Elevated concentrations of plasma α-melanocyte stimulating hormone are associated with reduced disease progression in HIV-infected patients

To determine whether concentrations of the anti-inflammatory peptide melanocyte stimulating hormone (alpha-MSH) are associated with accelerated or reduced disease progression in patients with HIV infection, plasma concentrations of alpha-MSH and two other anticytokine molecules, interleukin-l receptor antagonist (IL-1 ra) and soluble tumor necrosis factor receptor (s TNF r), were taken repeatedly from HIV-positive patients over a 1-year period. Samples from 87 patients were collected by using special precautions to ensure accurate measurement of the peptide, alpha-MSH concentrations were determined by radioimmunoassay; IL-l ra and s TNF r concentrations were measured by using enzyme-linked immunosorbent assays, Clinical and immunologic variables were recorded to determine whether there is an association between cytokine antagonist concentrations and disease progression, Elevated concentrations of circulating alpha-MSH were associated with reduced progression of the disease, Circulating alpha-MSH was greater in nonprogressors than in progressors; the association between elevated alpha-MSH and reduced disease progression was even more pronounced in patients with baseline CD4(+) T cell counts less than 200/mu L. No such association was observed for the other two anticytokine molecules, and there was no significant correlation between the plasma concentration of either cytokine antagonist and alpha-MSH. The present evidence and previous findings indicate that elevated concentrations of alpha-MSH are associated with reduced disease progression in HIV-infected patients.