Anti-interleukin-8 autoantibodies in patients at risk for acute respiratory distress syndrome

Objective: To test the hypothesis that elevated concentrations of interleukin-8 associated with anti-interleukin-8 autoantibodies (anti-interleukin-8:interleukin-8 complexes) are found in patients at risk for acute respiratory distress syndrome who developed the disease. Design: Measurement of anti-interleukin-8:interleukin-8 complex concentrations in previously collected bronchoalveolar lavage fluids. These fluids were obtained from patients at risk for acute respiratory distress syndrome who subsequently either recovered or developed acute respiratory distress syndrome. Patients: A unique population of patients at risk for acute respiratory distress syndrome was studied. There were 26 patients at risk for acute respiratory distress syndrome who were divided into three groups. Group I patients had high interleukin-8 concentrations and developed acute respiratory distress syndrome, group II had high interleukin-8 concentrations and did not develop acute respiratory distress syndrome, and group III had low interleukin-8 concentrations and did not develop acute respiratory distress syndrome. These patients were selected to test the hypothesis that presence of elevated concentrations of anti-interleukin-8:interleukin-8 complexes differentiates patients at risk for acute respiratory distress syndrome who developed acute,respiratory distress syndrome from patients who did not. Measurements and Main Results: Bronchoalveolar lavage fluid concentrations of interleukin-8 associated with the anti-interleukin-8 autoantibodies were significantly different between groups (p < .03). The amount of interleukin-8 bound to the anti-interleukin-8 autoantibody was higher in group I than in group II and group IIl. Conclusions: Bronchoalveolar lavage fluid concentration of anti-interleukin-8:interleukin-8 complexes may serve as a marker of disease progression in patients at risk for acute respiratory distress syndrome.