Short-term efficacy of the IL6 receptor antibody tocilizumab in patients with HIV-associated multicentric Castleman disease: report of two cases

Multicentric Castleman disease (MCD) is a lymphoproliferative disorder caused by human herpesvirus 8 (HHV8) infection HIV associated MCD (HIV-MCD) presents with various clinical symptoms. Many HIV-negative MCD patients are often treated with anti-human interleukin-6 (IL6) receptor monoclonal antibodies (tocilizumab), and successful results have been reported. IL-6 plays an important role in the development of both HIV-positive and HIV-negative MCD; however, the efficacy of tocilizumab in HIV-MCD patients is unknown. We herein report the clinical and biologic courses of two HIV-MCD patients treated with tocilizumab. In both cases, a significant and rapid clinical improvement was observed after the first infusion. However, the treatment efficacy was not maintained for a long period, and relapse occurred at 15 and 22 weeks, respectively. Both patients received rituximab and subsequently achieved complete clinical remission. Our report, in addition to data presented in the literature, suggests that tocilizumab could be an initial treatment option in patients with HIV-MCD.