Cryptococcus neoformans and its cell wall components induce similar cytokine profiles in human peripheral blood mononuclear cells despite differences in structure.

We studied the cytokine profile of peripheral blood mononuclear cells after stimulation with various cryptococcal strains or its purified cell wall components. After 3 h of stimulation, tumor necrosis factor (TNF) alpha levels were strongly increased, whereas interferon (IFN) gamma and interleukin (IL) 10 levels were increased only slightly, or not at all (respectively). In contrast, after 18 h, TNF-alpha and IFN-gamma levels were (strongly) decreased, whereas the IL-10 levels were increased. The IL-1beta, IL-6 and IL-8 levels were equally high throughout the experiment. In order to establish which of the cryptococcal envelope components contributed most to the observed cytokine profile induced by whole cryptococci, glucuronoxylomannan, galactoxylomannan and mannoproteins were purified and partially characterized biochemically. All cryptococcal components elicited a similar cytokine pattern despite the differences in structure.

Plasma HIV-1 RNA quantitation in HIV infected adult Zimbabweans.

OBJECTIVES: To determine HIV-1 RNA levels in plasma of HIV infected Zimbabwean adults and to correlate these with CD4+ cell counts. DESIGN: Prospective observational study. SETTING: Specialist Immunology Laboratory, Harare, Zimbabwe. SUBJECTS: 49 consecutive HIV infected patients. MAIN OUTCOME MEASURES: CD4+ cell counts and plasma HIV-1 RNA levels. RESULTS: Based on the CDC HIV classification system five patients were in early stage infection, 15 in middle, 17 in late and 12 in advanced stage of infection. The median CD4+ cell count was 165/microL (Q1 = 4; Q3 = 866). The median HIV-1 RNA levels were 73,097 RNA copies/ml (Q1 = 753; Q3 = 750,000). Eighty percent of the patients had HIV-1 RNA levels > 10,000 copies/ml and 49% had > 100,000 RNA copies/ml. Median viral loads among the four categories of infection were found to be highly significant (p < 0.001). The correlation between CD4+ cell counts and HIV-1 RNA copies for the 49 patients was highly significant (r = -0.76; p < 0.001). CONCLUSIONS: High treatment HIV-1 RNA levels were determined in the majority of patients. A highly significant correlation was obtained between plasma HIV-1 RNA levels and CD4+ cell counts.