Prospective observational study of antiphospholipid antibodies in acute lung injury and acute respiratory distress syndrome: comparison with catastrophic antiphospholipid syndrome

Abstract

Detection of antiphospholipid (aPL) antibodies in bronchoalveolar lavage fluid (BALF) of patients with acute respiratory distress syndrome (ARDS) suggests involvement of autoimmune mechanisms in the pathogenesisof ARDS. We investigated whether aPL antibodies could be detected in the serum as well as BALF of patients with acute lung injury (ALI) and ARDS. IgG anticardiolipin, IgG anti-b2-glycoproteinI, IgG antiphosphatidicacid and IgG antiphosphatidylserineantibodieswere detected by ELISA in low titers within the normal range in the BALF and serum of nine patients with ALI and 17 patients with ARDS. However, one out of 27 patients investigatedhad high levelsof aPL antibodies in both BALF and serum. This patient suffered from severe ARDS due to sepsis. The high aPL antibodylevels in serum possibly triggered by sepsis were associated with high aPL antibody levels in BALF, which can be explained by high capillary-alveolar permeability. Computed tomography scan revealed widespread infarctions in brain, spleen and kidneys, and pulmonary thromboembolism, suggesting the diagnosis of catastrophic antiphospholipid syndrome.