Objectives: To assess the incidence, predictors, and outcomes of Kaposi sarcoma-associated paradoxical immune reconstitution inflammatory syndrome (KS-IRIS) in antiretroviral therapy (ART)-naive HIV-infected patients with Kaposi sarcoma initiating ART in both well resourced and limited-resourced settings.
Design: Pooled analysis of three prospective cohorts of ART-naive HIV-infected patients with Kaposi sarcoma from sub-Saharan Africa (SSA) and one from the UK.
Methods: KS-IRIS case definition was standardized across sites. Cox regression and Kaplan–Meier survival analysis were used to identify the incidence and predictors of KS-IRIS and Kaposi sarcoma-associated mortality.
Results: Fifty-eight of 417 (13.9%) eligible individuals experienced KS-IRIS with an incidence 2.5 times higher in the African vs. European cohorts (P = 0.001). ART alone as initial Kaposi sarcoma treatment (hazard ratio 2.97, 95% confidence interval (CI) 1.02–8.69); T1 Kaposi sarcoma stage (hazard ratio 2.96, 95% CI 1.26–6.94); and plasma HIV-1 RNA more than 5 log10 copies/ml (hazard ratio 2.14, 95% CI 1.25–3.67) independently predicted KS-IRIS at baseline. Detectable plasma Kaposi sarcoma-associated herpes virus (KSHV) DNA additionally predicted KS-IRIS among the 259 patients with KSHV DNA assessed (hazard ratio 2.98, 95% CI 1.23–7.19). Nineteen KS-IRIS patients died, all in SSA. Kaposi sarcoma mortality was 3.3-fold higher in Africa, and was predicted by KS-IRIS (hazard ratio 19.24, CI 7.62–48.58), lack of chemotherapy (hazard ratio 2.35, 95% CI 1.09–5.05), pre-ART CD4 cell count less than 200 cells/μl (hazard ratio 2.04, 95% CI 0.99–4.2), and detectable baseline KSHV DNA (hazard ratio 2.12, 95% CI 0.94–4.77).
Conclusion: KS-IRIS incidence and mortality are higher in SSA than in the UK. This is largely explained by the more advanced Kaposi sarcoma disease and lower chemotherapy availability. KS-IRIS is a major contributor to Kaposi sarcoma-associated mortality in Africa. Our results support the need to increase awareness on KS-IRIS, encourage earlier presentation, referral and diagnosis of Kaposi sarcoma, and advocate on access to systemic chemotherapy in Africa.