title: Nickel, palladium and rhodium induced IFN-gamma and IL-10 production as assessed by in vitro ELISpot-analysis in contact dermatitis patients.
abstract: BACKGROUND
  Recent attempts to diminish nickel use in most industrial products have led to an increasing utilization of alternative metal compounds for destinations such as the alloys used in orthopaedics, jewellery and dentistry. The present study was undertaken with the aim to evaluate the potential for an allergic response to nickel, palladium and rhodium on the basis of antigen-specific induction of inflammatory/regulatory cytokines, and to characterize, according to the cytokine profiles, the nature of simultaneous positive patch tests elicited in vivo. Peripheral blood mononuclear cells (PBMC) from 40 patients with different patch test results were kept in short term cultures in the presence of optimized concentrations of NiSO4 x 6H2O, PdCl2 and Rh(CH3COO)2. The production of IFN-gamma and IL-10 elicited by metal compounds were analyzed by the ELISpot assay.
  
  
  RESULTS
  We found a specific IFN-gamma response by PBMC upon in vitro stimulation with nickel or palladium in well recognized allergic individuals. All controls with a negative patch test to a metal salt showed an in vitro IL-10 response and not IFN-gamma production when challenged with the same compound. Interestingly, all subjects with positive patch test to both nickel and palladium (group 3) showed an in vitro response characterized by the release of IFN-gamma after nickel stimulation and production of IL-10 in response to palladium.
  
  
  CONCLUSIONS
  These results strongly suggest that the different cytokine profiles elicited in vitro reflect different immune responses which may lead to the control of the allergic responses or to symptomatic allergic contact dermatitis. The development of sensitive and specific in vitro assays based on the determination of the cytokine profiles in response to contact allergens may have important diagnostic and prognostic implications and may prove extremely useful in complementing the diagnostic limits of traditional patch testing.
authors.affiliation: Laboratory of Clinical Pathology, Department of Allergology and Laboratory of Skin Physiopathology, Institute San Gallicano, IRCCS, IFO, Rome, Italy. bordignon@ifo.it
authors.forename: Valentina
authors.initials: V
authors.lastname: Bordignon
authors.forename: Francesca
authors.initials: F
authors.lastname: Palamara
authors.forename: Paola
authors.initials: P
authors.lastname: Cordiali-Fei
authors.forename: Antonella
authors.initials: A
authors.lastname: Vento
authors.forename: Arianna
authors.initials: A
authors.lastname: Aiello
authors.forename: Mauro
authors.initials: M
authors.lastname: Picardo
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Ensoli
authors.forename: Antonio
authors.initials: A
authors.lastname: Cristaudo
mesh_terms: D000328:Adult; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D007114:Immunization; D007371:Interferon-gamma / Q000378:metabolism*; D016753:Interleukin-10 / Q000378:metabolism*; D008297:Male; D009532:Nickel / Q000276:immunology* / Q000494:pharmacology; D010165:Palladium / Q000276:immunology* / Q000494:pharmacology; D010328:Patch Tests; D012238:Rhodium / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D016753:Interleukin-10; D010165:Palladium; D009532:Nickel; D007371:Interferon-gamma; D012238:Rhodium; C008756:palladium chloride