Persistent poor clinical outcomes of people living with HIV presenting with AIDS and late HIV diagnosis – results from the ICONA cohort in Italy, 2009-2022

Objectives: Limited data are available on the long-term outcomes in recent years for late HIV diagnosis (LD). Methods: All subjects with HIV enrolled in the ICONA cohort in 2009-2022 who started antiretroviral treatment (ART) within 4 months from diagnosis were included and divided into: (i) pre-ART CD4 count ≥350/mm3 without AIDS (non-LD), (ii) pre-ART CD4 count <350/mm3 without AIDS (LD asymptomatic), and (iii) with AIDS events pre-ART (LD-AIDS). The estimated probability and independent risk for mortality (all-cause and cause-specific) and treatment failure were evaluated. Results: Of 6813 participants (2448 non-LD, 3198 LD asymptomatic, and 1167 LD-AIDS), 161 (2.4%) died after ART initiation. At survival analysis, a higher probability of all-cause mortality has been identified for LD than non-LD (P <0.001) and within the former, for LD-AIDS over LD asymptomatic (P <0.001). After adjusting for confounders, LD showed a higher risk of all-cause mortality (vs non-LD adjusted hazard ratio (aHR) 5.51, P <0.001) and, in particular, being an AIDS presenter predicted a greater risk of all-cause (aHR = 4.42, P <0.001), AIDS-related (adjusted subhazard ratio [aSHR] = 16.86, P <0.001), and non-AIDS–related mortality (aSHR = 1.74, P = 0.022) than the rest of the late presenters. Among the short-term survivors in the LD-AIDS group, the long-term mortality was mediated by the lack of immune recovery at 2 years. Finally, LD compared with non-LD and, particularly, among the former, LD-AIDS over LD asymptomatic showed a greater risk of treatment failure. Conclusions: In recent years, LD subjects, particularly, AIDS presenters, remained at a higher risk of poorer outcomes. Public health strategies for early HIV diagnosis are urgently needed to constrain the mortality gap.