[Chest Disease Reports 2017; 5:6203] [page 3] Epidemiology of interstitial lung disease in Palestine: first national data Hasan S. Yamin, 1 Amro Y. Alastal, 1 Izzedin Bakri 2 1 Pulmonary, Critical care and Sleep Medicine Division, Internal Medicine Department, Makassed Hospital, Mount of Olives; 2 Clinical Pathology Department, Makassed Hospital, Jerusalem, Palestine Abstract Significant progress has been made in recent years in understanding the epidemi- ology of interstitial lung diseases (ILD) across the world, but the amount of infor- mation available is still small compared to other respiratory diseases like obstructive lung diseases or lung cancer. In this study we tried to explore the epidemiology of ILD in a virgin area of the world (Palestine), by describing a retrospectively collected cohort of newly diagnosed ILD cases in a single – and the only – Pulmonology center in Palestine over two years. Introduction Interstitial lung diseases, also called dif- fuse parenchymal lung diseases are a large and diverse group of fibrotic and non- fibrotic conditions that affect the bronchi- oles, alveoli and interstitium of the lungs. Several factors play role in the pathogenesis of these diseases including genetics, drug and radiation toxicities, smoking, environ- mental and occupational exposures. They could also be idiopathic. DPLD are classi- fied based on etiology into four groups: DPLD of known cause (like drugs or CTD associated), Idiopathic interstitial pneumo- nias (like IPF), Granulomatous DPLD (like sarcoidosis), and others (like Lymphangioleiomyomatosis). The inci- dence of these diseases has been increasing based on population based analyses. 1,2 Most of these studies came from the Western hemisphere, with few Mediterranean stud- ies. Unfortunately there are no data about the epidemiology of ILD in Palestine. In this study we examined all cases of newly diagnosed ILD presented to our Hospital (which is the first Pulmonology center in Palestine), between the years 2014-2015. Materials and Methods This is a retrospective analysis of all 82 undiagnosed patients, who were suspected to have ILD, and who presented to our hos- pital, in the period between January 1 st 2014 and December 31 st 2015. Data were collected from Bronchoscopy unit records over that period, which means we included only patients who required a bronchoscopic procedure in order to make a diagnosis, regardless of DPLD classification. A total of 83 diagnos- tic procedures were used, including 82 Bronchoalveolar lavages (BAL) with trans- bronchial biopsies, and only one surgical lung biopsy. Each case was discussed by a pulmonologist and a radiologist and a pretest differential diagnosis list was gener- ated. The pathologist reviewed the clinical and radiologic information, and then exam- ined pathologic specimens in light of the most likely differential diagnosis. The combination of clinical-radiologic- pathologic correlation yielded confident and accurate diagnosis in 86% of all the bronchoscopic procedures and in the one surgical lung biopsy performed. Results We identified 82 patients with suspect- ed ILD, including 36 males (44%) and 46 females (56%), with a mean age of 49.3 years (50.5 for males, 49 for females). Most patients were never smokers 48 (58.5%), 11 (13.4%) were ex-smokers and only 10 patients (12%) were active smokers at the time of diagnosis. Data about smoking sta- tus could not be retrieved in 13 patients (15.8%) (Table 1). A history of relevant occupational or environmental exposure was documented in 25 patients (30%). These included 11 patients (44%) who were exposed to con- struction dust, 5 patients (20%) who were exposed to chemicals, other exposures included farm dust, tobacco farming, asbestos, metals, tear gas and others (Table 2). Patients were also distributed geograph- ically according to their place of residence. Most patients came from Hebron (23%), Jerusalem (12%), Ramallah (11%), Nablus (9.7%), and Gaza (7.3%), these numbers were probably biased by the ease of access to our hospital from surrounding cities com- pared to others and by different population sizes of these cities (Table 3). As stated previously, a final diagnosis was made in 68 out of 82 patients (diagnos- tic accuracy of 86%), more than 15 different interstitial lung diseases were identified. The most common ILD in Palestine was Sarcoidosis, diagnosed in 22 patients (26.8%), this was also the most common diagnosis in males (25%) and females (28.2%) alone, being slightly more common in females. The second most common diagnosis made was Non-specific interstitial Pneumonitis (NSIP), surprisingly NSIP was more common in males than in females at 19.4% in males compared to 17.3% in females. The third most common ILD was Occupational lung disease in males (16.6%) and Vasculitis, LIP, Bronchiolitis and Alveolar proteinosis in females, each mak- ing up to 6.5% of diagnoses. all 4 Alveolar proteinosis cases were diagnosed in 2014,and none in 2015. See table4 for other diagnoses (Table 4). All patients underwent Chest x-ray and Ct chest as part of their evaluation, the most common finding was bilateral interstitial infiltrates in more than 89% of patients. Discussion As expected interstitial lung diseases were more common in females compared to males (1.27:1), probably because of higher incidence of associated diseases, like vas- culitis and connective tissue diseases in females. The most common diagnosis made was Sarcoidosis, followed by NSIP in both genders. While Sarcoidosis was more com- mon in females (1:0.69), NSIP was slightly more common in males compared to females (1.16:1). The third most common diagnosis was Occupational lung disease in males-mostly due to exposure to construc- Chest Disease Reports 2017; volume 5:6203 Correspondence: Hasan S. Yamin, Internal Medicine Department, Makassed Hospital, Mount of Olives, Jerusalem P.O. Box 19481, Code 91190. Tel: 00972-599289736. E-mail: dr.h.yamin@gmail.com Key words: Interstitial lung disease, Epidemiology, Trans bronchial biopsy. Received for publication: 26 July 2016. Revision received: 8 May 2017. Accepted for publication: 15 May 2017. This work is licensed under a Creative Commons Attribution NonCommercial 4.0 License (CC BY-NC 4.0). ©Copyright H.S. Yamin et al., 2017 Licensee PAGEPress, Italy Chest Disease Reports 2017; 5:6203 doi:10.4081/cdr.2017.6203 Non commercial use only