Serum S1P level in interstitial lung disease (ILD) is a potential biomarker reflecting the severity of pulmonary function.

BACKGROUND: sphingosine-1-phosphate (S1P), a naturally occurring sphingolipid, has been involved in pulmonary interstitial remodeling signaling. However, no study has examined its clinical merits for interstitial lung disease (ILD). This study aimed to investigate the serum level of S1P in ILD patients and its clinical correlation with the severity of disease in the two main types of ILDs: the IPF and the CTD-ILD patients. METHODS: This retrospective observational pilot study included 67 ILD patients and 26 healthy controls. These patients were stratified into the IPF group (35) and the CTD-ILD group (32). The severity of ILD was evaluated through pulmonary function indicators and the length of hospital stay. RESULTS: Serum S1P level was statistically higher in ILD patients than in health control (p = 0.002), while the Serum S1P levels in CTD-ILD and IPF patients were comparable. Serum S1P level further showed statistically negative correlation with pulmonary function indexes (TLC% pred, FVC% pred and FEV1% pred) and positive correlation with length of hospital stay (r = -0.38, p = 0.04; r = -0.41, p = 0.02, r = -0.37, p = 0.04; r = 0.42, p = 0.02, respectively) in CTD-ILD patients, although serum S1P level was not significantly correlated with inflammatory indexes. The IPF patients failed to exhibit a significant correlation of serum S1P level with pulmonary function and length of hospital stay. CONCLUSIONS: Serum S1P level might be a clinically useful biomarker in evaluating the severity of CTD-ILD patients rather than IPF patients.

Myositis Autoantibody Profiles and Clinical Significance in Patients with Inflammatory Myopathies in Southwest China.

BACKGROUND: The purpose of this study is to analyze the distribution of myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs) in patients with idiopathic inflammatory myopathies (IIMs) in southwest China and to explore the relevance between each subtype, each clinical feature, and to explore the relevance between the laboratory indexes. METHODS: For this study, 200 patients with IIMs were tested for myositis autoantibodies. Clinical manifestations and laboratory metrics were collected and the correlations between autoantibodies and clinical phenotypes were analyzed. RESULTS: MSAs were found in 73.5% of the patients. The most frequently MSAs were anti-MDA5 (26.8%), followed by anti-ARS (18.5%). Anti-Ro52 was the most prevalent in MAAs (46.2%). Interstitial lung disease (ILD) and arthralgia were more frequent in anti-MDA5 and anti-Jo-1 positive groups (each p < 0.05). Anti-TIF1-γ and anti-NXP2 were associated with dysphagia (each p < 0.05). Different antibody subtypes were associated with laboratory indicators of response to muscle damage and immune status. Logistic regression showed that anti-MDA5 and anti-Jo-1 were independent risk factors for ILD (OR = 4.542, p = 0.004; OR = 4.290, p = 0.018, respectively) and arthralgia (OR = 7.856, p = 0.000; OR = 5.731, p = 0.004, respectively), whereas anti-TIF1-γ and anti-NXP2 were independent risk factors for dysphagia (OR = 4.521, p = 0.009; OR = 6.889, p = 0.017, respectively). CONCLUSIONS: Different antibody subtypes were associated with specific clinical features. Anti-MDA5 and anti-Jo-1 were independent risk factors for ILD and arthralgia. Anti-TIF1-γ and anti-NXP2 were independent risk factors for dysphagia.

Multidimensional biomarker approach integrating tumor markers, inflammatory indicators, and disease activity indicators may improve prediction of rheumatoid arthritis-associated interstitial lung disease.

INTRODUCTION: Rheumatoid arthritis (RA) often leads to interstitial lung disease (ILD), significantly affecting patient outcomes. This study explored the diagnostic accuracy of a multi-biomarker approach to offer a more efficient and accessible diagnostic strategy for RA-associated ILD (RA-ILD). METHODS: Patients diagnosed with RA, with or without ILD, at Beijing Tiantan Hospital from October 2019 to October 2023 were analyzed. A total of 125 RA patients were included, with 76 diagnosed with RA-ILD. The study focused on three categories of indicators: tumor markers, inflammatory indicators, and disease activity measures. The heatmap correlation analysis was employed to analyze the correlation among these indicators. Logistic regression was used to determine odds ratios (OR) for indicators linked to RA-ILD risk. Receiver-operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic potential of these indicators for RA-ILD. RESULTS: The results of logistic regression analysis showed that tumor markers (carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), and cytokeratin 19 fragment (CYFRA21-1)), as well as inflammatory indicators (neutrophil, neutrophil-to-lymphocyte ratio (NLR), platelet, C-reactive protein (CRP)) and disease activity measures (disease activity score-28-CRP (DAS28-CRP), rheumatoid factor (RF), and anti-cyclic peptide containing citrulline (anti-CCP)), were significantly associated with RA-ILD. The correlation coefficients among these indicators were relatively low. Notably, the combination indicator 4, which integrated the aforementioned three categories of biomarkers, demonstrated improved diagnostic accuracy with an AUC of 0.857. CONCLUSION: The study demonstrated that combining tumor markers, inflammatory indicators, and disease activity measures significantly enhanced the prediction of RA-ILD. Key Points • Multidimensional strategy: Integrated tumor markers, inflammatory indicators, and disease activity measures to enhance early detection of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). • Diagnostic accuracy: Employed heatmap correlation and logistic regression, identifying significant associations and improving diagnostic accuracy with a multidimensional biomarker combination. • Superior performance: The combined multidimensional biomarker strategy demonstrated higher diagnostic precision compared to individual or dual-category indicators. • Clinical relevance: Offers a promising, accessible approach for early detection of RA-ILD in clinical settings, potentially improving patient outcomes.

Clinical and prognostic associations of anti-Jo-1 antibody levels in patients with antisynthetase syndrome.

OBJECTIVE: To investigate the association of serum anti-Jo-1 antibody levels with the disease activity and prognosis in anti-Jo-1-positive patients with antisynthetase syndrome (ASS). METHODS: This study included 115 anti-Jo-1-positive patients with ASS who were admitted to China-Japan Friendship Hospital between 2009 and 2019. Anti-Jo-1 antibody serum levels at initial admission and follow-up were determined by enzyme-linked immunosorbent assay (ELISA). Global and organ disease activity was assessed at baseline and follow-up according to the International Myositis Assessment and Clinical Studies guidelines. RESULTS: Among enrolled patients, 70 (60.9%) patients initially presented with interstitial lung disease (ILD), and 46 (40%) patients presented with with muscle weakness at initial admission. At baseline, patients with ILD had lower levels of anti-Jo-1 antibodies than those without ILD (p = 0.012). Baseline anti-Jo-1 antibody levels were higher in patients with muscle weakness, skin involvement, and arthritis (all p < 0.05) compared to those without these manifestations. Baseline anti-Jo-1 antibody levels were positively correlated with skin visual analogue scale (VAS) scores (r = 0.25, p = 0.006), but not with disease activity in other organs. However, changes in anti-Jo-1 antibody levels were significantly positively correlated with the changes in PGA (ß = 0.002, p = 0.001), muscle (ß = 0.003, p < 0.0001), and pulmonary (ß = 0.002, p = 0.013) VAS scores, but not with skin and joint VAS scores. Older age of onset (hazard ratio [HR] 1.069, 95% confidence interval [CI]:1.010-1.133, p = 0.022) and higher C-reactive protein (CRP) levels (HR 1.333, 95% CI: 1.035-1.717, p = 0.026) were risk factors for death. CONCLUSION: Anti-Jo-1 titers appear to correlate more with disease activity changes over time rather than with organ involvement at baseline, which provides better clinical guidance for assessing the disease course using anti-Jo-1 levels.

Prognostic value of serum oncomarkers for patients hospitalized with acute exacerbation of interstitial lung disease.

BACKGROUND: Different types of inflammatory processes and fibrosis have been implicated in the pathogenesis of interstitial lung disease (ILD), a heterogeneous, diffuse, parenchymal lung disease. Acute exacerbation (AE) of ILD is characterized by significant respiratory deterioration and is associated with high mortality rates. Several serum oncomarkers have been used to determine the prognosis of ILD; however, the prognostic value of serum oncomarker levels in patients with AE-ILD remains unclear. OBJECTIVE: To evaluate the prognostic value of serum oncomarker levels in patients with AE-ILD and its main subtypes. DESIGN: Retrospective study. METHODS: The serum levels of 8 oncomarkers in 281 patients hospitalized with AE-ILD at our institution between 2017 and 2022 were retrospectively reviewed. The baseline characteristics and serum oncomarker levels were compared between the survival and non-survival groups of AE-ILD and its main subtypes. Multivariate logistic regression analysis was performed to identify independent prognosis-related markers, and the best prognostic predictor was analyzed using receiver operating characteristic curve (ROC) analysis. RESULT: Idiopathic pulmonary fibrosis (IPF; n = 65), idiopathic nonspecific interstitial pneumonia (iNSIP; n = 26), and connective tissue disease-associated interstitial lung disease (CTD-ILD; n = 161) were the three main subtypes of ILD. The in-hospital mortality rate among patients with AE-ILD was 21%. The serum oncomarker levels of most patients with AE-ILD and its main subtypes in the non-survival group were higher than those in the survival group. Multivariate analysis revealed that ferritin and cytokeratin 19 fragments (CYFRA21-1) were independent prognostic risk factors for patients hospitalized with AE-ILD or AE-CTD-ILD. CYFRA21-1 was identified as an independent prognostic risk factor for patients hospitalized with AE-IPF or AE-iNSIP. CONCLUSION: CYFRA21-1 may be a viable biomarker for predicting the prognosis of patients with AE-ILD, regardless of the underlying subtype of ILD. Ferritin has a prognostic value in patients with AE-ILD or AE-CTD-ILD.

Diagnostic Value of Krebs von den Lungen (KL-6) for Interstitial Lung Disease: A European Prospective Cohort.

INTRODUCTION: Krebs von den Lungen 6 (KL-6) is a mucin-1 glycoprotein produced by type II pneumocytes. High levels of KL-6 in blood may be found in patients with lung fibrosis. In Asia this biomarker is used for diagnosis and prognosis in interstitial lung diseases (ILD). There is a lack of information regarding KL-6 cut-off point for diagnosis and prognosis in European population. The aim of this study was to establish the cut-off point for serum KL-6 associated with the presence of ILD in the Spanish population. METHODS: Prospective study including subjects who underwent chest HRCT, PFTs and autoimmune blood analysis. Two groups were created: non-ILD subjects and ILD patients. Serum KL-6 concentrations were measured using a Lumipulse KL-6 reagent assay and the optimal cut-off value was evaluated by a ROC analysis. Data on demographics and smoking history was also collected. RESULTS: One hundred seventy-nine patients were included, 102 with ILD. Median serum KL-6 values overall were 762U/mL, 1080 (±787)U/mL for the ILD group vs 340 (±152)U/mL for the non-ILD group (p<0.0001). The main radiological pattern was NSIP (43%). ROC analysis showed greater specificity (86%) and sensitivity (82%) for KL-6 465U/mL for detecting ILD patients. The multivariate logistic regression model pointed to the male sex, higher KL-6 values, lower FVC and low DLCO values as independent factors associated with ILD. CONCLUSION: Serum KL-6 values greater than 465U/mL have excellent sensitivity and specificity for detecting ILD in our Spanish cohort. Multicentre studies are needed to validate our results.

Serum netrin-1 levels are high in Rheumatoid arthritis associated interstitial lung disease.

BACKGROUND: Recent data show that netrin-1 has a role in development of pulmonary fibrosis. This study was aimed to investigate serum netrin-1 level and its relation to interstitial lung disease(ILD) in patients with rheumatoid arthritis (RA). METHOD: 42 RA patients with RA-ILD, 58 RA patients without RA-ILD (RA non-ILD group), and 61 healthy volunteers were included in this study. The modified DAS28-ESR score was used to calculate disease activity in RA patients. Using the quantitative immunoassay method, Serum netrin-1 levels were measured with an ELISA kit (Catalog number: E-EL-H2328; lab science, lot number: GZWTKZ5SWK, Texas, USA). RESULTS: The median value of netrin-1 was found to be significantly higher in the RA-ILD group (82.9 [59.9-124]) compared to both the RA non-ILD group(52.9 [49.5-73.1])(B = -0.006, OR = 0.994, CI 95 %=0.989-0.999, P = 0.018) and the control group(53.5 [49.5-87.5]) (B: -0.005, OR: 0.994, CI 95 %: 0.990-0.999, p: 0.022). A cut-off value of 61.78 for netrin-1 was found to have a sensitivity of 73.8 % and a specificity of 69 % for the diagnosis of RA-ILD (AUC [95 %Cl] = 0.771 [0.679-0.862], p < 0.0001).It was found that high serum netrin-1 level was strongly associated with the RA-usual interstitial pneumonia(UIP) pattern and poorly related to the RA-nonspecific interstitial pneumonia(NSIP) pattern compared to the RA non-ILD group. CONCLUSIONS: Netrin-1 is elevated in the serum of patients with RA-ILD, especially in the UIP pattern. Netrin-1 may be a potential candidate for predicting the development of RA-ILD that should be investigated in the pathophysiological and therapeutic fields..

Clinical risk factors in patients with interstitial lung disease associated with anti-MDA5 autoantibodies / Factores de riesgo clínicos en pacientes con enfermedad pulmonar intersticial con anticuerpos anti-MDA5

Introduction The anti-MDA5-associated autoimmune disease represents a poorly understood entity. The study's objectives were to describe a cohort of interstitial lung disease (ILD) patients who were positive for anti-MDA5 autoantibody and identify clinical risk factors associated with survival. Methods This single-center cohort study included ILD patients positive for anti-MDA5 autoantibody. Baseline clinical features were registered, and survival analysis was performed to identify risk factors associated with worse survival. Results Fifty-three ILD-MDA5 positive patients were included; twelve died during follow-up due to rapidly progressive interstitial lung disease (RP-ILD). Dermatological signs of anti-MDA5 (Gottron papules, Gottron sign, palmar papules, V-neck sign, facial dermatomyositis rashes, and skin ulcers) were strongly associated with death secondary to RP-ILD (HR: 3.7, 95% CI: 1.02–13.35). Patients with dermatological signs were younger, had higher anti-MDA5 autoantibodies titers, more frequent inflammatory patterns in HRCT evaluation, and less fibrosis extent in HRCT. Conclusion Dermatological manifestation in ILD patients to anti-MDA5 autoantibodies are associated with RP-ILD and short-term fatal outcomes. Dermatological signs may identify a subgroup of ILD-positive to anti-MDA5 patients with a high risk of RP-ILD (AU)

Introducción La enfermedad autoinmune asociada a los anticuerpos anti-MDA5 es una entidad poco estudiada. Los objetivos de este estudio son describir una cohorte de sujetos con enfermedad pulmonar intersticial (EPI) positivos al anticuerpo anti-MDA5 e identificar los factores clínicos de riesgo asociados con la supervivencia. Métodos Estudio de cohorte de un solo centro de pacientes con EPI y positivos al anticuerpo anti-MDA5. Se registraron las características clínicas basales y se realizó un análisis de supervivencia para identificar los factores de riesgo asociados con la supervivencia. Resultados Se incluyeron 53 pacientes con EPI y positivos a anti-MDA5; 12 pacientes fallecieron por una enfermedad intersticial rápidamente progresiva (EPI-RP). Los signos dermatológicos asociados a anti-MDA5 (pápulas de Gottron, signo de Gottron, pápulas palmares, signo de la V del escote, eritema facial de dermatomiositis y úlceras cutáneas) se asociaron fuertemente con la EPI-RP (HR: 3,7, IC 95%: 1,02-13,35). Los pacientes con manifestaciones dermatológicas eran más jóvenes, tenían mayores títulos de anticuerpos anti-MDA5, tenían mayor frecuencia de patrones inflamatorios en la tomografía de tórax de alta resolución y menor extensión de la fibrosis en la TCAR. Conclusión Las manifestaciones dermatológicas en los pacientes con EPI positivos a anticuerpos anti-MDA5 están asociados a EPI-RP y a desenlaces fatales al corto plazo. Los signos dermatológicos pueden identificar un subgrupo de pacientes positivos a anti-MDA5 con mayor riesgo de EPI-RP (AU)

Serum heme oxygenase-1 as a prognostic biomarker in patients with acute exacerbation of interstitial lung disease.

Serum heme oxygenase (HO)-1 level has been reported as a clinically reliable diagnostic biomarker for acute exacerbation of interstitial lung disease (ILD); however, its utility for predicting mortality among these patients is unclear. Serum HO-1 levels of patients newly diagnosed with acute exacerbation of ILD were measured at the time of initiating steroid pulse therapy. The relationship between serum HO-1 and various other serum biomarkers, change in HRCT findings, and disease prognosis at 12 weeks after diagnosis of acute exacerbation was evaluated in 51 patients, of whom 17 (33%) had idiopathic pulmonary fibrosis (IPF). Serum HO-1 was higher in patients with acute exacerbation of IPF than in patients with acute exacerbation of other ILDs. Serum HO-1 levels were higher in patients who died within these 12 weeks than in survivors. Among age, sex, comorbidities, IPF diagnosis, HRCT findings, and blood biomarkers, serum HO-1 was a primary predictor of 12-week mortality. In 41 patients who underwent repeat HRCT, serum HO-1 was higher in patients with honeycomb progression than in those without. Serum HO-1 measurement could be useful for evaluating disease mortality and morbidity of patients with acute exacerbation of ILDs.

High-titer rheumatoid factor seropositivity predicts mediastinal lymphadenopathy and mortality in rheumatoid arthritis-related interstitial lung disease.

Rheumatoid arthritis-related interstitial lung disease (RA-ILD) is a common connective tissue disease-related ILD (CTD-ILD) associated with high morbidity and mortality. Although rheumatoid factor (RF) seropositivity is a risk factor for developing RA-ILD, the relationship between RF seropositivity, mediastinal lymph node (MLN) features, and disease progression is unknown. We aimed to determine if high-titer RF seropositivity predicted MLN features, lung function impairment, and mortality in RA-ILD. In this retrospective cohort study, we identified patients in the University of Chicago ILD registry with RA-ILD. We compared demographic characteristics, serologic data, MLN size, count and location, and pulmonary function over 36 months among patients who had high-titer RF seropositivity (≥ 60 IU/ml) and those who did not. Survival analysis was performed using Cox regression modeling. Amongst 294 patients with CTD-ILD, available chest computed tomography (CT) imaging and serologic data, we identified 70 patients with RA-ILD. Compared to RA-ILD patients with low-titer RF, RA-ILD patients with high-titer RF had lower baseline forced vital capacity (71% vs. 63%; P = 0.045), elevated anti-cyclic citrullinated peptide titer (122 vs. 201; P = 0.001), CT honeycombing (50% vs. 80%; P = 0.008), and higher number of MLN ≥ 10 mm (36% vs. 76%; P = 0.005). Lung function decline over 36 months did not differ between groups. Primary outcomes of death or lung transplant occurred more frequently in the high-titer RF group (HR 2.8; 95% CI 1.1-6.8; P = 0.028). High-titer RF seropositivity was associated with MLN enlargement, CT honeycombing, and decreased transplant-free survival. RF titer may be a useful prognostic marker for stratifying patients by pulmonary disease activity and mortality risk.

Role of MUC1 rs4072037 polymorphism and serum KL-6 levels in patients with antisynthetase syndrome.

Mucin 1/Krebs von den Lungen-6 (KL-6) is proposed as a serum biomarker of several interstitial lung diseases (ILDs), including connective tissue disorders associated with ILD. However, it has not been studied in a large cohort of Caucasian antisynthetase syndrome (ASSD) patients. Consequently, we assessed the role of MUC1 rs4072037 and serum KL-6 levels as a potential biomarker of ASSD susceptibility and for the differential diagnosis between patients with ILD associated with ASSD (ASSD-ILD +) and idiopathic pulmonary fibrosis (IPF). 168 ASSD patients (149 ASSD-ILD +), 174 IPF patients and 523 healthy controls were genotyped for MUC1 rs4072037 T > C. Serum KL-6 levels were determined in a subgroup of individuals. A significant increase of MUC1 rs4072037 CC genotype and C allele frequencies was observed in ASSD patients compared to healthy controls. Likewise, MUC1 rs4072037 TC and CC genotypes and C allele frequencies were significantly different between ASSD-ILD+ and IPF patients. Additionally, serum KL-6 levels were significantly higher in ASSD patients compared to healthy controls. Nevertheless, no differences in serum KL-6 levels were found between ASSD-ILD+ and IPF patients. Our results suggest that the presence of MUC1 rs4072037 C allele increases the risk of ASSD and it could be a useful genetic biomarker for the differential diagnosis between ASSD-ILD+ and IPF patients.

Metabolic characteristics in patients with COVID-19 and no-COVID-19 interstitial pneumonia with mild-to-moderate symptoms and similar radiological severity.

BACKGROUND AND AIMS: It is known that the highest COVID-19 mortality rates are among patients who develop severe COVID-19 pneumonia. However, despite the high sensitivity of chest CT scans for diagnosing COVID-19 in a screening population, the appearance of a chest CT is thought to have low diagnostic specificity. The aim of this retrospective case-control study is based on evaluation of clinical and radiological characteristics in patients with COVID-19 (n = 41) and no-COVID-19 interstitial pneumonia (n = 48) with mild-to-moderate symptoms. METHODS AND RESULTS: To this purpose we compared radiological, clinical, biochemical, inflammatory, and metabolic characteristics, as well as clinical outcomes, between the two groups. Notably, we found similar radiological severity of pneumonia, which we quantified using a disease score based on a high-resolution computed tomography scan (COVID-19 = 18.6 ± 14.5 vs n-COVID-19 = 23.2 ± 15.2, p = 0.289), and comparable biochemical and inflammatory characteristics. However, among patients without diabetes, we observed that COVID-19 patients had significantly higher levels of HbA1c than n-COVID-19 patients (COVID-19 = 41.5 ± 2.6 vs n-COVID-19 = 38.4 ± 5.1, p = 0.012). After adjusting for age, sex, and BMI, we found that HbA1c levels were significantly associated with the risk of COVID-19 pneumonia (odds ratio = 1.234 [95%CI = 1.051-1.449], p = 0.010). CONCLUSIONS: In this retrospective case-control study, we found similar radiological and clinical characteristics in patients with COVID-19 and n-COVID-19 pneumonia with mild-to-moderate symptoms. However, among patients without diabetes HbA1c levels were higher in COVID-19 patients than in no-COVID-19 individuals. Future studies should assess whether reducing transient hyperglycemia in individuals without overt diabetes may lower the risk of SARS-CoV-2 infection.

sFlt-1 and CA 15.3 are indicators of endothelial damage and pulmonary fibrosis in SARS-CoV-2 infection.

COVID-19 pandemic led to a worldwide increase of hospitalizations for interstitial pneumonia with thrombosis complications, endothelial injury and multiorgan disease. Common CT findings include lung bilateral infiltrates, bilateral ground-glass opacities and/or consolidation whilst no current laboratory parameter consents rapidly evaluation of COVID-19 risk and disease severity. In the present work we investigated the association of sFLT-1 and CA 15.3 with endothelial damage and pulmonary fibrosis. Serum sFlt-1 has been associated with endothelial injury and sepsis severity, CA 15.3 seems an alternative marker for KL-6 for fibrotic lung diseases and pulmonary interstitial damage. We analysed 262 SARS-CoV-2 patients with differing levels of clinical severity; we found an association of serum sFlt-1 (ROC AUC 0.902, decision threshold > 90.3 pg/mL, p < 0.001 Sens. 83.9% and Spec. 86.7%) with presence, extent and severity of the disease. Moreover, CA 15.3 appeared significantly increased in COVID-19 severe lung fibrosis (ICU vs NON-ICU patients 42.6 ± 3.3 vs 25.7 ± 1.5 U/mL, p < 0.0001) and was associated with lung damage severity grade (ROC AUC 0.958, decision threshold > 24.8 U/mL, p < 0.0001, Sens. 88.4% and Spec. 91.8%). In conclusion, serum levels of sFlt-1 and CA 15.3 appeared useful tools for categorizing COVID-19 clinical stage and may represent a valid aid for clinicians to better personalise treatment.

Circulating bioactive bacterial DNA is associated with immune activation and complications in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is characterized by profound primary antibody defects and frequent infections, yet autoimmune/inflammatory complications of unclear origin occur in 50% of individuals and lead to increased mortality. Here, we show that circulating bacterial 16S rDNA belonging to gut commensals was significantly increased in CVID serum (P < 0.0001), especially in patients with inflammatory manifestations (P = 0.0007). Levels of serum bacterial DNA were associated with parameters of systemic immune activation, increased serum IFN-γ, and the lowest numbers of isotype-switched memory B cells. Bacterial DNA was bioactive in vitro and induced robust host IFN-γ responses, especially among patients with CVID with inflammatory manifestations. Patients with X-linked agammaglobulinemia (Bruton tyrosine kinase [BTK] deficiency) also had increased circulating bacterial 16S rDNA but did not exhibit prominent immune activation, suggesting that BTK may be a host modifier, dampening immune responses to microbial translocation. These data reveal a mechanism for chronic immune activation in CVID and potential therapeutic strategies to modify the clinical outcomes of this disease.

Association of Red Blood Cell Distribution Width Levels with Connective Tissue Disease-Associated Interstitial Lung Disease (CTD-ILD).

OBJECTIVE: The aim of this study was to evaluate the diagnostic and prognostic value of red blood cell distribution width (RDW) in patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). METHODS: We retrospectively reviewed 213 CTD-ILD patients and 97 CTD patients without ILD from February 2017 to February 2020. Hospital and office records were used as data sources. CTD-ILD patients were followed up. RESULTS: Patients with CTD-ILD had significantly higher RDW than those with CTD without ILD (p < 0.001). The area under the receiver operating characteristic curve (AUROC) of RDW for discriminating CTD-ILD from CTD without ILD was 0.64 (95% CI: 0.57-0.70, p < 0.001). The cutoff value of RDW for discriminating CTD-ILD from CTD without ILD was 13.95% with their corresponding specificity (55.9%) and sensitivity (70.1%). Correlation analyses showed that the increased RDW was significantly correlated with decreased DLCO%predicted (r = -0.211, p = 0.002). Cox multiple regression analysis indicated that RDW (HR = 1.495, p < 0.001) was an independent factor in the survival of CTD-ILD. The best cutoff value of RDW to predict the survival of patients with CTD-ILD was 14.05% (AUC = 0.78, 95% CI: 0.72-0.84, p < 0.001). The log-rank test showed a significant difference in survival between the two groups (RDW > 14.05% and RDW < 14.05%). CONCLUSION: RDW was higher in CTD-ILD patients and had a negative correlation with DLCO%predicted. RDW may be an important serum biomarker for severity and prognosis of patients with CTD-ILD.

Plasma-Derived Exosomal hsa-miR-4488 and hsa-miR-1228-5p: Novel Biomarkers for Dermatomyositis-Associated Interstitial Lung Disease with Anti-Melanoma Differentiation-Associated Protein 5 Antibody-Positive Subset.

The present study is aimed at profiling circulating exosome-derived microRNAs (miRNAs/miRs) from patients with dermatomyositis (DM), in particular those complicated with interstitial lung disease (ILD) with anti-melanoma differentiation-associated protein 5 (MDA5) antibody-positive. Fifteen participants were enrolled, including five patients with DM complicated with ILDs prior to treatment with circulating anti-MDA5 antibody-positive status [DM-ILD-MDA5 Ab(+)], five DM patients without ILDs who were negative for 16 detectable myositis-specific antibodies [DM-nonILD-MSA16(-)], and five age- and gender-matched healthy donor controls (HCs). The characteristics of the exosomes extracted by Ribo™ Exosome Isolation Reagent were identified using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and flow cytometry. Differentially expressed miRNAs, determined by next-generation deep sequencing, were identified through the criteria of ∣log2 fold change | ≥1 and P < 0.01. A total of 38 miRNAs were significantly upregulated in exosomes from patients with DM-ILD-MDA5 Ab(+) compared to those from HC, while 21 miRNAs were significantly downregulated. Compared to exosomes derived from patients with DM-nonILD-MSA16(-), 51 miRNAs were significantly upregulated and 33 miRNAs were significantly downregulated from patients with DM-ILD-MDA5 Ab(+). A total of 73 exosomal miRNAs were significantly differentially expressed between DM-nonILD-MSA16(-) and HC. In particular, two miRNAs, Homo sapiens- (hsa-) miR-4488 and hsa-miR-1228-5p, were common differentially expressed miRNAs among three comparisons. GO and KEGG analyses suggested that several pathways may contribute the pathogenesis of DM-ILD-MDA5 Ab(+) and DM-nonILD-MSA16(-), while PPI network analysis of hsa-miR-4488 and hsa-miR-1228-5p indicated that their predicted target genes, DExD-box helicase 39B and MDM2, may be involved in the mechanisms of DM-ILD-MDA5 Ab(+).

Serum levels of IgG antibodies against Aspergillus fumigatus and the risk of hypersensitivity pneumonitis and other interstitial lung diseases.

Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) caused by the inhalation of antigens. Antigen-specific IgG antibodies (sIgG) are used as biomarkers of exposure when diagnosing HP, but little is known about the longitudinal relation between antibody levels and risk of HP or other ILD. In a follow-up design, we explored the relationship between sIgG antibodies against Aspergillus fumigatus and the diagnosis of HP in 647 subjects suspected of HP. We showed that IgG levels above the reference value resulted in a hazard ratio of 9.5 for subsequent HP. Our findings support a relationship between high levels of sIgG against A. fumigatus and risk of HP.

A proposed prognostic prediction score for pleuroparenchymal fibroelastosis.

BACKGROUND: Clinical course of pleuroparenchymal fibroelastosis (PPFE) shows considerable variation among patients, but there is no established prognostic prediction model for PPFE. METHODS: The prediction model was developed using retrospective data from two cohorts: our single-center cohort and a nationwide multicenter cohort involving 21 institutions. Cox regression analyses were used to identify prognostic factors. The total score was defined as the weighted sum of values for the selected variables. The performance of the prediction models was evaluated by Harrell's concordance index (C-index). We also examined the usefulness of the gender-age-physiology (GAP) model for predicting the prognosis of PPFE patients. RESULTS: We examined 104 patients with PPFE (52 cases from each cohort). In a multivariate Cox analysis, a lower forced vital capacity (FVC [defined as FVC < 65%]; hazard ratio [HR], 2.23), a history of pneumothorax (HR, 3.27), the presence of a lower lobe interstitial lung disease (ILD) (HR, 2.31), and higher serum Krebs von den Lungen-6 (KL-6) levels (> 550 U/mL, HR, 2.56) were significantly associated with a poor prognosis. The total score was calculated as 1 × (FVC, < 65%) + 1 × (history of pneumothorax) + 1 × (presence of lower lobe ILD) + 1 × (KL-6, > 550 U/mL). PPFE patients were divided into three groups based on the prognostic score: stage I (0-1 points), stage II (2 points), and stage III (3-4 points). The survival rates were significantly different in each stage. The GAP stage was significantly associated with the prognosis of PPFE, but no difference was found between moderate (stage II) and severe (stage III) disease. Our new model for PPFE patients (PPFE Prognosis Score) showed better performance in the prediction of mortality in comparison to the GAP model (C-index of 0.713 vs. 0.649). CONCLUSIONS: Our new model for PPFE patients could be useful for predicting their prognosis.

Interstitial Lung Disease in Connective Tissue Disease: A Common Lesion With Heterogeneous Mechanisms and Treatment Considerations.

Connective tissue disease (CTD) related interstitial lung disease (CTD-ILD) is one of the leading causes of morbidity and mortality of CTD. Clinically, CTD-ILD is highly heterogenous and involves rheumatic immunity and multiple manifestations of respiratory complications affecting the airways, vessels, lung parenchyma, pleura, and respiratory muscles. The major pathological features of CTD are chronic inflammation of blood vessels and connective tissues, which can affect any organ leading to multi-system damage. The human lung is particularly vulnerable to such damage because anatomically it is abundant with collagen and blood vessels. The complex etiology of CTD-ILD includes genetic risks, epigenetic changes, and dysregulated immunity, which interact leading to disease under various ill-defined environmental triggers. CTD-ILD exhibits a broad spectra of clinical manifestations: from asymptomatic to severe dyspnea; from single-organ respiratory system involvement to multi-organ involvement. The disease course is also featured by remissions and relapses. It can range from stability or slow progression over several years to rapid deterioration. It can also present clinically as highly progressive from the initial onset of disease. Currently, the diagnosis of CTD-ILD is primarily based on distinct pathology subtype(s), imaging, as well as related CTD and autoantibodies profiles. Meticulous comprehensive clinical and laboratory assessment to improve the diagnostic process and management strategies are much needed. In this review, we focus on examining the pathogenesis of CTD-ILD with respect to genetics, environmental factors, and immunological factors. We also discuss the current state of knowledge and elaborate on the clinical characteristics of CTD-ILD, distinct pathohistological subtypes, imaging features, and related autoantibodies. Furthermore, we comment on the identification of high-risk patients and address how to stratify patients for precision medicine management approaches.

Clinical characteristics of interstitial lung diseases positive to different anti-synthetase antibodies.

ABSTRACT: To analyze the clinical, serological, and imaging characteristics of patients with interstitial lung diseases (ILD) positive to different anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies.The clinical data, serological indexes, pulmonary high-resolution computed tomography (HRCT) imaging features and pulmonary functions, and bronchoalveolar lavage fluid of 84 ILD patients with anti-ARS antibody positive in Beijing Chao-yang Hospital, Capital Medical University were reviewed.(1) Anti-ARS antibodies included anti-Jo-1 (42.86%), anti-PL-7 (26.19%), anti-PL-12 (10.71%), anti-EJ (14.29%), and anti-OJ (5.95%). (2) Nonspecific interstitial pneumonia was the main type of patients with ILD positive to antibodies of anti-Jo-1, anti-PL-7, and anti-EJ, organizing pneumonia was the main type of patients with ILD positive to anti-PL-12 antibody and usual interstitial pneumonia was the main type of patients with ILD positive to anti-OJ antibody. (3) Only 14.29% of the patients had typical "triad syndrome" (interstitial pneumonia, myositis, and non-erosive arthritis). Myositis mainly occurred in patients with ILD positive to antibodies of anti-PL-7, anti-Jo-1, and anti-EJ. The incidence of arthritis in ILD patients with anti-Jo-1 was higher than that in ILD patients with anti-PL-12 and anti-EJ (P < .05). The incidence of mechanic's hand in ILD patients with anti-Jo-1 was higher than that in ILD patients with anti-PL-12 (P < .05).ILD positive to anti-Jo-1 antibody is associated with multiple organ involvement, mainly manifested as myositis, mechanic's hand, and arthritis. As other clinical manifestations of some ILD patients are relatively hidden, ILD patients should pay attention to the screening of the anti-ARS antibodies and guard against anti-synthetase syndrome.