Cristaudo A, Bordignon V, Petrucci F, Caimi S, De Rocco M, Picardo M, Cordiali Fei P, Ensoli F
Department of Allergy, San Gallicano Dermatology Institute, Rome, Italy.
Int J Immunopathol Pharmacol. 2009 Jul-Sep;22(3):605-14. doi: 10.1177/039463200902200306.
The increased use of Palladium (Pd) for biomedical applications, which has more than doubled in the last ten years, appears to be associated with an increased frequency of adverse reactions to Pd. The aim of this study is to investigate the relationship between the implant of a biomechanical apparatus containing Pd and the setting of a hypersensitivity to Pd by determining the levels of the metal released in biological fluids, assessing the effects of Pd on peripheral blood mononuclear cell (PBMC) cytokine production and exploring the clinical setting of skin sensitization. Of a total of 3,093 subjects examined in 2006, sensitization to Pd alone or in association with nickel (Ni) was observed in 1.6% and 13.03% of the individuals, respectively. Of these, a group of six subjects positive to Pd and negative to Ni at patch testing were selected on the basis of the oral clinical symptoms in order to measure both the levels of Pd in biological fluids and the degradation of the dental prostheses. Specific Pd measurements were carried out on salivary fluid, urine and serum samples by High Resolution Inductively Coupled Plasma-Mass Spectrometry. In addition, the degradation of the dental prostheses was assessed by both a leaching test and an analysis of the micro morphology of orthodontic prostheses. The induction of IFN-gamma production by Pd was assessed in PBMC by the ELISpot assay. Skin sensitization to Pd was evaluated by patch testing and clinical examination. Ten healthy subjects were comparatively tested as controls. We found a specific induction of an IFN-gamma response by Pd in PBMC collected from all the subjects positive to Pd at patch testing. On the contrary, control subjects did not show any response to Pd as assessed by IFN-gamma ELISpot assay or by skin testing. Remarkably, the levels of Pd in all biological samples (saliva, sera, urine) were significantly higher in Pd-sensitized patients than in those collected from controls, reaching the highest concentrations in the urine. The leaching studies gave additional evidence that the dental appliances can release measurable levels of Pd in saliva. Oral clinical symptoms in patients with Pd dental prostheses were associated with measurable levels of Pd in the biological fluids, the induction of Pd-specific IFN-gamma responses in PBMC and the clinical evidence of skin sensitization to Pd. These data suggest that dental appliances may represent an active source of Pd in the body, and this, in turn, can favour the clinical setting of a hypersensitivity to this metal.
钯（Pd）在生物医学应用中的使用量增加，在过去十年中增加了一倍多，这似乎与对Pd不良反应的频率增加有关。本研究的目的是通过测定生物流体中释放的金属水平、评估Pd对外周血单核细胞（PBMC）细胞因子产生的影响以及探索皮肤致敏的临床情况，来研究含Pd生物力学装置的植入与对Pd过敏反应之间的关系。在2006年检查的总共3093名受试者中，分别有1.6%和13.03%的个体观察到单独对Pd或与镍（Ni）联合致敏。其中，根据口腔临床症状选择了一组在斑贴试验中对Pd呈阳性而对Ni呈阴性的6名受试者，以测量生物流体中的Pd水平和牙科修复体的降解情况。通过高分辨率电感耦合等离子体质谱法对唾液、尿液和血清样本进行特定的Pd测量。此外，通过浸出试验和正畸修复体微观形态分析来评估牙科修复体的降解情况。通过ELISpot试验评估Pd在PBMC中诱导IFN-γ产生的情况。通过斑贴试验和临床检查评估对Pd的皮肤致敏情况。以10名健康受试者作为对照进行比较测试。我们发现在斑贴试验中对Pd呈阳性的所有受试者采集的PBMC中，Pd特异性诱导了IFN-γ反应。相反，通过IFN-γ ELISpot试验或皮肤试验评估，对照受试者对Pd没有任何反应。值得注意的是，Pd致敏患者所有生物样本（唾液、血清、尿液）中的Pd水平显著高于对照组采集的样本，尿液中的浓度最高。浸出研究提供了额外的证据，表明牙科器具可在唾液中释放可测量水平的Pd。佩戴含Pd牙科修复体的患者的口腔临床症状与生物流体中可测量的Pd水平、PBMC中Pd特异性IFN-γ反应的诱导以及对Pd皮肤致敏的临床证据相关。这些数据表明，牙科器具可能是体内Pd的一个活跃来源，进而可能促进对这种金属过敏反应的临床发生。
