The spleen in HIV infection--morphological evidence of HIV-associated macrophage dysfunction.

One-hundred spleens from HIV-infected patients which were studied by conventional morphological and immunohistochemical methods exhibited alterations in lymphatic tissue as well as in the mononuclear phagocyte system (MPS); these were probably related directly to HIV infection of lymphocytes and MPS cells. There was ample evidence of impairment of macrophage activation, accompanied by decreased expression of functional markers and an enhanced reactivity with antibodies against S100 protein. This impairment of macrophage function is related to the particular morphology and aggressive clinical behaviour of some opportunistic infections in AIDS.