RESUMO
INTRODUCTION: Semaphorin-4D (CD100), generated by CD4/CD8 T-cells and its receptor on B cells - CD72, play a role in immune regulation. Both have soluble forms - sCD100/sCD72. METHODS: sCD100 and sCD72 levels were determined by ELISA (MyBioSource, USA). RESULTS: 28 chronic HIV patients and 50 matched healthy volunteers participated in our study. Before treatment, CD4 T-cells counts were 267⯱â¯216â¯cells/mcl and viral load (VL) was 586,675⯱â¯1897,431â¯copies/ml. Two years following HAART, CD4 T-cells counts rose to 475⯱â¯264â¯cells/mcl and VL dropped to 2050⯱â¯10,539â¯copies/ml. CD8 T-cells counts were stable. sCD72 levels prior (4.13⯱â¯2.03â¯ng/ml) and following HAART (3.53⯱â¯2.01â¯ng/ml) were similar to control levels (4.51⯱â¯2.66â¯ng/ml). sCD100 levels before (40.47⯱â¯31.4â¯ng/ml) and following HAART (37.68⯱â¯29.44â¯ng/ml) were significantly lower compared to controls (99.67⯱â¯36.72â¯ng/ml) despite the significant increase in CD4 T-cells counts. CONCLUSIONS: The permanent low levels of the immunoregulator sCD100 suggest a role for CD100 in the immune dysfunction and T cells exhaustion of HIV.