CD4 and AIDS: All of the PTMs developed significant lymphadenopathy during the acute infection and exhibited signs of disease progression during the follow-up: two experienced weight loss during acute infection, followed by rapid progression to AIDS (78 and 104 days postinfection, dpi); two additional PTMs progressed to AIDS within a year postinfection; the remaining PTM did not progress to AIDS during the follow-up, but showed profound CD4+ T cell depletion and persistently high VLs, which are indicative of progressive, pathogenic infection.