Depletion of CD4 counts by chemotherapy is associated with rises in circulating IL-7 followed by declines occurring concomitant with recovery of CD counts.

Plot of serum IL-7 level (l) and absolute CD4 count (n) versus time in 3 representative patients treated with dose-intensive chemotherapy for solid tumors. ● and solid line indicate IL-7; ■ and broken line, CD4.