Stratification of cohort into HIV-1 disease progression groupings.

1CD4+ T cell decline without adjusting for first CD4 count and age of the participant.2CD4+ T cell decline after adjusting for first CD4 count and age of the participant.Table 1 illustrates the stratification of 110 chronically HIV-1 adults into distinct progression groups. Six-monthly retrospective CD4 counts were used in a multilevel regression model to derive individual participant CD4 slopes. The slopes were calculated over a median observation time of 610 months (minimum-maximum 18–97 months). Annual CD4+ T-cell changes are expressed as medians with interquartile ranges. Positive (+) symbols indicate increasing CD4+ counts while (−) indicates decreasing CD4+ counts over time. Individuals in the extreme stratification group 1 were selected as rapid progressors (RP, n = 7) while those in group 5 were selected as slow progressors (SP, n = 14). Groups 2, 4and 4 were categorised as normal progressors (NP, n = 89). Normal progressors were those with CD4 slopes between −91/year to +10/year; RPs had CD4 slopes +10/year.