CD52 antigen may be a therapeutic target for eosinophilic rhinosinusitis.

Allergic rhinosinusitis involves several types of inflammatory cells. The dominant inflammatory cells include mast cells, eosinophils, lymphocytes, and monocytes/macrophages. Since eosinophils are one type of inflammatory cell that is often related to allergy, we investigated in this study whether the eosinophils present in rhinosinusitis may be potential targets for CD52 antibody treatment. First, we found that circulating eosinophils in renal recipients were almost completely depleted after iv bolus of treatment with Campath-1H, a humanized antibody against CD52 antigen. Second, we showed morphologically that eosinophils, lymphocytes, and monocytes gave positive staining reactions for CD52. Third, using an automated clinical imaging system, we found that tissue sections of sinus contents with prominent eosinophils (eosinophilic rhinosinusitis) yielded significantly higher CD52 staining scores than those with lymphocytes as the dominant component (lymphocytic rhinosinusitis). These findings indirectly support the hypothesis that CD52 may be a target for treating eosinophilic rhinosinusitis with Campath 1H.