Distinct human and vIL-6 cytokine profiles during KSHV-MCD activity. Three representative patients illustrate the 3 h/vIL-6 flare patterns encountered (h+VIL-6, hIL-6 alone, and vIL-6 alone). Levels of vIL-6, hIL-6, and KSHV VL in are shown during their initial therapy. Periods where KSHV-MCD clinical manifestations were present are shaded gray. In all cases, KSHV VL is elevated during flares. Three distinct cytokine profiles are seen: vIL-6 and hIL-6 elevation (left); vIL-6 elevation without hIL-6 (center), and hIL-6 with undetectable vIL-6 (right).