The widespread introduction of effective ART reduced the burden of AIDS-related Kaposi Sarcoma (KS), even if KS does still occur also in individuals with well-controlled HIV infection.
We included naïve HIV-infected individuals (PLHIV) enrolled in the ICONA cohort over 1997-2019. Prevalent cases were PLHIV with a diagnosis of KS prior and up to 30 days after enrolment. Incident cases were defined as new KS diagnoses occurring after ART initiation. Patients’ characteristics at the date of enrolment were compared by prevalent KS status and associations identified by logistic regression modelling. In the subset of people KS-free at enrolment, standard Kaplan-Meier curves were used to model time from ART initiation to development of KS and a Cox regression model to identify factors associated with this outcome. A similar analysis was performed in PLHIV with prevalent KS to identify factors associated with their risk of KS relapse or death after ART (clinical failure).
Among 17,742 PLHIV enrolled in the ICONA cohort over 1997-2019, 248 prevalent KS cases and 36 incident KS cases were identified. Prevalent cases were mostly male (93%), with median age of 45 years (IQR 37-53) and median CD4+ count of 76/mmc (IQR 24-193). No significant differences in prevalence (by year of enrolment) and incidence (by year of ART initiation) of KS were observed (Figure). At multivariable logistic regression, the only factor independently associated with prevalent KS was mode of HIV transmission (MSM versus PWID, adjusted odds ratio [aOR]: 5.24 (1.35, 20,39)). In contrast, factors independently associated with the risk of incident KS were pre-ART CD4+ count (adjusted relative hazard (aHR): 0.57 (0.42, 0.77) for 100 cells/mmc higher) and mode of HIV transmission (MSM versus HS, aHR: 3.82 (1.62, 9.02)).
Over 1,316 PYFU, clinical failure after ART introduction was observed in 52 prevalent cases (29 deaths and 23 relapses) with an incidence rate of 3.9% (95% CI: 2.9-5.1). However, none of the considered factors showed an association with the risk of clinical failure.
Despite universal ART access, we did not observe a reduction of KS prevalence and incidence in recent years. The strong association of pre-ART CD4+ count with incidence of KS in ART-treated PLHIV strengthens the role of immune competence in KS. Further KSHV and HIV immune-virological characterization is warranted to better identify factors associated with KS occurrence in PLHIV.