Evaluation of HLA-A, -B, -Cw, and -DRB1 alleles frequency in Turkish patients with nasal polyposis

HLA and Nasal Polyposis Susceptibility: A Meta-analysis of Worldwide Studies

OBJECTIVES

Nasal polyposis (NP) is a common and recurrent condition of the sinonasal cavity which has significant impact on patients' quality of life. NP pathophysiology involves a complex interplay of genetic, environmental, and immunological factors. Several studies have explored the association between human leukocyte antigen (HLA) class II alleles and NP, but the results have been conflicting. The aim of this meta-analysis is to investigate the association between HLA class II alleles, specifically HLA-DQA1, HLA-DQB1, and HLA-DRB1and NP risk.

METHODS

A systematic review was conducted using electronic databases, including PubMed, Google Scholar, and Cochrane Library, to identify studies investigating the association between HLA class II alleles and NP. Eligible studies were identified by specific inclusion and exclusion criteria. The odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association between HLA class II alleles and NP risk. A random-effects model was used to calculate the pooled OR and corresponding 95% CI, and a study required a heterogeneity assessment value I2 < 25% to be considered for analysis.

STUDY DESIGN

Meta-analysis.

RESULTS

A total of four studies were included in this meta-analysis, involving a total of 258 NP alleles and 802 control alleles. The analysis indicated that DQA1*0201 (OR = 3.08, 95% CI [1.70, 5.59]) and DRB1*7 (OR = 2.04, 95% CI [1.14, 3.66]) were significantly associated with increased risk of NP. The analysis of the NP risk alleles DQA1*0201 and DRB1*7 had an I2 < 0% representing low heterogeneity. Sensitivity analysis with LFK indices showed minor asymmetry in either allele.

CONCLUSIONS

This meta-analysis provides evidence that the HLA-DQA1*0201 and HLA-DRB1*7 alleles are risk factors for the development of NP. These findings could contribute to a better understanding of the genetic predisposition of NP and may have implications for the development of novel approaches for the prevention and treatment of this condition.

Genetics and epigenetics of chronic rhinosinusitis

Discerning the genetics and epigenetics of chronic rhinosinusitis (CRS) may optimize outcomes through early diagnostics, personalized and novel therapeutics, and early prognostication. CRS associated with cystic fibrosis and primary ciliary dyskinesia has well-characterized genetic mutations. Most CRS subjects, however, do not exhibit identifiable monogenic alterations. Clustering in related individuals is seen in CRS with nasal polyps. Spouses of subjects with CRS without nasal polyps also may be at increased risk of the same disease. These observations generate questions on genetic and environmental influences in CRS. Genome-wide association studies have identified variations and polymorphisms between CRS and control subjects in genes related to innate and adaptive immunity. Candidate gene and transcriptomics studies have investigated and identified genetic variations related to immunity, inflammation, epithelial barrier function, stress-response, antigen processing, T-cell regulation, and cytokines in CRS. Epigenetic studies have identified mechanisms through which environmental factors may affect these gene functions. However, causality is not determined for most variations. Inferences drawn from these data must be measured because most investigations report unreplicated results from small study populations. Large, replicated studies in tight cohorts across diverse populations remain a pressing need in studying CRS genetics.

The effects of oral steroid therapy on prolidase enzyme activity in patients with nasal polyps

Objective

To compare prolidase enzyme activity (PEA) in serum and polyp specimens of patients with nasal polyps obtained before and after the oral steroid therapy.

Materials and methods

Thirty three patients with nasal polyps (39 ± 13 years) received 1 mg/kg of oral steroids. Serum samples were collected from each patient, but nasal polyp specimens could be obtained only from 23 patients (38 ± 13 years) before and after the oral steroid therapy. PEA was measured by ELISA method.

Results

Serum PEA values were 210 (176–242) U/L and 184 (147–217) U/L before and after the oral steroid therapy, respectively (p = 0.015). Polyp tissue PEA was 1337 (738–2130) U/g and 871 (590–1663) U/g before and after the oral steroid therapy, respectively (p = 0.429).

Conclusion

In patients with nasal polyps, significantly lower serum PEA after the oral steroid therapy may be a consequence of the role of prolidase enzyme in inflammatory processes which are important for the development of nasal polyps. More comprehensive studies with larger sample sizes are needed to elucidate the role of PEA in the pathogenesis of nasal polyps.

An Overview of the Application of Systems Biology in an Understanding of Chronic Rhinosinusitis (CRS) Development

Chronic rhinosinusitis (CRS) is an inflammatory disease of the paranasal sinuses. It is defined as the presence of a minimum of two out of four main symptoms such as hyposmia, facial pain, nasal blockage, and discharge, which last for 8–12 weeks. CRS significantly impairs a patient’s quality of life. It needs special treatment mainly focusing on preventing local infection/inflammation with corticosteroid sprays or improving sinus drainage using nasal saline irrigation. When other treatments fail, endoscopic sinus surgery is considered an effective option. According to the state-of-the-art knowledge of CRS, there is more evidence suggesting that it is more of an inflammatory disease than an infectious one. This condition is also treated as a multifactorial inflammatory disorder as it may be triggered by various factors, such as bacterial or fungal infections, airborne irritants, defects in innate immunity, or the presence of concomitant diseases. Due to the incomplete understanding of the pathological processes of CRS, there is a continuous search for new indicators that are directly related to the pathogenesis of this disease—e.g., in the field of systems biology. The studies adopting systems biology search for possible factors responsible for the disease at genetic, transcriptomic, proteomic, and metabolomic levels. The analyses of the changes in the genome, transcriptome, proteome, and metabolome may reveal the dysfunctional pathways of inflammatory regulation and provide a clear insight into the pathogenesis of this disease. Therefore, in the present paper, we have summarized the state-of-the-art knowledge of the application of systems biology in the pathology and development of CRS.

The effects of systemic steroid therapy on macrophage migration inhibitory factor concentrations in patients with nasal polyps

OBJECTIVES

This study aimed to compare serum macrophage migration inhibitory factor concentrations before and after oral steroid therapy in nasal polyps patients, and determine whether there is a difference between pre-treatment macrophage migration inhibitory factor concentrations and healthy individuals.

METHODS

The study included 24 patients with nasal polyps and 25 healthy individuals. The patient group received 1 mg/kg oral steroid.

RESULTS

The mean macrophage migration inhibitory factor concentration before oral steroid therapy was 3889.79 pg/ml in the patient group and 2334.52 pg/ml in the control group. Macrophage migration inhibitory factor concentrations were statistically significantly higher in the pre-oral steroid therapy patient group than in the control group (p = 0.017). The mean pre- and post-oral steroid therapy serum macrophage migration inhibitory factor concentrations were 3889.79 pg/ml and 2451.25 pg/ml, respectively. The reduction in macrophage migration inhibitory factor concentrations was statistically significant (p = 0.010).

CONCLUSION

These findings suggest that concentrations of macrophage migration inhibitory factor may play a role in the pathogenesis of nasal polyps.

What is the evidence for genetics in chronic rhinosinusitis?

PURPOSE OF REVIEW

To perform analysis of evidence in current literature on the topic of genetics and chronic rhinosinusitis (CRS), with a particular focus on recent findings in the cystic fibrosis transmembrane regulator (CFTR), genes associated with primary ciliary dyskinesia, and taste receptor T2R38. Other genes that have been found to have association with CRS are also presented and discussed.

RECENT FINDINGS

Recent studies in CFTR and CRS research have investigated possible CFTR-potentiators for treatment of refractory CRS. The T2R38 gene has been shown to be applicable in the clinical setting with a testable phenotype and may have a role in the prognosis and influencing management strategies of CRS patients. Many genes of the immune system have been studied, with genome-wide association studies and candidate-gene approaches identifying new associations that will need replication and further elucidation.

SUMMARY

CRS is a multifactorial disease, with strong evidence of a genetic component in its pathophysiology for some cases. Currently, there are over 70 genes that have been genetically associated with CRS in the past 15 years. Future investigations into genetic causes and predispositions of CRS may allow for improved prognostication and development of disease-prevention strategies as well as novel therapeutic targets.

A family-based genome-wide association study of chronic rhinosinusitis with nasal polyps implicates several genes in the disease pathogenesis

BACKGROUND

The pathogenesis of chronic rhinosinusitis with nasal polyps is largely unknown. Previous studies have given valuable information about genetic variants associated with this disease but much is still unexplained. Our goal was to identify genetic markers and genes associated with susceptibility to chronic rhinosinusitis with nasal polyps using a family-based genome-wide association study.

METHODS

427 patients (293 males and 134 females) with CRSwNP and 393 controls (175 males and 218 females) were recruited from several Swedish hospitals. SNP association values were generated using DFAM (implemented in PLINK) and Efficient Mixed Model Association eXpedited (EMMAX). Analyses of pathway enrichment, gene expression levels and expression quantitative trait loci were then performed in turn.

RESULTS

None of the analysed SNPs reached genome wide significant association of 5.0 x 10-8. Pathway analyses using our top 1000 markers with the most significant association p-values resulted in 138 target genes. A comparison between our target genes and gene expression data from the NCBI Gene Expression Omnibus database showed significant overlap for 36 of these genes. Comparisons with data from expression quantitative trait loci showed the most skewed allelic distributions in cases with chronic rhinosinusitis with nasal polyps compared with controls for the genes HLCS, HLA-DRA, BICD2, VSIR and SLC5A1.

CONCLUSION

Our study indicates that HLCS, HLA-DRA, BICD2, VSIR and SLC5A1 could be involved in the pathogenesis of chronic rhinosinusitis with nasal polyps. HLA-DRA has been associated with chronic rhinosinusitis with nasal polyps in previous studies and HLCS, BICD2, VSIR and SLC5A1 may be new targets for future research.

HLA-DRB and HLA-DQ genetic variability in patients with aspirin-exacerbated respiratory disease

BACKGROUND

Major histocompatibility complex (MHC) class II is involved in T-cell activation, cytokine secretion, and induction of immune responses. Cytokines, staphylococcus super antigens, and eosinophil activation are proposed to play important roles in aspirin-exacerbated respiratory disease (AERD).

OBJECTIVES

This study is aimed at investigating the association of HLA-DRB and DQ genetic variabilities in patients with AERD.

METHODS

A genetic association analysis in three different groups, including 33 patients with AERD, 17 patients with aspirin-tolerant asthma (ATA), and 100 healthy controls was performed. Oral aspirin challenge (OAC) test was performed to identify aspirin hypersensitivity. Pulmonary function test (PFT) was performed for all patients. Eosinophil percentage in nasal smear and peripheral blood and serum immunoglobin (Ig)E were investigated. HLA-DRB, HLA-DQA1, and HLA-DQB1 were genotyped using polymerase chain reaction.

RESULTS

HLA-DQB1*0302 (OR, 5.49, 95% confidence interval [CI],(2.40-12.59)), HLA-DQA1*0301 (OR, 2.90, 95% CI, (1.49-5.67)), HLA-DRB4 (OR, 2.94, 95% CI, (1.61-5.36)), and HLA-DRB1*04 (OR, 3.19, 95% CI, (1.57-6.47)) were higher in patients with AERD compared with controls. In patients with AERD, HLA-DQB1*0301 (OR,0.22, 95% CI, (0.09-0.54)), HLA-DQA1*0501 (OR, 0.42, 95% CI, (0.21-0.81)), HLA-DRB1*11 (OR, 0.30, 95% CI, (0.12-0.73)), and HLA-DRB3 (OR, 0.38, 95% CI, (0.21-0.70)) were significantly lower compared with healthy controls. Patients with AERD had lower frequencies of HLA-DQB1*0301 (OR, 0.27, 95% CI, (0.08-0.86)), and HLA-DRB1*011 (OR, 0.27, 95% CI, (0.08-0.86)) compared with ATA. Haplotypes of HLA-DRB1*04/ DQA1*0301/ DQB1*0302 (OR, 4.25, 95% CI, (1.94-9.29)) and HLA-DRB1*07 /DQA1*0201/ DQB1*0201 (OR, 3.52, 95% CI, (1.54-8.06)) were higher in patients with AERD compared with controls (all p < 0.05).

CONCLUSIONS

Results of this study suggest that HLA-DQB1*0302 and HLA-DRB1*04 and their related haplotypes are genes involved in predisposing patients to AERD, whereas HLA-DQB1*0301 and HLA-DRB1*011 have negative association with AERD.

Risk factors for chronic rhinosinusitis

PURPOSE OF REVIEW

To review the recent literature on risk factors for chronic rhinosinusitis (CRS) with an emphasis on genetic, comorbid diseases and environmental factors associated with CRS. Through identifying potential risk factors for CRS, we aim to glean insights into the underlying pathogenic mechanisms essential for developing effective therapeutic strategies.

RECENT FINDINGS

Recent findings demonstrate that genetics and comorbid medical conditions including airway diseases, gastroesophageal reflux disease, inflammatory and autoimmune diseases, and various demographic and environmental factors are associated with having a CRS diagnosis. Limitations of current studies include variable application of disease definitions, lack of prospective longitudinal studies and a disproportionate focus on tertiary care populations.

SUMMARY

CRS has a broad spectrum of associations ranging from genetics to comorbid diseases and environmental factors. These predisposing factors may provide valuable information for possible designing of therapeutic and preventive interventions. However, to better understand whether these associations cause CRS, further studies are needed to independently replicate findings, establish temporal relationships between exposure and disease onset, evaluate the influence of exposure dose on disease severity, and to understand the biological effects of these risk factors in the context of CRS.

ICON: chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a public health problem that has a significant socio-economic impact. Moreover, the complexity of this disease due to its heterogeneous nature based on the underlying pathophysiology - leading to different disease variants - further complicates our understanding and directions for the most appropriate targeted treatment strategies. Several International/national guidelines/position papers and/or consensus documents are available that present the current knowledge and treatment strategies for CRS. Yet there are many challenges to the management of CRS especially in the case of the more severe and refractory forms of disease. Therefore, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), a collaboration between EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus (ICON) on Chronic Rhinosinusitis. The purpose of this ICON on CRS is to highlight the key common messages from the existing guidelines, the differences in recommendations as well as the gaps in our current knowledge of CRS, thus providing a concise reference. In this document we discuss the definition of the disease, its relevance, pharmacoeconomics, pathophysiology, phenotypes and endotypes, genetics and risk factors, natural history and co-morbidities as well as clinical manifestations and treatment options in both adults and children comprising pharmacotherapy, surgical interventions and more recent biological approaches. Finally, we have also highlighted the unmet needs that wait to be addressed through future research.

The molecular genetics of inflammatory, autoimmune, and infectious diseases of the sinonasal tract: a review

CONTEXT

The sinonasal tract is frequently affected by a variety of nonneoplastic inflammatory disease processes that are often multifactorial in their etiology but commonly have a molecular genetic component.

OBJECTIVE

To review the molecular genetics of a variety of nonneoplastic inflammatory diseases of the sinonasal tract.

DATA SOURCES

Inflammatory lesions of the sinonasal tract can be divided into 3 main categories: (1) chronic rhinosinusitis, (2) infectious diseases, and (3) autoimmune diseases/vasculitides. The molecular diagnosis and pathways of a variety of these inflammatory lesions are currently being elucidated and will shed light on disease pathogenesis and treatment.

CONCLUSIONS

The sinonasal tract is frequently affected by inflammatory lesions that arise through complex interactions of environmental, infectious, and genetic factors. Because these lesions are all inflammatory in nature, the molecular pathology surrounding them is most commonly due to upregulation and down-regulation of genes that affect inflammatory responses and immune regulation.

Can HLA-DRB4 Help to Identify Asthmatic Patients at Risk of Churg-Strauss Syndrome?

HLA-DRB4 gene is associated with Churg-Strauss syndrome (CSS), a systemic eosinophilic vasculitis with a prodromal phase characterized by severe asthma, eosinophilia, nasal polyposis, and sinusitis. Aim of this study was to evaluate if the presence of HLA-DRB4 in asthmatic patients is associated with a clinical picture resembling that of the prodromal phase of CSS. HLA-DRB1 was determined in a cohort of 159 asthmatic patients and its frequency was compared with that of 1808 blood donors. HLA-DRB4 presence/absence was correlated with clinical features, including sinusitis, nasal polyposis, eosinophils, antiasthmatic drugs, asthma severity, and pulmonary function tests. HLA-DRB4 gene was associated with severe persistent asthma before treatment (P < 0.02), near fatal or severe hypoxemic asthma (P < 0.01), sinusitis (P < 0.01), nasal polyposis (P < 0.01), number of patients with eosinophils >1000/ μ l: (P < 0.05), need of beclomethasone >1000-2000  μ g/daily (P < 0.001), use of a third controller (P < 0.05), and oral prednisone (P < 0.02). HLA-DRB4 gene is associated in asthmatic patients with a clinical picture characterized by asthma severity, sinusitis, nasal polyposis, and eosinophilia closely resembling that of the prodromal phase of CSS and might be useful to suspect corticosteroids-masked cases of CSS.

Genetics of chronic rhinosinusitis: state of the field and directions forward

The cause of chronic rhinosinusitis (CRS) remains unclear. Study of the genetic susceptibility to CRS might be a valuable strategy to understand the pathogenesis of this burdensome disorder. The purpose of this review is to critically evaluate the current literature regarding the genetics of CRS in a comprehensive fashion. The most promising findings from candidate gene studies include the cystic fibrosis transmembrane conductance regulator gene (CFTR), as well as genes involved in antigen presentation, innate and adaptive immune responses, tissue remodeling, and arachidonic acid metabolism. We also review the few hypothesis-independent genetic studies of CRS (ie, linkage analysis and pooling-based genome-wide association studies). Interpretation of the current literature is limited by challenges with study design, sparse replication, few functional correlates of associated polymorphisms, and inadequate examination of linkage disequilibrium or expression quantitative trait loci for reported associations. Given the relationship of CRS to other airway disorders with well-characterized genetic components (eg, asthma), study of the genetics of CRS deserves increased attention and investment, including the organization of large, detailed, and collaborative studies to advance knowledge of the mechanisms that underlie this disorder.

HLA-DRA polymorphisms associated with risk of nasal polyposis in asthmatic patients

BACKGROUND

Nasal polyps, part of the aspirin triad symptoms, are edematous protrusions arising from the mucosa of the nasal sinuses. Although the causative factors and pathogenesis of the polyps are unknown, the significant effect of human leukocyte antigen-DR (HLA-DR) expression in nasal polyps and genetic associations of the major histocompatibility complex class II, DR alpha (HLA-DRA) with immune-mediated diseases have been revealed.

METHODS

To investigate the associations of HLA-DRA polymorphisms with nasal polyposis in asthmatic patients and in aspirin-hypersensitive subgroups, 22 single nucleotide polymorphisms (SNPs) were genotyped in a total of 467 asthmatic patients including 158 nasal polyp-positive and 309 polyp-negative subjects.

RESULTS

Statistical analysis showed that four SNPs (p = 0.0005-0.02; Pcorr = 0.009-0.033) and one haplotype (p = 0.002; Pcorr = 0.029) were significantly associated with the presence of nasal polyposis in asthmatic patients. In further analysis, although significant signals disappeared after corrections for multiple testing, two HLA-DRA polymorphisms (rs9268644C>A, rs3129878A>C) were found to be potential markers for nasal polyp development in aspirin-tolerant asthma (p = 0.005 and 0.007, respectively) compared with the aspirin-exacerbated respiratory disease (p > 0.05) subgroup. In silico analysis predicted major "C" allele of rs14004C>A in 5'-untranslated region as a potential binding site for regulatory glucocorticoid receptor. In addition, sequence nearby rs1051336G>A is suspected to be a pyrimidine-rich element that affects mRNA stability.

CONCLUSION

Despite the need for replication in larger cohorts and/or functional evaluations, our findings suggest that HLA-DRA polymorphisms might contribute to nasal polyposis susceptibility in patients with asthma.