383 Reductions of Serum Melatonin Levels in HIV-1 Infected Individuals Parallel Disease Progression: Correlation with Serum Interleukin-12 Levels G. Nunnari*1,2, L. Nigro2, F. Palermo2, D. Leto2, R. J. Pomerantz1, B. Cacopardo2 1Thomas Jefferson Univ, Philadelphia, PA and 2Univ of Catania, Italy
Background: During the natural history of human immunodeficiency virus type I (HIV-1) infection, an impairment of interleukin-12 (IL-12) production precedes a switch from a T-helper 1 to a T-helper 2 stage of cellular immunity. Melatonin, the main hormone produced by the pineal gland, seems to promote a T-helper 1 response by increasing the production of IL-12 in vitro. The aim of this study was to measure and correlate serum levels of melatonin and IL-12 in a cohort of HIV-1 infected individuals.
Methods: Fifty-seven (57) subjects with evidence of HIV-1 infection were enrolled: 10 were in CDC stage A, 25 in CDC stage B and 22 in CDC stage C. Thirty (30) healthy HIV-1-seronegative subjects were recruited as controls. Interleukin-12 and melatonin concentrations were quantitated in serum samples, by enzymatic immuno-assays and radioimmuno-assays, respectively.
Results: Mean levels of serum melatonin were significantly lower in HIV-1-infected individuals in comparison with controls (p < 0.001). Within the HIV-1-seropositive group, mean melatonin and IL-12 concentrations were significantly lower in patients in CDC stage C, as compared with patients in CDC stages B and A (p < 0.001). Furthermore, we found in HIV-1 infected individuals a positive correlation between melatonin and IL-12 levels and a negative correlation between melatonin and plasma HIV-1 RNA viral load.
Conclusions: During the natural history of HIV-1 disease, serum melatonin levels are progressively reduced. This reduction may be related to the impairment of T-helper 1 immunoresponses. This represents the first study to demonstrate a clear correlation of serum melatonin and HIV-1 disease progression. Further studies are important to dissect the precise immunopathogenesis of melatonin’s effects on HIV-1 disease progression.
