Expression of CD52 in peripheral T-cell lymphoma.

Peripheral T-cell lymphoma unspecified (PTCL/U) is a rare tumor characterized by poor treatment response and a dismal prognosis. We studied CD52 expression in 97 PTCL/U cases by immunohistochemistry on tissue-microarrays. Furthermore, CD52 gene expression was studied in 28 cases for which RNA was available. We found that CD52 is expressed in approximately 40% of PTCLs/U at the same level as in normal T-lymphocytes. Although other factors may play a role in the in vivo response to alemtuzumab, an anti-CD52 monoclonal antibody, the estimation of CD52 expression may provide a rationale for the selection of patients with a higher probability of treatment response.