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.
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
Stephen
S
Farrell
Cyril
C
McMaster
David
D
Gibson
Michael D
MD
Shields
William A
WA
McCallion
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