-meter-gait-speed test may serve as a simple initial field test to assess exercise performance in patients with pulmonary fibrosis. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 317-326)

A Real-Life Multicenter National Study on Nintedanib in Severe Idiopathic Pulmonary Fibrosis

BACKGROUND

Two therapeutic options are currently available for patients with mild-to-moderate idiopathic pulmonary fibrosis (IPF): pirfenidone and nintedanib. To date, there is still insufficient data on the efficacy of these 2 agents in patients with more severe disease.

OBJECTIVES

This national, multicenter, retrospective real-life study was intended to determine the impact of nintedanib on the treatment of patients with severe IPF.

METHODS

All patients included had severe IPF and had to have at least 6 months of follow-up before and at least 6 months of follow-up after starting nintedanib. The aim of the study was to compare the decline in lung function before and after treatment. Patient survival after 6 months of therapy with nintedanib was assessed.

RESULTS

Forty-one patients with a forced vital capacity (FVC) ≤50% and/or a diffusing capacity of the lung for carbon monoxide (DLCO) ≤35% predicted at the start of nintedanib treatment were enrolled. At the 6-month follow-up, the decline of DLCO (both absolute and % predicted) was significantly reduced compared to the pretreatment period (absolute DLCO at the -6-month, T0, and +6-month time points (5.48, 4.50, and 5.03 mmol/min/kPa, respectively, p = 0.03; DLCO% predicted was 32.73, 26.54, and 29.23%, respectively, p = 0.04). No significant beneficial effect was observed in the other functional parameters analyzed. The 1-year survival in this population was 79%, calculated from month 6 of therapy with nintedanib.

CONCLUSIONS

This nationwide multicenter experience in patients with severe IPF shows that nintedanib slows down the rate of decline of absolute and % predicted DLCO but does not have significant impact on FVC or other lung parameters.

The association between air pollution and the incidence of idiopathic pulmonary fibrosis in Northern Italy

Acute exacerbations and worsening of idiopathic pulmonary fibrosis (IPF) have been associated with exposure to ozone (O3), nitrogen dioxide (NO2) and particulate matter, but chronic exposure to air pollution might also affect the incidence of IPF. We investigated the association between chronic exposure to NO2, O3and particulate matter with an aerodynamic diameter <10 μm (PM10) and IPF incidence in Northern Italy between 2005 and 2010.

Daily predictions of PM10concentrations were obtained from spatiotemporal models, and NO2and O3hourly concentrations from fixed monitoring stations. We identified areas with homogenous exposure to each pollutant. We built negative binomial models to assess the association between area-specific IPF incidence rate, estimated through administrative databases, and average overall and seasonal PM10, NO2, and 8-hour maximum O3concentrations.

Using unadjusted models, an increment of 10 µg·m−3in NO2concentration was associated with an increase between 7.93% (95% CI 0.36–16.08%) and 8.41% (95% CI −0.23–17.80%) in IPF incidence rate, depending on the season. After adjustment for potential confounders, estimated effects were similar in magnitude, but with larger confidence intervals.

Although confirmatory studies are needed, our results trace a potential association between exposure to traffic pollution and the development of IPF.

Recent advances in managing idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a rare pulmonary disease with a poor prognosis and severe impact on quality of life. Early diagnosis is still challenging and important delays are registered before final diagnosis can be reached. Available tools fail to predict the variable course of the disease and to evaluate response to antifibrotic drugs. Despite the recent approval of pirfenidone and nintedanib, significant challenges remain to improve prognosis and quality of life. It is hoped that the new insights gained in pathobiology in the last few years will lead to further advances in the diagnosis and management of IPF. Currently, early diagnosis and prompt initiation of treatments reducing lung function loss offer the best hope for improved outcomes. This article aims at providing an overview of recent advances in managing patients with IPF and has a particular focus on how to reach a diagnosis, manage comorbidities and lung transplantation, care for the non-pharmacological needs of patients, and address palliative care.

Six-Minute Walk Test as a Predictor of Diagnosis, Disease Severity, and Clinical Outcomes in Scleroderma-Associated Pulmonary Hypertension: The DIBOSA Study

BACKGROUND

Pulmonary hypertension (PH) is a common complication of scleroderma (SSc) and is a leading cause of morbidity and mortality.

OBJECTIVES

To explore the utility of the 6MWT in the prediction of SSc-PH and to assess its prognostic implications.

METHODS

A retrospective review of SSc patients from 2003 to 2013, with 6MWT and echocardiogram (n = 286), was conducted. Presence of PH was defined by right heart catheterization. Patients were randomized into development and validation cohorts. Using regression techniques, we developed a scoring system to predict the presence of SSc-PH and tested it in our validation cohort. Trends of mortality and disease severity were studied for incremental scores.

RESULTS

The DIBOSA scoring system includes DIstance walked in 6 min, BOrg dyspnea index, and SAturation of oxygen at 6 min. The DIBOSA score in the development cohort ranged from 0 to 3, resulting in an area of 0.858 (P < 0.0001) under the ROC curve. A score of 0 had a NPV of 100% and a score of 3 had a PPV of 86.58%. The validation cohort had an area under the ROC curve of 0.842. The DIBOSA score correlated with both pulmonary artery pressures and mortality. The 3-year survival rates for DIBOSA scores of 0, 1, 2, and 3 were 100, 100, 87.67, and 66.67%, respectively (HR = 3.92, P < 0.0001).

CONCLUSIONS

DIBOSA score is a sensitive tool for the prediction of SSc-PH. The DIBOSA score is a direct predictor of mortality in SSc-PH and strongly correlates with pulmonary pressures. 6MWT can be used to predict clinical outcomes in SSc-PH.

Predicting survival of patients with idiopathic pulmonary fibrosis using GAP score: a nationwide cohort study

Background

The clinical course of idiopathic pulmonary fibrosis (IPF) varies widely. Although the GAP model is useful for predicting mortality, survivals have not yet been validated for each GAP score. We aimed to elucidate how prognosis is related to GAP score and GAP stage in IPF patients.

Methods

The Korean Interstitial Lung Disease Study Group conducted a national survey to evaluate various characteristics in IPF patients from 2003 to 2007. Patients were diagnosed according to the 2002 criteria of the ATS/ERS. We enrolled 1,685 patients with IPF; 1,262 had undergone DL_CO measurement. Patients were stratified based on GAP score (0–7): GAP score Group 0 (n = 26), Group 1 (n = 150), Group 2 (n = 208), Group 3 (n = 376), Group 4 (n = 317), Group 5 (n = 138), Group 6 (n = 39), and Group 7 (n = 8).

Results

Higher GAP score and GAP stage were associated with a poorer prognosis (p < 0.001, respectively). Survival time in Group 3 was lower than those in Groups 1 and 2 (p = 0.043 and p = 0.039, respectively), and higher than those in groups 4, 5, and 6 (p = 0.043, p = 0.032, and p = 0.003, respectively). Gender, age, and DL_CO (%) differed significantly between Groups 2 and 3. All four variables in the GAP model differed significantly between Groups 3 and 4.

Conclusion

The GAP system showed significant predictive ability for mortality in IPF patients. However, prognosis in IPF patients with a GAP score of 3 were significantly different from those in the other stage I groups and stage II groups of Asian patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-016-0454-0) contains supplementary material, which is available to authorized users.

Long-acting muscarinic antagonists

Chronic obstructive pulmonary disease (COPD) is a major cause of death and disability worldwide. Inhaled bronchodilators are the mainstay of COPD pharmacological treatment. Long-acting muscarinic antagonists (LAMAs) are a major class of inhaled bronchodilators. Some LAMA/device systems with different characteristics and dosing schedules are currently approved for maintenance therapy of COPD and a range of other products are being developed. They improve lung function and patient-reported outcomes and reduce acute bronchial exacerbations with good safety. LAMAs are used either alone or associated with long-acting β₂-agonists, eventually in fixed dose combinations. Long-acting β₂-agonist/LAMA combinations assure additional benefits over the individual components alone. The reader will obtain a view of the safety and efficacy of the different LAMA/device systems in COPD patients.

Epidemiology of Idiopathic Pulmonary Fibrosis in Northern Italy

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is the most common and severe form of idiopathic interstitial pneumonia. Despite its clinical relevance, few studies have examined the epidemiology of IPF and temporal variation in disease incidence and prevalence. Aim of the study was to investigate the prevalence, incidence and trends of IPF in Lombardy, a region with nearly 10 million inhabitants, during 2005-2010.

METHODS

For the identification of IPF patients, we used healthcare administrative databases of Lombardy Healthcare System and adopted three algorithms: generic, broad and narrow case definition (GCD, BCD, NCD). IPF cases were identified according to diagnoses reported in inpatient and outpatient claims occurred during 2000-2010. We estimated age- and sex-adjusted annual prevalence and incidence rates from 2005 to 2010, thus allowing for a 5-year washout period.

RESULTS

The mean annual incidence rate was estimated at 2.3 and 5.3 per 100,000 person-years using NCD and GCD, respectively. IPF incidence was higher among males, and increased with age. Trend remained stable over the years. The estimated annual prevalence rate was 35.5, 22.4, and 12.6 per 100,000 person-years using GCD, BCD and NCD, respectively, and increased with age. Moreover, we observed a positive trend over the years. Using BCD and NCD, prevalence was higher among males.

CONCLUSIONS

The results of this study, which is one of the largest population-based survey ever conducted according to strict criteria, indicated that prevalence of IPF increased across the years while incidence remained stable, thus suggesting that survival with IPF has improved.

Non-invasive Imaging of Idiopathic Pulmonary Fibrosis Using Cathepsin Protease Probes

Idiopathic pulmonary fibrosis (IPF) is a lethal, chronic, progressive disease characterized by formation of scar tissue within the lungs. Because it is a disease of unknown etiology, it is difficult to diagnose, to predict disease course and to devise treatment strategies. Recent evidence suggests that activated macrophages play key roles in the pathology of IPF. Therefore, imaging probes that specifically recognize these pools of activated immune cells could provide valuable information about how these cells contribute to the pathobiology of the disease. Here we demonstrate that cysteine cathepsin-targeted imaging probes can be used to monitor the contribution of macrophages to fibrotic disease progression in the bleomycin-induced murine model of pulmonary fibrosis. Furthermore, we show that the probes highlight regions of macrophage involvement in fibrosis in human biopsy tissues from IPF patients. Finally, we present first-in-human results demonstrating non-invasive imaging of active cathepsins in fibrotic lesions of patients with IPF. Together, our findings validate small molecule cysteine cathepsin probes for clinical PET imaging and suggest that they have the potential to be used to generate mechanistically-informative molecular information regarding cellular drivers of IPF disease severity and progression.

Non-invasive Imaging of Idiopathic Pulmonary Fibrosis Using Cathepsin Protease Probes

Idiopathic pulmonary fibrosis (IPF) is a lethal, chronic, progressive disease characterized by formation of scar tissue within the lungs. Because it is a disease of unknown etiology, it is difficult to diagnose, to predict disease course and to devise treatment strategies. Recent evidence suggests that activated macrophages play key roles in the pathology of IPF. Therefore, imaging probes that specifically recognize these pools of activated immune cells could provide valuable information about how these cells contribute to the pathobiology of the disease. Here we demonstrate that cysteine cathepsin-targeted imaging probes can be used to monitor the contribution of macrophages to fibrotic disease progression in the bleomycin-induced murine model of pulmonary fibrosis. Furthermore, we show that the probes highlight regions of macrophage involvement in fibrosis in human biopsy tissues from IPF patients. Finally, we present first-in-human results demonstrating non-invasive imaging of active cathepsins in fibrotic lesions of patients with IPF. Together, our findings validate small molecule cysteine cathepsin probes for clinical PET imaging and suggest that they have the potential to be used to generate mechanistically-informative molecular information regarding cellular drivers of IPF disease severity and progression.

Serum metalloproteinases 1 and 7 in the diagnosis of idiopathic pulmonary fibrosis and other interstitial pneumonias

INTRODUCTION

Accurate diagnosis of idiopathic pulmonary fibrosis (IPF) has important therapeutic and prognostic implications and would be greatly aided by reliable diagnostic biomarkers as IPF has sometimes overlapping features with other interstitial lung diseases (ILD).

OBJECTIVES

To explore the value of serum metalloproteinases (MMP) 1 and 7 levels in the differential diagnosis of IPF with other ILD.

METHODS

MMP-1/7 serum levels were measured using Luminex xMAP technology in 139 patients- 47 IPF, 36 non-IPF Usual Interstitial Pneumonia (UIP), 14 idiopathic Nonspecific Interstitial Pneumonia (iNSIP), 29 secondary NSIP (secNSIP), 13 stage IV sarcoidosis- and 20 healthy controls, and compared using the Mann-Whitney U test.

RESULTS

MMP-1 was significantly higher in IPF than non-IPF UIP (P = .042) and sarcoidosis (P = .027). MMP-7 was significantly higher in IPF than controls (P < .001), non-IPF UIP (P = .003), secNSIP (P < .001), and sarcoidosis (P < .001). The Area Under the Curve for IPF versus other ILD was 0.63 (95%CI, 0.53-0.73) for MMP-1, 0.73 (95%CI, 0.65-0.81) for MMP-7, and 0.74 (95%CI, 0.66-0.82) for MMP-1/MMP-7 combined. Sensitivity and specificity for MMP-7 cutoff = 3.91 ng/mL was 72.3% and 66.3%, respectively, Positive Predictive Values = 52.3% and Negative Predictive Values = 82.4%.

CONCLUSIONS

MMP-1 and particularly MMP-7 serum levels were significantly higher in IPF than in non-IPF UIP, the main entity in differential diagnosis. The value of these biomarkers as additional tools in a multidisciplinary approach to IPF diagnosis needs to be considered and further explored.

Idiopathic pulmonary fibrosis: diagnosis and prognostic evaluation

Idiopathic pulmonary fibrosis (IPF) is the most common type of idiopathic interstitial pneumonia and has a dismal prognosis. Median age at IPF onset is 60-70 years and it is mainly related to cigarette smoke exposure. Its clinical profile is heterogeneous and different clinical phenotypes are now better defined: familial IPF, slow and rapid progressors, combined pulmonary fibrosis and emphysema, anti-neutrophil cytoplasmic antibodies/microscopic polyangiitis and IPF, and IPF associated with lung cancer. Acute exacerbation associated with rapid functional decline is an event that does not happen infrequently and affects survival. Diagnosis requires a typical usual interstitial pneumonia (UIP) pattern on computed tomography in the appropriate clinical setting or morphological confirmation of the UIP pattern when imaging findings are not characteristic enough. Surgical lung biopsy is the gold standard to obtain valuable information for histological analysis. However, less invasive procedures (transbronchial lung biopsy or even improved transbronchial lung biopsy by cryoprobes) are now under consideration. Prognostic indicators are mainly derived by pulmonary function tests. Recently, staging systems have been proposed.

The clinical assessment of protease-activated receptor-2 expression in inflammatory cells from peripheral blood and bronchoalveolar lavage fluid in idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a lethal pulmonary fibrotic disease. In general, the exaggerated activation of the coagulation cascade has been observed during initiation or maintenance of the fibrotic disease. In our recent study, immunohistochemical expression of protease-activated receptor-2 (PAR-2), which plays a key role in coagulation cascade, was observed in surgical specimen of IPF patients, and associated with poor clinical outcome. The aim of this study was to evaluate the overexpression of PAR-2 in inflammatory cells from peripheral blood and bronchoalveolar lavage fluid in IPF patients.

Methods

From May 2011 to March 2012, IPF patients and controls were enrolled in Seoul National University Hospital. Peripheral blood and bronchoalveolar lavage fluid were collected for analysis of PAR-2 expression. Flow cytometry and reverse transcription polymerase chain reaction were used for PAR-2 receptor and mRNA assessment.

Results

Twelve IPF patients and 14 controls were included in this study. Among them, flow cytometry analysis was conducted from 26 peripheral blood (patient group, 11; control group, 13) and 7 bronchoalveolar lavage fluid (patient group, 5; control group, 2). The expression of PAR-2 receptor was not different between patient and control groups (p=0.074). Among all 24 population, PAR-2 mRNA assessment was performed in 19 persons (patient group, 10; control group, 9). The mRNA expression of PAR-2 was not significant different (p=0.633).

Conclusion

In IPF patients, PAR-2 receptor and mRNA expression were not different from control group.

Clinical implication of protease-activated receptor-2 in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a lethal pulmonary disease which is characterized by progressive fibrosis. In general, the exaggerated activation of the coagulation cascade has been observed during initiation or maintenance of the fibrotic disease. In a recent study, protease-activated receptor (PAR)-2, which plays a key role in coagulation cascade, was up-regulated in IPF patients, however, its clinical implications have not been understood. The objective of the present study was to evaluate the clinical significance of PAR-2 expression in the alveolar epithelial cells of IPF patients. PAR-2 expression was evaluated by immunohistochemical method in formalin-fixed and paraffin-embedded tissues of surgical lung biopsies from patients with IPF. Fibrosis scores from hematoxylin and eosin-stained lung sections and honeycombing scores in chest CT were calculated. Medical records were retrospectively reviewed and the correlation between the expression of PAR-2 and clinical profiles were assessed. Among thirty-three IPF patients, PAR-2 expression was observed in 25 (75.8%). The lymphocyte counts in peripheral blood (2317 vs. 1753, p = 0.044) and honeycombing scores in chest CT (4.0 vs. 3.0 p = 0.046) were higher in PAR-2 positive group compared with PAR-2 negative group. During a follow-up duration of median 40.3 months, 7 (21.2%) patients died and they were all included in the PAR-2 positive group (p = 0.113). We conclude that PAR-2 is expressed in the alveolar epithelial cells of a substantial number of IPF patients, and the expression of PAR-2 significantly correlates with the extent of honeycombing shown in chest CT.

Sry, more than testis determination?

The Sry locus on the mammalian Y chromosome is the developmental switch responsible for testis determination. Inconsistent with this important function, the Sry locus is transcribed in adult males at times and in tissues not involved with testis determination. Sry is expressed in multiple tissues of the peripheral and central nervous system. Sry is derived from Sox3 and is similar to other SOXB family loci. The SOXB loci are responsible for nervous system development. Sry has been demonstrated to modulate the catecholamine pathway, so it should have functional consequences in the central and peripheral nervous system. The nervous system expression and potential function are consistent with Sry as a SOXB family member. In mammals, Sox3 is X-linked and undergoes dosage compensation in females. The expression of Sry in adult males allows for a type of sexual differentiation independent of circulating gonadal hormones. A quantitative difference in Sox3 plus Sry expression in males vs. females could drive changes in the transcriptome of these cells, differentiating male and female cells. Sry expression and its transcriptional effects should be considered when investigating sexual dimorphic phenotypes.