The Role and Importance of Flexible Bronchoscopy in Immunosuppressed Children presenting with Pulmonary Complications

<bold>Aim and background:</bold> This study aims to investigate the role and value of FB and BAL in determining the causes of pulmonary complications in children with primary and secondary immunodeficiency and to comparatively evaluate the results of FB and BAL procedures and pre-procedure radiological findings. <bold>Method:</bold> Between January 2014 and December 2023, the records of 80 immunocompromised children who underwent FB with BAL were retrospectively reviewed. BAL and FOB results were compared between primary and secondary immunodeficiency cases, as well as pre-procedural clinical, laboratory, and radiological findings. <bold>Results:</bold> Sixty-one patients (76.3%) had been diagnosed with immunodeficiency and 19 with childhood malignancy and hematologic diseases. Of these, 46 (57.5%) were male, with a median age at the time of FFB of 7 years (IQR: 1.5; 13.7). Among those with BAL growth, age was significantly lower (p=0.032), CRP levels were significantly higher (p=0.035), and ground glass appearance on CT scans was significantly more frequent (p=0.004). Additionally, cavity appearance on CT scans was significantly higher in those with positive fungal cultures from BAL (p=0.007), and interstitial appearance on CT scans was significantly more common in those with positive CMV PCR from BAL (p=0.002).BAL diagnostic yield was found to be 67.9%. <bold>Conclusion:</bold> FB and BAL are a safe clinical tool that may be useful in influencing clinical management in a significant proportion of immunocompromised patients with pulmonary involvement.