Pepsin in bronchoalveolar lavage fluid: a specific and sensitive method of diagnosing gastro-oesophageal reflux-related pulmonary aspiration.
OBJECTIVE
Gastro-oesophageal reflux (GOR)-related aspiration is associated with respiratory disease, but the current "gold standard" investigation, the lipid-laden macrophage index (LLMI), is flawed. A specific marker of GOR-related aspiration should originate in the stomach, but not the lung. An assay to detect gastric pepsin in the bronchoalveolar lavage (BAL) of children was developed and validated.


METHODS
Gastro-oesophageal reflux was diagnosed in 33 children using intra-oesophageal pH monitoring. Thirteen asymptomatic negative controls requiring endotracheal intubation for elective surgery and 5 positive control patients with observed aspiration were recruited. All subjects received a BAL; the fluid obtained was analysed for the pepsin content and the LLMI.


RESULTS
All subjects in the negative control group were negative for pepsin. The positive control group had a significantly greater median pepsin level (P < .01) compared with negative controls. Patients with proximal oesophageal GOR and chronic cough also had significantly elevated pepsin levels (P = .04). The LLMI was not significantly elevated by the presence of cough or GOR.


CONCLUSIONS
This study suggests that GOR-related aspiration plays a role in chronic cough in children with known GOR. Detecting pepsin in BAL fluid may therefore become an important adjunct in patient selection for antireflux surgery.
Farrell
Stephen
S
Department of Child Health, Queen's University Belfast, Royal Victoria Hospital, Institute of Clinical Science, Belfast, BT12 6BJ Northern Ireland, UK. s.farrell@qub.ac.uk
McMaster
Cyril
C
Gibson
David
D
Shields
Michael D
MD
McCallion
William A
WA
D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications*; D006801:Humans; D007118:Immunoassay; D008297:Male; D010434:Pepsin A / Q000032:analysis*; D011015:Pneumonia, Aspiration / Q000175:diagnosis* / Q000209:etiology*; D012120:Respiration Disorders / Q000175:diagnosis; D012680:Sensitivity and Specificity
D010434:Pepsin A