HLA-DRB1 and HLA-DQB1 genes on susceptibility to and protection from allergic bronchopulmonary aspergillosis in patients with cystic fibrosis

Exploring the immunopathology of type 2 inflammatory airway diseases

Significant advancements have been achieved in understanding the roles of different immune cells, as well as cytokines and chemokines, in the pathogenesis of eosinophilic airway conditions. This review examines the pathogenesis of Chronic Rhinosinusitis with Nasal Polyps (CRSwNP), marked by complex immune dysregulation, with major contributions from type 2 inflammation and dysfunctional airway epithelium. The presence of eosinophils and the role of T-cell subsets, particularly an imbalance between Treg and Th17 cells, are crucial to the disease's pathogenesis. The review also investigates the pathogenesis of eosinophilic asthma, a unique asthma subtype. It is characterized by inflammation and high eosinophil levels, with eosinophils playing a pivotal role in triggering type 2 inflammation. The immune response involves Th2 cells, eosinophils, and IgE, among others, all activated by genetic and environmental factors. The intricate interplay among these elements, chemokines, and innate lymphoid cells results in airway inflammation and hyper-responsiveness, contributing to the pathogenesis of eosinophilic asthma. Another scope of this review is the pathogenesis of Eosinophilic Granulomatosis with Polyangiitis (EGPA); a complex inflammatory disease that commonly affects the respiratory tract and small to medium-sized blood vessels. It is characterized by elevated eosinophil levels in blood and tissues. The pathogenesis involves the activation of adaptive immune responses by antigens leading to T and B cell activation and eosinophil stimulation, which causes tissue and vessel damage. On the other hand, Allergic Bronchopulmonary Aspergillosis (ABPA) is a hypersensitive response that occurs when the airways become colonized by aspergillus fungus, with the pathogenesis involving activation of Th2 immune responses, production of IgE antibodies, and eosinophilic action leading to bronchial inflammation and subsequent lung damage. This analysis scrutinizes how an imbalanced immune system contributes to these eosinophilic diseases. The understanding derived from this assessment can steer researchers toward designing new potential therapeutic targets for efficient control of these disorders.

Polymorphisms in Innate and Adaptive Immune Genes in Subjects with Allergic Bronchopulmonary Aspergillosis Complicating Asthma

Innate and adaptive immunity play a crucial role in allergic bronchopulmonary aspergillosis (ABPA) pathogenesis. We performed next-generation sequencing using the Illumina TruSight One panel (4,811 human disease-associated genes, at least 20 × coverage) and selected 22 known immune genes (toll-like receptors (TLRs), C-type lectin, interleukin-4 receptor, and others). We included ABPA (n = 18), asthma without ABPA (n = 12), and healthy controls (n = 8). We analyzed 3011 SNPs from 22 genes and identified 145 SNPs (13 genes) that were present only in the disease groups and absent in controls. The SNP frequency overall was significantly higher in ABPA than in asthmatics (89/145 [61.4%] vs. 56/145 [38.6%], p = 0.0001). The SNP frequency in the TLR10 gene was also significantly higher in ABPA than in asthma (p = 0.017). Association analysis further revealed three genes having significant associations. Of these, NOS3 and HLA-DQB1 are associated with antimicrobial activity and adaptive immunity. More extensive studies are required to confirm our findings.

Associations between HLA class II alleles and IgE sensitization to allergens in the Qatar Biobank cohort

Background

Allergic disorders are the consequence of IgE sensitization to allergens. Population studies have shown that certain human leukocyte antigen (HLA) alleles are associated with increased or decreased risk of developing allergy.

Objective

We aimed to characterize the relationship between HLA class II allelic diversity and IgE sensitization in an understudied Arab population.

Methods

We explored associations between IgE sensitization to 7 allergen mixes and mesquite (comprising 41 food or aeroallergens) and 45 common classical HLA class II alleles in a well-defined cohort of 797 individuals representing the general adult population of Qatari nationals and long-term residents. To do so, we performed HLA calling from whole genome sequencing data at 2-field resolution using 2 independent algorithms. We then applied 3 different regression models to assess either each allergen mix independently, in the context of IgE sensitization to other allergens tested, or polysensitization.

Results

More than half (n = 447) of the study participants showed IgE sensitization to at least 1 allergen, most of them (n = 400) to aeroallergens (Phadiatop). We identified statistically significant negative and positive associations with 24 HLA class II alleles. These have been reported to confer risk or protection from variety of diseases; however, only a few have previously been associated with allergy in other populations.

Conclusions

Our study reveals several new risk and protective genetic markers for allergen-specific IgE sensitization. This is a first and essential step toward a better understanding of the origins of allergic diseases in this understudied population.

Mucosal Immunity in Cystic Fibrosis

The highly complex and variable genotype-phenotype relationships observed in cystic fibrosis (CF) have been an area of growing interest since the discovery of the CF transmembrane conductance regulator (CFTR) gene >30 y ago. The consistently observed excessive, yet ineffective, activation of both the innate and adaptive host immune systems and the establishment of chronic infections within the lung, leading to destruction and functional decline, remain the primary causes of morbidity and mortality in CF. The fact that both inflammation and pathogenic bacteria persist despite the introduction of modulator therapies targeting the defective protein, CFTR, highlights that we still have much to discover regarding mucosal immunity determinants in CF. Gene modifier studies have overwhelmingly implicated immune genes in the pulmonary phenotype of the disease. In this context, we aim to review recent advances in our understanding of the innate and adaptive immune systems in CF lung disease.

HLA-DRB1 alleles as predisposing and resisting factor in women suffering from vulvovaginal candidiasis

BACKGROUND

Vulvovaginal candidiasis (VVC) is a vaginal mucosal infection that usually affects women in their reproductive age. When the signs of VVC persist on a daily basis or last for a long time and repeat at least three times per year, the disease is considered chronic and recurrent.

OBJECTIVE

The purpose of this study was to evaluate the frequency of HLA-DRB1 alleles in patients with recurrent vulvovaginal candidiasis (RVVC).

STUDY DESIGN

120 patients with RVVC and 136 age-matched healthy controls underwent low-resolution HLA-DRB typing performed using the polymerase chain reaction-sequence-specific primers (PCR-SSP) technique.

RESULTS

In the present work, we studied different genes that encode HLA-DRB (HLA-DRB1 / HLA-DRB3 / HLA-DRB4 / HLA-DRB5) and showed that HLA-DRB1×14, found in 25% of the patients. In the present study, the significant frequency of HLA-DRB1×10 in the control group suggests a resistant role of this allele to RVVC infections CONCLUSIONS: In the HLA-DRB region, the DRB1×14 allele showed a higher frequency in the patients with RVVC than in the controls. Moreover, the higher frequency of DRB1×10 observed in the controls than in the patients with RVVC. These results demonstrate the HLA-DRB1 alleles are in relation with both susceptibility and immunity factors in RVVC infection and possible susceptible role of HLA-DRB1×14.

Identification of key genes in allergic rhinitis by bioinformatics analysis

Objective

This study aimed to explore the potential molecular mechanism of allergic rhinitis (AR) and identify gene signatures by analyzing microarray data using bioinformatics methods.

Methods

The dataset GSE19187 was used to screen differentially expressed genes (DEGs) between samples from patients with AR and healthy controls. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were applied for the DEGs. Subsequently, a protein–protein interaction (PPI) network was constructed to identify hub genes. GSE44037 and GSE43523 datasets were screened to validate critical genes.

Results

A total of 156 DEGs were identified. GO analysis verified that the DEGs were enriched in antigen processing and presentation, the immune response, and antigen binding. KEGG analysis demonstrated that the DEGs were enriched in Staphylococcus aureus infection, rheumatoid arthritis, and allograft rejection. PPI network and module analysis predicted seven hub genes, of which six (CD44, HLA-DPA1, HLA-DRB1, HLA-DRB5, MUC5B, and CD274) were identified in the validation dataset.

Conclusions

Our findings suggest that hub genes play important roles in the development of AR.

CF Fungal Disease in the Age of CFTR Modulators

Fungi are increasingly recognised to have a significant role in the progression of lung disease in Cystic fibrosis with Aspergillus fumigatus the most common fungus isolated during respiratory sampling. The emergence of novel CFTR modulators has, however, significantly changed the outlook of disease progression in CF. In this review we discuss what impact novel CFTR modulators will have on fungal lung disease and its management in CF. We discuss how CFTR modulators affect antifungal innate immunity and consider the impact of Ivacaftor on fungal disease in individuals with gating mutations. We further review the increasing complication of drug-drug interactions with concurrent use of azole antifungal medication and highlight key unknowns that require addressing to fully understand the impact of CFTR modulators on fungal disease.

AllerScreener – A Server for Allergenicity and Cross-Reactivity Prediction

Allergenicity of proteins is a subtle property encoded in their structures. The prediction of allergenicity of novel proteins saves time and resources for subsequent experimental work. In the host antigen-presenting cells, the allergens are processed as antigens by the means of Human Leukocyte Antigens (HLA) class II proteins. Sometimes, people allergic to a given protein show allergic reaction to a different protein, even when the two proteins have different routes of exposure. This phenomenon is termed cross-reactivity. Here, we describe a server for allergenicity and cross-reactivity prediction based on the abilities of allergenic proteins to generate binders to HLA class II proteins. The generated peptides are compared to HLA binders originating from known allergens. As a result, the server returns a list of common binders, origin proteins, and species. Different species generate common HLA binders and this determines their cross-reactivity. The server is named AllerScreener and is freely accessible at: http://www.ddg-pharmfac.net/AllerScreener .

Mining GWAS and eQTL data for CF lung disease modifiers by gene expression imputation

Genome wide association studies (GWAS) have identified several genomic loci with candidate modifiers of cystic fibrosis (CF) lung disease, but only a small proportion of the expected genetic contribution is accounted for at these loci. We leveraged expression data from CF cohorts, and Genotype-Tissue Expression (GTEx) reference data sets from multiple human tissues to generate predictive models, which were used to impute transcriptional regulation from genetic variance in our GWAS population. The imputed gene expression was tested for association with CF lung disease severity. By comparing and combining results from alternative approaches, we identified 379 candidate modifier genes. We delved into 52 modifier candidates that showed consensus between approaches, and 28 of them were near known GWAS loci. A number of these genes are implicated in the pathophysiology of CF lung disease (e.g., immunity, infection, inflammation, HLA pathways, glycosylation, and mucociliary clearance) and the CFTR protein biology (e.g., cytoskeleton, microtubule, mitochondrial function, lipid metabolism, endoplasmic reticulum/Golgi, and ubiquitination). Gene set enrichment results are consistent with current knowledge of CF lung disease pathogenesis. HLA Class II genes on chr6, and CEP72, EXOC3, and TPPP near the GWAS peak on chr5 are most consistently associated with CF lung disease severity across the tissues tested. The results help to prioritize genes in the GWAS regions, predict direction of gene expression regulation, and identify new candidate modifiers throughout the genome for potential therapeutic development.

A major genetic determinant of autoimmune diseases is associated with the presence of autoantibodies in hypersensitivity pneumonitis

Background

Hypersensitivity pneumonitis is an immune-mediated disease triggered by exposure to organic particles in susceptible individuals. It has been reported that a subgroup of patients with hypersensitivity pneumonitis develops autoantibodies with or without clinical manifestations of autoimmune disease. However, the mechanisms involved in this process and the effect of the autoantibodies on clinical course in hypersensitivity pneumonitis is unknown. We evaluated the association between human leukocyte antigen (HLA) class II alleles and hypersensitivity pneumonitis patients with and without autoantibodies.

Methods

170 hypersensitivity pneumonitis patients were included. We analysed the presence of antinuclear antibodies, rheumatoid factor, anti-SSA/Ro, anti-SSB/La and anti-CCP at the time of diagnosis. In addition, in a subset of patients we evaluated anti-Scl-70, anti-neutrophil cytoplasmic antibody, and anti-DNA. HLA typing was performed using PCR sequence-specific primers in a high-resolution modality, including HLA-DRB1 and HLA-DQB1 loci. Statistical analysis was performed employing Epi-Info v7 and SPSS v20.

Results

60 hypersensitivity pneumonitis patients showed sera autoantibodies (HPAbs⁺), and 110 hypersensitivity pneumonitis patients did not (HPAbs⁻). The frequency of the allele HLA-DRB1*03:01 was remarkably increased in the HPAbs⁺ group (10.8% versus 0.45%; OR 30.14, 95% CI 3.83–237.1; p=1.65×10^-4 after Bonferroni's correction). Likewise, we found that the haplotype DRB1*03:01-DQB1*02:01, which is part of the 8.1 ancestral haplotype, a major genetic determinant of autoimmune diseases, confers significant risk to develop autoantibodies (OR 19.23, 95% CI 2.37–155.9; p=0.0088 after Bonferroni's correction). In addition, the HLA-DRB1*03:01 allele was associated with higher mortality in patients with hypersensitivity pneumonitis (adjusted OR 5.9, 95% CI 1.05–33.05; p=0.043).

Conclusions

A subset of hypersensitivity pneumonitis patients presents circulating autoantibodies and higher mortality that are associated with some alleles of 8.1 ancestral haplotype.

Alleles from 8.1 ancestral haplotype (#HLA-DRB1 and DQB1 loci) are associated with #autoantibodies production in #hypersensitivity #pneumonitis in a cohort of Mexican mestizo patientshttps://bit.ly/3bprPeB

How Environmental Fungi Cause a Range of Clinical Outcomes in Susceptible Hosts

Environmental fungi are globally ubiquitous and human exposure is near universal. However, relatively few fungal species are capable of infecting humans, and among fungi, few exposure events lead to severe systemic infections. Systemic infections have mortality rates of up to 90%, cost the US healthcare system $7.2 billion annually, and are typically associated with immunocompromised patients. Despite this reputation, exposure to environmental fungi results in a range of outcomes, from asymptomatic latent infections to severe systemic infection. Here we discuss different exposure outcomes for five major fungal pathogens: Aspergillus, Blastomyces, Coccidioides, Cryptococcus, and Histoplasma species. These fungi include a mold, a budding yeast, and thermal dimorphic fungi. All of these species must adapt to dramatically changing environments over the course of disease. These dynamic environments include the human lung, which is the first exposure site for these organisms. Fungi must defend themselves against host immune cells while germinating and growing, which risks further exposing microbe-associated molecular patterns to the host. We discuss immune evasion strategies during early infection, from disruption of host immune cells to major changes in fungal cell morphology.

A Case of Allergic Broncopulmonary Aspergillosis Associated With Hematopoietic Stem Cell Transplantation Due to Chronic Granulomatous Disease

Allergic bronchopulmonary aspergillosis is an immunologic pulmonary disorder caused by hypersensitivity to Aspergillus fumigatus. This disorder is most commonly seen in patients with poorly controlled asthma and cystic fibrosis. It is rarely reported in chronic granulomatous disease patients; however, there are no cases reported with hematopoietic stem cell transplantation in the English literature. Herein, we report a patient with chronic granulomatous disease who had hematopoietic stem cell transplantation and subsequently developed allergic bronchopulmonary aspergillosis.

Developing collaborative works for faster progress on fungal respiratory infections in cystic fibrosis

Cystic fibrosis (CF) is the major genetic inherited disease in Caucasian populations. The respiratory tract of CF patients displays a sticky viscous mucus, which allows for the entrapment of airborne bacteria and fungal spores and provides a suitable environment for growth of microorganisms, including numerous yeast and filamentous fungal species. As a consequence, respiratory infections are the major cause of morbidity and mortality in this clinical context. Although bacteria remain the most common agents of these infections, fungal respiratory infections have emerged as an important cause of disease. Therefore, the International Society for Human and Animal Mycology (ISHAM) has launched a working group on Fungal respiratory infections in Cystic Fibrosis (Fri-CF) in October 2006, which was subsequently approved by the European Confederation of Medical Mycology (ECMM). Meetings of this working group, comprising both clinicians and mycologists involved in the follow-up of CF patients, as well as basic scientists interested in the fungal species involved, provided the opportunity to initiate collaborative works aimed to improve our knowledge on these infections to assist clinicians in patient management. The current review highlights the outcomes of some of these collaborative works in clinical surveillance, pathogenesis and treatment, giving special emphasis to standardization of culture procedures, improvement of species identification methods including the development of nonculture-based diagnostic methods, microbiome studies and identification of new biological markers, and the description of genotyping studies aiming to differentiate transient carriage and chronic colonization of the airways. The review also reports on the breakthrough in sequencing the genomes of the main Scedosporium species as basis for a better understanding of the pathogenic mechanisms of these fungi, and discusses treatment options of infections caused by multidrug resistant microorganisms, such as Scedosporium and Lomentospora species and members of the Rasamsonia argillacea species complex.

Aspergillus fumigatus in cystic fibrosis: An update on immune interactions and molecular diagnostics in allergic bronchopulmonary aspergillosis

A wide spectrum of pathological conditions may result from the interaction of Aspergillus fumigatus and the immune system of its human host. Allergic bronchopulmonary aspergillosis is one of the most severe A. fumigatus-related diseases due to possible evolution toward pleuropulmonary fibrosis and respiratory failure. Allergic bronchopulmonary aspergillosis occurs almost exclusively in cystic fibrosis or asthmatic patients. An estimated 8%-10% of patients with cystic fibrosis experience this condition. The diagnosis of allergic bronchopulmonary aspergillosis relies on criteria first established in 1977. Progress in the understanding of host-pathogen interactions in A. fumigatus and patients with cystic fibrosis and the ongoing validation of novel laboratory tools concur to update and improve the diagnosis of allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis in patients with cystic fibrosis

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disorder that often occurs in patients with asthma or cystic fibrosis (CF) and is characterized by a hypersensitivity response to the allergens of the fungus Aspergillus fumigatus. In patients with CF, growth of A. fumigatus hyphae within the bronchial lumen triggers an immunoglobulin E (IgE)-mediated hypersensitivity response that results in airway inflammation, bronchospasm, and bronchiectasis. In most published studies, the prevalence of ABPA is about 8.9% in patients with CF. Since the clinical features of this condition overlap significantly with that of CF, ABPA is challenging to diagnose and remains underdiagnosed in many patients. Diagnosis of ABPA in CF patients should be sought in those with evidence of clinical and radiologic deterioration that is not attributable to another etiology, a markedly elevated total serum IgE level (while off steroid therapy) and evidence of A. fumigatus sensitization. Management of ABPA involves the use of systemic steroids to reduce inflammation and modulate the immune response. In patients who do not respond to steroids or cannot tolerate them, antifungal agents should be used to reduce the burden of A. fumigatus allergens. Recent studies suggest that omalizumab may be an effective option to reduce the frequency of ABPA exacerbations in patients with CF. Further randomized controlled trials are needed to better establish the efficacy of omalizumab in managing patients with CF and ABPA.

The long and winding road to IgA deficiency: causes and consequences

INTRODUCTION

The most common humoral immunodeficiency is IgA deficiency. One of the first papers addressing the cellular and molecular mechanisms underlying IgA deficiency indicated that immature IgA-positive B-lymphocytes are present in these patients. This suggests that the genetic background for IgA is still intact and that class switching can take place. At this moment, it cannot be ruled out that genetic as well as environmental factors are involved. Areas covered: A clinical presentation, the biological functions of IgA, and the management of IgA deficiency are reviewed. In some IgA deficient patients, a relationship with a loss-of-function mutation in the TACI (transmembrane activator and calcium-modulating cyclophilin ligand interaction) gene has been found. Many other genes also have been associated. Gut microbiota are an important environmental trigger for IgA synthesis. Expert commentary: Expression of IgA deficiency is due to both genetic and environmental factors and a role for gut microbiota cannot be excluded.

Association of HLA-DRB1 Gene Polymorphism with Risk of Asthma: A Meta-Analysis

BACKGROUND The relationship between HLA-DRB1 alleles and asthma is controversial. The purpose of this study was to evaluate the relationship between HLA-DRB1 alleles and risk of asthma. MATERIAL AND METHODS We searched PubMed, Chinese National Knowledge Infrastructure (CNKI), Wan Fang (Chinese) database, and Chinese Biomedical Medical databases (CBM) to find studies on the relationship between HLA-DRB1 alleles and risk of asthma. We calculated the pooled odds ratio (OR) and 95% confidence interval (CI) using STATA 12.0. Finally, a total of 24 studies were included in this meta-analysis. RESULTS The results revealed that DRB1*03 was positively associated with risk of asthma (OR=1.51, 95%CI=1.27-1.80), and DRB1*15 was negatively associated with risk of asthma (OR=0.63, 95%CI=0.42-0.93), but no association was found in other HLA-DRB1 alleles. Subgroup analysis by age revealed that DRB1*03, DRB1*04, DRB1*09, and DRB1*15 were associated with asthma in children. Subgroup analysis by ethnicity showed that DRB1*03 and DRB1*15 were associated with asthma in whites, and DRB1*07 and DRB1*14 were associated with asthma in Asians. CONCLUSIONS This results of this meta-analysis suggest that HLA-DRB1 alleles are associated with asthma.

Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA), a progressive fungal allergic lung disease, is a common complication of asthma or cystic fibrosis. Although ABPA has been recognized since the 1950s, recent research has underscored the importance of Th2 immune deviation and granulocyte activation in its pathogenesis. There is also strong evidence of widespread under-diagnosis due to the complexity and lack of standardization of diagnostic criteria. Treatment has long focused on downregulation of the inflammatory response with prolonged courses of oral glucocorticosteroids, but more recently concerns with steroid toxicity and availability of new treatment modalities has led to trials of oral azoles, inhaled amphotericin, pulse intravenous steroids, and subcutaneously-injected anti-IgE monoclonal antibody omalizumab, all of which show evidence of efficacy and reduced toxicity.

Genome-wide association meta-analysis identifies five modifier loci of lung disease severity in cystic fibrosis

The identification of small molecules that target specific CFTR variants has ushered in a new era of treatment for cystic fibrosis (CF), yet optimal, individualized treatment of CF will require identification and targeting of disease modifiers. Here we use genome-wide association analysis to identify genetic modifiers of CF lung disease, the primary cause of mortality. Meta-analysis of 6,365 CF patients identifies five loci that display significant association with variation in lung disease. Regions on chr3q29 (MUC4/MUC20; P=3.3 × 10(-11)), chr5p15.3 (SLC9A3; P=6.8 × 10(-12)), chr6p21.3 (HLA Class II; P=1.2 × 10(-8)) and chrXq22-q23 (AGTR2/SLC6A14; P=1.8 × 10(-9)) contain genes of high biological relevance to CF pathophysiology. The fifth locus, on chr11p12-p13 (EHF/APIP; P=1.9 × 10(-10)), was previously shown to be associated with lung disease. These results provide new insights into potential targets for modulating lung disease severity in CF.

Diagnosis and treatment of pulmonary aspergillosis syndromes

Both inherited and acquired immunodeficiency and chronic pulmonary disease predispose to the development of a variety of pulmonary syndromes in response to Aspergillus, a fungus that is ubiquitous in the environment. These syndromes include invasive aspergillosis, which is now recognized to occur in patients with critical illness without neutropenia and in those with mild degrees of immunosuppression, including from corticosteroid use in the setting of COPD. Chronic pulmonary aspergillosis includes simple aspergilloma, which is occasionally complicated by life-threatening hemoptysis, and progressive destructive cavitary disease requiring antifungal therapy. Allergic bronchopulmonary aspergillosis occurs almost exclusively in patients with asthma or cystic fibrosis. Recent advances in each of these syndromes include a greater understanding of the underlying pathophysiology and hosts at risk; improved diagnostic algorithms; and the availability of more effective and well-tolerated therapies. Improvement in outcomes for Aspergillus pulmonary syndromes requires that physicians recognize the varied and sometimes subtle presentations, be aware of populations at risk of illness, and institute potentially life-saving therapies early in the disease course.

Gene expression in transformed lymphocytes reveals variation in endomembrane and HLA pathways modifying cystic fibrosis pulmonary phenotypes

Variation in cystic fibrosis (CF) phenotypes, including lung disease severity, age of onset of persistent Pseudomonas aeruginosa (P. aeruginosa) lung infection, and presence of meconium ileus (MI), has been partially explained by genome-wide association studies (GWASs). It is not expected that GWASs alone are sufficiently powered to uncover all heritable traits associated with CF phenotypic diversity. Therefore, we utilized gene expression association from lymphoblastoid cells lines from 754 p.Phe508del CF-affected homozygous individuals to identify genes and pathways. LPAR6, a G protein coupled receptor, associated with lung disease severity (false discovery rate q value = 0.0006). Additional pathway analyses, utilizing a stringent permutation-based approach, identified unique signals for all three phenotypes. Pathways associated with lung disease severity were annotated in three broad categories: (1) endomembrane function, containing p.Phe508del processing genes, providing evidence of the importance of p.Phe508del processing to explain lung phenotype variation; (2) HLA class I genes, extending previous GWAS findings in the HLA region; and (3) endoplasmic reticulum stress response genes. Expression pathways associated with lung disease were concordant for some endosome and HLA pathways, with pathways identified using GWAS associations from 1,978 CF-affected individuals. Pathways associated with age of onset of persistent P. aeruginosa infection were enriched for HLA class II genes, and those associated with MI were related to oxidative phosphorylation. Formal testing demonstrated that genes showing differential expression associated with lung disease severity were enriched for heritable genetic variation and expression quantitative traits. Gene expression provided a powerful tool to identify unrecognized heritable variation, complementing ongoing GWASs in this rare disease.

Omalizumab: a new treatment option for allergic bronchopulmonary aspergillosis in patients with cystic fibrosis

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) is a severe complication in patients with cystic fibrosis (CF), resulting in deterioration of lung function and impairment of overall prognosis. Standard therapy consists of high dosage, long-term corticosteroid treatment. This carries the risk of serious side effects such as immune suppression, diabetes and osteoporosis. Antifungal drugs such as itraconazole may cause interactions with other drugs and drug levels need to be monitored. Omalizumab treatment has been tried in several case studies.

METHODS

This was a retrospective study of six patients (four female, two male, age 4-33 years old) with CF and ABPA treated with omalizumab within an observation period of 7.5 years.

RESULTS

All patients showed clinical and laboratory stability or even an improvement within the treatment and post-treatment observation period, although omalizumab therapy was less effective in patients with progressed lung disease and long-term ABPA. Side effects of systemic steroids were reduced.

CONCLUSION

Omalizumab has the potential to be an additional and solitary treatment option in patients with CF and ABPA. Early onset treatment may be beneficial and patients with early stage of lung disease seem to benefit more.

HLA and asthma phenotypes/endotypes: a review

Asthma is a complex chronic inflammatory disease of the airways caused by the interaction of genetic susceptibility with environmental influences. Genome-wide association studies (GWAS) represent the most powerful approach for asthma, that have identified several genes (e.g., IL18R1, IL33, SMAD3, ORMDL3, HLA-DQ and IL2RB loci). HLA super-locus is a genomic region in the chromosomal position 6p21. Since no gene can be considered as an asthma gene, able to reflect the complex etiology and the heterogeneity of the disease the terms 'phenotype' and more recently 'endotype' have been used. This review, according to literature availability, focuses on the relationship between human leukocyte antigens (HLA) region specifically the HLA class II genes and different asthma phenotypes/endotypes, such as allergic asthma/Th2 associated, occupational and aspirin-sensitive asthma. The most common HLA haplotypes in the different asthma phenotypes are HLA-DRB1in allergic asthma, HLA-DQB1in occupational asthma and HLA-DPB1 in aspirin-sensitive asthma. However, it is difficult to study the role of class II genes in vivo because of the heterogeneity of human population, the complexity of MHC, and the strong linkage disequilibrium among different class II genes. Despite the variation and the inconsistency of the HLA haplotypes and alleles in different types of asthma, the association between HLA class II genes and asthma has been demonstrated in the majority of studies.