Path Links Immunology, Scunthorpe General Hospital, Scunthorpe, United Kingdom; Department of Immunology, Hull Royal Infirmary, University of Hull, Hull, United Kingdom.
Department of Immunology, Hull Royal Infirmary, University of Hull, Hull, United Kingdom; Post graduate Medical Institute, University of Hull, Hull, United Kingdom.
Allergol Int. 2010 Sep;59(3):305-308. doi: 10.2332/allergolint.09-OA-0154. Epub 2010 Jul 25.
Screening patients for latex allergy prior to surgery is an important but intensive procedure. The appropriate testing strategy for diagnosing latex (Hevea brasiliensis) allergy involves in-vitro specific IgE or skin prick testing. The sensitivity and specificity of both tests are influenced by patient-specific factors or manufacturing processes that alter the clinically relevant allergens in skin testing solutions.
Total IgE and latex-specific IgE testing was introduced as a screening test. Skin prick testing was done on patients with a high probability of latex allergy and negative specific IgE with total IgE <100 kU/L. SDS-PAGE was done on the non-ammoniated latex (NAL) and newly introduced ammoniated latex (AL) reagents for the clinically relevant allergens.
51 patients had a total IgE <100 (range, 2.8-99.0 kU/L), and 10% had a positive skin test. 60% of positive skin tests would have been missed with lower total IgE cut-offs of 50 kU/L (6% of referrals). SDS-PAGE of the NAL solution showed 3 prominent bands with molecular weights of approximately 20, 24 and 42 kDa that correlated with Hev b 6, Hev b 3 and Hev b 7/13, respectively. In contrast, the AL solution showed 3 very faint higher molecular weights bands that did not correlate with clinically relevant antigens.
Increasing the cut-off value of total IgE for allergen-specific IgE testing increased the sensitivity of the specific IgE test. The NAL reagent had a greater number of clinically significant allergens at higher concentrations than AL, which may have implications for the clinical sensitivity of the newer AL reagent.
手术前对乳胶过敏患者进行筛查是一项重要但密集的程序。诊断乳胶（巴西橡胶树）过敏的适当测试策略包括体外特异性 IgE 或皮肤点刺测试。这两种测试的敏感性和特异性都受到患者特异性因素或制造过程的影响，这些因素改变了皮肤测试溶液中与临床相关的过敏原。
总 IgE 和乳胶特异性 IgE 测试被引入作为筛选测试。对总 IgE<100 kU/L 且特异性 IgE 阴性但高度怀疑乳胶过敏的患者进行皮肤点刺测试。对非氨化乳胶（NAL）和新引入的氨化乳胶（AL）试剂进行 SDS-PAGE，以确定与临床相关的过敏原。
51 例患者总 IgE<100（范围，2.8-99.0 kU/L），10%皮肤试验阳性。如果总 IgE 截断值较低（50 kU/L，占转诊患者的 6%），则会漏诊 60%的阳性皮肤试验。NAL 溶液的 SDS-PAGE 显示 3 个分子量约为 20、24 和 42 kDa 的明显条带，分别与 Hev b 6、Hev b 3 和 Hev b 7/13 相关。相比之下，AL 溶液显示 3 个非常微弱的高分子量条带，与临床相关抗原不相关。
增加过敏原特异性 IgE 检测中总 IgE 的截止值会提高特异性 IgE 检测的敏感性。NAL 试剂在更高浓度下具有更多的临床意义过敏原，这可能对新型 AL 试剂的临床敏感性产生影响。
