title: Evaluation of immunologic profile in patients with nickel sensitivity due to use of fixed orthodontic appliances.
abstract: The aim of this study was to develop a new approach to testing the impact of nickel antigen on in vitro cell-proliferation assay, to identify adverse reactions to casting alloys among orthodontic patients. Cell-proliferation assay in vitro was used as the basic methodology to assess the influence of such variables as source of nickel antigen, type of serum used to supplement the culture medium, and number of cells in the culture. We selected 35 orthodontic patients who were classified as nickel sensitive and non-nickel sensitive, based on their clinical records. Our results showed that hexahydrated nickel sulfate at 10 microg/mL, 10% of autologous sera, and 2 x 10(5) cells was the best condition for inducing the most marked nickel proliferation response in vitro. This optimized method was able to distinguish nickel-sensitive from non-nickel-sensitive dental patients and also to discriminate those with positive skin tests. Our data suggest that continuous exposure to nickel casting alloys might lead to oral tolerance mechanisms that modulate nickel sensitivity, as evidenced by the lower cell proliferation index in patients undergoing orthodontic treatment over 24 months. Finally, our findings demonstrated a known nickel-induced type 2 immune response and a marked lack of type 1 immunity (interferon gamma) as the hallmarks of nickel-sensitive patients. Further studies are needed to clarify the major cell phenotype associated with this type 2 immune response and the lack of type 1 immunity observed in nickel-sensitive people.
authors.affiliation: Núcleo de Pesquisa em Imunologia, Faculdade de Ciências da Saúde, Universidade Vale do Rio Doce, Governador Valadares, Minas Gerais, Brazil. iomarigo@goval.com.br
authors.forename: Marcelo
authors.initials: M
authors.lastname: Marigo
authors.forename: Darcy Flávio
authors.initials: DF
authors.lastname: Nouer
authors.forename: Marisa Cristina Santos
authors.initials: MC
authors.lastname: Genelhu
authors.forename: Luiz Cosme Cotta
authors.initials: LC
authors.lastname: Malaquias
authors.forename: Virgínia Ramos
authors.initials: VR
authors.lastname: Pizziolo
authors.forename: Alexandre Sylvio Vieira
authors.initials: AS
authors.lastname: Costa
authors.forename: Olindo Assis
authors.initials: OA
authors.lastname: Martins-Filho
authors.forename: Lucia Fraga
authors.initials: LF
authors.lastname: Alves-Oliveira
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000937:Antigen-Antibody Reactions / Q000276:immunology; D000941:Antigens / Q000276:immunology; D001769:Blood; D002478:Cells, Cultured; D002648:Child; D003470:Culture Media; D003722:Dental Alloys / Q000009:adverse effects / Q000737:chemistry*; D017449:Dermatitis, Allergic Contact / Q000276:immunology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D009532:Nickel / Q000009:adverse effects / Q000276:immunology*; D009967:Orthodontic Appliances / Q000009:adverse effects; D012882:Skin Tests
chemical_list: D000941:Antigens; D003470:Culture Media; D003722:Dental Alloys; C029938:nickel sulfate; D009532:Nickel; D007371:Interferon-gamma