Effect of splenectomy on T lymphocyte subsets in patients infected with the human immunodeficiency virus. Clin Infect Dis

A case-control study was conducted at two institutions to determine whether the absolute CD4 lymphocyte count or the percentage of lymphocytes bearing the CD4 marker (i.e., the CD4 percentage) is a more accurate indicator of underlying immune status in splenectomized patients infected with human immunodeficiency virus (HIV). Each of nine splenectomized HIV-infected cases was matched with six nonsplenectomized HIV-infected controls—three matched for CD4 lymphocyte count and three for CD4 percentage. In analyses including the eight cases with an initial CD4 lymphocyte count of>200/mm 3, controlling for the CD4 count revealed differences between cases and controls in terms of CD4 percentage (range, 10%-41 % and 17%-54%, respec-tively; P <.01) and Centers for Disease Control and Prevention (CDC) clinical stage (P =.06). Controlling for the CD4 percentage revealed a significant difference between cases and controls in terms of CD4 count (range, 396-1,040 and 55-784 cells/mm 3, respectively; P <.01) but not CDC clinical stage (P>.7). These data suggest that the numerical relationship between the CD4 lymphocyte count and the CD4 percentage among splenectomized HIV-infected patients with more than 200 CD4 cells/mm 3 differs from that among nonsplenectomized patients. The CD4 percentage appears to be a more accurate indicator of the underlying level of immune function i