Serum and alveolar IGA and IGG2 levels may help to predict ventilator-associated pneumonia outcome

Methods All immunocompetent patients over 18 years old admitted to the Intensive Care Unit of the Hospital Universitario and Politecnico la Fe (Valencia, Spain), undergoing mechanical ventilation for more than 48 hours were included. Patients with clinical suspicion of ventilatorassociated respiratory infection were considered as cases and compared with a selection of controls matched by age, comorbidities, severity scales and days of mechanical ventilation. At the moment of intubation and each 72 hours until the moment of extubation, clinical surveillance was performed and respiratory samples (minibronchoalveolar lavage, mini-BAL) were taken to evaluate clinical and microbiological response. Samples of plasma and mini-BAL were also taken for immunoglobulins IgG1 IgG4, IgM, IgA and IgE determination. Comparison of numerical and categorical variables was performed with the Mann-Whitney U test. Results were expressed as medians with interquartile (25% to 75%) ranges (IR) in brackets.