ABSTRACT

Background

HIGM syndrome is a rare form of primary immunodeficiencies characterized by normal/increased amounts of serum IgM and decreased serum levels of other switched immunoglobulin classes. Since the affected patients are continuously infected with various types of pathogens and are susceptible for cancers, diagnostic and therapeutic tests including imaging techniques are recommended for the diagnosis and treatment of these patients, which predispose them to higher accumulated doses of radiation. Given the evidence of class switching recombination machinery defect and its association with an increased rate of DNA repair, we aimed to evaluate radiation sensitivity among a group of patients diagnosed with HIGM syndrome.

Methods

19 HIGM patients (14 CD40 L and 3 AID deficiencies and 2 unsolved cases without known genetic defects) and 17 control subjects (10 healthy subjects as negative control group, 7 ataxia-telangiectasia patients as positive control group) were enrolled. G2 assay was carried out for the determination of radiosensitivity.

Results

Based on radiation-induced chromosomal changes among the studied HIGM patients and their comparison with the controls, almost all (95%) the patients had degrees of radiosensitivity: 6 patients with low to moderate, 1 patient with moderate, 11 patients with severe and 1 patient without radiation sensitivity.

Conclusion

Today, X-ray radiation plays a very important role in diagnostic and therapeutic procedures; while increased exposure has devastating effects especially in radiosensitive patients. Considering higher sensitivity in HIGM patients, utilizing radiation-free techniques could partly avoid unnecessary and high-level exposure to radiation, thus preventing or reducing its harmful effects on the affected patients.

中文翻译：

---

高 IgM 综合征患者辐射敏感性评估

摘要

背景

HIGM 综合征是一种罕见的原发性免疫缺陷，其特征是血清 IgM 量正常/增加，以及其他转换免疫球蛋白类别的血清水平降低。由于受影响的患者不断感染各种类型的病原体并且易患癌症，因此建议对这些患者进行诊断和治疗测试，包括成像技术，这会使他们容易受到更高的累积辐射剂量。鉴于类别转换重组机制缺陷的证据及其与 DNA 修复率增加的关联，我们旨在评估一组诊断为 HIGM 综合征的患者的辐射敏感性。

方法

入组19例HIGM患者（14例CD40L和3例AID缺陷，2例无已知遗传缺陷的未解决病例）和17例对照组（10例健康受试者为阴性对照组，7例共济失调毛细血管扩张症患者为阳性对照组）。进行 G2 测定以测定放射敏感性。

结果

根据所研究的 HIGM 患者中辐射诱导的染色体变化及其与对照组的比较，几乎所有 (95%) 患者都有放射敏感性：6 例低至中度患者，1 例中度患者，11 例重度患者和 1 例患者对辐射不敏感的病人。

结论

今天，X 射线辐射在诊断和治疗过程中发挥着非常重要的作用。而增加的暴露具有毁灭性的影响，尤其是对放射敏感的患者。考虑到 HIGM 患者的更高敏感性，使用无辐射技术可以部分避免不必要的高水平辐射暴露，从而防止或减少其对受影响患者的有害影响。