ORIGINAL ARTICLE Bali Medical Journal (Bali Med J) 2017, Volume 6, Number 2: 415-420 P-ISSN.2089-1180, E-ISSN.2302-2914 415 Open access: www.balimedicaljournal.org and ojs.unud.ac.id/index.php/bmj CrossMark Published by DiscoverSys ABSTRACT Objectives: To evaluate the association between exposure to wood dust and occupational asthma and investigate the immunopathogenesis behind the disease by examining IgE, CD4, and eosinophil levels. Methods: Subjects were diagnosed with occupational asthma based on the findings derived from the questionnaire titled “Work-Related Asthma Questionnaire” and Peak Expiratory Flow Rate (PEFR) variability for two weeks. Exposure to wood dust exposure was measured using a personal dust sampler for two days on the subjects during working hours. Results: Out of the 104 samples chosen for the study, 17% of the subjects were diagnosed with occupational asthma. Analysis showed that there were correlations between exposure to wood dust exposure and occupational asthma (r = 0.384, p = 0.000). ROC methods revealed that exposure to wood dust was 70.5 mg/m3/year, which is associated with a greater risk of occupational asthma, especially in light of the higher values measured for sensitivity at 87.5% and specificity at 75%. Study findings showed that exposure to wood dust was significantly correlated with higher serum CD4 level (r = 0.455, p = 0.000). However, eosinophil level did not correlate with CD4 level or exposure to wood dust. Conclusion: Exposure to Merbau and Bangkirai wood is indeed a risk factor for occupational asthma. The process of how exposure to wood induces occupational asthma can be defined as a non-eosinophilic mechanism and denotes a significant correlation between occupational asthma and the elevated presence of CD4 serum. Keywords: Non-eosinophilic, Asthma, Merbau, Bangkirai Cite This Article: Rai, I.B.N., Suryana, K., Artana, I.G.B.N., Kusumawardani, I.A.J.D. 2017. Non-eosinophilic occupational asthma due to exposure of Merbau and Bangkirai Wood. Bali Medical Journal 6(2): 415-420. DOI:10.15562/bmj.v6i2.617 Non-eosinophilic occupational asthma due to exposure of Merbau and Bangkirai Wood Ida Bagus Ngurah Rai, Ketut Suryana, I Gusti Bagus Ngurah Artana, * Ida Ayu Jasminarti Dwi Kusumawardani INTRODUCTION Occupational asthma is one of the most common forms of occupational lung diseases in industrial countries. Te adverse efects of the disease include mortality, morbidity, and disability. Approximately 15% of asthma cases in the United States are caused by exposure to airborne dust particles in workplace environments 1 . Occupational asthma is a disease characterized by variable airfow limitation and airway hyperresponsiveness due to causes and conditions attributable to a particular occupa- tional environment and not to stimuli encountered outside the workplace 2 . Wood dust is one of the main asthma genes pres- ent in the workplace. Exposure to dust from certain kinds of woods, such as Western red cedar, oak, iroko, abachi, and mahogany, can cause asthma. Te pathogenesis mechanism of how asthma is induced by exposure to wood dust exposure is unclear. Wood dust is a low-molecular-weight (LMW) agent. Te study showed elevated eosinophil levels in sputum induction and bronchoalveolar lavage in subjects who were exposed to wood dust. Lemiere et al. reported that occupational asthma induced by LMW exposure would elevate eosinophil count in sputum and serum during working hours compared to periods outside of working hours, for exam- ple, during vacations 3 . However, Di Franco et al. reported higher levels of neutrophil in the sputum of asthma patients due to exposure LMW agents compared to HMW agent or non-occupational asthma. Tere are two variants of occupational asthma due to exposure to LMW agents, which are (a) eosinophilic and (b) non-eosinophilic 4 . In South East Asia, wood-cutting and process- ing are a major industry. Indonesia’s natural forest reserves are the largest in Asia, and the second largest in the world and is estimated to extend over 100 million hectares. Merbau, bangkirai, teak, and other trees in Indonesia are tropical hardwood tree species. In this study, we investigate how exposure to hardwood dust induces occupational asthma and analyze the immunopathogenesis behind the devel- opment of occupational asthma. METHODS Tis is a cross-sectional analytic study. Te study was conducted in wood manufacture indus- trial units in Indonesia. Subjects eligible for this study are in the age range of 17–60 years and have worked in the wood industry for more than 1-year. Te exclusion criteria include subjects with Pulmonology Department, Udayana University, Bali, Indonesia * Correspondence to: bagusartana@gmail.com Received: 2017-04-12 Accepted: 2017-05-26 Published: 2017-05-31