Increased levels of nuclear factor κB and Fos-related antigen 1 in lung tissues from patients with acute respiratory distress syndrome.

CONTEXT: Both nuclear factor κB and Fos-related antigen 1 have been implicated in the pathogenesis of inflammatory lung diseases, including acute lung injury/acute respiratory distress syndrome. OBJECTIVE: To evaluate lung tissues from patients with acute respiratory distress syndrome for presence of nuclear factor κB and Fos-related antigen 1. DESIGN: Lung tissue sections from 5 patients with acute respiratory distress syndrome and sections of normal lung tissues of 4 patients were stained with antibodies against epithelial cell marker (surfactant protein B) and nuclear factor κB or Fos-related antigen 1. Samples were analyzed using confocal laser microscopy. RESULTS: We have detected significantly increased levels of activated nuclear factor κB and Fos-related antigen 1 in lung tissues from patients with acute respiratory distress syndrome compared with control tissues, suggesting that these transcription factors undergo activation in lungs of patients suffering from acute respiratory distress syndrome. CONCLUSIONS: Our data demonstrate that activated nuclear factor κB and Fos-related antigen 1 are elevated in epithelial cells in lung tissues of patients with acute respiratory distress syndrome.

Anti-interleukin 8 autoantibody:interleukin 8 immune complexes visualized by laser confocal microscopy in injured lung.

CONTEXT: Anti-interleukin 8 autoantibody:interleukin 8 (anti-IL-8 autoantibody:IL-8) complexes are present in lung fluids of patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS), and levels of these complexes correlate with progression to and the outcome of ARDS. Fc gammaRIIa, an immunoglobulin G (IgG) receptor, mediates proinflammatory activity of the complexes. OBJECTIVE: To evaluate lung tissues from patients with ARDS for presence of anti-IL-8 autoantibody:IL-8 complexes and to establish whether the complexes associate with Fc gammaRIIa. DESIGN: Lung tissue sections from 3 patients with ARDS and sections of normal lung tissues from 3 patients were stained with antibodies against IL-8 and IgG to detect immune complexes and with antibody against Fc gammaRIIa. In some experiments, sections were blocked with anti-Fc gamma RIIa antibody before staining. Samples were analyzed using confocal microscopy. RESULTS: Interleukin 8 costained with IgG and Fc gammaRIIa in lung tissues from patients with ARDS but not in control tissues, suggesting that anti-IL-8 autoantibody:IL-8 complexes are deposited in lungs of patients with ARDS via Fc gammaRIIa. Further, colocalization between IL-8 and Fc gammaRIIa could be blocked by anti-Fc gammaRIIa. CONCLUSIONS: Our data demonstrate that anti-IL-8 autoantibody:IL-8 complexes are present in lung tissues of patients with ARDS, and are attached to Fc gammaRIIa.