Exhaled nitric oxide and exhaled breath condensate pH in severe refractory asthma

BACKGROUND

Distinct inflammatory cellular phenotypes of severe refractory asthma (SRA) have been reported. Fractional exhaled nitric oxide (FeNO) primarily is related to eosinophilic inflammation. Exhaled breath condensate (EBC) pH has been suggested as a noninvasive tool in the assessment of patients with asthma. We sought to determine whether FeNO and EBC pH could identify the presence and type of the underlying cellular inflammation in patients with SRA.

METHODS

Twenty-nine patients with SRA, 27 patients with moderate asthma, and 17 healthy subjects underwent FeNO measurement, EBC collection for pH measurement, and sputum induction for cell count identification.

RESULTS

FeNO was significantly higher and pH significantly lower in patients with SRA than in the other groups. In SRA, FeNO levels of > 19 parts per billion were associated with a sensitivity of 0.78 and a specificity of 0.73 for sputum eosinophilia, whereas FeNO levels of < 19 parts per billion were associated with a sensitivity of 0.63 and a specificity of 0.9 for sputum neutrophilia irrespective of the presence of eosinophils. The pH failed to predict the cellular profile in SRA, but a cutoff value of < 7.37 could predict sputum eosinophilia in moderate asthma.

CONCLUSIONS

In patients with SRA, different FeNO threshold values can identify those with predominant eosinophilia as well as those with neutrophilia. FeNO levels were reduced in patients with predominant neutrophilia regardless of the concomitant presence of eosinophilia. Although pH could not identify the cellular profile in SRA, it seemed to be a better index for predicting eosinophilia in moderate asthma.

Combined pulmonary fibrosis and emphysema: The many aspects of a cohabitation contract

Combined pulmonary fibrosis and emphysema (CPFE) is a clinical entity characterized by the coexistence of upper lobe emphysema and lower lobe fibrosis. Patients with this condition experience severe dyspnea and impaired gas exchange with preserved lung volumes. The diagnosis of the CPFE syndrome is based on HRCT imaging, showing the coexistence of emphysema and pulmonary fibrosis both in varying extent and locations within the lung parenchyma. Individual genetic background seem to predispose to the development of the disease. The risk of the development of pulmonary hypertension in patients with CPFE is high and related to poor prognosis. CPFE patients also present a high risk of lung cancer. Mortality is significant in patients with CPFE and median survival is reported between 2.1 and 8.5 years. Currently, no specific recommendations are available regarding the management of patients with CPFE. In this review we provide information on the existing knowledge on CPFE regarding the pathophysiology, clinical manifestations, imaging, complications, possible therapeutic interventions and prognosis of the disease.

Exhaled nitric oxide and exhaled breath condensate pH as predictors of sputum cell counts in optimally treated asthmatic smokers

BACKGROUND AND OBJECTIVE

Smoking is thought to modify the pattern of airway inflammation. Induced sputum provides useful information on cellular phenotype in inflammatory airways disorders; however, it is time-consuming and difficult to implement in everyday clinical practice. The aim of this study was to determine whether exhaled NO (FeNO) and exhaled breath condensate (EBC) pH differed in asthmatic smokers compared with asthmatic non-smokers and healthy subjects, and to evaluate the performance of FeNO and EBC pH for predicting the cellular phenotype of induced sputum.

METHODS

Asthmatic smokers (n = 40) and non-smoking asthmatic patients (n = 43) were recruited for the study. Healthy smoking (n = 30) or non-smoking (n = 30) subjects served as controls. FeNO and EBC pH were measured and all subjects underwent sputum induction for assessment of cell counts.

RESULTS

EBC pH was significantly lower in asthmatic smokers compared with non-smokers (P < 0.01). FeNO levels were also significantly lower in asthmatic smokers compared with non-smokers (P < 0.001). EBC pH was inversely associated with sputum eosinophils in both asthmatic smokers and non-smokers (P < 0.001), whereas it was inversely associated with sputum neutrophils only in asthmatic smokers (P < 0.001). FeNO was positively associated with sputum eosinophils both in asthmatic smokers and non-smokers (P < 0.001) but was not associated with sputum neutrophils. In asthmatic smokers, FeNO was a better predictor of sputum eosinophilia, whereas EBC pH was a better predictor of sputum neutrophilia. A combination of FeNO ≤ 14 ppb together with EBC pH > 7.20 predicted the paucigranulocytic induced sputum phenotype.

CONCLUSIONS

EBC pH and FeNO levels were significantly lower in asthmatic smokers compared with non-smokers. Combined specific cut-off levels for FeNO and EBC pH may predict the paucigranulocytic phenotype in asthmatic smokers.

Vascular endothelial growth factor and cysteinyl leukotrienes in sputum supernatant of patients with asthma

BACKGROUND

Vascular endothelial growth factor (VEGF) is considered to be the most important angiogenic factor in asthma. Cysteinyl leukotrienes (Cyst-LTs) have been implicated in vascular permeability in asthma. Cyst-LTs receptor antagonists modulate vascular permeability by reducing VEGF expression.

OBJECTIVE

We aimed to determine the levels of VEGF and Cyst-LTs in sputum supernatants of patients with asthma and to investigate possible associations within them and with airway vascular permeability (AVP) index. Possible confounding factors were also assessed.

METHODS

One hundred twenty one patients with asthma (38 with severe refractory asthma, 41 smokers) and 30 healthy subjects (15 smokers) were studied. All subjects underwent lung function tests, and sputum induction for cell count identification and VEGF, Cyst-LTs, measurement in supernatants. AVP index was also assessed.

RESULTS

Both VEGF & Cyst-LTs (pg/ml) levels were significantly elevated in patients with asthma compared to normal subjects (median, interquartile ranges 845 [487-1034] vs. 432 (327-654) and 209 [171-296] vs. 92 [75-114] respectively, p < 0.001 for both). Multivariate regression analysis in the whole group showed a significant association of Cyst-LTs levels in sputum supernatants with VEGF levels in sputum supernatants and AVP index. A similar positive association was observed between VEGF levels in sputum supernatants and AVP index. The presence of Severe asthma was a significant covariate for both associations.

CONCLUSION

Our results indicate that Cyst-LTs may modulate vascular permeability by up-regulating VEGF expression. The above effect seems to be affected by asthma severity.

Serum Levels of Surfactant Proteins in Patients with Combined Pulmonary Fibrosis and Emphysema (CPFE)

Introduction

Emphysema and idiopathic pulmonary fibrosis (IPF) present either per se or coexist in combined pulmonary fibrosis and emphysema (CPFE). Serum surfactant proteins (SPs) A, B, C and D levels may reflect lung damage. We evaluated serum SP levels in healthy controls, emphysema, IPF, and CPFE patients and their associations to disease severity and survival.

Methods

122 consecutive patients (31 emphysema, 62 IPF, and 29 CPFE) and 25 healthy controls underwent PFTs, ABG-measurements, 6MWT and chest HRCT. Serum levels of SPs were measured. Patients were followed-up for 1-year.

Results

SP-A and SP-D levels differed between groups (p = 0.006 and p<0.001 respectively). In post-hoc analysis, SP-A levels differed only between controls and CPFE (p<0.05) and CPFE and emphysema (p<0.05). SP-D differed between controls and IPF or CPFE (p<0.001 for both comparisons). In IPF SP-B correlated to pulmonary function while SP-A, correlated to the Composite Physiological Index (CPI). Controls current smokers had higher SP-A and SP-D levels compared to non-smokers (p = 0.026 and p = 0.023 respectively). SP-D levels were higher in CPFE patients with extended emphysema (p = 0.042). In patients with IPF, SP-B levels at the upper quartile of its range (≥26 ng/mL) presented a weak association with reduced survival (p = 0.05).

Conclusion

In conclusion, serum SP-A and SP-D levels were higher where fibrosis exists or coexists and related to disease severity, suggesting that serum SPs relate to alveolar damage in fibrotic lungs and may reflect either local overproduction or overleakage. The weak association between high levels of SP-B and survival needs further validation in clinical trials.

Treating CTDs related fibrotic ILDs by immunosuppressants: "facts and faults"

Fibrotic interstitial lung diseases (ILDs) are commonly encountered in scleroderma where they significantly influence prognosis. The mainstay of treatment in idiopathic fibrotic ILDs for the past 30 years was based on the combined administration of prednisone and cyclophosphamide (CYC) or prednisone, azathioprine plus N-acetyl cysteine, recently proved ineffective and harmful. Rheumatologists also despite "facts" showing that CYC treatment has no beneficial impact on fibrotic ILDs in scleroderma continue to commit the same, in a manner of speaking, "faults" by "treating their fibrotic ILDs by immunosuppressants." In this issue of the journal, Panopoulos et al. (Lung, 191, 483-489, 2013) recognizing the minimal effect of CYC on fibrotic ILDs in scleroderma patients and the increased use in clinical practice of mycophenolate mofetil (MMF) as an alternative, report that MMF use to replace CYC in this setting is not supported, confirming that restoration of purely fibrotic damage in the lungs remains one of the most challenging fields in medicine.

Surfactant Proteins in Smoking-Related Lung Disease

Pulmonary surfactant is a highly surface-active mixture of proteins and lipids that is synthesized and secreted in the alveoli by type II epithelial cells and is found in the fluid lining the alveolar surface. The protein part of surfactant constitutes two hydrophilic proteins (SP-A and SP-D) that regulate surfactant metabolism and have immunologic functions, and two hydrophobic proteins (SP-B and SP-C), which play a direct role in the organization of the surfactant structure in the interphase and in the stabilization of the lipid layers during the respiratory cycle. Several studies have shown that cigarette smoke seems to affect, in several ways, both surfactant homeostasis and function. The alterations in surfactants' biophysical properties caused by cigarette smoking, contribute to the development of several smoking related lung diseases. In this review we provide information on biochemical and physiological aspects of the pulmonary surfactant and on its possible association with the development of two major chronic diseases of the lung known to be related to smoking, i.e. chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Additional information on the possible role of surfactant protein alterations and/or dysfunction in the combination of these two conditions, recently described as combined pulmonary fibrosis and emphysema (CPFE) are also provided.

Myelodysplastic syndromes and idiopathic pulmonary fibrosis: a dangerous liaison

Previous studies have shown that the co-existence of bone marrow failure and pulmonary fibrosis in a single patient or in a family is suggestive of telomere related genes (TRG) germline mutations. This study presents the genetic background, clinical characteristics, and outcome of a group of five Greek patients co-affected with IPF and MDS. Four out of five patients developed an IPF acute exacerbation that was not reversible. We failed to detect any mutation in the TERT, TERC, DKC1, TINF2, RTEL1, PARN, NAF1, ACD, NHP2 and NOP10 genes in any patient. Moreover, telomere length was normal in the two patients tested. This could suggest that although the co-occurence of IPF and MDS are suggestive of TRG mutation in patients < 65 years old, in the elderly it may occur without germline mutations and could negatively affect prognosis. Physicians should be aware for possible IPF deterioration and therapeutic options for MDS should be wisely considered.

Device use errors among patients with asthma and COPD and the role of training: a real-life study

Background and objectives: Administration of inhaled medication for asthma and COPD is often difficult and incorrect device use is associated with unfavorable outcomes. We aimed to evaluate device use errors in asthma and COPD patients and to associate incorrect use with the patient's characteristics and medical history.Methods: Demographics and medical history were recorded. The use of each prescribed device was evaluated according to predefined steps.Results: 607 patients (49.9% male, median age (IQR) 63 (51, 70) years performed 663 demonstrations (56 patients were using 2 different types of devices). 51.4% were treated for asthma and 48.6% for COPD. 79.6% of demonstrations were performed using DPIs. Errors were documented on 41.2% of demonstrations and were associated with the type of device, p < 0.001. Elderly patients were less frequently using their devices correctly compared to younger patients, 50.8% vs 62.2%, respectively, p = 0.007. Correct demonstrations were more among asthmatics compared to COPD patients 63.1% vs 54.5%, p = 0.024. Incorrect use was associated with more acute exacerbations in the preceding year [median(IQR), 1(0, 2) vs 1(0, 1)], for incorrect and correct use, respectively, p < 0.001. Upon demonstration, 15.5% of patients have never been trained (i.e., undergone actual demonstrations and observation while using their device) by anyone. Errors occurred more frequently among patients who reported not to be trained compared to those who were trained, 67.0% vs 14.6%, respectively, p < 0.001. The commonest error was associated with the inspiration maneuver and accounted for the 48.3% of errors in the DPIs and 53.0% of errors in the MDIs.Conclusion: Device use errors are common and associated with unfavorable outcomes. Trained patients were more likely to use the device correctly.

Cardiovascular risk in pulmonary alveolar proteinosis

We hypothesized that cardiovascular events and/or indices of cardiac dysfunction may be increased in pulmonary alveolar proteinosis (PAP). Systemic and pulmonary arterial hypertension, arrhythmias, pulmonary embolism, stroke and ischemic heart attack were reported. Patients underwent serum anti-GM-CSF antibodies, disease severity score (DSS), Doppler transthoracic echocardiograph, glucose, thyroid hormones, lipids, troponin and pro-Brain natriuretic peptide (BNP) examination. Thirteen patients (8 female) were studied, median age of 47. Pro-BNP inversely related to DLCO% and TLC%; troponin directly related to DSS, age, P(A-a)O2, left atrium-, left ventricle-end-diastole diameter and BMI. On multiple regression analysis DSS was the only parameter significantly and strongly related with troponin (R(2) = 0.776, p = 0.007). No cardiovascular event was reported during follow-up. In PAP cardiovascular risk indices relate to lung disease severity. Therefore, PAP patients could be at increased risk for cardiovascular events. Quantitation of its magnitude and potential links to lungs' physiologic derangement will be addressed in future studies.

Prevalence, distribution and clinical significance of joints, muscles and bones in sarcoidosis: an 18F-FDG-PET/CT study

OBJECTIVES

In Sarcoidosis joints-muscles-bones (JMBs) localizations are of the least common. ¹⁸F-FDG-PET/CT imaging revolutionized detection of JMBs involvement by adding metabolic activity information and allowing for a comprehensive, whole-body mapping of the disease.

AIM AND METHODS

This study investigated prevalence, distribution, and clinical significance of JMBs sarcoidosis in 195 consecutive patients that underwent ¹⁸F-FDG PET/CT examination.

RESULTS

Joint and bone involvement were encountered in 15% of patients with a mean of the maximum-standardized-uptake-value (SUV_max) of 6.1. Most common location was the axial skeleton. Hypercalciuria was significantly more frequent in patients with osseous involvement (p = 0.003). Muscle activity (SUVmax = 2.4) was encountered in 20% of the patients, most frequently in treatment-naïve (p = 0.02). The muscles of the lower extremities were affected the most. Muscle and bone localization coexist in 50% of the cases. JMBs disease was almost asymptomatic, not related to chronicity but to pulmonary, nodal, and systemic disease. Long-term follow-up and treatment response of affected patients confirmed sarcoidosis.

CONCLUSION

¹⁸F-FDG-PET/CT revealed JMBs localizations and coexistence with other organ sites supporting the concept that sarcoidosis is a systemic disease. By allowing an integrative interpretation of multi-organ involvement in the context of a pattern highly suggestive of sarcoidosis, it strongly keeps-off the diagnosis of malignancy.

OP0014 CTLA4-Ig INDUCES TOLEROGENIC PROPERTIES OF DENDRITIC CELLS BY ALTERING CELLULAR METABOLISM

Background

Dendritic cells (DCs) are well-recognized for their dual role either for T cell activation (1) or for inducing T cells tolerance (2). Their ability to modulate T-cell responses has made them an interesting tool for the immunotherapy of autoimmune diseases (3). Cytotoxic T lymphocyte antigen 4 (CTLA4) is a negative co-stimulatory molecule, which binds to CD80/CD86 on DCs. CTLA4 induces its immunoregulatory function through trans-endocytosis resulting in impaired co-stimulation (4), or through the induction of indoleamine-pyrrole 2,3-dioxygenase (IDO) enzyme (5). Moreover, it has been demonstrated that CTLA4 impairs the autophagic machinery of DCs and therefore suppresses DC inflammatory function (6). Nevertheless, the molecular mechanisms underlying the CTLA4-mediated immunomodulatory phenotype, require a more comprehensive understanding.

Objectives

In this study we focused on tolerogenic DCs (tolDCs) and we applied CTLA4-Ig as a tool to induce them. We aim to assess the immunoregulatory potential of CTLA4-mediated tolDCs and to investigate thoroughly the intracellular pathways that are involved in the induction of tolerance.

Methods

Healthy human monocytes were isolated from peripheral blood and differentiated into monocyte-derived dendritic cells (DCs). After 6 days, immature DCs activated with LPS were treated with CTLA4-Ig or IgG control for 18 hours. The anti-inflammatory function of DCs was validated using RT-PCR and flow cytometry and DCs proceeded to RNA sequencing. The metabolic pathways were studied using a Seahorse bioanalyzer.

Results

CTLA4-Ig-treated DCs showed significantly decreased HLA-DR, CD80/CD86 expression as compared to IgG-treated cells (n=4, p=0,0294, n=5 p=0,0079). Moreover, IL6 and TNFα mRNA expression, hallmarks of inflammatory cytokines secreted by DCs, was reduced upon CTLA4-Ig (n=5, p=0,0079). To elucidate the pathways involved in DC reprogramming upon CTLA4-Ig treatment, we performed RNA sequencing and we concluded with 1270 differentially expressed genes (p-value <0.05 counts>10). Interestingly, transcriptomic analysis revealed that the majority of genes (n=900) participated in metabolic processes, specifically in OXPHOS pathway and mitochondrial function. To further support the above metabolic changes, we performed Seahorse assays and confirmed that tolDCs had lower basal OXPHOS and decreased ATP production compared with mature DCs. Furthermore, expression of phosphorylated mammalian target of rapamycin (mTOR) and AKT1, central regulators of metabolism, was increased in CTLA4-mediated tolDCs (n=3, p= 0,0308 and p=0,0347).

Conclusion

Herein we confirmed that CTLA4 restricts the pro-inflammatory properties of activated DCs. RNA-seq analysis revealed that this anti-inflammatory deviation of DCs is characterized by the modification of the expression of genes implicated in cellular metabolism. Metabolic experiments confirmed that CTLA4-mediated tolDCs have reduced OXPHOS and ATP production, whereas, mTOR signaling is upregulated. In future experiments, we will investigate the mechanism that CTLA4 may promote metabolic changes thus contributes to the immunoregulatory phenotype of DCs and could represent a therapeutic target.

References

[1]Van Brussel et al., Mediators Inflamm2012, 690-643 (2012).

[2]B. Pulendran et al., Nature immunology11, 647-655 (2010).

[3]B. E. Phillips et al., Front Immunol8, 1279 (2017).

[4]O. S. Qureshi et al., Science332, 600-603 (2011).

[5]D. H. Munn et al., J Immunol172, 4100-4110 (2004).

[6]T. Alissafi et al., J Clin Invest127, 2789-2804 (2017).

Acknowledgements

This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning» in the context of the project “Strengthening Human Resources Research Potential via Doctorate Research” (MIS-5000432), implemented by the State Scholarships Foundation (ΙΚΥ).

Disclosure of Interests

None declared.

AB0090 BASELINE IgG-Fc N-GLYCOSYLATION PROFILE IS ASSOCIATED WITH LONG-TERM OUTCOME IN A COHORT OF EARLY INFLAMMATORY ARTHRITIS PATIENTS

Background

Rheumatoid arthritis (RA) is a systemic autoimmune disease which causes chronic joint inflammation and functional limitation1,2. The diagnosis of rheumatoid arthritis (RA) is mainly based on clinical data and RA specific autoantibodies, while the prediction of long-term prognosis from disease outset is not clinically reliable3,4. The importance of immunoglobulin G (IgG) and its Fc N-glycosylation in inflammation of RA has been described, with changes in the glycosylation profiles observed years before the diagnosis of RA5.

Objectives

We herein sought to assess the value of total serum IgG Fc N-glycosylation as a diagnostic and prognostic biomarker in patients with early inflammatory arthritis (EIA). Specifically, we aim to assess whether IgG N-glycoform levels may predict the diagnosis of RA or undifferentiated arthritis (UA) and the long-term disease‘s outcome in patients with EIA arthritis patients naïve to treatment.

Methods

The “Early Arthritis Clinic” of the University Hospital of Heraklion is a prospective cohort of patients with inflammatory arthritis. For the present study, we selected a group of patients naïve to any immunosuppressive treatments with available serum at baseline evaluation (n=118). At baseline, demographics, RA clinical characteristics (DAS28, HAQ-DI) and laboratory tests [autoantibodies (RF and/or ACPA)], were also recorded. The patients were prospectively followed for two years, with clinical, laboratory and disease-related treatments documented. A diagnosis of RA or UA was based on established classification criteria6. In order to assess long-term prognosis we formulated a combined “index” of favourable outcome if the patients fulfilled all the following at 24 months of follow-up: remission or low disease activity (based on DAS28 < 3.2) and normal functionality (based on HAQ ≤ 0.25) while on treatment with csDMARDs and never use bDMARDs. We applied a state-of-the-art liquid chromatography - mass spectrometry (LC-MS) based workflow for analysis of subclass-specific IgG Fc N-glycosylation at the baseline7.

Results

We studied 118 EIA patients [age (mean, SD) (53, 15.6) years, females (80.5%), symptoms duration (53.8, 8.7) years, ACPA positive (16%), DAS28 (4.8, 0.14)]. During the 2 years of follow-up, 60% of the patients were diagnosed with RA and 40% with UA. Although patients with UA had higher relative abundances of galactosylated and sialylated N-glycoforms (H4N4F1, H5N4F1 and H5N4F1S1) in all IgG subclasses at baseline compared to RA patients, differences were not statistically important. Interestingly, we observed a significant association between high levels of IgG2/3 galactosylation for H5N4F1 [effect 0.63, adjusted p=0.036)] and H3N4F1 [effect -0.55122, adjusted p=0.0496) and favorable outcome after two years of treatment.

Conclusion

In our cohort of EIA we found IgG2/3 Fc N-glycoforms to be associated with a favorable prognosis after 2 years of follow-up. Should the present data be confirmed in a larger cohort could be of clinical value. Since currently available prognostic tools have significant limitations, further research should aim to the development of a predictive tool of high specificity and sensitivity based on the combination of clinical, serological data and novel biomarkers.

References

[1]Smolen JS, et al. Lancet (2016) 388(10055):2023-38. doi: 10.1016/S0140-6736(16)30173-8

[2]Firestein GS, McInnes IB. Immunity (2017) 46(2):183-96. doi: 10.1016/j.immuni.2017.02.006.

[3]Scott DL, et al.J. Lancet (2010) 376(9746):1094-108. doi: Doi 10.1016/S0140-6736(10)60826-4.

[4]Weyand CM, Goronzy JJ. Nat Immunol (2021) 22(1):10-8. doi: 10.1038/s41590-020-00816-x.

[5]Ligier S, et al. Br J Rheumatol (1998) 37(12):1307-14. doi: 10.1093/rheumatology/37.12.1307.

[6]Aletaha D, et al. Ann Rheum Dis (2010) 69(9):1580-8. doi: 10.1136/ard.2010.138461.

[7]De Leoz MLA, et al. Molecular & Cellular Proteomics (2020) 19(1):11-30. doi: 10.1074/mcp.RA119.001677.

Acknowledgements

This research was funded by the GlySign and SYSCID – European Union’s Horizon 2020 research and innovation programs under the Marie Skłodowska-Curie, grant numbers 722095 and 733100, respectively.

Disclosure of Interests

Thomas Sénard: None declared, Irini Flouri: None declared, Frano Vučković Employee of: Genos Ltd, Garyfalia Papadaki: None declared, Panagiota Goutakoli: None declared, Aggelos Banos: None declared, Maja Pučić-Baković Employee of: Genos Ltd, Marija Pezer Employee of: Genos Ltd, George Bertsias: None declared, Gordan Lauc Shareholder of: Genos Ltd, a private research organization that specializes in high-throughput glycomic analyses and has several patents in this field., Prodromos Sidiropoulos: None declared