Longitudinal CD4 T-cell counts after rhIL-7 treatment. PBMCs were assayed by flow cytometry. The blue lines in panels A-E represent CD4 T cells in the weeks after rhIL-7 initiation. rhIL-7 was administered as a series of injections once per week for 3 weeks. Each dotted vertical orange line represents a dose of rhIL-7. (A) Patient who experienced a hypersensitivity reaction after the sixth rhIL-7 dose at week 26, including the titer of non-neutralizing anti-IL-7 antibodies (Ab). (B-E) Patients received repeated rhIL-7 dosing after week 48 for CD4 T cells that remained at <350/μL.