Study objectives: Bronchoscopy with BAL is being used increasingly in the investigation of acute and chronic lung inflammation. The scope of the acute phase response induced by the procedure is not fully evaluated. The purpose of the study is to characterize the acute phase response induced by bronchoscopy with BAL.
Design: Observational study.
Setting: A human study research facility.
Participants: Normal nonsmoking volunteers.
Intervention: A total of 28 subjects were recruited. Under local anesthesia, the subjects underwent bronchoscopy with a videofiberoptic bronchoscope. One subsegment of the lingular segment of the left upper lobe and the right middle lobe were lavaged each with 170 to 270 mL of sterile normal saline solution.
Measurements and results: CBC count, serum levels of indexes of iron homeostasis, fibrinogen, C-reactive protein (CRP), and plasma mediators related to neutrophil migration and endothelial cell activation, including interleukin (IL)-8, angiotensin converting enzyme (ACE), soluble intercellular adhesion molecule (sICAM)-1, and nitrite/nitrate, were measured. Measurements of these plasma markers were done immediately before, immediately after, and 24 h after bronchoscopy. Changes in acute phase response were detected primarily at 24 h after the procedure. WBCs, primarily neutrophils, increased by approximately 50%. Fibrinogen increased by 25% while CRP increased by more than sevenfold. Serum ferritin increased by 25% while serum iron, total iron-binding capacity, and transferrin saturation decreased, indicating dysregulation of iron homeostasis. There were no changes in IL-8, ACE, sICAM-1, or nitrite/nitrate plasma levels.
Conclusions: Bronchoscopy with BAL induces a variety of acute phase responses that includes peripheral neutrophilia, dysregulation of iron homeostasis, and increased levels of fibrinogen and CRP. Human research that employs BAL may need to consider the biological effects induced by the procedure-related acute phase response.