BACKGROUND:Fungal sensitization is an increasingly recognized endophenotype in chronic respiratory disease; however, its role in bronchiectasis remains poorly defined. This study aimed to provide the most comprehensive evaluation to date of fungal sensitization and its clinical relevance in bronchiectasis using an expanded panel of crude and recombinant fungal allergens. RESEARCH QUESTION:What are the prevalence and clinical implications of fungal sensitization in bronchiectasis? STUDY DESIGN AND METHODS:An international, multicenter evaluation of fungal sensitization was conducted across 6 tertiary centers in 4 countries (Singapore, Malaysia, the United Kingdom, and Italy), prospectively recruiting 277 individuals with bronchiectasis. Using a comprehensive, expanded allergen panel including 11 crude and 24 recombinant fungal allergens (total of 35 allergens and 9,695 individual assays), sensitization responses were assessed in relation to clinical characteristics, exacerbation frequency, and geographic origin. Low baseline exacerbations were defined as < 3 and high baseline exacerbations as ≥ 3 in the preceding 12 months of study recruitment. RESULTS:Our results showed that sensitization to recombinant Aspergillus fumigatus (rAsp f) was linked to bronchiectasis severity. Measurable responses to rAsp f allergens 12, 15, and 17 were associated with severe (hospitalized) exacerbations, particularly in those with low baseline exacerbations (low risk). "Sensitized" low-risk individuals exhibited significantly greater disease severity and higher occurrence of bronchiectasis-COPD overlap compared with nonsensitized, low-risk individuals, a relationship absent in those with high baseline exacerbations. Polysensitization to the same allergens conferred further additional risks of severe (hospitalized) exacerbations. Notably, Asian patients sensitized to rAsp f allergens 12, 15, and 17 exhibited the poorest clinical outcomes with increased symptoms, poorer lung function, and severe disease. INTERPRETATION:This study shows that A fumigatus sensitization, particularly to rAsp f allergens 12, 15, and 17, is a clinically significant and potentially treatable trait in bronchiectasis. This finding is of highest relevance in individuals with lower baseline exacerbation frequency and of Asian descent.

Rationale: Chronic infection and inflammation shapes the airway microbiome in bronchiectasis. Utilizing whole-genome shotgun metagenomics to analyze the airway resistome provides insight into interplay between microbes, resistance genes, and clinical outcomes. Objectives: To apply whole-genome shotgun metagenomics to the airway microbiome in bronchiectasis to highlight a diverse pool of antimicrobial resistance genes: the "resistome," the clinical significance of which remains unclear. Methods: Individuals with bronchiectasis were prospectively recruited into cross-sectional and longitudinal cohorts (n = 280), including the international multicenter cross-sectional Cohort of Asian and Matched European Bronchiectasis 2 (CAMEB 2) study (n = 251) and two independent cohorts, one describing patients experiencing acute exacerbation and a further cohort of patients undergoing Pseudomonas aeruginosa eradication treatment. Sputum was subjected to metagenomic sequencing, and the bronchiectasis resistome was evaluated in association with clinical outcomes and underlying host microbiomes. Measurements and Main Results: The bronchiectasis resistome features a unique resistance gene profile and increased counts of aminoglycoside, bicyclomycin, phenicol, triclosan, and multidrug resistance genes. Longitudinally, it exhibits within-patient stability over time and during exacerbations despite between-patient heterogeneity. Proportional differences in baseline resistome profiles, including increased macrolide and multidrug resistance genes, associate with shorter intervals to the next exacerbation, whereas distinct resistome archetypes associate with frequent exacerbations, poorer lung function, geographic origin, and the host microbiome. Unsupervised analysis of resistome profiles identified two clinically relevant "resistotypes," RT1 and RT2, the latter characterized by poor clinical outcomes, increased multidrug resistance, and P. aeruginosa. Successful targeted eradication in P. aeruginosa-colonized individuals mediated reversion from RT2 to RT1, a more clinically favorable resistome profile demonstrating reduced resistance gene diversity. Conclusions: The bronchiectasis resistome associates with clinical outcomes, geographic origin, and the underlying host microbiome. Bronchiectasis resistotypes link to clinical disease and are modifiable through targeted antimicrobial therapy.

Introduction: Plasmids are involved in the dissemination of antimicrobial resistance (AMR) and as virulence factors in microbes, however, total plasmid content (the plasmidome) remains unexplored by metagenomics and its role in bronchiectasis unclear. Methods: Sputum samples (n=251) from patients with stable bronchiectasis were prospectively collected across four countries (Singapore, Malaysia, Scotland, and Italy) and subjected to shotgun metagenomic sequencing. Contigs of plasmid origin were identified using PlasForest and plasmid identity determined by BLAST homology against a PLSDB plasmid database. AMR, virulence, and toxins were subsequently evaluated with PathoFact. Differentially adundant plasmids were determined using Linear discriminant analysis Effect Size. Results: The plasmidome in bronchiectasis associates with diverse AMR, virulence, and toxin genes. Plasmidome composition significantly differs across countries (p<0.01) and in frequent exacerbators (p<0.05) irrespective of geographic origin. Differentially abundant plasmids associated with frequent exacerbators include those isolated from Pseudomonas spp. (44%) and Klebsiella spp. (11%) which harbour resistance to macrolide-lincosamide-streptogramin (MLS) antibiotics, and exhibit significantly increased virulence (p<0.05). Conclusion: Plasmidome signatures associate with frequent exacerbator status in bronchiectasis independent of geographic origin. The plasmidome presents a novel opportunity for endophenotyping bronchiectasis, demonstrating clinical relevance particularly in informing antibiotic use. Funding: This research is supported by the Singapore Ministry of Health9s NMRC under its Clinician Scientist Award (MOH-000710) (S.H.C).

Neisseria species are frequently identified in the bronchiectasis microbiome, but they are regarded as respiratory commensals. Using a combination of human cohorts, next-generation sequencing, systems biology, and animal models, we show that bronchiectasis bacteriomes defined by the presence of Neisseria spp. associate with poor clinical outcomes, including exacerbations. Neisseria subflava cultivated from bronchiectasis patients promotes the loss of epithelial integrity and inflammation in primary epithelial cells. In vivo animal models of Neisseria subflava infection and metabolipidome analysis highlight immunoinflammatory functional gene clusters and provide evidence for pulmonary inflammation. The murine metabolipidomic data were validated with human Neisseria-dominant bronchiectasis samples and compared with disease in which Pseudomonas-, an established bronchiectasis pathogen, is dominant. Metagenomic surveillance of Neisseria across various respiratory disorders reveals broader importance, and the assessment of the home environment in bronchiectasis implies potential environmental sources of exposure. Thus, we identify Neisseria species as pathobionts in bronchiectasis, allowing for improved risk stratification in this high-risk group.

Objective Bronchiectasis is a heterogeneous disease with distinct phenotypes. The post-tuberculosis (post-TB) bronchiectasis phenotype is prevalent in many countries but is under-studied. Our aim was to identify distinct phenotypic characteristics of post-TB bronchiectasis. Methods We recruited adults admitted between Jan 2010-Oct 2017 at Changi General Hospital, Singapore for bronchiectasis exacerbation. We collected demographics, symptoms, lung function, microbiology and FACED scores. Participants were followed-up until the next hospitalized exacerbation or end of study, whichever was sooner. Participants diagnosed by their attending respiratory specialist to have post-TB bronchiectasis were compared to those with bronchiectasis from other aetiologies. Results 148 participants were included with mean±standard deviation age 63 ± 9 years; 46 (31.1%) had post-TB bronchiectasis and 102 (68.9%) other aetiologies. Compared to other aetiologies, participants with post-TB bronchiectasis had significantly lower body mass index (BMI), more frequent presentation with haemoptysis, lower forced expiratory volume in one second (FEV1), more frequent isolation of nontuberculous mycobacteria (NTM), and higher FACED scores indicating greater disease severity. Over a median follow-up of 21 months, post-TB bronchiectasis was associated with shorter time to next hospitalized exacerbation (49 vs 76 months, Log-Rank p = .01). Conclusion Post-TB bronchiectasis is a distinct entity with higher rates of haemoptysis and NTM isolation, more frequent exacerbations, and greater disease severity.

Introduction: Few studies have assessed the resistome in bronchiectasis despite high antibiotic use Methods: By performing airway metagenomics in the largest study to date, a bronchiectasis cohort (n=269) recruited from 4 countries: Singapore, Malaysia (Kuala Lumpur), Scotland (Dundee) and Italy (Milan) were assessed. N=18 longitudinally sampled patients were included. Individuals from Asian and European cohorts were ‘matched’ by age, sex, exacerbation frequency and lung function to allow for robust geographic comparison. Metagenomic reads were mapped to the Comprehensive Antibiotic Resistance Database (CARD) and expressed as normalized gene counts (RPKM) to define resistome profiles with concurrent assessment of microbiome and bacteriophage profiles. Results: Longitudinal analysis reveal a stable baseline resistome profile over time and during exacerbations in individual patients however baseline profile did associate with time to next exacerbation. Cross-sectional analyses reveals the link between resistomes and clinical outcomes in bronchiectasis including exacerbation frequency, lung function and aetiology. Aetiology-associated resistome profiling strongly correlated with geographic patient origin. Unsupervised analysis uncovered bronchiectasis ‘resistotypes’ each with clinical relevance and accompanying microbiome-bacteriophage profiles. Conclusion: The resistome in bronchiectasis demonstrates clinical relevance and may be useful to improve patient risk stratification in clinical settings. Funding: Singapore Ministry of Health9s National Medical Research Council under its Clinician-Scientist Individual Research Grant (MOH-000141) (S.H.C) and Clinician Scientist Award (MOH-000710) (S.H.C).

Introduction: The clinical relevance of bacteriophages in bronchiectasis remains unknown. Aim: To evaluate the bacteriophagome in bronchiectasis and assess correlation with antimicrobial resistance (AMR) and clinical status. Methods: We performed the largest metagenomic study in bronchiectasis to date (n=251) recruiting patients from four countries: Singapore (n=94), Malaysia (Kuala Lumpur) (n=38), Scotland (Dundee) (n=94) and Italy (Milan) (n=25). Patients were ‘matched’ by age, gender, and exacerbation status to allow for geographic comparisons. All specimens were subjected to whole-genome shotgun metagenomic sequencing and bioinformatic analysis to assess bacteriophages and AMR genes. Results: In supervised analysis, geographic differences in bacteriophages were evident, with Myoviridae increased in Europeans (Dundee/Milan) and Phycodnaviridae overrepresented in Asians (Singapore/Malaysia) (p<0.001). Multidrug resistance genes including those associated with resistance to aminoglycoside, triclosan, bicyclomycin, phenicol and peptide antibiotics were increased in frequent exacerbators (p<0.05). Unsupervised patient stratification based on bacteriophages identified two patient clusters distinguished by AMR gene profiles and long-term antibiotic exposure (p <0.005) highlighting an association of bacteriophages with AMR. Conclusion: Our multi-centre international study reveals, for the first time, the importance and clinical relevance of the ‘bacteriophagome’ in bronchiectasis highlighting patient sub-groups with potential implication for antimicrobial therapy. Funding: This research is supported by the Singapore Ministry of Health’s National Medical Research Council under its Clinician-Scientist Individual Research Grant (MOH-000141)

Introduction: The airway microbiome in bronchiectasis exhibits important differences in the abundance of Neisseria spp., enriched in patients of Asian origin that correlate with exacerbations. Aim: To determine the pathogenic potential of Neisseria spp. in the airway immunopathology underpinning bronchiectasis. Methods: 16S bacteriome sequencing of samples from the Cohort of Asian and Matched European Bronchiectasis (CAMEB) (n=225) highlight distinct Neisseria-dominant profiles in bronchiectasis, enriched in Asians. Culturable Neisseria were used in mouse and primary human epithelial cell challenge models to assess its pathogenic potential through a systems biology approach using transcriptomic and comparative metabo-lipidomic analyses. Results:Neisseria-dominant microbiomes associate with exacerbations. Neisseria subflava challenge studies confirm its infective potential in mouse and human models. Systems-based analyses of infected mouse lung through transcriptomics and metabo-lipidomics reveals a significant upregulation of genes and metabolic pathways involved in anti-microbial defences, the immuno-inflammatory response and airway remodeling. Metabolomic analysis of mouse and human sera identify intersecting metabolite clusters associated with Neisseria. Conclusion: We report a previously unrecognized bronchiectasis phenotype, enriched in Asians characterised by a Neisseria-dominant microbiome profile and delineate ‘pathobiont’ signatures associated with infection. Funding: This research is supported by the Singapore Ministry of Health’s National Medical Research Council under its Clinician-Scientist Individual Research Grant (MOH-000141) (S.H.C).

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is associated with frequent exacerbations and poor outcomes in chronic respiratory disease, but remains under-diagnosed. The role of fungal sensitization in bronchiectasis-COPD overlap (BCO) is unknown. RESEARCH QUESTION: What is the occurrence and clinical relevance of Aspergillus sensitization and ABPA in BCO when compared with individuals with COPD or bronchiectasis without overlap? STUDY DESIGN: Prospective, observational, cross-sectional study. METHODS: We prospectively recruited 280 patients during periods of clinical stability with bronchiectasis (n = 183), COPD (n = 50), and BCO (n = 47) from six hospitals across three countries (Singapore, Malaysia, and Scotland). We assessed sensitization responses (as specific IgE) to a panel of recombinant Aspergillus fumigatus allergens and the occurrence of ABPA in relationship to clinical outcomes. RESULTS: Individuals with BCO show an increased frequency and clinical severity of ABPA compared with those with COPD and bronchiectasis without overlap. BCO-associated ABPA is associated with more severe disease, higher exacerbation rates, and lower lung function when compared with ABPA occurring in the absence of overlap. BCO with a severe bronchiectasis severity index (BSI; > 9) is associated significantly with the occurrence of ABPA that is unrelated to underlying COPD severity. CONCLUSIONS: BCO demonstrates a high frequency of ABPA that is associated with a severe BSI (> 9) and poor clinical outcomes. Clinicians should maintain a high index of suspicion for the potential development of ABPA in patients with BCO with high BSI.

OBJECTIVE:To determine prevalence and characteristics of mesiotemporal diffusion weighted imaging (DWI) lesions in transient global amnesia (TGA), and to determine prevalence of "missed" DWI lesions on routine radiological reporting. METHODS:This is a retrospective study of patients with TGA admitted to a tertiary care hospital over ten years. Patients with TGA, who underwent magnetic resonance imaging (MRI) of the brain within one week of index event, were included in this study. MRI's were reviewed by two independent raters. Clinical data and other investigations were collated. RESULTS:Of the 55 patients of TGA, 19 (35 %) had hyperintense DWI lesions with concordant apparent diffusion coefficient (ADC) hypointensity in the mesiotemporal region. Fifteen out of 19 (79 %) had unilateral lesions (6 left, 9 right). Twelve out of 19 DWI lesions were reported at the time of index scan. The false negative reporting rate was 36.8 %. DWI slice thickness (5 mm versus 3 mm), MRI machine strength (1.5 versus 3 T) and time interval from symptom onset to MRI brain (>24 h versus ≤ 24 h) were not significantly different between patients with or without DWI lesions and as well between patients with DWI lesions missed and initially reported at the time of index scan. CONCLUSION:Punctuate DWI mesiotemporal lesions in TGA are prone to under-reporting. These lesions need to be categorically searched for at the time of reporting MRI Brain.

Bronchiectasis, a progressive chronic airway disease, is characterized by microbial colonization and infection. We present an approach to the multi-biome that integrates bacterial, viral and fungal communities in bronchiectasis through weighted similarity network fusion ( https://integrative-microbiomics.ntu.edu.sg ). Patients at greatest risk of exacerbation have less complex microbial co-occurrence networks, reduced diversity and a higher degree of antagonistic interactions in their airway microbiome. Furthermore, longitudinal interactome dynamics reveals microbial antagonism during exacerbation, which resolves following treatment in an otherwise stable multi-biome. Assessment of the Pseudomonas interactome shows that interaction networks, rather than abundance alone, are associated with exacerbation risk, and that incorporation of microbial interaction data improves clinical prediction models. Shotgun metagenomic sequencing of an independent cohort validated the multi-biome interactions detected in targeted analysis and confirmed the association with exacerbation. Integrative microbiomics captures microbial interactions to determine exacerbation risk, which cannot be appreciated by the study of a single microbial group. Antibiotic strategies probably target the interaction networks rather than individual microbes, providing a fresh approach to the understanding of respiratory infection.

Background: To date, no study has integrated bacterial, viral and fungal microbiomes to provide a holistic assessment of the true in-vivo state. Methods: We report the first integrated ‘multi-biome’ analysis integrating bacteriome, virome and mycobiomes in bronchiectasis (n=217) employing weighted Similarity Network Fusion coupled to co-occurrence network analysis to evaluate the ‘interactome’. Interactome dynamics at baseline, during exacerbations and following recovery was assessed in n=17 patients with bronchiectasis. Results: “Integrative microbiomics” identifies patients at high-risk of exacerbation. Frequent exacerbators exhibit reduced α-diversity and elevated antagonistic interactions. Assessment of the Pseudomonas-interactome reveals that its network rather than abundance is key in determining exacerbation risk. Longitudinal ‘interactome’ analysis reveals increased antagonistic interactions during exacerbations which resolve following treatment within an otherwise stable microbiome. The interactome has ‘core’ and ‘ancillary’ components, the latter altered during exacerbation. Conclusion: “Integrative microbiomics” captures interactions determining exacerbation risk otherwise unaccounted by specific microbes. Antibiotic strategies likely target interaction networks rather than individual microbes providing fresh approaches to understanding respiratory infection. Funding: Singapore Ministry of Health’s National Medical Research Council under its Transition Award (NMRC/TA/0048/2016) (S.H.C); Clinician-Scientist Individual Research Grant (MOH-000141) (S.H.C) and the NTU Integrated Medical, Biological and Environmental Life Sciences (NIMBELS) [NIM/03/2018] (S.H.C).

Introduction: The role of viruses in bronchiectasis remains uncertain as detection in stable disease has been previously reported. Aim: To characterise the presence of viral species in the established CAMEB cohort using a panel of RNA viruses. Methods: N=228 airway specimens from CAMEB were subjected to real-time quantitative polymerase chain reaction (RT-qPCR) against a panel of 10 viruses including Coronaviruses (OC43, SARS, NL63, 229E), Parainfluenza viruses (PIV1-4), Rhinovirus and Enterovirus. Results: Virus was detected in N=143 patients (62.7%) with a median viral load of 3.1 x 104 genome copies/g sputum (IQR; 6.6 x 103– 8.2 x 104). The most frequently detected virus was PIV3 in N=135 patients (59.2%) with a median viral load of 2.4 x 104 genome copies/g sputum (IQR; 5.9 x 103– 5.9 x 104) and was commoner in Asians (75% vs 39%, p < 0.001). Rhinovirus was detected in N=17 (7.5% of patients) at a median viral load of 4.4 x 108 (IQR; 4.8 x 107– 1.2 x 109) with equal distribution between Asians and Europeans. PIV4 was detectable in N=10 (4.4%) while Coronavirus 229E, Enterovirus and PIV2 were each detected in a single patient. Conclusion: We have performed the most comprehensive viral analysis in stable bronchiectasis to date which reveals high rates of viral carriage predominantly PIV3. Further work is necessary to elucidate the significance of these findings. Funding: This research is supported by the Singapore Ministry of Health’s National Medical Research Council under its Transition Award (NMRC/TA/0048/2016) (S.H.C).

Rationale: Allergic sensitization is associated with poor clinical outcomes in asthma, chronic obstructive pulmonary disease, and cystic fibrosis; however, its presence, frequency, and clinical significance in non-cystic fibrosis bronchiectasis remain unclear. Objectives: To determine the frequency and geographic variability that exists in a sensitization pattern to common and specific allergens, including house dust mite and fungi, and to correlate such patterns to airway immune-inflammatory status and clinical outcomes in bronchiectasis. Methods: Patients with bronchiectasis were recruited in Asia (Singapore and Malaysia) and the United Kingdom (Scotland) (n = 238), forming the Cohort of Asian and Matched European Bronchiectasis, which matched recruited patients on age, sex, and bronchiectasis severity. Specific IgE response against a range of common allergens was determined, combined with airway immune-inflammatory status and correlated to clinical outcomes. Clinically relevant patient clusters, based on sensitization pattern and airway immune profiles ("immunoallertypes"), were determined. Measurements and Main Results: A high frequency of sensitization to multiple allergens was detected in bronchiectasis, exceeding that in a comparator cohort with allergic rhinitis (n = 149). Sensitization was associated with poor clinical outcomes, including decreased pulmonary function and more severe disease. "Sensitized bronchiectasis" was classified into two immunoallertypes: one fungal driven and proinflammatory, the other house dust mite driven and chemokine dominant, with the former demonstrating poorer clinical outcome. Conclusions: Allergic sensitization occurs at high frequency in patients with bronchiectasis recruited from different global centers. Improving endophenotyping of sensitized bronchiectasis, a clinically significant state, and a "treatable trait" permits therapeutic intervention in appropriate patients, and may allow improved stratification in future bronchiectasis research and clinical trials.

Introduction: No studies to date have assessed the metagenomics of the respiratory antibiotic ‘resistome’ across chronic disease states. Aim: To characterize the airway resistome in non-diseased controls (NDC) and patients with chronic respiratory disease. Methods: Sputum DNA from NDC (n=13), patients with severe asthma (n= 11), COPD (n=15) or bronchiectasis (n=15) were sequenced to an average depth of 20.3 million reads. Resultant sequence data was filtered for quality and human DNA and aligned to the Comprehensive Antibiotic Resistance Database (CARD) and normalized gene counts expressed (RPKM). Results: High prevalence of macrolide, fluoroquinolone, beta-lactam and tetracycline resistance genes was observed across all samples. Interestingly, non-diseased and severe asthma exhibited comparable ‘resistome’ profiles while COPD and bronchiectasis illustrated higher abundance of multi-drug resistance genes, largely encoding multipartite efflux systems and regulatory proteins (median RPKM; 0 vs 0.5, p<0.05). Macrolide resistance genes were abundant and include msrD, ermX, ermB and ermF of which ermX was significantly increased in patients with chronic respiratory disease (median RPKM; 0 vs 7.4, p<0.005). Conclusion: While diverse ‘resistomes’ were observed, the high prevalence of macrolide resistance genes is notable given their widespread use in respiratory medicine. The increased abundance of multidrug resistance genes in COPD and bronchiectasis likely reflects a more diversified and resilient ‘resistome’ inherent in these disease states. Funding: This work was supported by NTU Integrated Medical, Biological and Environmental Life Sciences (NIMBELS), Nanyang Technological University, Singapore[NIM/03/2018].

Non-cystic fibrosis bronchiectasis (NCFB) characterized by permanent bronchial dilatation and recurrent infections has been clinically managed by long-term intermittent inhaled antibiotic therapy among other treatments. Herein we investigated dry powder inhaler (DPI) formulation of ciprofloxacin (CIP) nanoplex with mannitol/lactose as the excipient for NCFB therapy. The DPI of CIP nanoplex was evaluated against DPI of native CIP in terms of their (1) dissolution characteristics in artificial sputum medium, (2) ex vivo mucus permeability in sputum from NCFB and healthy individuals, (3) antibacterial efficacy in the presence of sputum against clinical Pseudomonas aeruginosa strains (planktonic and biofilm), and (4) cytotoxicity towards human lung epithelial cells. Despite their similarly fast dissolution rates in sputum, the DPI of CIP nanoplex exhibited superior mucus permeability to the native CIP (5-7 times higher) attributed to its built-in ability to generate highly supersaturated CIP concentration in the sputum. The superior mucus permeability led to the CIP nanoplex's higher antibacterial efficacy (>3 log10 CFU/mL). The DPI of CIP nanoplex exhibited similar cytotoxicity towards the lung epithelial cells as the native CIP indicating its low risk of toxicity. These results established the promising potential of DPI of CIP nanoplex as a new therapeutic avenue for NCFB.

SESSION TITLE: Diffuse Lung Disease SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/10/2018 01:00 pm - 02:00 pm PURPOSE: To elucidate the phenotypic features of post-tuberculous(TB) bronchiectasis. METHODS: Longitudinal observational study of patients with presenting with acute exacerbation of bronchiectasis to Changi General Hospital, Singapore between Jan 2010-Aug 2017. Patients were categorized according to post-TB bronchiectasis or non post-TB bronchiectasis. Demographics, clinical features, lung function, microbiology and outcomes were compared between the two groups. RESULTS: 148 patients were recruited, mean±standard deviation (SD) age at first admission within the study period was 63±9y, 84 (56.8%) were male and 94 (63.5%) were Chinese ethnicity, mean±SD body mass index (BMI) was 22.1 ± 6. The most common etiology was idiopathic (n=94, 63.5%) followed by post-TB bronchiectasis (n=46, 30.1%). Post-TB bronchiectasis patients had lower body mass index(BMI) (21.3±6.4 vs 23.6±5.7, p=0.049), higher prevalence of non-tuberculous mycobacteria isolation from respiratory specimens (28.3% vs 5.9%, p<0.001), more frequent presentation with hemoptysis (32.6% vs 11.8%, p=0.002), lower FEV1 % predicted (64±27 vs 79±25, p=0.009 ) and higher rate of recurrent admissions for bronchiectasis exacerbation (23.6%/year vs 8.5%/year, Poisson regression rate ratio 2.6, 95% confidence interval 1.01-6.6, p=0.048) compared to non-post-TB bronchiectasis patients. No significant differences were found for C-reactive protein, procalcitonin, Pseudomonas colonization/infection rates or mMRC dyspnea scores. CONCLUSIONS: Post-TB bronchiectasis was associated with a lower FEV1, lower BMI, hemoptysis, non tuberculous mycobacteria colonization and frequent admissions for bronchiectasis exacerbation compared to patients with other etiologies of bronchiectasis. CLINICAL IMPLICATIONS: Bronchiectasis is a heterogeneous disease with distinct clinicopathobiologic subtypes. There is scarce data on post-tuberculous bronchiectasis, especially in Asia where the burden of disease is high. This paper serves to elucidate the phenotypic features of the post-TB bronchectasis patient in an Asian population. DISCLOSURES: No relevant relationships by Isaac Fong, source=Web Response No relevant relationships by Sandra HUI, source=Web Response No relevant relationships by Teck Boon Low, source=Admin input No relevant relationships by Anthony Yii, source=Web Response