β2-microglobulin, soluble CD8 and soluble interleukin-2-receptor in sera from HIV-1 and HIV-2 infected subjects

Background. β2-Microglobulin (β2M), soluble CD8 (sCD8) and soluble interleukin-2-receptor (sIL-2R) are markers of immune cell activation that have been associated with the progression of HIV-1 disease. We compared the serum levels of β2M, sCD8 and sIL-2R in asymptomatics with HIV-1 and/or HIV-2 from Verona (Italy) and from Bissau (Guinea-Bissau) respectively to investigate any differences between the two infections. Methods. Fourteen HIV-1 infected subjects, seronegative for HBV infection and syphilis and 17 HIV-2 subjects negative for the above-mentioned infections and for malaria parasites were included in the study. Four out of 17 HIV-2 subjects had coinfection with HIV-1 and were not statistically evaluated. Results. Serum sCD8 levels were higher in the HIV-2 (1008 ± 303 U/mL) than in the HIV-1 group (581 ± 308 U/mL). On the contrary, serum levels of sIL-2R were higher in HIV-1 infected subjects (1304 ± 375 U/mL) than in HIV-2 positive subjects (703 ± 206). The difference between the β2M levels of the two groups was not significant. Conclusious. HIV-2 seropositives differ from HIV-1 subjects with respect to their higher levels of sCD8 and lower levels of sIL-2R, suggesting a potential use of differential markers and possibly different pathogenic mechanisms in these infections