Recent data highlight the importance of inflammatory markers during human immunodeficiency virus type 1 (HIV) infection. HIV-associated multicentric Castleman disease (HIV-MCD) presents with systemic symptoms attributed to cytokine disarray, and we have previously shown that the use of the anti-CD20 monoclonal antibody rituximab induces clinical remissions. Before and during successful rituximab therapy, 15 plasma cytokines were measured as were adaptive (CD4, CD8, CD19) and innate (CD16/56) immune cell populations and HIV-1 viral loads. A significant reduction from baseline of the CD19 B-cell count, consistent with rituximab's mechanism of action, was observed. Markedly elevated cytokine levels were observed before rituximab therapy, and a reduction from baseline values with rituximab therapy was observed for interleukin (IL)-5, IL-6, and IL-10. Therapies that reduce the inflammatory cytokine response are likely to be successful in a range of diseases, including HIV-MCD, and in the future may be used to guide therapeutic strategies.