CD38 and malaria: Moreover, the CD4+ T cell activation level, as indicated by the percentage of HLA-DR + CD38 + CD4+ T cells, was shown to be positively correlated with the percentage of annexin V + CD4+ TCM and TEM cells during the malaria phase (P = 0.031, r = 0.44 and P = 0.050, r = 0.404; respectively; Figure 4B and C).