Histamine Responsiveness in Patients With McCune-Albright Syndrome
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 22
- 试验地点
- 1
研究概览
简要总结
McCune-Albright syndrome (MAS) is a syndrome caused by a genetic mutation that causes a specific protein in the body called a G protein to be constantly active. Children with McCune-Albright syndrome classically have early puberty, areas of increased skin pigmentation, and bone lesions resulting from the constant activity of the specific protein involved.
Histamines are known to play a role in allergies and related allergic problems. The effects of histamines are controlled by the same G protein that is overly active in McCune-Albright syndrome. Thus, one could predict that patients with McCune-Albright may be at high risk for allergic problems. To date, no studies have documented any form of histamine excess or allergic difficulties in patients with McCune-Albright syndrome. However, the investigators have made the observation that a high percentage of their patients with MAS exhibit a range of allergic symptoms, from mild symptoms, to severe, life-threatening symptoms.
The purpose of this study is to demonstrate increased histamine response by using a histamine skin test in patients with MAS. If increased reactions to histamines can be documented in MAS patients when compared to controls, severe and potentially life threatening allergic reactions in children with MAS could be anticipated and avoided.
详细描述
Objectives of this study are to determine if:
- Patients with McCune-Albright syndrome differ from unaffected controls in wheal and flare response to histamine and codeine.
- Affected skin will differ from unaffected skin in wheal and flare response to histamine and codeine.
- IgE and IL-4 levels in MAS patients differ from normal controls.
Specific Aims:
- Compare the skin response of MAS patients to normal controls using standard histamine and codeine skin testing.
- Compare skin testing response in MAS patients with known standards for skin testing. Compare response to histamine and codeine skin testing in MAS patient's affected (café-au-lait) skin to unaffected (normal) skin.
- Compare IgE and IL-4 levels in patients with MAS to controls.
Background:
研究设计
- 研究类型
- Observational
- 观察模型
- Case Control
- 时间视角
- Prospective
入排标准
- 年龄范围
- — 至 39 Years（Child, Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Children with MAS ranging from toddlers to young adults.
- •Diagnosis of MAS will be made on a clinical basis. Blood testing is not helpful in this condition, as bone marrow progenitor cells with the Gαs mutation display a survival disadvantage. All patients are mixed chimeras, as this mutation is lethal if it occurs in germline cells.
- •Patients who exhibit two or more of the following clinical findings fit the diagnosis of MAS:
- •GnRH independent precocious puberty
- •Polyostotic fibrous dysplasia
- •Café-au-lait spots with coast of Maine borders and respect for the midline.
- •Non-autoimmune hyperthyroidism.
- •Ten controls will also be recruited from family members of patients with MAS with no known allergies. An additional control group of ten unrelated subjects, also with no known allergies, will be recruited from the Endocrine Clinic for comparison.
排除标准
- •Any MAS patient or control who has not, or cannot, discontinue(d) any home regimens of antihistamines or glucocorticoids (including inhaled steroids) at least seven days prior to skin testing.
- •Any MAS patient or control on tricyclic antidepressants within two weeks prior to skin testing.