KS-IRIS was defined as ≥2 of the following: abrupt increase in number of KS lesions, appearance or exacerbation of lung-opacities or lymphedema, concomitantly with an increase in CD4+ cell-count ≥50 cells/mm3 and a decrease of >1 log in viral-load once started cART. Here, CD4 is linked to Kaposi's sarcoma.