High levels of sulfated mucins in bronchoalveolar lavage fluid of ICU patients with ventilator-associated pneumonia

Objective: To compare the levels of sulfated mucins in bronchoalveolar lavage fluid (BALF) in ICU patients with ventilator-associated pneumonia (VAP) with those in non-infectious controls, i.e., ventilated ICU patients without VAP, and nonventilated patients. Design and setting: Prospective study in a mixed intensive care unit and outpatient clinic of a university hospital. Patients: The study included 56 ventilated ICU patients with VAP, 21 ventilated ICU patients without VAP, and 26 nonventilated outpatients with no pulmonary infection. Measurements and results: Total cell count and differential cell count of BALF samples were determined, and sulfated mucin levels were measured. For this we used the monoclonal antibody F2 against the sulfated Lewis C structure (SO3-3Galbeta1-3GlcNAc). Sulfated mucin levels were significantly increased in ICU patients with VAP than in those without VAP and nonventilated patients. No statistical difference was found between the two groups of ICU patients regarding APACHE II score and the duration of mechanical ventilation prior to the bronchoalveolar lavage. Conclusions: The increased levels of sulfated mucins in ICU patients with VAP are associated with infection and not with ventilation. The increase in sulfated mucins may favor the persistence of those micro-organisms that possess mucin sulfatase activity, which enable them to survive within the mucus, especially Pseudomonas aeruginosa.