Chronic Cough as a Genetic Neurological Disorder? Insights from Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS).

Chronic cough is common, and in many cases unexplained or refractory to otherwise effective treatment of associated medical conditions. Cough hypersensitivity has developed as a paradigm that helps to explain clinical and research observations that frequently point towards chronic cough as a neuropathic disorder. Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a recently described neurological condition whose clinical features include gait ataxia, unsteadiness, peripheral neuropathy, and autonomic dysfunction. Chronic cough is also a common feature of the syndrome, with features of hypersensitivity, often preceding core neurological symptoms by up to 30 years or more. The genetic basis in a majority of cases of CANVAS appears to be biallelic variable repeat intron expansion sequences within RFC1, a gene normally involved in the regulation of DNA replication and repair. The same polymorphism has now been identified at an increased frequency in patients with unexplained or refractory chronic cough in the absence of defining clinical features of CANVAS. This review expands on these points, aiming to increase the awareness of CANVAS amongst clinicians and researchers working with chronic cough. We discuss the implications of a link between RFC1 disease and cough. Improved understanding of CANVAS may lead to an enhanced grasp of the pathophysiology of chronic cough, and new approaches to antitussive treatments.

Effects of spray cryotherapy on cough receptors and airway microenvironment in a canine model of chronic bronchitis.

The aim of this study was to explore the effects of spray cryotherapy (SCT) on cough receptors and airway microenvironment in a canine model of chronic bronchitis. We examined the expression of transient receptor potential vanilloid 1/4 (TRPV1/4) and the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) at the gene and protein levels before and after SCT. In addition, we explored whether TRPV1/4 could regulate inflammatory factors via mediator adenosine triphosphate (ATP). The levels of ATP and cytokines in alveolar lavage fluid and cell supernatant were measured using ELISA. SCT effectively downregulated the expression of TRPV1/4 and SP/CGRP in canine airway tissues with chronic bronchitis and reduced the levels of inflammatory mediators and cytokines that affect cough receptor sensitivity, achieving cough relief. TRPV1/4 - ATP - inflammatory cytokines axis has been demonstrated at the cellular level, which in turn modulate the milieu of the airways and promote the formation of a cough feedback loop. Our study has fully revealed the specific mechanism of SCT in treating cough in a canine model of chronic bronchitis, providing a solid theoretical basis for future clinical treatment.

A randomized trial of genotype-guided perindopril use.

OBJECTIVE: Cough caused by angiotensin-converting enzyme inhibitors (ACEIs) limits their clinical application and cardiovascular benefits. This randomized trial investigated whether genotype-guided perindopril use could reduce drug-related cough in 20 to 79-year-old individuals with hypertension. METHODS: After screening 120 patients and randomization, 68 were assigned to genotyping ( n  = 41) and control ( n  = 27) groups. NELL1 p.Arg382Trp (rs8176786) and intron (rs10766756) genotype information was used to subdivide the genotyping group into high-risk and low-risk subgroups with at least one or no risk alleles for ACEI-related cough, respectively. The high-risk subgroup received candesartan (8 mg/day) for 6 weeks, whereas the low-risk subgroup received perindopril (4 mg/day). The control group, which was not genotyped, received perindopril (4 mg/day). The primary outcome variables were cough and moderate/severe cough; the secondary outcome variable was any adverse event. RESULTS: During the 6-week period, the risk of cough was lower in the genotyping group than in the control group [five (12.2%) and nine (33.3%) participants, respectively; hazard ratio: 0.25; log-rank P  = 0.017]. The moderate/severe cough risk was also lower in the genotyping group [one (2.4%) and five (18.5%) participants, respectively; hazard ratio: 0.12; log-rank P  = 0.025]. Differences in cough (hazard ratio: 0.56; log-rank P  = 0.32) and moderate/severe cough risk (hazard ratio: 0.26; log-rank P  = 0.19) between the low-risk and control groups were not significant. The risk of total adverse events was similar between any two groups. CONCLUSION: Cough risk was lower during genotype-guided treatment than during conventional treatment. These results support the utility of NELL1 variant data in clinical decision making to personalize renin-angiotensin system blocker therapy use. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT05535595 (retrospectively registered at September 7, 2022).

Pharmacogenetic predictors of development of secondary to enalapril dry cough in hypertensive patients.

OBJECTIVES: Development of the secondary to ACEI cough leads to discontinuation of the drugs of this group. Assessing the safety of the ACEIs with further development of customized approaches for their administration is a major scientific and practical problem. The objective of this study was to assess the association of the genetic markers with the development of the adverse drug reaction in the form of secondary to enalapril dry cough in the patients with essential arterial hypertension. METHODS: Study involved 113 patients with the secondary to enalapril cough and 104 patients without development of the secondary to enalapril adverse drug reaction. RESULTS: The patients carriers of the genotype AA rs2306283 of gene SLCO1B1 had 2-fold higher odds of developing the dry cough than those with the genotypes AG and GG (ОR=2.01, 95%CI=1.10-3.66, р=0.023). Similarly, the patients heterozygous for rs8176746 of gene АВО had 2.3-fold higher odds of developing the ADR in the form of dry cough than the carriers of the genotypes GG and TT (ОR=2.30, 95%CI=1.24-4.29, р=0.008). CONCLUSIONS: Statistically significant association between the development of the ADR in the form of secondary to enalapril dry cough and polymorphisms rs2306283 of gene SLCO1B1 and rs8176746 of gene ABO was revealed.

Patient-reported outcomes in capmatinib-treated patients with METex14-mutated advanced NSCLC: Results from the GEOMETRY mono-1 study.

INTRODUCTION: Capmatinib, a MET inhibitor, showed substantial antitumour activity with manageable side effects in patients with MET exon 14 (METex14)-mutated advanced non-small cell lung cancer (aNSCLC) in the GEOMETRY mono-1 study. We report patient-reported outcomes (PROs) from this study. METHODS: Enrolled treatment-naïve (1L) or pre-treated (2L+) patients with aNSCLC with a METex14-skipping mutation received 400 mg capmatinib twice daily during 21-day treatment cycles. PROs were collected at baseline and every six weeks thereafter using EORTC QLQ-C30 global health status/quality of life (GHS/QoL), QLQ-LC13 symptoms, and EQ-5D-5L visual analogue scale (VAS) questionnaires. RESULTS: As of 6 January 2020, 27/28 1L and 65/69 2L+ patients had completed PROs at baseline; compliance rates remained >70%. Cough improved early, with meaningful improvements (≥10-point change from baseline) observed throughout cycles (mean change from baseline [SD] by week 7: 1L -13.0 [39.9], 2L+ -8.2 [28.4]; week 43: 1L -28.2 [26.7], 2L+ -10.5 [27.3]). QoL, assessed by GHS/QoL and VAS, improved by week 7 in 1L and 2L+ patients, with improvements generally sustained over time. Median time to definitive deterioration (TTDD) in GHS/QoL was 16.6 months (95% CI: 9.7, not estimable [NE]) in 1L and 12.4 months (95% CI: 4.2, 19.4) in 2L+ patients. Median TTDD for dyspnoea was 19.4 months (95% CI: 12.4, NE) and 22.1 months (95% CI: 9.9, NE) for 1L and 2L+ patients, respectively, and NE for cough and chest pain. CONCLUSIONS: Capmatinib was associated with clinically meaningful improvements in cough and preserved QoL, further supporting its use in patients with METex14-mutated aNSCLC. TRIAL REGISTRATION: ClinicalTrials.gov registry number: NCT02414139.

Chromosome-Level Genome Sequences, Comparative Genomic Analyses, and Secondary-Metabolite Biosynthesis Evaluation of the Medicinal Edible Mushroom Laetiporus sulphureus.

Laetiporus sulphureus mushroom is a complementary and alternative medicine that has anticancer, antioxidation, and analgesic effects and immunomodulatory activity; it is used as a treatment for cough and rheumatism and is a functional food that can improve physical fitness. Even though L. sulphureus has garnered considerable biotechnological and pharmacological interest due to its excellent cellulose-degrading ability and diverse biological activities, its biosynthetic potential regarding polysaccharides and secondary metabolites has not been thoroughly examined. In this study, we sequenced and assembled the whole genome of a wild L. sulphureus isolate, NWAFU-1, from the Qinling Mountains in China. Comparative genomes analysis revealed genomic differences between subspecies, and phylogenomic analysis revealed evolutionary divergence as well as genome expansion and contraction of individual Polyporaceae family species. Bioinformatics investigation identified candidate genes associated with mating type, polysaccharide synthesis, carbohydrate-active enzymes, and secondary-metabolite biosynthesis, which included multiple terpenoids, nonribosomal peptides, and polyketides. The locations of biosynthetic core genes were mapped and displayed on chromosomes and contigs. Totals of 143 proteins from 126 coding genes were identified and divided into 14 cytochrome P450 families. Furthermore, the biosynthetic network of tetracyclic triterpenoid active components was postulated by genome mining of related genes combined with the molecular network of metabolites. The genome analysis of L. sulphureus in this study improves the understanding of the biosynthesis of active compounds, which will lay a theoretical foundation for subsequent research on active-compound biosynthesis and promote the application of Laetiporus in the field of drug research and functional-food creation. IMPORTANCE L. sulphureus is a parasitic basidiomycete fungus that causes brown rot. The fruiting bodies of L. sulphureus are used as ancient medicines in China and Europe to cure cancer, analgesia, cough, and rheumatism and are considered a functional food that regulates the body and improves health. L. sulphureus was inferred to be a tetrapolar system based on a high-quality genome, which will aid molecular breeding and artificial farming. Screening polysaccharide synthesis candidate genes and comparing carbohydrate-associated genes in brown-rot basidiomycetes help understand their growth. Identifying core genes for secondary-metabolite biosynthesis, gene cluster family analysis, and comparative cluster analysis will guide heterologous-biosynthesis investigations of these genes and help elucidate the biosynthetic pathways for L. sulphureus bioactive natural components. The biosynthesis network of tetracyclic triterpenes was mapped using metabolite profiling and genome scanning. This work explores the biosynthetic capacity of L. sulphureus-derived natural products and lays the foundation for biosynthetic studies of them.

Polygenic risk score for ACE-inhibitor-associated cough based on the discovery of new genetic loci.

AIMS: To search for sequence variants associated with ACEi discontinuation and to test their association with ACEi-associated adverse drug reactions (ADRs). METHODS AND RESULTS: A genome-wide association study (GWAS) on ACEi discontinuation was conducted, including 33 959 ACEi-discontinuers and 44 041 controls. Cases were defined as persons who switched from an ACEi treatment to an angiotensin receptor blocker. Controls were defined as persons who continued ACEi treatment for at least 1 year. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed for ACEi discontinuation risk by mixed model regression analysis. Summary statistics from the individual cohorts were meta-analyzed with a fixed-effects model. To test for association with specific ACEi-associated ADRs, any genome-wide significant (P < 5 × 10-8) ACEi discontinuation variants was tested for association with ACEi-associated cough and angioedema. A polygenetic risk score (PRS) based on ACEi discontinuation GWAS data was constructed and tested for association with ACEi-associated cough and angioedema in two population-based samples. In total, seven genetic genome-wide loci were identified, of which six were previously unreported. The strongest association with ACEi discontinuation was at 20q13.3 (NTSR1; OR: 1.21; 95% CI: 1.17-1.24; P = 2.1 × 10-34). Five of seven lead variants were associated with ACEi-associated cough, whereas none were associated with ACEi-associated angioedema. The ACEi discontinuation PRS was associated with ACEi-associated cough in a dose-response manner but not with ACEi-associated angioedema. ACEi discontinuation was genetically correlated with important causes for cough, including gastro-esophageal reflux disease, allergic rhinitis, hay fever, and asthma, which indicates partly shared genetic underpinning between these traits. CONCLUSION: This study showed the advantage of using prescription patterns to discover genetic links with ADRs. In total, seven genetic loci that associated with ACEi discontinuation were identified. There was evidence of a strong association between our ADR phenotype and ACEi-associated cough. Taken together, these findings increase insight into the pathophysiological processes that underlie ACEi-associated ADRs.

Genetic Variants Associated with Adverse Events after Angiotensin-Converting Enzyme Inhibitor Use: Replication after GWAS-Based Discovery.

PURPOSE: Angiotensin-converting enzyme inhibitors (ACEIs) are medications generally prescribed for patients with high cardiovascular risk; however, they are suboptimally used due to frequent adverse events (AEs). The present study aimed to identify and replicate the genetic variants associated with ACEI-related AEs in the Korean population. MATERIALS AND METHODS: A two-stage approach employing genome-wide association study (GWAS)-based discovery and replication through target sequencing was used. In total, 1300 individuals received ACEIs from 2001 to 2007; among these, 228 were selected for GWAS. An additional 336 patients were selected for replication after screening 1186 subjects treated from 2008 to 2018. Candidate genes for target sequencing were selected based on the present GWAS, previous GWASs, and data from the PharmGKB database. Furthermore, association analyses were performed between no AE and AE or cough groups after target sequencing. RESULTS: Five genes, namely CRIM1, NELL1, CACNA1D, VOPP1, and MYBPC1, were identified near variants associated with ACEI-related AEs. During target sequencing of 34 candidate genes, six single-nucleotide polymorphisms (SNPs; rs5224, rs8176786, rs10766756, rs561868018, rs4974539, and rs10946364) were replicated for association with all ACEI-related AEs. Four of these SNPs and rs147912715 exhibited associations with ACEI-related cough, whereas four SNPs (rs5224, rs81767786, rs10766756, and rs4974539 near BDKRB2, NELL1, NELL1 intron, and CPN2, respectively) were significantly associated with both categories of AEs. CONCLUSION: Several variants, including novel and known variants, were successfully replicated and found to have associations with ACEI-related AEs. These results provide rare and clinically relevant information for safer use of ACEIs.

RFC1 repeat expansions: A recurrent cause of sensory and autonomic neuropathy with cough and ataxia.

BACKGROUND AND PURPOSE: Ataxia and cough are rare features in hereditary sensory and autonomic neuropathies (HSAN), a group of diseases of mostly unknown genetic cause. Biallelic repeat expansions in RFC1 are associated with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS). This study aimed to investigate the prevalence of RFC1 repeat expansions in a cohort of HSAN patients. METHODS: After unremarkable whole-exome sequencing (WES) analysis, we performed repeat-primed PCR to detect intronic RFC1 expansions in 12 HSAN families, who all presented with chronic cough. RESULTS: In these patients, 75% carried biallelic expansions of the pathogenic AAGGG motif. Compared with RFC1-/- cases, RFC1+/+ cases presented more consistently with positive sensory and autonomic symptoms. Afferent ataxia was more severe in the RFC1+/+ cohort and cerebellar ataxia was a common feature (21%). CONCLUSIONS: We demonstrate that RFC1 is a frequent cause of (WES-negative) HSAN with chronic cough and ataxia. The diagnostic yield of RFC1 repeat-primed PCR was surprisingly high, given that HSAN is genetically poorly understood. This combination of HSAN, ataxia, and chronic cough symptoms represents a new nosological entity within the neuropathy-ataxia spectrum.

Association of the CFTR gene with asthma and airway mucus hypersecretion.

INTRODUCTION: Asthma with airway mucus hypersecretion is an inadequately characterized variant of asthma. While several studies have reported that hypersecreting patients may carry genetic variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, many of those studies have been questioned for their numerous limitations and contradictory results. OBJECTIVES: (1) To determine the presence of genetic variants of the CFTR gene in patients with asthma with and without airway mucus hypersecretion. (2) To identify the clinical, inflammatory and functional characteristics of the asthma phenotype with airway mucus hypersecretion. METHOD: Comparative multicentre cross-sectional descriptive study that included 100 patients with asthma (39 hypersecretors and 61 non-hypersecretors). Asthmatic hypersecretion was defined as the presence of cough productive of sputum on most days for at least 3 months in 2 successive years. The patients were tested for fractional exhaled nitric oxide, spirometry, induced sputum cell count, total immunoglobulin E (IgE), peripheral blood eosinophil count, C-reactive protein, blood fibrinogen and blood albumin and underwent a skin prick test. Asthma control and quality of life were assessed by the Asthma Control Test and Mini Asthma Quality of Life questionnaires, respectively. Blood DNA samples were collected from the patients and next-generation sequencing using a MiSeq sequencer and the Illumina platform was used for the CFTR gene analysis. RESULTS: Genetic differences were observed in the c.1680-870T>A polymorphism of the CFTR gene, significantly more evident in hypersecretors than in non-hypersecretors: 78.94% vs. 59.32% in the majority allele and 21.05% vs. 40.67% in the minority allele (p = 0.036). Clinically, asthma hypersecretors compared to non-hypersecretors were older (57.4 years vs. 49.4 years; p = 0.004); had greater asthma severity (58.9% vs. 23.7%; p = 0.005); experienced greater airway obstruction (FEV1/FVC% 64.3 vs. 69.5; p = 0.041); had poorer asthma control (60% vs. 29%; p = 0.021); had lower IgE levels (126.4 IU/mL vs. 407.6 IU/mL; p = 0.003); and were less likely to have a positive prick test (37.5% vs. 68.85%; p = 0.011). CONCLUSION: The results suggest that patients with asthma and with mucus hypersecretion (1) may have a different phenotype and disease mechanism produced by an intronic polymorphism in the CFTR gene (NM_000492.3:c.1680-870T>A), and (2) may have a poorer clinical outcome characterized by severe disease and poorer asthma control with a non-allergic inflammatory phenotype.

Occupational exposures and genetic susceptibility to occupational exposures are related to sickness absence in the Lifelines cohort study.

In this cross-sectional study, we investigated the association between occupational exposures and sickness absence (SA), the mediating role of respiratory symptoms, and whether genetic susceptibility to SA upon occupational exposures exists. Logistic regression was used to examine associations and structural equation modelling was used for mediation analyses. Genetic susceptibility was investigated by including interactions between occupational exposures and 11 candidate single nucleotide polymorphisms (SNPs). Biological dust, mineral dust, and pesticides exposure were associated with a lower prevalence of any SA (OR (95% CI) = 0.72 (0.58-0.89), 0.88 (0.78-0.99), and 0.70 (0.55-0.89), respectively) while gases/fumes exposure was associated with a higher prevalence of long-term SA (1.46 (1.11-1.91)). Subjects exposed to solvents and metals had a higher prevalence of any (1.14 (1.03-1.26) and 1.68 (1.26-2.24)) and long-term SA (1.26 (1.08-1.46) and 1.75 (1.15-2.67)). Chronic cough and chronic phlegm mediated the association between high gases/fumes exposure and long-term SA. Two of 11 SNPs investigated had a positive interaction with exposure on SA and one SNP negatively interacted with exposure on SA. Exposure to metals and gases/fumes showed a clear dose-response relationship with a higher prevalence of long-term SA; contrary, exposure to pesticides and biological/mineral dust showed a protective effect on any SA. Respiratory symptoms mediated the association between occupational exposures and SA. Moreover, gene-by-exposure interactions exist.

Serum Protein Profiling Reveals a Landscape of Inflammation and Immune Signaling in Early-stage COVID-19 Infection.

Coronavirus disease 2019 (COVID-19) is a highly contagious infection and threating the human lives in the world. The elevation of cytokines in blood is crucial to induce cytokine storm and immunosuppression in the transition of severity in COVID-19 patients. However, the comprehensive changes of serum proteins in COVID-19 patients throughout the SARS-CoV-2 infection is unknown. In this work, we developed a high-density antibody microarray and performed an in-depth proteomics analysis of serum samples collected from early COVID-19 (n = 15) and influenza (n = 13) patients. We identified a large set of differentially expressed proteins (n = 132) that participate in a landscape of inflammation and immune signaling related to the SARS-CoV-2 infection. Furthermore, the significant correlations of neutrophil and lymphocyte with the CCL2 and CXCL10 mediated cytokine signaling pathways was identified. These information are valuable for the understanding of COVID-19 pathogenesis, identification of biomarkers and development of the optimal anti-inflammation therapy.

PNPT1 and PCGF3 variants associated with angiotensin-converting enzyme inhibitor-induced cough: a nested case-control genome-wide study.

Aim: We aimed to identify genetic variants associated with ACE inhibitor (ACEI)-induced cough. Materials & methods: A nested case-control study was performed among hypertensive Chinese patients receiving enalapril-only therapy. Whole-exome sequencing and genome-wide association analysis were performed. Results: We identified that PNPT1 rs13015243 (odds ratio [OR]: 0.47; 95% CI: 0.34-0.66; p = 7.45 × 10-6), PNPT1 rs13009649 (OR: 0.48; 95% CI: 0.35-0.67; p = 9.96 × 10-6) and PCGF3 rs1044147 (OR: 2.67; 95% CI: 1.71-4.17; p = 9.91 × 10-6) were significantly associated with ACEI-induced cough. Nearly genome-wide significant associations in previously reported candidate risk genes CLASP1, ACE, CES1, CPN1, XPNPEP1, PDE11A or SLC38A were detected in our dataset. Conclusion: Our results suggest that ACEI-induced cough is associated with noncoding SNPs of PNPT1 and PCGF3, all of which are independent of the bradykinin pathway. Study registration: NCT03259399.

Intronic variant in IQGAP3 associated with hereditary neuropathy with proximal lower dominancy, urinary disturbance, and paroxysmal dry cough.

In 2008, we reported a clinically and genetically new type of autosomal dominant disorder of motor and sensory neuropathy with proximal dominancy in the lower extremities, urinary disturbance, and paroxysmal dry cough. To identify the nucleotide variant causative of this disease, we reanalyzed the linkage of the original Japanese pedigree including seven newly ascertained subjects with updated information. We assigned the locus of the disease to 1p13.3-q23 (maximum logarithm-of-odds score = 2.71). Exome sequencing for five patients and one healthy relative from the pedigree revealed 2526 patient-specific single-nucleotide variants (SNVs). By rigorous filtering processes using public databases, our linkage results, and functional prediction, followed by Sanger sequencing of the pedigree and 520 healthy Japanese individuals, we identified an intronic SNV in IQGAP3, a gene known to be associated with neurite outgrowth. Upon pathological examination of the sural nerve, moderate, chronic, mainly axonal neuropathy was observed. By histochemical analyses, we observed a patient-specific increase of IQGAP3 expression in the sural nerve. We concluded that the variant of IQGAP3 is associated with the disease in our pedigree.

Identification of the Molecular Mechanisms of Peimine in the Treatment of Cough Using Computational Target Fishing.

Peimine (also known as verticine) is the major bioactive and characterized compound of Fritillariae Thunbergii Bulbus, a traditional Chinese medicine that is most frequently used to relieve a cough. Nevertheless, its molecular targets and mechanisms of action for cough are still not clear. In the present study, potential targets of peimine for cough were identified using computational target fishing combined with manual database mining. In addition, protein-protein interaction (PPI), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using, GeneMANIA and Database for Annotation, Visualization and Integrated Discovery (DAVID) databases respectively. Finally, an interaction network of drug-targets-pathways was constructed using Cytoscape. The results identified 23 potential targets of peimine associated with cough, and suggested that MAPK1, AKT1 and PPKCB may be important targets of pemine for the treatment of cough. The functional annotations of protein targets were related to the regulation of immunological and neurological function through specific biological processes and related pathways. A visual representation of the multiple targets and pathways that form a network underlying the systematic actions of peimine was generated. In summary, peimine is predicted to exert its systemic pharmacological effects on cough by targeting a network composed of multiple proteins and pathways.

Multiple single nucleotide polymorphisms of the transient receptor potential vanilloid 1 (TRPV1) genes associate with cough sensitivity to capsaicin in healthy subjects.

BACKGROUND: Cough is a common symptom in several respiratory diseases and may occur in healthy subjects as a defense mechanism against noxious inhalants. Cough response is mediated by transient receptor potential vanilloid-1 (TRPV1) expressed by C-fibers in the airways. Capsaicin (CPS) activates TRPV1 and is regularly used as a tool to study cough response. Although single nucleotide polymorphisms (SNPs) of TRPV1 are implicated in CPS binding, their role in cough response is not fully elucidated. AIMS: In this study we investigated the relationship between capsaicin cough challenge sensitivity and multiple TRPV1 polymorphisms. METHODS: The dose-response of cough induced by CPS inhalation was determined in 20 unselected healthy volunteers and the concentration of CPS causing two coughs (C2) was calculated. The SNPs I585V(rs8065080), T505A(rs17633288), T469I(rs224534), I315 M(rs222747), P91S(rs222749), and K2N(rs9894618) were characterized in blood DNA from each subject. The association between combinations of TRPV1 SNPs and CPS sensitivity of each subject was assessed by linear regression. RESULTS: All subjects were wild type for T505A and K2N, while they exhibited two to six SNPs with high capsaicin responsiveness. The major contribution to CPS sensitivity in vivo (C2) was due to four combined SNPs: 315 M, 585I, 469I and 91S (p = 0.015). We found, however, that the presence of a minimum of two polymorphisms, such as 91S combined with 315 M (p = 0.032) or 91S with 585I (p = 0.025), was sufficient to detect an effect on C2. CONCLUSION: Capsaicin cough challenge sensitivity in healthy subjects is dependent on multiple TRPV1 polymorphisms.

Pharmacogenomics and Placebo Response in a Randomized Clinical Trial in Asthma.

Genetic variation may differentially modify drug and placebo treatment effects in randomized clinical trials. In asthma, although lung function and asthma control improvements are commonplace with placebo, pharmacogenomics of placebo vs. drug response remains unexamined. In a genomewide association study of subjective and objective outcomes with placebo treatment in Childhood Asthma Management Program of nedocromil/budesonide vs. placebo (N = 604), effect estimates for lead single nucleotide polymorphisms (SNPs) were compared across arms. The coughing/wheezing lead SNP, rs2392165 (ß = 0.94; P = 1.10E-07) mapped to BBS9, a gene implicated in lung development that contains a lung function expression quantitative trait locus. The effect was attenuated with budesonide (Pinteraction  = 1.48E-07), but not nedocromil (Pinteraction  = 0.06). The lead forced vital capacity SNP, rs12930749 (ß = -5.80; P = 1.47E-06), mapped to KIAA0556, a locus genomewide associated with respiratory diseases. The rs12930749 effect was attenuated with budesonide (Pinteraction  = 1.32E-02) and nedocromil (Pinteraction  = 1.09E-02). Pharmacogenomic analysis revealed differential effects with placebo and drug treatment that could potentially guide precision drug development in asthma.