CD4 and Kaposi's sarcoma: In the study conducted by Volkow et al., KS-IRIS diagnosis was considered if a clinical abrupt worsening of previously existing KS (“paradoxical”) or the development of KS (“unmasked”) occurred within the first 6 months after the initiation of ART, associated with a reduction of at least 1 log10 of HIV-1 RNA and/or an increase of ≥50 cells/mm3 or ≥two fold rise in baseline CD4+ cell count.