Elevated concentrations of soluble IL-2 receptor in both bronchoalveolar lavage fluid and serum in a patient with BOOP.

Activated soluble IL-2 receptor (sIL-2R) levels are elevated in a variety of diseases associated with T-cell activation. There are no reports of sIL-2R elevations in broncholitis obliterans organizing pneumonia/cryptogenic organizing pneumonia (BOOP/COP), although activated T cells are increased in BOOP/COP. We present a patient with BOOP/COP with an elevated concentration of soluble IL-2 receptors in both serum and bronchoalveolar lavage fluid. Concomitant resolution of the high serum sIL-2R and the roentogenographic findings after steroid treatment suggested that serum sIL-2R levels increase in response to a localized lymphocytic inflammatory reaction in the lung.