Spontaneous release of soluble p75-TNFR was analyzed in cell-free PBMC (3 × 10⁶ cells/mL) supernatants after 20 hours (h) in four symptomatic non-AIDS patients (▨, CDC group B), four AIDS patients (, CDC group C), and five healthy controls (□). *P < .05 versus controls, **P < .05 versus both controls and CDC group B.