IL-4 production by CD8+ lymphomatoid papulosis, type C, attracts background eosinophils

Abstract

There are two subsets of CD8+ T cells: Tc1 and Tc2. INF-γ production by Tc1 cells causes granulomatous inflammation. IL-4 production by Tc2 cells attracts eosinophils. A 76-year-Caucasian female presented with CD8+ lymphomatoid papulosis (LyP), type C. We hypothesized that the LyP cells belonged to the Tc2 subset because of abundant background eosinophils. Hematoxylin and eosin and immunohistochemical stains were carried out on tissue sections from a skin punch biopsy. Antibodies for immunohistochemical stains included CD3, CD4, CD5, CD7, CD8, CD30, CD56, ALK-1, clusterin and IL-4. There was involvement of the dermis by a dense lymphoid infiltrate composed of large atypical cells and numerous eosinophils. The LyP cells expressed CD5, CD8, CD30 and IL-4. Keratinocytes showed a membranous pattern of immunoreactivity for IL-4. IL-4 production by CD8+ LyP, type C indicates that it belongs to the Tc2 subset. The cytokine milieu produced by the LyP cells attracted eosinophils. The IL-13R complex on keratinocytes bound IL-4 and produced a membranous staining pattern. Although CD8+ LyP is rare, we believe that this CD30+ lymphoproliferative disorder should be included in the World Health Organization-European Organization for Research and Treatment of Cancer classification of cutaneous T-cell lymphomas. © Blackwell Munksgaard 2008.