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.

Immunological Similarities and Differences between Post-COVID-19 Lung Sequelae and Idiopathic Pulmonary Fibrosis.

INTRODUCTION: Pulmonary fibrosis is an irreversible condition that may be caused by known (including viral triggers such as SARS-CoV-2) and unknown insults. The latter group includes idiopathic pulmonary fibrosis (IPF), which is a chronic, progressive fibrosing interstitial pneumonia of unknown cause. The longer the insult acts on lung tissue, the lower the probability of a complete resolution of the damage. An emerging clinical entity post-COVID-19 is pulmonary fibrosis (PCPF), which shares many pathological, clinical, and immunological features with IPF. The fibrotic response in both diseases-IPF and PCPF-is orchestrated in part by the immune system. An important role regarding the inhibitory or stimulatory effects on immune responses is exerted by the immune checkpoints (ICs). The aim of the present study was to analyse the similarities and differences between CD4+, CD8+, and NK cells in the peripheral blood of patients affected by fibrotic disease, IPF, and PCPF compared with sarcoidosis patients and healthy controls. The second aim was to evaluate the expression and co-expression of PD-1 and TIGIT on CD4, CD8, and NK cells from our patient cohort. METHODS: One hundred and fifteen patients affected by IPF, PCPF, and sarcoidosis at the rare pulmonary disease centre of the University of Siena were enrolled. Forty-eight patients had an IPF diagnosis, 55 had PCPF, and 12 had sarcoidosis. Further, ten healthy controls were enrolled. PCPF patients were included between 6 and 9 months following hospital discharge for COVID-19. The peripheral blood samples were collected, and through flow cytometric analysis, we analysed the expression of CD4, CD8, NK cells, PD-1, and TIGIT. RESULTS: The results show a greater depletion of CD4 and NK cells in IPF patients compared to other groups (p = 0.003), in contrast with CD8 cells (p < 001). Correlation analysis demonstrated an indirect correlation between CD4 and CD8 cells in IPF and sarcoidosis patients (p < 0.001 = -0.87 and p = 0.042; r = -0.6, respectively). Conversely, PCPF patients revealed a direct correlation between CD4 and CD8 cells (p < 0.001; r = 0.90) accentuating an immune response restoration. The expression of PD-1 and TIGIT was abundant on T and NK cell subsets of the two lung fibrotic groups, IPF and PCPF. Analogously, the co-expression of PD-1 and TIGIT on the surfaces of CD4 and CD8 were increased in such diseases. Conclusions: Our study shines a spotlight on the immune responses involved in the development of pulmonary fibrosis, idiopathic and secondary to SARS-CoV-2 infection. We observed a significant imbalance not only in CD4, CD8, and NK blood percentages in IPF and PCPF patients but also in their functional phenotypes evaluated through the expression of ICs.

Role of BAL and Serum Krebs von den Lungen-6 (KL-6) in Patients with Pulmonary Fibrosis.

Background: Interstitial lung diseases (ILDs) encompass a diverse group of disorders affecting the lung interstitium, leading to inflammation, fibrosis, and impaired respiratory function. Currently, the identification of new diagnostic and prognostic biomarkers for ILDs turns out to be necessary. Several studies show the role of KL-6 in various types of interstitial lung disease and suggest that serum KL-6 levels can be used as a prognostic marker of disease. The aim of this study was to analyze KL-6 expression either in serum or bronchoalveolar lavage samples in order to: (i) make a serum vs. BAL comparison; (ii) better understand the local behavior of fibrosis vs. the systemic one; and (iii) evaluate any differences in patients with progressive fibrosis (PPF) versus patients with non-progressive fibrosis (nPPF). Methods: We used qRT-PCR to detect KL-6 expression both in serum and BAL samples. Mann-Whitney's U test was used to compare the differential expression between groups. Results: In serum, KL-6 is more highly expressed in PPF than in non-progressive fibrosis (p = 0.0295). This difference is even more significant in BAL (p < 0.001). Therefore, it is clear that KL-6 values are related to disease progression. Significant differences were found by making a comparison between BAL and serum. KL-6 was markedly higher in serum than BAL (p = 0.0146). Conclusions: This study identifies KL-6 as a promising biomarker for the severity of the fibrosing process and disease progression in ILDs, with significantly higher levels observed in PPF compared to nPPF. Moreover, the marked difference in KL-6 levels between serum and BAL emphasizes its potential diagnostic and prognostic relevance, providing enlightening insights into both the local and systemic aspects of ILDs.

Efficacy and Safety of Upadacitinib in Rheumatoid Arthritis: Real-Life Experience from a Prospective Longitudinal Multicentric Study.

BACKGROUND: We provide the first prospective longitudinal multicenter experience on Upadacitinib efficacy and safety profile in Rheumatoid Arthritis (RA) in a real-life context, focusing on clinimetric and ultrasonographic (US) data. METHODS: RA patients referred to three Italian tertiary Centers who started Upadacitinib were enrolled as per ACR/EULAR classification criteria and prospectively reviewed. The primary aim of this study was to assess changes in clinimetric and ultrasonographic scores through time (at baseline, after 1 month, 3 months, and 6 months from the beginning of the therapy). Secondary aims were to: (i) estimate the impact of biologic lines of treatment and concomitant therapies on response to therapy; (ii) explore changes in laboratory parameters; and (iii) find potential predictive factors associated with response to therapy. RESULTS: Seventy-one patients (49 Females and 22 Males) were included. Clinimetric scores, including the Disease Activity Score (DAS28-CRP) and Simplified Clinical Disease Activity Index (SDAI), and US findings (synovial hypertrophy and power Doppler) significantly improved (p = 0.029, p = 0.001, p = 0.001, p = 0.001, respectively). Regression analysis revealed a significant association between the concomitant csDMARDs therapy at baseline and the lack of improvement in synovial hypertrophy [OR -4.824, p = 0.010] as well as with DAS28-CRP [OR -0.690, p = 0.045], whereas the presence of increased ESR or CRP at baseline was able to predict a significant improvement in SDAI [OR 8.481, p = 0.003]. No adverse events, such as deep venous thrombosis, pulmonary embolism, or herpes zoster virus infection, were reported during this study observation. CONCLUSION: Our real-life experience confirms the efficacy of Upadacitinib in terms of clinical and ultrasonographic improvement, as well as displaying a good safety profile.

Tocilizumab Vs Methotrexate in a Cohort of Patients Affected by Active GCA: A Comparative Clinical and Ultrasonographic Study.

Introduction: No head-to-head study has assessed the superiority of tocilizumab versus methotrexate in giant cell arteritis (GCA), and few studies have demonstrated its effectiveness in terms of ultrasonographic findings, but without a control group. The primary endpoint was to assess whether tocilizumab was superior to methotrexate in inducing normalization of US findings, whereas the secondary endpoint was to assess the effectiveness of precocious withdrawal of glucocorticoids. Methods: We prospectively enrolled all the patients with active GCA at our clinic. The inclusion criteria were clinical diagnosis of GCA; active disease; and clinical, laboratory, and US data, evaluated using the halo count (HC) and OMERACT GCA Ultrasonography Score (OGUS). Evaluations were repeated at 3, 6, and 12 months. Results: Twenty patients were treated with Tocilizumab and 9 with Methotrexate. All but three tocilizumab-treated patients achieved remission at six months, whereas at 12 months, all patients were in glucocorticoid-free remission. Up to three of the nine methotrexate patients experienced a lack of efficacy or minor relapses. Tocilizumab-treated patients showed a statistically significant difference between baseline and all follow-ups in terms of OGUS and HC, whereas the difference in the Methotrexate group was significant after 1 year. The mean glucocorticoid dosage significantly decreased in both groups. No severe adverse events or major relapses were reported. Conclusion: Our study demonstrates the superiority in terms of rapidity of a tocilizumab-based scheme over a methotrexate-based scheme in inducing clinical and US remission. Precocious withdrawal of glucocorticoids did not increase the risk of relapse.

Predictive Role of Cytokine and Adipokine Panel in Hospitalized COVID-19 Patients: Evaluation of Disease Severity, Survival and Lung Sequelae.

Coronavirus disease 2019 (COVID-19) may determine a multisystemic chronic syndrome after resolution of SARS-CoV-2 infection in a significant percentage of patients. Persistent cytokine dysregulation can contribute to long-lasting inflammation and tissue damage, resulting in the diverse, often debilitating symptoms experienced by some patients (so-called long COVID syndrome). The aim of our study was to evaluate the value of a panel of serum biomarkers of severity and prognosis in patients hospitalized for COVID-19 and also as predictive factors for the development of post-COVID lung sequelae after discharge from the hospital. All blood sampling was performed in the first 24 h after admission to the hospital. Serum analyte concentrations of IL-4, IL-2, CXCL10 (IP-10), IL-1ß, TNF-α, CCL2 (MCP-1), IL-17A, IL-6, IL-10, IFN-γ, IL-12p70 and TGF-ß1 were quantified by bead-based multiplex LEGENDplex™ analysis and commercially available ELISA kits. A total of 108 COVID-19 patients were enrolled in the study. Comparative analysis of these proteins showed higher levels of TGF-ß and IL-6 and lower levels of RBP-4 and IL-10 in the severe group. Age, adiponectin, IL-8 and IL-32 resulted as the best predictors for survival. Moreover, IL-1ß, IL17A, TNF-α, TGF-ß, IL-4 and IL-6 were significantly higher in patients who showed HRCT evidence of fibrotic interstitial alterations at follow-up than patients who did not. The initial inflammatory status of patients on admission to the hospital with COVID-19, as reflected by the present panel of adipose tissue-related biomarkers and cytokines, offered insights into medium-term prognosis.

The effect of anti-IL5 monoclonal antibodies on regulatory and effector T cells in severe eosinophilic asthma.

INTRODUCTION: Biological treatments have redesigned the clinical management of severe eosinophilic asthmatic (SA) patients. Despite emerging evidence supporting the role of natural Killer (NK), and T regulatory cells (Treg) in the pathogenesis of asthma, no data is available on the effects of anti-IL5/IL5R therapies on these cell subsets. METHODS: We prospectively enrolled fourteen SA patients treated with benralizumab (n = 7) or mepolizumab (n = 7) and compared them with healthy controls (HC) (n = 11) and mild to moderate asthmatic (MM) patients (n = 9). Clinical parameters were collected at baseline (T0) and during follow-up. Cellular analysis, including the analysis of T/NK cell subsets, was determined through multicolor flow cytometry. RESULTS: At T0, SA patients showed higher percentages of CD4 TEM (33.3 ± 17.9 HC, 42.6 ± 16.6 MM and 66.1 ± 19.7 in SA; p < 0.0001) than HC and MM patients. With different timing, the two drugs induce a reduction of CD4 TEM ( 76 ± 19 T0; 43 ± 14 T1; 45 ± 23 T6; 62 ± 18 at T24; p < 0.0001 for mepolizumab and 55 ± 21 T0; 55 ± 22 T1; 43 ± 14 T6; 27 ± 12 at T24; p < 0.0001 for benralizumab) and an increase of Treg cells (1.2 ± 1.3 T0; 5.1 ± 2.5 T1; 6.3 ± 3.4 T6; 8.4 ± 4.6 at T24; p < 0.0001 for mepolizumab and 3.4 ± 1.7 T0; 1.9 ± 0.8 T1; 1.9 ± 1 T6; 5.1 ± 2.4 at T24; p < 0.0001 for benralizumab). The change of CD56dim PD-1+ significantly correlated with FEV1% (r = - 0.32; p < 0.01), while Treg expressing PD-1 correlates with the use of oral steroids ( r = 0.36 p = 0.0008) and ACT score (r = 0.36 p = 0.0008) p < 0.001) CONCLUSIONS: Beyond the clinical improvement, anti-IL-5 treatment induces a rebalancing of Treg and T effector cells in patients with SA.

Effect of Ambulatory Oxygen on the Respiratory Pattern during the 6 Min Walking Test in Patients with Interstitial Lung Diseases.

INTRODUCTION: Patients with pulmonary fibrosis experience early oxyhemoglobin desaturation under effort, which limits their ability to exercise and their quality of life. Recent studies have shown that in resting normoxaemic patients who become hypoxemic under exertion, administration of outpatient oxygen significantly improves stress dyspnoea and quality of life. It is unclear how this happens, since oxygen administration does not act directly on dyspnoea, and does not appear to have much effect on the heart rate and pulmonary artery pressure. We tested the hypothesis that correcting the hypoxaemia could reduce the increase in respiratory effort during the 6 min walking test, recording the breathing pattern during administration of oxygen or placebo. METHODS: We evaluated 20 patients with fibrotic interstitial lung diseases (17 males and 3 females; mean age 72 ± 2 years; M ± SE) with a resting SpO2 ≥92 that fell to ≤88% during the 6 min walk test (6MWT). After first establishing the oxygen flow necessary to prevent desaturation, the patients underwent two further 6MWT, 15-20 min apart, one with administration of medical air and one with oxygen at the same flow, in randomized double-blind order. During the test, SpO2, heart rate, respiratory rate, tidal volume and minute ventilation (VE) were recorded, using a Spiropalm spirometer (Cosmed, Rome, Italy). RESULTS: Oxygen saturation during the 6MWT decreased to a minimum value of 82.3% (95% CI 80.1-84.5%) during placebo and to 92% (90.3-93.7%) during oxygen with an average difference of 9.7% (7.8-11.6%, p < 0.0001). On the contrary, heart rate showed an increasing trend with walking time reaching a significantly higher maximum rate during placebo, with a difference of 5.4 bpm (2.9-8.7, p < 0.005) compared to oxygen. The distance walked was slightly but significantly greater after oxygen by 28 m (2-53, p < 0.05) and end of test dyspnoea after placebo by 0.6 points (0.1-1.1, p < 0.05). Respiratory rate increased over time, without differences between oxygen and placebo in the first minute of walking, then increasing significantly more during placebo (p < 0.0005). With placebo, tidal volume increased rapidly reaching a plateau at about 48% of FVC after 3 min, while with oxygen, the increase was slower, reaching a maximum of about 45% of FVC at the end of the test. Nevertheless, the difference was highly significant (p < 0.0005) at all the time points. Minute ventilation also increased significantly with walking time but remained at a highly significant lower level during oxygen than placebo at all the time points. Mean reduction in VE during the test with oxygen compared to placebo was 4.4 L/min (3.9-4.9, p < 0.0005). CONCLUSION: In our ILD patients, administration of outpatient oxygen during walking was related to a reduced increase in heart rate, respiratory rate, tidal volume and minute ventilation necessary to meet increased oxygen requirements, resulting in a lower workload on the cardiovascular system and on respiratory muscles and a consequent reduction in dyspnoea.

Anti-Cytosolic 5'-Nucleotidase 1A in the Diagnosis of Patients with Suspected Idiopathic Inflammatory Myopathies: An Italian Real-Life, Single-Centre Retrospective Study.

BACKGROUND: Anti-cytosolic 5'-nucleotidase 1A (anti-cN1A) antibodies were proposed as a biomarker for the diagnosis of inclusion body myositis (IBM), but conflicting specificity and sensitivity evidence limits its use. Our study aimed to assess the diagnostic accuracy of anti-cN1A in a cohort of patients who underwent a myositis line immunoassay for suspected idiopathic inflammatory myopathies (IIM). We also assessed the agreement between two testing procedures: line immunoassay (LIA) and enzyme-linked immunoassay (ELISA). MATERIALS AND METHODS: We collected retrospective clinical and serological data for 340 patients who underwent a myositis antibody assay using LIA (EUROLINE Autoimmune Inflammatory Myopathies 16 Ag et cN-1A (IgG) line immunoassay) and verification with an anti-cN1A antibody assay using ELISA (IgG) (Euroimmun Lubeck, Germany). RESULTS: The serum samples of 20 (5.88%) patients (15 females, 5 males, mean age 58.76 ± 18.31) tested positive for anti-cN1A using LIA, but only two out of twenty were diagnosed with IBM. Seventeen out of twenty tested positive for anti-cN1A using ELISA (median IQR, 2.9 (1.9-4.18)). CONCLUSIONS: Our study suggests excellent concordance between LIA and ELISA for detecting anti-cN1A antibodies. LIA may be a rapid and useful adjunct, and it could even replace ELISA for cN1A assay. However, the high prevalence of diseases other than IBM in our cohort of anti-cN1A-positive patients did not allow us to consider anti-cN1A antibodies as a specific biomarker for IBM.

Clinical, laboratory and ultrasonographic findings at baseline predict long-term outcome of polymyalgia rheumatica: a multicentric retrospective study : Polymyalgia rheumatica predicted by ultrasonographic findings polymyalgia rheumatica outcome predicted early by ultrasound.

To assess the rate of PMR who, during the follow-up, undergo a diagnostic shift as well as to assess which clinical, laboratory and US findings are associated to a diagnostic shift and predict the long-term evolution of PMR. All PMR followed-up for at least 12 months were included. According to the US procedures performed at diagnosis, patients were subdivided into four subgroups. Clinical data from follow-up visits at 12, 24, 48 and 60 months, including a diagnostic shift, the number of relapses and immunosuppressive and steroid treatment, were recorded. A total of 201 patients were included. During the follow-up, up to 60% had a change in diagnosis. Bilateral LHBT was associated with persistence in PMR diagnosis, whereas GH synovitis and RF positivity to a diagnostic shift. Patients undergoing diagnostic shift had a higher frequency of GH synovitis, shoulder PD, higher CRP, WBC, PLT and Hb and longer time to achieve remission, while those maintaining diagnosis had bilateral exudative LHBT and SA-SD bursitis, higher ESR, lower Hb and shorter time to remission. Cluster analysis identified a subgroup of older patients, with lower CRP, WBC, PLT and Hb, lower PD signal or peripheral synovitis who had a higher persistence in PMR diagnosis, suffered from more flares and took more GCs. Most PMR have their diagnosis changed during follow-up. The early use of the US is associated with a lower dosage of GCs. Patients with a definite subset of clinical, laboratory and US findings seem to be more prone to maintain the diagnosis of PMR.

Imbalance of Lymphocyte Subsets and CD45RA-Expressing Cells in Intrathoracic Lymph Nodes, Alveolar Compartment and Bloodstream of Pulmonary Sarcoidosis Patients.

Sarcoidosis is a systemic granulomatous disease mainly affecting the lungs and hilomediastinal lymph nodes. It is characterized by non-caseating epithelioid cell granulomas in lymph nodes and lungs. Our study aimed to evaluate and compare T, B and NK cell subsets in the alveolar compartment, lymph nodes and the bloodstream simultaneously in the same patients to elucidate the immune responses associated with the development and progression of sarcoidosis. A secondary aim was to evaluate the distribution of CD45RA-expressing cells in the different anatomical compartments. Patients suspected to have sarcoidosis and who underwent bronchoscopy with bronchoalveolar lavage (BAL), lung-draining lymph node (LLN) biopsy by EBUS-TBNA and peripheral blood (PB) sampling were included in the study. They were monitored at the Regional Referral Centre of Siena University Hospital and the Respiratory Diseases Unit of Perugia Hospital. Multicolour flow cytometry analysis through FASCLyric was performed to assess T, B and NK cell subsets. Thirty-two patients (median age (IQR) 57 (52-58) years) were consecutively and prospectively enrolled. Machine learning analysis created a model which selected CD56dim16bright, CD8, Tfc, Th17, Th12, Tfh17, Tfh2, TcemRA, ThemRA, T naïve, Tc naïve, Breg, CD1d+CD5+, Th-reg, Tfh, Th1 and CD4 cells with an accuracy of 0.9500 (kappa 0.8750). Comparative analysis found 18 cell populations that differed significantly between the three anatomical compartments. The bloodstream was enriched in ThemRA (p = 0.0416), Tfh2 (p = 0.0189), Tfh17 (p = 0.0257), Th2 (p = 0.0212), Th17 (p = 0.0177), Th-naïve (p = 0.0368), CD56dimCD16bright (p < 0.0001), CD8 (p = 0.0319), TcemRA (p < 0.0001) and Tfc cells (p = 0.0004) compared with the alveolar compartment, while Th-reg were lower in PB than BAL (p = 0.0329). The alveolar compartment was enriched in Breg (p = 0.0249) and CD1d+CD5+ (p = 0.0013) with respect to LLN samples and PB. Conversely, Tfh (p = 0.0470), Th1 (p = 0.0322), CD4 (p = 0.0486) and Tc-naïve (p = 0.0009) were more abundant in LLN than in BAL and PB. It has been speculated that changes in the relative contents of PB cells could be related to changes in production and to the selective redistribution of PB cells to granulomatous foci. This study further supports the fact that sarcoidosis is multisystemic in nature. However, the low level of immune cells in peripheral blood of patients with sarcoidosis is concerning. A re-expression of CD45RA on CD4+ and CD8+ cells could result in a reduction in peripheral immune activity. Thus, changes in the spectrum of the bloodstream may reflect both pathogenic and compensatory processes.

Benralizumab affects NK cell maturation and proliferation in severe asthmatic patients.

INTRODUCTION: The mechanism of action of benralizumab is determined by its afucosylated constant fragment that binds CD16a receptors on the membrane of natural killer cells. Here we analysed changes in Natural Killer and T-cells in Severe asthmatic patients, before and after benralizumab. METHODS: Natural Killer and T-cell subsets were detected through multiparametric flow cytometry. The concentrations of serum cytokines levels were detected through multiplex assay. Functional proliferation assay was performed in follow-up samples in severe asthmatic patients. RESULTS: At baseline, severe asthmatic patients showed higher percentages of immature Natural Killer cells when compared with healthy controls. We demonstrate the proliferative capacity of these cells and their activation after benralizumab administration. Benralizumab shifted Natural Killer cell phenotypes towards maturity. Correlation between the Natural Killer cells and functional parameters and with steroid-sparing was observed. CONCLUSION: Together this data contributes to our understanding of the mechanisms of action of benralizumab in the resolution of inflammation in severe asthma patients.

Krebs von den Lungen-6 (KL-6) in cerebrospinal fluid from neurosarcoidosis patients.

BACKGROUND: Krebs von den Lungen-6 (KL-6) is a high molecular weight (MW) glycoprotein mainly secreted by type II pneumocytes because of lung damage or during regeneration. Neurosarcoidosis (NS), where sarcoid granulomas involve the nervous system, occurs in 5-20% of patients with sarcoidosis. No data is currently available on KL-6 in serum or CSF of NS patients. The present study compared KL-6 concentrations in serum and CSF of NS patients versus others with neurodegenerative (ND) or chronic inflammatory demyelinating (DM) diseases. MATERIALS AND METHODS: Nine NS patients (mean age 46.2 years, range 16-61 years, M/F 5/4), nine patients with a chronic neurodegenerative disease (mean age 53.1 years, range 37-65 years, M/F 5/4) and nine patients with a chronic demyelinating disease (mean age 46.3 years, range 18-65 years, M/F 5/4) were retrospectively enrolled. RESULTS: Measurable CSF concentrations of KL-6 were detected in 7/9 NS patients but in no ND or DM patients. No significant differences in CSF concentrations of ACE were observed between the three groups (p=0.0819). In NS patients, CSF concentrations of KL-6 were directly correlated with CSF albumin index (r=0.98; p<0.0001), albumin (r=0.979, p=0.0001), IgG (r=0.928, p=0.0009) and total protein concentrations (r=0.945, p=0.0004). DISCUSSION: KL-6 is a high MW protein, under physiological conditions it is unlikely to cross the blood-brain barrier. We found KL-6 in CSF from NS and not from ND and DM patients. The finding sustains the specificity of changes in KL-6 in this granulomatous disease, suggesting it as a candidate biomarker for recognition of NS.

Ultra-rare RTEL1 gene variants associate with acute severity of COVID-19 and evolution to pulmonary fibrosis as a specific long COVID disorder.

BACKGROUND: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a novel coronavirus that caused an ongoing pandemic of a pathology termed Coronavirus Disease 19 (COVID-19). Several studies reported that both COVID-19 and RTEL1 variants are associated with shorter telomere length, but a direct association between the two is not generally acknowledged. Here we demonstrate that up to 8.6% of severe COVID-19 patients bear RTEL1 ultra-rare variants, and show how this subgroup can be recognized. METHODS: A cohort of 2246 SARS-CoV-2-positive subjects, collected within the GEN-COVID Multicenter study, was used in this work. Whole exome sequencing analysis was performed using the NovaSeq6000 System, and machine learning methods were used for candidate gene selection of severity. A nested study, comparing severely affected patients bearing or not variants in the selected gene, was used for the characterisation of specific clinical features connected to variants in both acute and post-acute phases. RESULTS: Our GEN-COVID cohort revealed a total of 151 patients carrying at least one RTEL1 ultra-rare variant, which was selected as a specific acute severity feature. From a clinical point of view, these patients showed higher liver function indices, as well as increased CRP and inflammatory markers, such as IL-6. Moreover, compared to control subjects, they present autoimmune disorders more frequently. Finally, their decreased diffusion lung capacity for carbon monoxide after six months of COVID-19 suggests that RTEL1 variants can contribute to the development of SARS-CoV-2-elicited lung fibrosis. CONCLUSION: RTEL1 ultra-rare variants can be considered as a predictive marker of COVID-19 severity, as well as a marker of pathological evolution in pulmonary fibrosis in the post-COVID phase. This notion can be used for a rapid screening in hospitalized infected people, for vaccine prioritization, and appropriate follow-up assessment for subjects at risk. Trial Registration NCT04549831 ( www. CLINICALTRIAL: org ).

Immunological Pathways in Sarcoidosis and Autoimmune Rheumatic Disorders-Similarities and Differences in an Italian Prospective Real-Life Preliminary Study.

BACKGROUND: The pathogenesis of sarcoidosis involves T cells and B lymphocytes that produce autoantibodies. We compared the expression of different T and B cell subsets in sarcoidosis and three B-mediated rheumatic diseases that can affect the lungs in an attempt to identify similarities and differences that distinguish these diseases. METHODS: The study included patients referred to Siena University Hospital's respiratory disease and rheumatology units. Patients were enrolled prospectively and consecutively. Healthy volunteers were also included. Multicolor flow cytometry was performed on phenotype T and B cell subsets. Multivariate analysis was carried out to reduce the dimensionality of the data. RESULTS: Fifteen patients had a diagnosis of sarcoidosis, fourteen idiopathic inflammatory myopathies (IIM), five granulomatosis with polyangiitis (GPA), ten microscopic polyangiitis (MPA), and seven were controls. Thirty-five T and B cell subsets were phenotyped, 15 of which were significantly different in sarcoidosis, B-mediated rheumatic disorders, and controls. Principal components analysis distinguished the four groups of patients with a total explained variance of 54.7%. A decision tree was constructed to determine which clustering variables would be most useful for distinguishing sarcoidosis, IIM, MPA, and GPA. The model showed regulatory T helper cells (Th-reg) > 5.70% in 91% of sarcoidosis patients as well as Th-reg ≤ 5.70 and Th17 > 43.27 in 100% of MPA. It also showed Th-reg ≤ 5.70, Th17 ≤ 43.27 and Tfh-reg ≥ 7.81 in 100% of GPA patients, and Th-reg ≤ 5.70, Th17 ≤ 43.27 and Tfh-reg ≤ 7.81 in 100% of IIM patients. CONCLUSION: The immune cell profile sheds light on similarities and differences between sarcoidosis and B-mediated rheumatic diseases. Sarcoidosis and autoimmune diseases show similar patterns of cellular immune dysregulation, suggesting a common pathogenic pathway that may provide an opportunity for further understanding autoimmunity and exploring biological therapies to treat sarcoidosis.

MR-proADM as Prognostic Factor of Outcome in COVID-19 Patients.

BACKGROUND: Serum mid-regional proadrenomedullin (MR-proADM) has emerged as a marker of organ failure (mainly lungs and kidneys) and poor prognosis in patients admitted to intensive care (IC); some reports also suggest it and other markers, such as Krebs von den Lungen-6 (KL-6) and interleukin-6 (IL-6), as a prognostic biomarker of COVID-19. The aim of the study was to evaluate the performance MR-proADM in hospitalized COVID-19 patients for predicting in-hospital mortality and need for non-invasive or invasive respiratory support. METHODS: We enrolled 74 patients hospitalized in the COVID Unit of Siena Hospital from March to May 2020, for whom serum samples were available on admission for assay of MR-proADM, KL-6 and IL-6. Demographic data, comorbidities, medical history and clinical laboratory data on days 1-3 of admission and Simplified Acute Physiology Score and Simplified Organ Failure Assessment scores calculated at day 1 were collected retrospectively, as well as mortality and IC admission data. RESULTS: 12 patients died in hospital (16%) and 14 patients were admitted to IC (19%). Serum concentrations of MR-proADM on admission and on day 1 were higher among non-survivors than among survivors (p = 0.015 and p = 0.045, respectively), while those on day 3 were not significantly different. Patients needing respiratory support had higher MR-proADM concentrations on admission than the others (p = 0.046), and those requiring invasive mechanical ventilation had higher MR-proADM on day 1 (p = 0.017). Serum concentrations of KL-6 and IL-6 were significantly higher in non-survivors (p = 0.03 and p = 0.004, respectively). ROC curve analysis showed that serum MR-proADM on day 1 had the best accuracy in predicting death and/or IC admission (AUC = 0.9583, p = 0.0006); the combination of all three biomarkers further improved the accuracy of prediction of death or IC admission (AUC = 0.9793; p = 0.00004). CONCLUSIONS: Our data sustain the potential of serum MR-proADM as a reliable prognostic biomarker of hospitalized COVID-19 patients and confirms the utility of the three markers in the management and risk stratification of hospitalized patients. The markers are collected mini-invasively and are quick to analyze and cost-effective.

Prevalence of myositis specific and associated antibodies in a cohort of patients affected by idiopathic NSIP and no hint of inflammatory myopathies.

The presence of interstitial lung disease (ILD) is a common and fearsome feature of idiopathic inflammatory myopathies (IIM). Such patients show radiological pattern of non-specific interstitial pneumonia (NSIP). The present study aimed to assess the prevalence of myositis-specific and myositis-associated antibodies (MSA and MAA) in a cohort of patients with a previous diagnosis of NSIP and no sign or symptom of IIM. Secondly, it will be assessed whether patients displaying MSA and/or MAA positivity have a worse or a better outcome than idiopathic NSIP. All patients affected by idiopathic NSIP were enrolled. MSA and MAA were detected using EUROLINE Autoimmune Inflammatory Myopathies 20 Ag (Euroimmun Lubeck, Germany), line immunoassay. A total of 16 patients (mean age 72 ± 6.1 years old) were enrolled. Six out of 16 patients (37.5%) had significant MSA and/or MAA positivity: one displayed positivity of anti-PL-7 (+ +), one of anti-Zo (+ +), anti-TIF1γ (+ + +) and anti-Pm-Scl 75 (+ + +), one of anti-Ro52 (+ +), one of anti-Mi2ß (+ + +), one of anti-Pm-Scl 75 (+ + +) and the latter of both anti-EJ (+ + +) and anti-Ro52 (+ + +).Two out of 7 seropositive patients showed a significant impairment of FVC (relative risk 4.8, 95% CI 0.78-29.5; p = 0.0350). Accordingly, among the 5 patients that started antifibrotic treatment during the observation time, 4 were seronegative. Our findings highlighted a potential autoimmune or inflammatory in idiopathic NSIP patients and also in those without significant rheumatological symptoms. A more accurate diagnostic assessment may ameliorate diagnostic accuracy as well as may provide new therapeutic strategy (antifibrotic + immunosuppressive). A cautious assessment of NSIP patients with a progressive and non-responsive to glucocorticoids disease course should therefore include an autoimmunity panel comprising MSA and MAA.

Rituximab-induced hypogammaglobulinaemia in patients affected by idiopathic inflammatory myopathies: a multicentre study.

OBJECTIVES: Rituximab (RTX) is an anti-CD20 chimeric monoclonal antibody recommended as off-label treatment in patients with idiopathic inflammatory myopathies (IIM). The present study aimed to evaluate changes in immunoglobulin (Ig) levels during RTX-treatment and their potential association with infections in a cohort of IIM patients. METHODS: Patients evaluated in the Myositis clinic belonging to the Rheumatology Units of Siena, Bari and Palermo University Hospitals, and treated for the first time with RTX were enrolled. Demographic, clinical, laboratory and treatment variables, including previous and concomitant immunosuppressive drugs and glucocorticoid (GC) dosage were analysed before (T0) and after 6 (T1) and 12 (T2) months of RTX treatment. RESULTS: Thirty patients (median age, IQR 56 (42-66); 22 female) were selected. During the observational period, low levels of IgG (<700 mg/dl) and IgM (<40 mg/dl) occurred in 10% and 17% of patients, respectively. However, no one showed severe (IgG<400 mg/dl) hypogammaglobulinaemia. IgA concentrations were lower at T1 than T0 (p=0.0218), while IgG concentrations were lower at T2 compared to those at baseline (p=0.0335). IgM concentrations were lower at T1 and T2 than T0 (p<0.0001), as well at T2 than T1 (p=0.0215). Three patients suffered major infections, two others had paucisymptomatic COVID-19, one suffered from mild zoster. GC dosages at T0 were inversely correlated with IgA T0 concentrations (p=0.004, r=- 0.514). No correlation was found between demographic, clinical and treatment variables and Ig serum levels. CONCLUSIONS: Hypogammaglobulinaemia following RTX is uncommon in IIM and is not related to any clinical variables, including GC dosage and previous treatments. IgG and IgM monitoring after RTX treatment does not seem useful in stratifying patients who require closer safety monitoring and prevention of infection, due to the lack of association between hypogammaglobulinaemia and the onset of severe infections.

The Effects of Interstitial Lung Diseases on Alveolar Extracellular Vesicles Profile: A Multicenter Study.

Diagnosis of interstitial lung diseases (ILD) is difficult to perform. Extracellular vesicles (EVs) facilitate cell-to-cell communication, and they are released by a variety of cells. Our goal aimed to investigate EV markers in bronchoalveolar lavage (BAL) from idiopathic pulmonary fibrosis (IPF), sarcoidosis and hypersensitivity pneumonitis (HP) cohorts. ILD patients followed at Siena, Barcelona and Foggia University Hospitals were enrolled. BAL supernatants were used to isolate the EVs. They were characterized by flow cytometry assay through MACSPlex Exsome KIT. The majority of alveolar EV markers were related to the fibrotic damage. CD56, CD105, CD142, CD31 and CD49e were exclusively expressed by alveolar samples from IPF patients, while HP showed only CD86 and CD24. Some EV markers were common between HP and sarcoidosis (CD11c, CD1c, CD209, CD4, CD40, CD44, CD8). Principal component analysis distinguished the three groups based on EV markers with total variance of 60.08%. This study has demonstrated the validity of the flow cytometric method to phenotype and characterize EV surface markers in BAL samples. The two granulomatous diseases, sarcoidosis and HP, cohorts shared alveolar EV markers not revealed in IPF patients. Our findings demonstrated the viability of the alveolar compartment allowing identification of lung-specific markers for IPF and HP.