A transient benign lymph node-based proliferation of T-cells simulating non-Hodgkin lymphoma in a patient with psoriasis treated with tumor necrosis factor alpha and CD11a antagonists

We report a patient with psoriasis treated with the biologic agents efalizumab (Raptiva？) and etanercept (Enbrel？), who developed painless lymphadenopathy with peripheral lymphocytosis during treatment, simulating a non-Hodgkin lymphoma clinically and pathologically. Lymphocytosis and lymphadenopathy spontaneously remitted following cessation of etanercept therapy and have not recurred.Distinction between clinically benign lymphoid proliferations related to antipsoriasis therapy and malignant lymphoma avoids the unnecessary use of anti-lymphoma chemotherapy.In the epidermal milieu of psoriasis, activated CD4+ helper T-cells interact with CD8+ suppressor T-cells, dendritic cells, and keratinocytes, resulting in production of TH1-associated cytokines, the most important of which is tumor necrosis factor (TNF) [1]. In an effort to rationally treat psoriasis, several biologic therapies have been engineered. One of these is etanercept (Enbrel？), a dimeric fusion protein that blocks the effects of TNFα [2]. Another is efalizumab (Raptiva？), a humanized monoclonal antibody that binds to the CD11a subunit of lymphocyte function-associated antigen-1 (LFA-1) to inhibit activation, trafficking to the dermis and epidermis, and reactivation of pathogenic T-cells. Use of biologics has been associated with adverse effects such as infection and autoantibody generation. There may also be a slight increase in the risk of lymphoma, but the data is controversial and may be confounded by the increased incidence of lymphoma in the general psoriasis population [2].Like many diseases, psoriasis is postulated to induce relative immunosuppression. The increased incidence of infection and autoantibody generation suggests that further aberrations of immune status may be engendered by biologic therapy. This immunomodulation has been associated with a spectrum of lymphoproliferative disorders, some of which are clearly represent malignant lymphomas, others which are due to a dysregulated immune