Although we controlled the analyses for this variable, it is important to note that this difference between groups might have led to underestimate the association of a low CD4/CD8 ratio with non-AIDS-associated morbidity and mortality, given that in a recent study the CD4/CD8 ratio appeared to increase still after more than ten year of ART-mediated HIV RNA suppression [38], and in our study subjects who developed serious non-AIDS-related illnesses showed a lower CD4/CD8 ratio despite longer cumulative ART exposure. Here, CD4 is linked to AIDS.