Cause of Unexplained Anaphylaxis
|First Submitted Date||July 19, 2008|
|First Posted Date||July 22, 2008|
|Last Update Posted Date||October 19, 2017|
|Start Date||July 18, 2008|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures
|Original Primary Outcome Measures||Not Provided|
|Change History||Complete list of historical versions of study NCT00719719 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures||Not Provided|
|Original Secondary Outcome Measures||Not Provided|
|Current Other Outcome Measures||Not Provided|
|Original Other Outcome Measures||Not Provided|
|Brief Title||Cause of Unexplained Anaphylaxis|
|Official Title||Studies in the Pathogenesis of Idiopathic Anaphylaxis|
This study will explore the possible cause of unexplained, or idiopathic, anaphylaxis. Anaphylaxis is a rapid, life-threatening, severe reaction that occurs suddenly after contact with an allergy-causing substance, usually a particular food, drug or stinging insect. The allergen triggers mast cells to release several substances, including histamine. Histamine is responsible for many of the symptoms that may occur, such as flushing, hives, swelling of the palms and soles or tongue and vocal cords, nasal congestion, itching and tearing of the eyes, shortness of breath and wheezing, stomach pain, vomiting, low blood pressure, loss of consciousness, shock, and, rarely, death. Severe episodes of anaphylaxis are treated with epinephrine (adrenaline), followed by oral antihistamines and steroids. In more than half of cases of anaphylaxis, a clear cause is not identified. These cases are called idiopathic anaphylaxis. There is no cure or long-term preventive therapy for patients with recurrent episodes of idiopathic anaphylaxis.
People between 18 and 55 years of age who have idiopathic anaphylaxis episodes at least 6 times a year (with at least one episode every 3 months) may be eligible for this study.
Participants are evaluated at the NIH Clinical Center with the following tests and procedures:
Anaphylaxis is a severe life-threatening systemic hypersensitivity reaction caused by release of mediators from mast cells and basophils, characterized by cutaneous, respiratory, cardiovascular, or gastrointestinal signs and symptoms. The most common specific causes of anaphylaxis are venom, drug, and food allergies (i.e. patients with specific anaphylaxis, SA), When a causative factor is not identified in patients are said to have idiopathic anaphylaxis (IA). Evidence of an underlying clonal mast cell disease has been found in about I in 15 patients with IA in our studies and in about 1 in 12 patientswith venom induced anaphylaxis in a European study. (1) The number of patients with anaphylaxis to foods or drugs who have a clonal mast cell disease is not known and the number or patients with venom induced anaphylaxis in the US with clonal mast cell disease has not been determined. Thus, a more complete understanding of the prevalence of clonal mast cell disease in those experiencing anaphylaxis and a better understanding of the associated laboratory abnormalities and disrupted molecular signaling pathways will have a substantial impact of the clinical management of patients who present with anaphylaxis.
This protocol thus focuses on determining the prevalence of clonal mast cell disorders in patients with the anaphylaxis, whether unexplained (IA) or associated with exposure to an antigen (SA), and attendant changes in the mast cell compartment. Subjects 13 - 70 years old will be evaluated to correlate both clinical and laboratory features of anaphylaxis and to identify genetic and molecular pathways that may predispose to these events. Subjects may undergo bone marrow examination in addition to supporting laboratory studies when indicated. We plan to enroll up to 200 subjects.
|Study Design||Observational Model: Case-Only
Time Perspective: Prospective
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Study Groups/Cohorts||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Completion Date||Not Provided|
|Primary Completion Date||Not Provided|
|Ages||13 Years to 60 Years (Child, Adult)|
|Accepts Healthy Volunteers||No|
|Listed Location Countries||United States|
|Removed Location Countries|
|Other Study ID Numbers||080184
|Has Data Monitoring Committee||Not Provided|
|U.S. FDA-regulated Product||Not Provided|
|IPD Sharing Statement||Not Provided|
|Responsible Party||National Institutes of Health Clinical Center (CC) ( National Institute of Allergy and Infectious Diseases (NIAID) )|
|Study Sponsor||National Institute of Allergy and Infectious Diseases (NIAID)|
|PRS Account||National Institutes of Health Clinical Center (CC)|
|Verification Date||October 3, 2017|