Reduced naive and increased activated CD4 and CD8 cells in healthy adult Ethiopians compared with their Dutch counterparts

To assess possible differences in immune status, proportions and absolute n umbers of subsets of CD4(+) and CD8(+) T cells were compared between HIV- h ealthy Ethiopians (n = 52) and HIV- Dutch (n = 60). Both proportions and ab solute numbers of naive CD4(+) and CD8(+) T cells were found to be signific antly reduced in HIV- Ethiopians compared with HIV- Dutch subjects. Also, b oth proportions and absolute numbers of the effector CD8(+) T cell populati on as well as the CD4(+) CD45RA(-) CD27(-) and CD8(+) CD45RA(-) CD27(-) T c ell populations were increased in Ethiopians. Finally, both proportions and absolute numbers of CD4(+) and CD8(+) T cells expressing CD28 were signifi cantly reduced in Ethiopians versus Dutch. In addition, the possible associ ation between the described subsets and HIV status was studied by comparing the above 52 HIV- individuals with 32 HIV- Ethiopians with CD4 counts > 20 0/mu l and/or no AIDS-defining conditions and 39 HIV- Ethiopians with CD4 c ounts < 200/mu l or with AIDS-defining conditions. There was a gradual incr ease of activated CD4(+) and CD8(+) T cells, a decrease of CD8(+) T cells e xpressing CD28 and a decrease of effector CD8(+) T cells when moving from H IV- to AIDS. Furthermore, a decrease of naive CD8(+) T cells and an increas e of memory CD8(+) T cells in AIDS patients were observed. These results su ggest a generally and persistently activated immune system in HIV- Ethiopia ns. The potential consequences of this are discussed, in relation to HIV in fection.