In a multivariate Poisson model, a higher HHV8 Log10 viral load (IRR 1.5, 95%CI 1.2–2.0, p = 0.002), IL6 (IRR 1.07, 95%CI, 1.02–1.12, p = 0.004) and CRP at baseline (IRR 1.1, 95%CI 0.96–1.27) increased the risk to develop Severe-IRIS-KS and valganciclovir use significantly decreased the risk of Severe-IRIS-KS occurrence (adjusted IRR = 0.05, 95%CI 0.003–0.6 p = 0.02) (Table 2). This evidence concerns the gene CRP and Kaposi's sarcoma.