Lipid-Laden Alveolar Macrophages and pH Monitoring in Gastroesophageal Reflux-Related Respiratory Symptoms

Abstract

Lipid-laden alveolar macrophages and pH monitoring have been used in the diagnosis of chronic aspiration in children with gastroesophageal reflux (GER). This study was conducted to prove a correlation between the detection of alimentary pulmonary fat phagocytosis and an increasing amount of proximal gastroesophageal reflux. It was assumed that proximal gastroesophageal reflux better correlates with aspiration than distal GER. Patients from 6 months to 16 years with unexplained recurrent wheezy bronchitis and bronchial hyperreactivity, or recurrent pneumonia with chronic cough underwent 24-hour double-channel pH monitoring and bronchoscopy with bronchoalveolar lavage (BAL). Aspiration of gastric content was determined by counting lipid laden alveolar macrophages from BAL specimens. There were no correlations between any pH-monitoring parameters and counts of lipid-laden macrophages in the whole study population, even when restricting analysis to those with abnormal reflux index expressing clinically significant GER. Quantifying lipid-laden alveolar macrophages from BAL in children with gastroesophageal-related respiratory disorders does not have an acceptable specificity to prove chronic aspiration as an underlying etiology. Therefore, research for other markers of pulmonary aspiration is needed.

Lipid-laden bronchoalveolar macrophages in asthma and chronic cough

“…The association between aspiration and LLMI has been previously evaluated in children with some studies reporting a positive correlation [18,25] and suggesting that particular cut-off values may be a useful diagnostic test [26]. However, other studies have failed to confirm that LLMI, measured in lavage fluid or sputum, is an indicator of GORD [18,27], highlighting a lack of specificity to detect reflux-related respiratory disease [28]. In adults, LLMI has been proposed as a marker for aspiration pneumonia [10].…”

The Role of Microaspiration in the Pathogenesis of Gastroesophageal Reflux-related Chronic Cough

“…The LLM index was significantly lower in the surgical group. Opposing the reliability of LLM index as a marker of microaspiration, Kitz et al 27 conducted a study in children with GERD related respiratory symptoms and found no association between reflux events and LLM counts. But MII was not used in this study, and also underlying pulmonary disease of the selected patient population may cause more reduction in sensitivity and specificity of LLM index.…”

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Uncertainties and Controversies

“…Moreover, HMII (24-h multichannel intraluminal impedance) allows the measurement of bolus reflux, which provides more accurate identification of both acidic and weak acidic reflux [39]. Microaspiration may be indirectly suggested by the presence of GER [40], decreased bronchial mucosal pH [9], altered biomarker levels (e.g., pepsin, bile acids, lactate dehydrogenase, and C-reactive protein) [9, 10] or the detection of lipid-laden [55] or chlorophyllin-stained macrophages [56] in BALF, spectra of exhaled breath condensate [51, 57], induced sputum biomarkers, or atypical lung pathology [36]. A clinical trial (NCT trial No.…”