Department of Allergology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
J Allergy Clin Immunol. 2013 Jul;132(1):125-30. doi: 10.1016/j.jaci.2012.12.1578. Epub 2013 Mar 14.
Increased basal serum tryptase (bsT) levels are a well-described risk factor for Hymenoptera venom-induced anaphylaxis (HVAn) in patients allergic to Hymenoptera venom. Increased bsT levels might also indicate the presence of mastocytosis. In this study we evaluated whether the risk of HVAn increases with increasing mast cell load in patients with mastocytosis.
Consecutive patients with different subtypes of mastocytosis (n = 329) admitted to the University Medical Center Groningen were retrospectively assessed. As markers for mast cell load, levels of both bsT and the urinary histamine metabolites methylhistamine and methylimidazole acetic acid (MIMA) were used.
In the entire patient group, irrespective of disease subtype and Hymenoptera venom exposure, HVAn prevalence gradually increased with increasing marker levels to a maximum of 36% to 47% at a bsT level of 28.0 μg/L, a methylhistamine level of 231.0 μmol/mol creatinine, and a MIMA level of 2.7 mmol/mol creatinine but decreased thereafter with a further increase in these levels. In patients with indolent systemic mastocytosis with a history of Hymenoptera venom exposure after age 15 years or greater (n = 152), MIMA and age at the most recent Hymenoptera sting were independent predictors for HVAn (odds ratios of 0.723 [P = .001] and 1.062 [P < .001], respectively).
In patients with mastocytosis, HVAn prevalence does not increase constantly with increasing levels of mast cell load parameters: after a gradual increase to a maximum of near 50%, it decreases with a further increase in these levels. In the indolent systemic mastocytosis population, all mast cell load markers were independent negative predictors of HVAn. These findings suggest a complex pathophysiologic association between mast cell load and HVAn risk in patients with mastocytosis.
基础血清类胰蛋白酶（bsT）水平升高是已被充分描述的变应原性蜂类毒液（HVAn）的风险因素，存在于对蜂类毒液过敏的患者中。bsT 水平升高也可能表明肥大细胞增多症的存在。在这项研究中，我们评估了肥大细胞增多症患者的肥大细胞负荷增加是否会增加 HVAn 的风险。
回顾性评估了连续就诊于格罗宁根大学医学中心的不同类型肥大细胞增多症（n = 329）患者。使用 bsT 和尿组胺代谢物甲基组胺和甲基咪唑乙酸（MIMA）水平作为肥大细胞负荷的标志物。
在整个患者组中，无论疾病亚型和蜂类毒液暴露情况如何，HVAn 患病率逐渐随着标志物水平的增加而增加，在 bsT 水平为 28.0μg/L、甲基组胺水平为 231.0μmol/mol 肌酐和 MIMA 水平为 2.7mmol/mol 肌酐时达到最高的 36%至 47%，但此后随着这些水平的进一步增加而降低。在有 15 岁以后的蜂类毒液暴露史的惰性系统性肥大细胞增多症患者（n = 152）中，MIMA 和最近一次蜂蜇年龄是 HVAn 的独立预测因素（优势比分别为 0.723[P =.001]和 1.062[P <.001]）。
在肥大细胞增多症患者中，HVAn 患病率不会随着肥大细胞负荷参数水平的增加而持续增加：在逐渐增加到接近 50%的最大值后，随着这些水平的进一步增加而降低。在惰性系统性肥大细胞增多症人群中，所有肥大细胞负荷标志物都是 HVAn 的独立负预测因素。这些发现表明肥大细胞负荷与肥大细胞增多症患者 HVAn 风险之间存在复杂的病理生理关联。
