Serum Levels of IL-2, IL-1α, TNF-α, and Soluble Receptor of IL-2 in HIV-1-Infected Patients

Abstract

Serum levels of the interleukins (IL-1 alpha, IL-2), tumor necrosis factor-alpha (TNF-alpha), and soluble receptor of IL-2 (sIL-2R) were studied by enzyme-linked immunosorbent assay (ELISA) in 12 normal healthy controls and 52 HIV-1 seropositive patients. Results indicated that: (1) sIL-2R levels were significantly increased in most HIV-1 seropositive patients. This increase appeared to be correlated with low CD4 cell counts and with the presence of detectable levels of p25 antigen. Furthermore, initially high levels of sIL-2R appeared to be correlated with progression of disease. (2) IL-2 levels were found to be increased in about 43% of asymptomatic carriers (ASY) and subjects with lymphoadenopathy-associated syndrome (LAS) compared with 12% in the case of AIDS-related complex (ARC) and AIDS patients. (3) There was a positive correlation between serum levels of TNF-alpha and IL-1 alpha in nearly all patients. Detectable levels of both cytokines were found in 34% of ASY and LAS patients and only rarely were detectable in ARC and AIDS patients. (4) Sixteen patients in whom progression of disease was observed were studied initially and at the moment they upstaged. No significant modification of serum levels of the three cytokines and sIL-2R studied could be evidenced. It was concluded that sIL-2R could be a useful marker of disease activity and progression, though a prospective study is necessary. For IL-2, IL-1 alpha, and TNF-alpha, this study indicated the presence of variable alterations in serum levels in HIV-1-infected patients.