Cytokines Removal During Ex-Vivo Lung Perfusion: Initial Clinical Experience.

Ex Vivo Lung Perfusion (EVLP) can be potentially used to manipulate organs and to achieve a proper reconditioning process. During EVLP pro-inflammatory cytokines have been shown to accumulate in perfusate over time and their production is correlated with poor outcomes of the graft. Aim of the present study is to investigate the feasibility and safety of cytokine adsorption during EVLP. From July 2011 to March 2020, 54 EVLP procedures have been carried out, 21 grafts treated with an adsorption system and 33 without. Comparing the grafts perfused during EVLP with or without cytokine adsorption, the use of a filter significantly decreased the levels of IL10 and GCSFat the end of the procedure. Among the 38 transplanted patients, the adsorption group experienced a significant decreased IL6, IL10, MCP1 and GCSF concentrations and deltas compared to the no-adsorption group, with a lower in-hospital mortality (p = 0.03) and 1-year death rate (p = 0.01). This interventional study is the first human experience suggesting the safety and efficacy of a porous polymer beads adsorption device in reducing the level of inflammatory mediators during EVLP. Clinical impact of cytokines reduction during EVLP must be evaluated in further studies.

Validation of a Simple, Rapid, and Cost-Effective Method for Acute Rejection Monitoring in Lung Transplant Recipients.

Despite advances in immunosuppression therapy, acute rejection remains the leading cause of graft dysfunction in lung transplant recipients. Donor-derived cell-free DNA is increasingly being considered as a valuable biomarker of acute rejection in several solid organ transplants. We present a technically improved molecular method based on digital PCR that targets the mismatch between the recipient and donor at the HLA-DRB1 locus. Blood samples collected sequentially post-transplantation from a cohort of lung recipients were used to obtain proof-of-principle for the validity of the assay, correlating results with transbronchial biopsies and lung capacity tests. The results revealed an increase in dd-cfDNA during the first 2 weeks after transplantation related to ischemia-reperfusion injury (6.36 ± 5.36%, p < 0.0001). In the absence of complications, donor DNA levels stabilized, while increasing again during acute rejection episodes (7.81 ± 12.7%, p < 0.0001). Respiratory tract infections were also involved in the release of dd-cfDNA (9.14 ± 15.59%, p = 0.0004), with a positive correlation with C-reactive protein levels. Overall, the dd-cfDNA percentages were inversely correlated with the lung function values measured by spirometry. These results confirm the value of dd-cfDNA determination during post-transplant follow-up to monitor acute rejection in lung recipients, achieved using a rapid and inexpensive approach based on the HLA mismatch between donor and recipient.

Severe asthma and COVID-19: lessons from the first wave.

OBJECTIVE: Severe asthma is considered a risk factor for SARS-Coronavirus 2 (SARS-CoV-2) infection but scientific evidences are lacking. METHODS: we performed a literature search and review based on PubMed database national, international recommendations as well as papers on severe asthmatic patients and their management during SARS-CoV-2 pandemic. RESULTS: the majority of international recommendations, expert panels and editorials provide indications about management of severe asthmatic patients. No published studies evaluated the effects of biologic agents on severe asthmatic patients during SARS-CoV-2 pandemic. CONCLUSIONS: the relationship between SARS-CoV-2 and asthma is variable worldwide and severe asthmatic patients were seldom reported in published cohorts. International recommendations suggest maintaining asthma under control to limit exacerbations occurrence, by using all available treatment. The minimum steroid dosage effective to control symptoms should be maintained to avoid exacerbations; biologic agents administration should be regularly scheduled encouraging patient support programmes.

Future Perspectives of Revaluating Mild COPD.

In 2020, COPD was the third leading cause of death worldwide. Lung function is central for the diagnosis of this disease, and COPD severity is still partially classified based on airflow obstruction, which can range from "mild" (GOLD 1 group, FEV1 ≥80% predicted) to "very severe" (GOLD 4, FEV1 <30% predicted). However, the term "mild COPD" needs to be carefully analyzed. Several studies have shown that even in the presence of a mild obstruction, patients can have significant symptoms, physiological deterioration, evidence of emphysema, and suffer from recurrent exacerbations. Small airways pathology significantly correlates with the presence of symptoms, and it has been demonstrated that the onset of bronchiolitis occurs earlier than that of emphysema. These damages have long been known to not be detectable with conventional tests, and exclusive reliance on spirometry is not enough to adequately study and stage a patient with "mild COPD." Therefore, early identification of COPD is of utmost importance in the light of modifying the natural course of the disease. However, patients with early lung damage are yet to be included and studied in interventional clinical trials.

Is there life on the airway tree? A pilot study of bronchial cell vitality and tissue morphology in the ex vivo lung perfusion (EVLP) era of lung transplantation.

BACKGROUND: Ex vivo lung perfusion (EVLP) is a relevant procedure to increase the lung donor pool but could potentially increase the airway tree ischemic injury risk. METHODS: This study aimed to evaluate the direct effect of EVLP on the airway tree by evaluating bronchial cell vitality and tissue signs of injury on a series of 117 bronchial rings collected from 40 conventional and 19 EVLP-treated lung grafts. Bronchial rings and related scraped bronchial epithelial cells were collected before the EVLP procedure and surgical anastomosis. RESULTS: The preimplantation interval was significantly increased in the EVLP graft group (p < 0.01). Conventional grafts presented cell viability percentages of 47.07 ± 23.41 and 49.65 ± 21.25 in the first and second grafts which did not differ significantly from the EVLP group (first graft 50.54 ± 25.83 and second graft 50.22 ± 20.90 cell viability percentage). No significant differences in terms of histopathological features (edema, inflammatory infiltrate, and mucosa ulceration) were observed comparing conventional and EVLP samples. A comparison of bronchial cell viability and histopathology of EVLP samples retrieved at different time intervals revealed no significant differences. Accordingly, major bronchial complications after lung transplant were not observed in both groups. CONCLUSIONS: Based on these data, we observed that EVLP did not significantly impact bronchial cell vitality and airway tissue preservation nor interfere with bronchial anastomosis healing, further supporting it as a safe and useful procedure.

COVID-19 Diagnosis in Case of Two Negative Nasopharyngeal Swabs: Association between Chest CT and Bronchoalveolar Lavage Results.

See also the editorial by Little in this issue.

SARS-CoV-2 Detection on Bronchoalveolar Lavage: An Italian Multicenter experience.

BACKGROUND: Bronchoscopy with bronchoalveolar lavage (BAL) during the SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) pandemic should be reserved to a limited number of clinical indications. The yield of BAL for the diagnosis of suspected or confirmed pulmonary SARS-CoV-2 infection is still unknown. OBJECTIVES: We aimed to evaluate the diagnostic ratio of BAL in detecting SARS-CoV-2 pulmonary infection in patients undergoing bronchoscopy for different indications as well as describe the clinical, radiological, and endoscopic characteristics of patients with SARS-CoV-2 on BAL. METHOD: We conducted a multicenter retrospective study including all patients who underwent bronchoscopy for the detection of SARS-CoV-2 on BAL. Clinical, computed tomography (CT), endoscopic, and microbiologic data were gathered from March 16th to May 27th, 2020. RESULTS: 131 patients were included. Bronchoscopy was performed for suspected SARS-CoV-2 infection (65.5%), alternative diagnosis (12.9%), suspected superinfections (19.8%), and lung atelectasis (1.5%). SARS-CoV-2 was isolated on BAL 43 times (32.8%) and the highest isolation rate was in patients with suspected SARS-CoV-2 infection (74.4%); 76% of positive patients had a double-negative nasopharyngeal swab. Peripheral, posterior and multilobar CT opacities were more frequent in SARS-CoV-2 patients, and the number of CT findings was higher in positive patients, particularly those with suspected SARS-CoV-2 infection. We recorded a progressive reduction of SARS-CoV-2 isolation during the observation period. CONCLUSIONS: In our centers, the rate of detection of SARS-CoV-2 on BAL in patients with suspected infection was 37.2%. The agreement of BAL with nasopharyngeal swabs was high; CT alterations could predict the pretest probability of SARS-CoV-2 infection, but suspicion of viral infection should be always considered.

A Position Paper on IgM-Enriched Intravenous Immunoglobulin Adjunctive Therapy in Severe Acute Bacterial Infections: The TO-PIRO SCORE Proposal.

IgM-enriched immunoglobulins (e-IgM) may be useful in patients with severe acute bacterial infections. The evidence for the administration of e-IgM is not extensive and a definitive consensus has never been reached on its best use in patients with acute infections as well as in critically ill patients. However, the official indication in several countries, including Italy, is quite wide and mainly refers to supportive treatment of patients with acute severe bacterial infections. A multidisciplinary meeting of Italian Experts in Infectious Diseases, Anesthesia and Critical Care, Pneumology, Microbiology and Oncohaematology aimed to produce a statement on the best practical methodological score that could improve the use of e-IgM in patients with different infections, variable severity of disease and etiology. The Expert Panel reviewed the literature and the available guidelines, discussed the experience and eventually proposed to adapt the PIRO score to the practical methodological needs of a simple tool that could guide the administration of e-IgM.

Clinical and Functional Characteristics of COPD Patients Across GOLD Classifications: Results of a Multicenter Observational Study.

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease. The severity grading systems proposed by the Global initiative for Chronic Obstructive Lung Disease (GOLD) have changed over time. The aim of the study was to evaluate if the different GOLD classifications can capture the complexity of the disease by investigating the distribution of lung function and clinical parameters across the GOLD classification systems. This was an observational, retrospective, multicentre study. COPD patients were stratified according to the GOLD severity grading proposed in the 2007, and to the ABCD assessment tool present in the 2011, and 2017 versions of the initiative. Data from body plethysmography, DLCO, comorbidities, exacerbation history, pharmacological therapy and eosinophil counts were collected. A total of 1360 patients (73.4% males) were included in the analysis. Overall, 37% of the patients were severe-very severe according to GOLD 2007. Compared with GOLD 2011, applying the GOLD 2017 criteria, the proportion of the at risk categories (C and D) was reduced by ∼23%. Impairment in inspiratory capacity, DLCO and the prevalence of emphysema paralleled the GOLD 2007 classification only. The proportion of patients with ≥ 200 eosinophils/µL was higher in GOLD 2007 stages 3-4 compared with stages 1-2 (P = 0.008). Eosinophil levels were similar across risk classes in GOLD 2011 and 2017. Overall, 41.8% and 52.4% of the patients in the low risk groups according to GOLD 2011 and 2017 were exposed to inhaled corticosteroids. The GOLD 2011 and 2017 classifications, despite exploring symptoms and exacerbations, might miss other relevant patients' clinical characteristics such as lung function and phenotypes, which have a significant impact on outcomes and disease severity.

Basophil Membrane Expression of Epithelial Cytokine Receptors in Patients with Severe Asthma.

BACKGROUND: Severe asthma is a heterogeneous disease, which is characterized by airway damage and remodeling. All triggers of asthma, such as allergens, bacteria, viruses, and pollutants, interact with the airway epithelial cells, which drive the airway inflammatory response through the release of cytokines, particularly IL-25, IL-33, and thymic stromal lymphopoietin (TSLP). OBJECTIVES AND METHODS: To investigate whether the expression of the IL-25, IL-33, and TSLP receptors on the basophil membrane are associated with asthma severity. Twenty-six patients with asthma (11 severe and 15 moderate/mild) and 10 healthy subjects (controls) were enrolled in the study. The results of the basophil activation test and flow cytometry analysis were assessed to investigate basophil membrane expression of IL-25, TSLP, and IL-33 receptors before and after IgE stimulation. RESULTS: IL-25 and IL-33 receptor expression on the basophil membrane at baseline were significantly higher in patients with severe asthma than in those with mild/moderate asthma or healthy subjects, independent of atopy, eosinophilia, asthma control, and exacerbation frequency. Following IgE stimulation, a significantly higher increase in the IL-25 and IL-33 receptors was observed in mild/moderate versus severe asthma. CONCLUSIONS: The high expression of the IL-25 and IL-33 receptors on the basophil membrane of patients with severe asthma indicates an overstimulation of basophils by these cytokines in severe asthma. This finding can possibly be used as a biomarker of asthma severity.

Asthma management in a specialist setting: Results of an Italian Respiratory Society survey.

BACKGROUND: Asthma considerably impairs patients' quality of life and increases healthcare costs. Severity, morbidity, and degree of disease control are the major drivers of its clinical and economic impact. National scientific societies are required to monitor the application of international guidelines and to adopt strategies to improve disease control and better allocate resources. AIM: to provide a detailed picture of the characteristics of asthma patients and modalities of asthma management by specialists in Italy and to develop recommendations for the daily management of asthma in a specialist setting. METHOD: A quantitative research program was implemented. Data were collected using an ad hoc questionnaire developed by a group of specialists selected by the Italian Pneumology Society/Italian Respiratory Society. RESULTS: The records of 557 patients were analyzed. In the next few years, specialists are expected to focus their activity patients with more severe disease and will be responsible for selection of patients for personalized biological therapy; however, only 20% of patients attending Italian specialist surgery can be considered severe. In 84.4% of cases, the visit was a follow-up visit requested in 82.2% of cases by the specialist him/herself. The Asthma Control Test is used only in 65% of patients. When available, a significant association has been observed between the test score and asthma control as judged by the physician, although concordance was only moderate (κ = 0.68). Asthma was considered uncontrolled by the specialist managing the case in 29.1% of patients; nevertheless, treatment was not stepped up in uncontrolled or partly controlled patients (modified in only 37.2% of patients). CONCLUSIONS: The results of this survey support re-evaluation of asthma management by Italian specialists. More resources should be made available for the initial visit and for more severely ill patients. In addition, more extensive use should be made of validated tools, and available drugs should be used more appropriately.

Development of an EliSPOT assay for HSV-1 and clinical validation in lung transplant patients.

Cellular immunity plays a major role in the control of HSV-1 infection/reactivation with a potential impact on the clinical-therapeutic management of immunocompromised patients, such as transplant recipients. Herein, we quantitatively evaluated T-cell response directed at HSV-1 by a newly developed IFN-γ EliSPOT assay in 53 patients (including 45 lung transplant recipients and eight subjects in waiting list). Overall, 62.2% of transplant patients and 62.5% of subjects on the waiting list showed a response to HSV-1 with no significant difference in the level of virus-specific cellular immunity. Response tended to be lower in the first three months posttransplantation with a progressive recovery of pretransplantation status by the second year and in the presence of HSV-1 DNA positivity in bronchoalveolar lavage. As expected, no response was found in seronegative patients. No significant difference in the level of response according to IgM and IgG status was found. Further studies are required to define the role of HSV-1 specific immune response for the clinical-therapeutic management of lung transplant patients and in other clinical settings and to define cut-off levels discriminating between absence/low and strong response to be related to the risk of viral infection/reactivation.

Real time visualization may be advisable to exclude aspiration in patients undergoing capsule endoscopy examination.

Capsule endoscopy (CE) is currently considered as a first line diagnostic tool for small bowel examination. Some patients find swallowing the capsule difficult. However, capsule aspiration is relatively uncommon and is only reported in isolated cases. The majority of these cases are male (39/41; 95.1%) with an age ranging from 56-93 years and only 4 (9.8%) patients had a recorded history of dysphagia. Twenty-four out of 41 (58.5%) patients experienced symptoms of capsule aspiration. The aspiration self-resolved in 11/41 patients and the CE was retrieved during bronchoscopy in the other cases. We present the case of a 75 year old man with a history of chronic anemia who was referred for CE.

Delayed functional improvement after near-fatal bleeding complication following endobronchial valve therapy for emphysema.

Endoscopic treatment of emphysema is supported by different methods, including valves, coils and sealants. The mechanism is mainly related to volume reduction of targeted area. Endobronchial valves (EBV) appear the most studied method. In a multicentre randomised study, placement of unidirectional endobronchial valves resulted in a statistically significant functional improvement in the treated cohort compared to the control. Adverse events, occurring post procedure, included COPD exacerbations, haemoptysis, pneumothorax and pneumonia. In our centre we treated 30 patients, between January 2009 and February 2012, with variable improvement of lung function and only mild postoperative complications. The case we report here appears very interesting for the unusual near-fatal complication (massive alveolar haemorrage) followed by delayed strong functional improvement (FEV1 +23%; RV -18%; 6MWD:+33%) six months after the valve placement. This improvement could be attributable to the EBV procedure, but an alternative explanation is that the lung volume reduction may have been enhanced by the complication itself, as an effect of alveolar collapse.

Severe vitamin D deficiency is associated with frequent exacerbations and hospitalization in COPD patients.

BACKGROUND: Acute exacerbations of COPD (AECOPD) are common and strongly influence disease severity and relative healthcare costs. Vitamin D deficiency is frequent among COPD patients and its contributory role in disease exacerbations is widely debated. Our aim was to assess the relationship of serum vitamin D levels with COPD severity and AECOPD. METHODS: Serum vitamin D (25-hydroxyvitamin D) levels were measured in 97 COPD patients and related to lung function, comorbidities, FEV1 decline, AECOPD and hospital admission during the previous year. RESULTS: Most patients (96%) had vitamin D deficiency, which was severe in 35 (36%). No significant relationship was found between vitamin D and FEV1 or annual FEV1 decline. No difference between patients with and without severe vitamin D deficiency was found in age, gender, BMI, smoking history, lung function, and comorbidities, apart from osteoporosis (60.9% in severe deficiency vs 22.7%, p = 0.001). In multiple logistic regression models, severe deficiency was independently associated with AECOPD [adjusted odds ratios (aOR) of 30.5 (95% CI 5.55, 168), p < 0.001] and hospitalization [aOR 3.83 (95% CI 1.29, 11.4), p = 0.02]. The odds ratio of being a frequent exacerbator if having severe vitamin D deficiency was 18.1 (95% CI 4.98, 65.8) (p < 0.001), while that of hospitalization was 4.57 (95% CI 1.83, 11.4) (p = 0.001). CONCLUSIONS: In COPD patients severe vitamin D deficiency was related to more frequent disease exacerbations and hospitalization during the year previous to the measurement of vitamin D. This association was independent of patients' characteristics and comorbidities.

Oxidative stress and respiratory system: pharmacological and clinical reappraisal of N-acetylcysteine.

The large surface area for gas exchange makes the respiratory system particularly susceptible to oxidative stress-mediated injury. Both endogenous and exogenous pro-oxidants (e.g. cigarette smoke) trigger activation of leukocytes and host defenses. These mechanisms interact in a "multilevel cycle" responsible for the control of the oxidant/antioxidant homeostasis. Several studies have demonstrated the presence of increased oxidative stress and decreased antioxidants (e.g. reduced glutathione [GSH]) in subjects with chronic obstructive pulmonary disease (COPD), but the contribution of oxidative stress to the pathophysiology of COPD is generally only minimally discussed. The aim of this review was to provide a comprehensive overview of the role of oxidative stress in the pathogenesis of respiratory diseases, particularly COPD, and to examine the available clinical and experimental evidence on the use of the antioxidant N-acetylcysteine (NAC), a precursor of GSH, as an adjunct to standard therapy for the treatment of COPD. The proposed concept of "multilevel cycle" helps understand the relationship between respiratory diseases and oxidative stress, thus clarifying the rationale for using NAC in COPD. Until recently, antioxidant drugs such as NAC have been regarded only as mucolytic agents. Nevertheless, several clinical trials indicate that NAC may reduce the rate of COPD exacerbations and improve small airways function. The most plausible explanation for the beneficial effects observed in patients with COPD treated with NAC lies in the mucolytic and antioxidant effects of this drug. Modulation of bronchial inflammation by NAC may further account for these favorable clinical results.

The pathogenesis of OSA-related hypertension: what are the determining factors?

Sleep-disordered breathing has a relatively high prevalence, which varies from 3-7% in males and from 2-5% in females in the adult population. Studies published in the literature have shown that sleep apnea is closely related to an increased risk of developing various pathologies, among which arterial hypertension stands out. The prevalence of hypertension in patients suffering from obstructive sleep apnea (OSA) ranges from 35-80% and appears to be related to OSA severity. Approximately 40-50% of patients affected by hypertension are also affected by OSA and this association seems to be stronger in young and middle-aged adults (<50 years of age). The primary objective of this narrative review is to provide an update on what are the main contributing comorbidities to the development of a hypertensive state in patients suffering from OSA, an independent risk factor for diurnal hypertension, implicated as a risk factor for the first stroke, recurrent stroke, and post-stroke mortality. There are a lot of factors that contribute to developing a hypertensive state in OSA patients, some more decisive, others less. More evidence from longitudinal studies is needed on the impact of OSA on cardiovascular risk in females, on the causal link between OSA and arterial hypertension or metabolic diseases, like diabetes and glucose intolerance, and the effect of different kinds of OSA treatment.

Correlation between high-resolution computed tomography appearance and histopathological features in the diagnosis of interstitial lung diseases. A real-life study.

BACKGROUND: According to current guidelines, a surgical biopsy is rarely required when a high-confidence radiologic interstitial lung disease (ILD) diagnosis is made on thin-section high-resolution computed tomography (HRCT). Nevertheless, disowning HRCT scans diagnosed by biopsy are more common than presumed. Our study aimed to describe the concordance rate between HRCT scans and pathological diagnoses of ILDs obtained by surgical biopsy. The current guideline suggests the use of surgical lung biopsy (SLB) in patients with newly detected ILD of unknown cause. METHODS: Patients who underwent mini-invasive surgical biopsies for interstitial lung diseases from January 2018 to August 2022 were analyzed. The HRCT scans were reviewed by an observer blinded to the patient's clinical information. The concordance between histological and HRCT-scan were assessed. RESULTS: Data from 104 patients with uncertain low confidence diagnosis of interstitial lung diseases at HRCT were analyzed. Most of the patients are male (65; 62.5%). The more frequent HRCT pattern were: alternative diagnoses (46; 44.23%), UIP probable (42; 40.38%), UIP indeterminate (7; 6.73%), and non-specific interstitial pneumonia (NSIP) (9, 8.65%). The more common histological diagnosis was UIP definite (30; 28.84%), hypersensitivity pneumonia [HP](19; 18.44%), NSIP (15; 14.42%), sarcoidosis (10; 9.60%). In 7 (20%) cases, the final pathological finding denies HRCT-scans diagnoses; indeed, a moderate agreement was observed between HRCT-scan findings and the definitive histological diagnosis (kappa index: 0.428). CONCLUSIONS: HRCT-scan has limitations if the objective is to define interstitial lung diseases accurately. Consequently, pathological assessment should be taken into account in order to provide more accurate tailored treatment strategies because the risk is to wait from 12 to 24 months to ascertain if the ILD will be treatable as progressive pulmonary fibrosis (PPF). Undeniably true, video-assisted surgical lung biopsy (VASLB) with endotracheal intubation and mechanical ventilation is associated with a risk of mortality and morbidity that is far from nil. Nevertheless, in recent years a VASLB approach performed in awake subjects under loco-regional anesthesia (awake-VASLB) has been suggested as an effective method to obtain a highly confident diagnosis in patients with diffuse pathologies of the lung parenchyma.

The current practice in the diagnostic work-up of patients with hemoptysis of unknown etiology: an international survey.

BACKGROUND: Hemoptysis is a challenging and potentially life-threatening medical condition. The most appropriate diagnostic work-up is debated and several diagnostic approaches are implemented worldwide. METHODS: An international, online survey was carried out to investigate the current practice of the diagnostic work-up of patients with hemoptysis of unknown etiology. RESULTS: Overall, 604 physicians responded to the survey. At baseline, chest X-ray was suggested as the first diagnostic investigation by 342 (56.6%) participants. Computed tomography (CT) was suggested in each patient with non- and life-threatening hemoptysis by 310 (51.3%) and 526 (87.1%) respondents, respectively. Contrast-enhanced CT is the currently preferred technique (333, 55.1%). In case of patchy ground glass opacities and negative CT, 287 (47.5%) and 222 (36.8%) participants, respectively, would always offer bronchoscopy. Otorhinolaryngological evaluation was mostly suggested in case of suspected upper airways bleeding before other investigations (212, 35.1%). A follow-up was recommended for idiopathic hemoptysis by the majority of the participants (316, 52.3%). A multidisciplinary assessment is deemed crucial for each patient with life-threatening hemoptysis (437, 72.4%). CONCLUSIONS: Chest X-ray and contrast-enhanced CT are currently preferred as the first diagnostic investigations, regardless of hemoptysis severity. Bronchoscopy is suggested in case of negative radiological examination and when CT shows only ground glass opacities. Otorhinolaryngological evaluation is advised before any other investigations when upper airways bleeding is suspected. Patients with idiopathic hemoptysis are suggested to undergo a clinical follow-up and in case of life-threatening bleeding a multidisciplinary assessment is deemed crucial. Due to the heterogeneous approaches a consensus statement would be needed.