Lipid laden macrophages in patients with chronic cough

Background: Gastroesophageal reflux disease (GER) has been described as common cause of chronic cough by either esophageal acid-induced bronchoconstriction or recurrent microaspirations of gastric content. Lipid laden macrophages (LLM) in sputum can appear in these patients as a marker of aspiration. This finding could be interesting mainly when symptoms are absent (up to 75% percent or cases, “silent” GER). However, it is not clear what the presence of LLM in the airways could imply in terms of lung function, radiological lesions or symptoms. We aim to compare a group of patients with chronic cough and LLM in sputum with another group without LLM. Methods: Twenty five patients with chronic cough that could not be attibuted to any known etiology were included in the study group. Subjects were questioned for pulmonary and GER symptoms, Rhinitis, drugs and underwent physical examination, chest X-rays, bronchial challenge test with methacholine and sputum induction. Prepared cytospins were stained with oil red-O to detect lipid laden macrophages. Results: 68% were lipid laden positive but only 40% had reflux symptoms. Patients with LLM had similar dyspnea, phlegm9s but not rhinitis and 25% were methacholine positive and diagnosed of having asthma. Patients with LLM had radiological findings (mild lesions) in 60% of them and they had less FEV1 240 ml (11% of ref val) and FVC 364 ml (7% ref. val) when adjusted by asthma and anthrometric characteristics. Conclusions: The presence of LLM in sputum could represent worse pulmonary disease in patients with chronic cough even in absence of GER symptoms.