CD30 expression in monomorphic posttransplant lymphoproliferative disorder, diffuse large b-cell lymphoma correlates with greater regulatory t-cell infiltration

Objectives: CD30 is a protein thought to promote cell proliferation/survival and downregulate the immune response. Twenty percent to 40% of de novo diffuse large B-cell lymphomas (DLBCLs) express CD30, and some patients have been treated with the anti-CD30 agent brentuximab. In the solid organ transplant setting, allograft regulatory T cells (Tregs) have been shown to be modulated via CD30 signaling. Methods: Posttransplant lymphoproliferative disorders (PTLDs) constitute a heterogeneous group of lymphomas, and since CD30 expression has been rarely formally assessed in PTLDs, we analyzed a cohort of PTLDs. Results: We found that 26 (79%) of 33 PTLDs were CD30+. Of these, 17 (77%) of 22 DLBCL monomorphic PTLDs were CD30+ compared with 56 (38%) of 148 de novo DLBCLs (P = .009). The median FoxP3+ Treg count was higher in CD30+ than in CD30- PTLDs, 3.0 vs 0 (P = .012). Conclusions: These findings suggest a pathophysiologic link between CD30 activity and Tregs and may indicate differential expression of CD30 in B-cell lymphomas arising in the setting of immune dysregulation.