title: Reduction of serum melatonin levels in HIV-1-infected individuals' parallel disease progression: correlation with serum interleukin-12 levels.
abstract: 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 (Th1) to a T-helper 2 (Th2) stage of cellular immunity. Melatonin, the main hormone produced by the pineal gland, seems to promote a Th1 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
  77 anti-HIV-1-positive subjects were enrolled: 20 were in CDC stage A, 25 in CDC stage B and 32 in CDC stage C. 30 healthy HIV-1-seronegative subjects were recruited as controls. IL-12 and melatonin concentrations were quantitated in serum samples.
  
  
  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 < 0.01).
  
  
  CONCLUSIONS
  During the natural history of HIV-1 disease, serum melatonin levels are progressively reduced. This reduction may be related to the impairment of Th1 immunoresponses.
authors.affiliation: The Dorrance H. Hamilton Laboratories, Center for Human Virology, Division of Infectious Diseases, Dept. of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA. gnunnari@hotmail.com
authors.forename: G
authors.initials: G
authors.lastname: Nunnari
authors.forename: L
authors.initials: L
authors.lastname: Nigro
authors.forename: F
authors.initials: F
authors.lastname: Palermo
authors.forename: D
authors.initials: D
authors.lastname: Leto
authors.forename: R J
authors.initials: RJ
authors.lastname: Pomerantz
authors.forename: B
authors.initials: B
authors.lastname: Cacopardo
mesh_terms: D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D018791:CD4 Lymphocyte Count; D016516:CD4-CD8 Ratio; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D018664:Interleukin-12 / Q000032:analysis / Q000097:blood*; D016014:Linear Models; D008297:Male; D008550:Melatonin / Q000032:analysis / Q000097:blood*; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D018570:Risk Assessment; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D018664:Interleukin-12; D008550:Melatonin