Proliferative response and cytokine production by ICL PBMCs. (A-B) Proliferation of CD4⁺ (A) or CD8⁺ (B) T cells was assessed in the presence of Staphylococcus aureus enterotoxin B (SEB), tetanus toxin (TT), candidin (CANDI), purified protein derivative from Mycobacterium tuberculosis (PPD), or the mannoprotein antigen from Cryptococcus neoformans (MANO) among PBMCs from healthy subjects (left of each panel) and ICL patients (right of each panel). Results are expressed as percentages of proliferating CD4⁺ and CD8⁺ T lymphocytes (means ± SEM and percentiles) after antigenic stimulation, as measured by the fraction of cells with decreased CFSE staining. (C-D) IFN-γ (C) or TNF-α (D) production by PBMCs from healthy persons and ICL patients after in vitro stimulation. Supernatants were harvested 36 hours after stimulation and measured for cytokine levels by the cytometric bead array method. Values represent means ± SEM and percentile of triplicate supernatant samples. *P < .001 compared with control or ICL cells.