This retrospective cohort study was conducted on the patient’s recordings from 1 January 2020 to 18 April 2022 at the respiratory department of Aleppo University Hospital, Syria. A total of 174 patients were included in our study; they were referred or hospitalized to our department after diagnosis of ILD. At first, depending on the patient’s recordings, we determined the medical history, clinical findings, and radiographic findings of HRCT scans of the patients accepted in our department as ILD patients. After that, we performed flexible bronchoscopy (Olympus BF type PE2) under local anesthesia using xylocaine (4% spray – 2% instillation through the working channel), then taking an endoscopic TBLB by using disposable biopsy forceps (Olympus, model no. FB-231D, working length: 1150 mm, minimum channel size: 2.0 mm). We followed the guidelines10 (link),11 (link) for flexible fiberoptic bronchoscopy and TBLB, and the biopsy site was selected according to the radiologic lesion location on HRCT. The results of biopsies were studied in the Histopathology Department of Aleppo University Hospital. The process included entering the bronchoscope into the third bronchial branch and then fixing it in position, inserting the forceps until the specialist felt resistance or the patient felt pain; we asked the patient to take a deep inhalation, open the forceps, and then asked the patient to exhale deeply accompanied by closing the forceps. We determined many inclusion and exclusion criteria to select the included patients in our study as the following: Inclusion criteria – referred or hospitalized patients to our department in Aleppo University Hospital and above 18 years, after defining the diagnosis of diffuse parenchymal lung disease depending on HRCT and clinical findings with excluding another respiratory disease such as tuberculosis (TB) and coronavirus disease 2019, etc. Exclusion criteria – patients with a contraindication to conduct bronchoscopy or TBLB such as hypoxia, cardiac arrhythmias, hemorrhage abnormalities, etc. Patients with CT pathognomonic patterns follow the diagnosis criteria of ILD12 (link). Patients with typical manifestations and clinical history of connective tissue disease-associated ILDs, such as rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus, etc. Patients diagnosed with occupational lung disease depend on clinical, radiological, and laboratory examinations. The patients diagnosed with coronavirus disease 2019 depend on nasal smear PCR or TB, depending on the sputum gene Xpert MTP/RIF.
We confirm that the work has been reported in line with the Strengthening The Reporting Of Cohort Studies in Surgery (STROCSS) criteria13 (link).