New Perspectives in the Diagnosis and Management of Allergic Fungal Airway Disease

Role of IL-5 in asthma and airway remodelling

Asthma is a common and burdensome chronic inflammatory airway disease that affects both children and adults. One of the main concerns with asthma is the manifestation of irreversible tissue remodelling of the airways due to the chronic inflammatory environment that eventually disrupts the whole structure of the airways. Most people with troublesome asthma are treated with inhaled corticosteroids. However, the development of steroid resistance is a commonly encountered issue, necessitating other treatment options for these patients. Biological therapies are a promising therapeutic approach for people with steroid-resistant asthma. Interleukin 5 is recently gaining a lot of attention as a biological target relevant to the tissue remodelling process. Since IL-5-neutralizing monoclonal antibodies (mepolizumab, reslizumab and benralizumab) are currently available for clinical use, this review aims to revisit the role of IL-5 in asthma pathogenesis at large and airway remodelling in particular, in addition to exploring its role as a target for biological treatments.

Aspergillus-sensitized asthma in children

BACKGROUND

Asthma is the most common chronic respiratory disease in childhood. Aspergillus fumigatus sensitivity may be involved in the pathogenesis of asthma by leading to different clinical presentations.

OBJECTIVE

To investigate the demographic, clinical, laboratory, and radiological characteristics of A. fumigatus sensitivity in childhood asthma and identify associated risk factors and diagnostic parameters.

METHODS

A total of 259 children with asthma were included in the study, 7 (2.7%) with allergic bronchopulmonary aspergillosis (ABPA), 84 (32.4%) with A. fumigatus-sensitized asthma (Af-SA), and 168 (64.9%) with A. fumigatus-unsensitized asthma (Af-UA).

RESULTS

Aspergillus sensitivity was associated with early asthma onset and longer asthma duration. Total IgE level and asthma severity are highest in ABPA and higher in Af-SA. Absolute eosinophil count was higher, and FEV1 was lower in Af-SA and ABPA. Aspergillus fumigatus was associated with greater odds of being male (odds ratio [OR], 2.45), having atopic dermatitis (OR, 3.159), Alternaria sensitivity (OR, 10.37), and longer asthma duration (OR, 1.266). The best cut-off values for detecting A. fumigatus positivity were 363.5 IU/mL for total IgE and 455 cells/μL for absolute eosinophil count. In Af-SA compared to Af-UA, centrilobular nodules and peribronchial thickening were more common, and the bronchoarterial ratio was higher.

CONCLUSIONS

Aspergillus sensitivity is a strong allergic stimulus in asthma, leading to laboratory, structural, clinical, and functional consequences. Af-SA is a distinct asthma endotype independent of ABPA that is characterized by increased risk of severe clinical presentations and impaired lung function.

Aspergillus and the Lung

The filamentous fungus Aspergillus causes a wide spectrum of diseases in the human lung, with Aspergillus fumigatus being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of Aspergillus in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.

Outdoor airborne allergens: Characterization, behavior and monitoring in Europe

Aeroallergens or inhalant allergens, are proteins dispersed through the air and have the potential to induce allergic conditions such as rhinitis, conjunctivitis, and asthma. Outdoor aeroallergens are found predominantly in pollen grains and fungal spores, which are allergen carriers. Aeroallergens from pollen and fungi have seasonal emission patterns that correlate with plant pollination and fungal sporulation and are strongly associated with atmospheric weather conditions. They are released when allergen carriers come in contact with the respiratory system, e.g. the nasal mucosa. In addition, due to the rupture of allergen carriers, airborne allergen molecules may be released directly into the air in the form of micronic and submicronic particles (cytoplasmic debris, cell wall fragments, droplets etc.) or adhered onto other airborne particulate matter. Therefore, aeroallergen detection strategies must consider, in addition to the allergen carriers, the allergen molecules themselves. This review article aims to present the current knowledge on inhalant allergens in the outdoor environment, their structure, localization, and factors affecting their production, transformation, release or degradation. In addition, methods for collecting and quantifying aeroallergens are listed and thoroughly discussed. Finally, the knowledge gaps, challenges and implications associated with aeroallergen analysis are described.

Fungi in Early-Life House Dust Samples and the Development of Asthma: A Birth Cohort Study

Rationale: Fungal exposure has been associated with predisposing and protective effects on the development of childhood asthma. Objectives: To study whether early-life house dust mycobiota composition is associated with the development of asthma. Methods: Mycobiota were determined by amplicon sequencing from 382 dust samples collected from living room floors 2 months after birth in homes of the LUKAS cohort. Asthma status by 10.5 years of age was defined from questionnaires and assigned as ever asthma (n = 68) or current asthma (n = 27). Inhalant atopy was clinically determined at the same age. β-composition was analyzed using PERMANOVA-S, and asthma and atopy analyses were performed using discrete time hazard models and logistic regression, respectively. Results: The house dust mycobiota composition based on Bray-Curtis distance was different in the homes of children who later did or did not develop asthma. The first and the fourth axes scores of principal coordinates analysis based on Bray-Curtis were associated with ever asthma. Of the genera with the strongest correlation with these axes, the relative abundance of Boeremia, Cladosporium, Microdochium, Mycosphaerella, and Pyrenochaetopsis showed protective associations with asthma. None of these associations remained significant after mutual adjustment among the five genera or when mutually adjusted for other microbial cell wall markers and previously identified asthma-protective bacterial indices. Neither fungal α-diversity nor load was associated with asthma in the whole population, but higher fungal richness was a risk factor among children on farms. Higher fungal loads (measured via quantitative polymerase chain reaction) in house dust were associated with the risk of inhalant atopy. Conclusions: The results of our analyses from this well-characterized birth cohort suggest that the early-life house dust mycobiota in Finnish homes, characterized via DNA amplicon sequencing, do not have strong predisposing or protective effects on asthma development.

[Unmet Needs in Severe Allergic Asthma]

Severe asthma affects 3%-10% of the world's population, according to estimates by the Global Initiative for ASTHMA (GINA). Allergic asthma is one of the most common phenotypes of severe asthma and it is characterized by allergen-induced type 2 inflammation in which immunoglobulin E (IgE) is a key mediator, making it an important therapeutic target. The introduction of targeted biological therapies or treatments has entered the management for severe asthma in the era of precision medicine, and the goal of treatment is clinical remission of the disease. There is a significant percentage of patients with severe allergic asthma who do not respond to treatments and whose symptoms are not controlled. In this paper, a group of experts in the management of severe allergic asthma reviewed and evaluated the most relevant evidence regarding the pathophysiology and phenotypes of severe allergic asthma, the role of IgE in allergic inflammation, allergen identification, techniques, biomarkers and diagnostic challenges, available treatments and strategies for disease management, with a special focus on biological treatments. From this review, recommendations were developed and validated through a Delphi consensus process with the aim of offering improvements in the management of severe allergic asthma to the professionals involved and identifying the unmet needs in the management of this pathology.

Efficacy of dupilumab in patients with uncontrolled, moderate-to-severe asthma with fungal sensitization

BACKGROUND

Fungal sensitization (FS) exacerbates asthma in patients who have elevated type 2 inflammatory response. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin (IL)-4 and IL-13, key and central drivers of type 2 inflammation in multiple diseases.

OBJECTIVE

This post hoc analysis, funded by the manufacturers of dupilumab, was conducted to assess dupilumab efficacy in patients from the phase 3 LIBERTY ASTHMA QUEST trial (NCT02414854) and TRAVERSE open-label extension (NCT02134028) study who had uncontrolled, moderate-to-severe asthma with type 2 inflammatory phenotype (defined as blood eosinophil count ≥150 cells/μL or FeNO ≥25 ppb) and with FS (defined as IgE specific to Alternaria alternata, Aspergillus fumigatus or Cladosporium herbarum >0.35 IU/mL).

METHODS

We evaluated annualized rate of severe exacerbations (AER), change from baseline in pre-bronchodilator (BD) forced expiratory volume in 1 s (FEV1 ), asthma control (per 5-item Asthma Control Questionnaire [ACQ-5]) and biomarker levels (blood eosinophil count, fractional exhaled nitric oxide [FeNO], total IgE, fungal-specific IgEs, thymus and activation-regulated chemokine [TARC] and eotaxin-3).

RESULTS

Dupilumab vs. placebo reduced AER, improved pre-BD FEV1 and asthma control (ACQ-5), and reduced serum IgE levels, blood eosinophil count, TARC, eotaxin-3 and FeNO in patients both with and without FS after 52 weeks of treatment in QUEST. Reductions in asthma exacerbation rates and improvements in all other variables were sustained over the TRAVERSE open-label extension study.

CONCLUSION

Dupilumab demonstrated efficacy during prolonged treatment in patients with uncontrolled, moderate-to-severe asthma with FS.

Microbiome Interconnectedness throughout Environments with Major Consequences for Healthy People and a Healthy Planet

Microbiomes have highly important roles for ecosystem functioning and carry out key functions that support planetary health, including nutrient cycling, climate regulation, and water filtration. Microbiomes are also intimately associated with complex multicellular organisms such as humans, other animals, plants, and insects and perform crucial roles for the health of their hosts. Although we are starting to understand that microbiomes in different systems are interconnected, there is still a poor understanding of microbiome transfer and connectivity. In this review we show how microbiomes are connected within and transferred between different habitats and discuss the functional consequences of these connections. Microbiome transfer occurs between and within abiotic (e.g., air, soil, and water) and biotic environments, and can either be mediated through different vectors (e.g., insects or food) or direct interactions. Such transfer processes may also include the transmission of pathogens or antibiotic resistance genes. However, here, we highlight the fact that microbiome transmission can have positive effects on planetary and human health, where transmitted microorganisms potentially providing novel functions may be important for the adaptation of ecosystems.

Aspergillus sensitisation detection using point-of-care lateral flow assay in moderate to severe asthma

Allergic fungal airway diseases are associated with asthma exacerbations and poor control. However, the early identification of allergic Aspergillus airway diseases can be challenging, especially in resource-poor countries. We aimed to evaluate the clinical utility of the point-of-care Aspergillus IgG-IgM lateral flow assay in diagnosing Aspergillus airway diseases in patients with moderate-severe asthma. Patients with moderate-severe asthma, severe asthma with fungal sensitisation (SAFS) and allergic bronchopulmonary aspergillosis (ABPA) were recruited. Clinical information was extracted from clinical records. Blood samples were collected for serological tests. Serum samples were evaluated using Aspergillus immunochromatographic test (ICT). A total of 65 patients were recruited into the study, of whom 23.1% had clinical diagnosis of ABPA, 18.5% had SAFS and 58.5% had moderate-to-severe asthma who did not fit ABPA or SAFS criteria. The ICT test gave a sensitivity of 69 [95% confidence interval: 51-88]% and a specificity of 77 [60-88]% in predicting a positive Aspergillus IgG test. The sensitivity and specificity for a positive Aspergillus IgE were 77 [59-88]% and 86 [71-94]%, respectively. The majority (sensitivity: 87 [62-96]%) of patients with ABPA had positive ICT results, with a specificity of 70%. The negative predictive value was high (95 [82-99]%) with a low negative likelihood ratio (< 0.2), making it potentially useful in ruling out ABPA. The ICT assay may be valuable in ruling out ABPA in resource-limited countries where serological investigations are less feasible. The ICT assay may be particularly useful in ruling out ABPA and warrants further validation.

Nutritional Provision of Iron Complexes by the Major Allergen Alt a 1 to Human Immune Cells Decreases Its Presentation

Alternaria alternata is a common fungus strongly related with severe allergic asthma, with 80% of affected individuals being sensitized solely to its major allergen Alt a 1. Here, we assessed the function of Alt a 1 as an innate defense protein binding to micronutrients, such as iron-quercetin complexes (FeQ2), and its impact on antigen presentation in vitro. Binding of Alt a 1 to FeQ2 was determined in docking calculations. Recombinant Alt a 1 was generated, and binding ability, as well as secondary and quaternary structure, assessed by UV-VIS, CD, and DLS spectroscopy. Proteolytic functions were determined by casein and gelatine zymography. Uptake of empty apo- or ligand-filled holoAlt a 1 were assessed in human monocytic THP1 cells under the presence of dynamin and clathrin-inhibitors, activation of the Arylhydrocarbon receptor (AhR) using the human reporter cellline AZ-AHR. Human PBMCs were stimulated and assessed for phenotypic changes in monocytes by flow cytometry. Alt a 1 bound strongly to FeQ2 as a tetramer with calculated Kd values reaching pico-molar levels and surpassing affinities to quercetin alone by a factor of 5000 for the tetramer. apoAlt a 1 but not holoAlta 1 showed low enzymatic activity against casein as a hexamer and gelatin as a trimer. Uptake of apo- and holo-Alt a 1 occurred partly clathrin-dependent, with apoAlt a 1 decreasing labile iron in THP1 cells and holoAlt a 1 facilitating quercetin-dependent AhR activation. In human PBMCs uptake of holoAlt a 1 but not apoAlt a 1 significantly decreased the surface expression of the costimulatory CD86, but also of HLADR, thereby reducing effective antigen presentation. We show here for the first time that the presence of nutritional iron complexes, such as FeQ2, significantly alters the function of Alt a 1 and dampens the human immune response, thereby supporting the notion that Alt a 1 only becomes immunogenic under nutritional deprivation.

A scoping review: What are the cellular mechanisms that drive the allergic inflammatory response to fungal allergens in the lung epithelium?

Allergic airway disease (AAD) is a collective term for respiratory disorders that can be exacerbated upon exposure to airborne allergens. The contribution of fungal allergens to AAD has become well established over recent years. We conducted a comprehensive review of the literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to better understand the mechanisms involved in the allergic response to fungi in airway epithelia, identify knowledge gaps and make recommendations for future research. The search resulted in 61 studies for final analysis. Despite heterogeneity in the models and methods used, we identified major pathways involved in fungal allergy. These included the activation of protease-activated receptor 2, the EGFR pathway, adenosine triphosphate and purinergic receptor-dependent release of IL33, and oxidative stress, which drove mucin expression and goblet cell metaplasia, Th2 cytokine production, reduced barrier integrity, eosinophil recruitment, and airway hyperresponsiveness. However, there were several knowledge gaps and therefore we recommend future research should focus on the use of more physiologically relevant methods to directly compare key allergenic fungal species, clarify specific mechanisms of fungal allergy, and assess the fungal allergy in disease models. This will inform disease management and future interventions, ultimately reducing the burden of disease.

The Fungal and Bacterial Interface in the Respiratory Mycobiome with a Focus on Aspergillus spp

The heterogeneity of the lung microbiome and its alteration are prevalently seen among chronic lung diseases patients. However, studies to date have primarily focused on the bacterial microbiome in the lung rather than fungal composition, which might play an essential role in the mechanisms of several chronic lung diseases. It is now well established that Aspergillus spp. colonies may induce various unfavorable inflammatory responses. Furthermore, bacterial microbiomes such as Pseudomonas aeruginosa provide several mechanisms that inhibit or stimulate Aspergillus spp. life cycles. In this review, we highlighted fungal and bacterial microbiome interactions in the respiratory tract, with a focus on Aspergillus spp.

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.

Molecular detection of Aspergillus in respiratory samples collected from patients at higher risk of chronic pulmonary aspergillosis

OBJECTIVE

Aspergillosis diagnosis depends on the detection of Aspergillus in biological samples ─ usually using cultural and immunoenzyme techniques ─ but their sensitivity and specificity varies. We aimed to study the prevalence of Aspergillus in patients at higher risk of chronic pulmonary aspergillosis (i.e., HIV-infected patients and individuals with active or previous tuberculosis), and to determine the potential role of molecular approaches to increase detection of Aspergillus in respiratory samples.

METHODS

The DNA extracted from 43 respiratory samples that had been previously analyzed by immunoenzyme and/or cultural techniques was amplified by real-time multiplex PCR, and the results of these methods were compared. We also sequenced the ITS1 region and the calmodulin gene in 10 respiratory samples to perform a pilot metagenomic study to understand the ability of this methodology to detect potential pathogenic fungi in the lung mycobiome.

RESULTS

Real-time Aspergillus PCR test exhibited a higher positivity rate than the conventional techniques used for aspergillosis diagnosis, particularly in individuals at risk for chronic pulmonary aspergillosis. The metagenomic analysis allowed for the detection of various potentially pathogenic fungi.

CONCLUSIONS

Molecular techniques, including metagenomics, have great ability to detect potentially pathogenic fungi rapidly and efficiently in human biological samples.

Severe Fungal Asthma: A Role for Biologics and Inhaled Antifungals

Allergic asthma has traditionally been treated with inhaled and systemic glucocorticosteroids. A continuum of allergic fungal airways disease associated with Aspergillus fumigatus colonization and/or atopic immune responses that encompasses fungal asthma, severe asthma with fungal sensitization and allergic bronchopulmonary aspergillosis is now recognized along a phenotypic severity spectrum of T2-high immune deviation lung disease. Oral triazoles have shown clinical, anti-inflammatory and microbiologic efficacy in this setting; in the future inhaled antifungals may improve the therapeutic index. Humanized monoclonal antibody biologic agents targeting T2-high disease also show efficacy and promise of improved control in difficult cases. Developments in these areas are highlighted in this overview.

Acute eosinophilic pneumonia caused by composter vapor inhalation: A case report

A 65-year-old woman presented to a local hospital with a 4-day history of cough, fever, and dyspnea. She had started using a composter and had been exposed to the vapor for 18 days before her first visit. She was diagnosed with acute eosinophilic pneumonia (AEP) based on her symptoms, the presence of bilateral pulmonary opacities on computed tomography, and alveolar eosinophilia confirmed by bronchoalveolar lavage. Inhalation of the composter vapor was thought to be the cause of AEP. Aspergillus fumigatus was cultured from the composter soil and the bronchoalveolar lavage fluid. She fully recovered without systemic corticosteroid administration by avoiding the composter.

Clinical and immunological characteristics of Aspergillus fumigatus-sensitized asthma and allergic bronchopulmonary aspergillosis

Background

Aspergillus fumigatus (A.f) is a common airborne allergen that contributes to allergic asthma. In some patients, A.f can colonize in the airway and lead to allergic bronchopulmonary aspergillosis (ABPA). However, our understanding of the pathogenesis of A.f-sensitized asthma and ABPA remains inadequate.

Objective

We aimed to investigate the clinical and immunological characteristics of A.f-sensitized asthma and ABPA.

Methods

A total of 64 ABPA and 57 A.f-sensitized asthma patients were enrolled in the study, and 33 non-A.f-sensitized asthma patients served as the control group. The clinical and immunological parameters included lung function, fractional exhaled nitric oxide (FeNO), induced sputum and blood cell analysis, specific IgE/IgG/IgA of A.f and its components, cytokines (IL-33, IL-25, and TSLP) and CD4⁺T cell subsets.

Results

The eosinophils in blood, induced sputum, and FeNO were significantly higher in ABPA patients compared to that in A.f-sensitized patients. The combination of FeNO and eosinophils (EO) parameters presented good diagnostic efficiency in differentiating A.f (+) asthma from ABPA, with a sensitivity of 80% and a specificity of 100%. Specific IgE, IgG, and IgA against A.f also increased in ABPA patients. However, serum IL-25, IL-33, and TSLP showed no significant differences between the two groups. Cell analysis showed an increase in IFN-γ⁺Th1 cells in the ABPA patients. FlowSOM analysis further confirmed that the frequency of CD3⁺CD4⁺PD-1⁺CD127⁺IFN-γ⁺T cells was higher in ABPA patients.

Conclusion

Our findings suggest the distinct humoral and cell immunological responses in A.f-sensitized asthma and ABPA patients. ABPA patients have more severe eosinophilic inflammation and enhanced Th1 responses compared with A.f-sensitized asthma patients.

Fungal Allergen and Mold Allergy Diagnosis: Role and Relevance of Alternaria alternata Alt a 1 Protein Family

Alternaria is a genus of worldwide fungi found in different habitats such as soil, the atmosphere, plants or indoor environments. Alternaria species are saprobic-largely involved in the decomposition of organic material-but they can also act as animal pathogens, causing disease in humans and animals, developing infections, toxicosis and allergic diseases. A. alternata is considered one of the most important sources of fungal allergens worldwide and it is associated with severe asthma and respiratory status. Among the A. alternata allergens, Alt a 1 is the main sensitizing allergen and its usefulness in diagnosis and immunotherapy has been demonstrated. Alt a 1 seems to define a protein family that can be used to identify related pathogenic fungi in plants and fruits, and to establish taxonomic relationships between the different fungal divisions.

Aspergillus fumigatus-Host Interactions Mediating Airway Wall Remodelling in Asthma

Asthma is a chronic heterogeneous respiratory condition that is mainly associated with sensitivity to airborne agents such as pollen, dust mite products and fungi. Key pathological features include increased airway inflammation and airway wall remodelling. In particular, goblet cell hyperplasia, combined with excess mucus secretion, impairs clearance of the inhaled foreign material. Furthermore, structural changes such as subepithelial fibrosis and increased smooth muscle hypertrophy collectively contribute to deteriorating airway function and possibility of exacerbations. Current pharmacological therapies focused on airway wall remodelling are limited, and as such, are an area of unmet clinical need. Sensitisation to the fungus, Aspergillus fumigatus, is associated with enhanced asthma severity, bronchiectasis, and hospitalisation. How Aspergillus fumigatus may drive airway structural changes is unclear, although recent evidence points to a central role of the airway epithelium. This review provides an overview of the airway pathology in patients with asthma and fungal sensitisation, summarises proposed airway epithelial cell-fungal interactions and discusses the initiation of a tissue remodelling response. Related findings from in vivo animal models are included given the limited analysis of airway pathology in patients. Lastly, an important role for Aspergillus fumigatus-derived proteases in triggering a cascade of damage-repair events through upregulation of airway epithelial-derived factors is proposed.

Considering biomarkers in asthma disease severity

Amongst patients with asthma, reliance on the type/dose of prescribed medication and symptom control does not adequately capture those at risk of adverse outcomes, and we need biomarkers for risk and treatment stratification which are consistently accurate, readily quantifiable and reproducible. The majority of patients with severe asthma, regardless of age, have predominant type-2 (T2) inflammation mediated disease, making airway/blood eosinophils, FeNO, periostin and/or allergic sensitization potentially important biomarkers for severe disease. In both adult and pediatric asthma, there is scope to improve prediction of severe attacks by using a composite T2 biomarkers of blood eosinophils and FeNO. Technological advances in component-resolved diagnostics (CRD) microarray technologies coupled with the development of interpretation software offer a possibility to use CRD as biomarkers of asthma severity amongst sensitized asthmatics. Genetic predisposition and polygenic risk scores of relevant traits (e.g., lung function, host immune responses, biomarkers of exposure from the indoor and outdoor environment, infection and microbial dysbiosis) may also contribute to prediction algorithms. We challenge the idea that asthma can be accurately defined in an individual patient by a discrete and static "endotype" (e.g., T2-high asthma). As we traverse the new era of molecular endotyping in asthma, we need to understand how relevant mechanisms impact patient outcomes, and in parallel develop new tools and approaches to stratify therapies and define individual patient trajectories.