Mechanisms of HIV non-progression; robust and sustained CD4+ T-cell proliferative responses to p24 antigen correlate with control of viraemia and lack of disease progression after long-term transfusion-acquired HIV-1 infection

Dyer, Wayne B; Zaunders, John J; Yuan, Fang Fang; Wang, Bin; Learmont, Jennifer C; Geczy, Andrew F; Saksena, Nitin K; McPhee, Dale A; Gorry, Paul R; Sullivan, John S

Non-progressors are considered to represent the tail end of the distribution curve of rates of disease progression, and although elite non-progressors are extending this curve even further, disease progression may be inevitable in this rare group of individuals. Recent analyses of the SBBC may support this suggestion [13, 17] . However, death from other causes has prevented the establishment of definitive proof of disease progression in some individ- pool X1 X2 X3 X4 X5 X6 X7 X8 X9 X0 control SFC 505 155 0 100 185 3600 225 150 390 425 10 5 1 2 3 4 5 6 7 8 uals. Two SBBC subjects that did not consent to prospective analysis died from unrelated causes in 1987 and 1994, and the sole SBBC recipient on therapy (C98) has since died from non-HIV causes. Two other elderly subjects also died from non-HIV causes (C18 and C54), but control of viraemia at low levels along with normal CD4 T cell counts suggested there was no evidence for loss LTNP status before death. This leaves the three elite nonprogressors from the SBBC described in this study, and one is also advanced in age. One of the elderly Cohort 2 LTNP (with wild-type HIV infection) also died recently from non-HIV causes aged 84 (C122). We may have an opportunity to determine the factors involved in disease progression in the other two Cohort 2 non-progressors (C13 and C53). Both had very low but detectable viraemia, but a recent inversion of CD4 : CD8 T cell ratio in C13 is evident of a change in HIV-induced immune activation. Based on the decline in the proliferative response to p24 preceding this recent increase in viraemia, it is likely that these together signify a transitionary stage toward disease progression in C13.