Lerch Marianne, Keller Monika, Britschgi Markus, Kanny Gisele, Tache Valerie, Schmid Daphne A, Beeler Andreas, Gerber Basil O, Luethi Michael, Bircher Andreas J, Christiansen Cathrine, Pichler Werner J
Clinic for Rheumatology and Clinical Immunology/Allergology, Inselspital, University of Bern, Bern, Switzerland.
J Allergy Clin Immunol. 2007 Jun;119(6):1529-36. doi: 10.1016/j.jaci.2007.02.007. Epub 2007 Apr 6.
Approximately 3% of patients exposed to iodinated contrast media develop delayed hypersensitivity reactions.
We wanted to better understand the molecular basis of contrast media cross-reactivity.
Cross-reactivity was assessed by skin testing and measurement of T-cell activation (CD69 upregulation) and proliferation ((3)H-thymidine uptake, 5,6-carboxyfluorescein diacetate succinimidyl ester staining) of PBMCs, T-cell lines, and T-cell clones of 2 patients with delayed hypersensitivity reactions to iohexol and iomeprol, respectively. Thirteen different contrast media and potassium iodide were compared.
Skin testing and analyses of PBMCs, T-cell lines, and clones showed broad cross-reactivity in both patients. Broad as well as more restricted cross-reactivity patterns were found in iohexol-specific and iomeprol-specific CD4(+) T-cell clones, whereas 1 iomeprol-specific CD8(+) T-cell clone showed no cross-reactivity at all. The reactivity to equimolar concentrations of iohexol and its dimer iodixanol was very similar, suggesting that the dimer was not more stimulatory than its monomer. Consistently low reactivity to iobitridol was found in both patients, but never to iodide. A frequency analysis of contrast medium-specific peripheral T cells gave values between 0.6 % (iomeprol) and 0.05 % (iobitridol).
Clinically observed cross-reactivity between different contrast media is a result of the presence of contrast media-specific T cells, some of which show a broad cross-reactivity pattern. Iodide ions, known to be present at low concentration in contrast media solutions, do not seem to be the causative moiety.
Detailed in vitro analysis might help identify noncross-reactive contrast media.
接触碘化造影剂的患者中约3%会发生迟发型过敏反应。
我们希望更好地了解造影剂交叉反应性的分子基础。
通过皮肤试验以及对2例分别对碘海醇和碘美普尔发生迟发型过敏反应患者的外周血单个核细胞（PBMC）、T细胞系和T细胞克隆进行T细胞活化（CD69上调）和增殖（³H-胸腺嘧啶核苷摄取、5,6-羧基荧光素二乙酸琥珀酰亚胺酯染色）检测，评估交叉反应性。比较了13种不同的造影剂和碘化钾。
皮肤试验以及对PBMC、T细胞系和克隆的分析显示，两名患者均存在广泛的交叉反应性。在碘海醇特异性和碘美普尔特异性CD4⁺T细胞克隆中发现了广泛以及更具限制性的交叉反应模式，而1个碘美普尔特异性CD8⁺T细胞克隆则完全没有交叉反应性。对等摩尔浓度的碘海醇及其二聚体碘克沙醇的反应性非常相似，表明二聚体并不比其单体更具刺激性。两名患者对碘比醇的反应性始终较低，但对碘化物从未有过反应。对造影剂特异性外周T细胞的频率分析得出的值在0.6%（碘美普尔）至0.05%（碘比醇）之间。
临床上观察到的不同造影剂之间的交叉反应性是由于存在造影剂特异性T细胞，其中一些表现出广泛的交叉反应模式。已知在造影剂溶液中以低浓度存在的碘离子似乎不是致病部分。
详细体外分析可能有助于识别无交叉反应性的造影剂。
