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| Sponsored by: |
National Institute of Allergy and Infectious Diseases (NIAID) |
|---|---|
| Information provided by: | National Institutes of Health Clinical Center (CC) |
| ClinicalTrials.gov Identifier: | NCT00719719 |
Purpose
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:
| Condition |
|---|
|
Anaphylaxis |
| Study Type: | Observational |
| Study Design: | Prospective |
| Official Title: | Studies in the Pathogenesis of Idiopathic Anaphylaxis |
| Estimated Enrollment: | 100 |
| Study Start Date: | July 2008 |
Anaphylaxis is a severe life-threatening systemic hypersensitivity reaction resulting from the release of mediators from mast cells and basophils, and is characterized by the presence of cutaneous, respiratory, cardiovascular, or gastrointestinal signs and symptoms. Although the most common causes of anaphylaxis are reactions to foods, pharmaceutical agents, and stinging insects, a causative factor is not identified in up to 50% of individuals with recurrent anaphylaxis. These individuals are thus said to have idiopathic anaphylaxis (IA). The mechanistic cause of IA remains uncertain, although elevated levels of urinary histamine, plasma histamine, and serum tryptase are consistent with mast cell activation.
This protocol will focus on the pathogenesis of IA. Adults subjects with frequent episodes of unexplained anaphylaxis will be evaluated in order to correlate both clinical and laboratory features that are typical of idiopathic anaphylaxis to identify genetic and molecular pathways that may predispose to these events and to determine signaling abnormalities in mast cells. We plan to enroll up to 100 subjects in this study. We anticipate that our findings will be a first step toward the development of novel targeted therapies.
Eligibility| Ages Eligible for Study: | 16 Years to 55 Years |
| Genders Eligible for Study: | Both |
| Accepts Healthy Volunteers: | No |
Subject must be at least 16 years of age and no older than 55 years of age.
Diagnosis of IA is a diagnosis of exclusion that is made only after other causes of anaphylaxis and other differential diagnoses have been considered and rejected.
Documented history of anaphylaxis that occurs at least 3-6 times per year with at least 1 event per quarter and with 1 of the following documented on at least 1 occasion (with in the last three years):
Emergency room visit or hospitalization with documented anaphylaxis without etiology established; with involvement of the skin, mucosal tissue, or both (e.g., generalized hives, pruritus, or flushing, swollen lips-tongue-uvula) and at least one of the following:
Letter of referral, with copies of pertinent medical history and laboratory studies, from prospective study participant's referring physician.
Ability to give informed consent.
Willing to donate blood for sample storage to be used for future research.
EXCLUSION CRITERIA:
Presence of conditions which in the judgment of the investigator or the referring physician may put the subject at undue risk for travel (including frequent episodes of IA not preventable by pre-medication, acute infection, severe thrombocytopenia [minimum platelet count of 30,000], or significant cardiovascular disease)
Any condition that in the view of the principal investigator would make the subject unsuitable for enrollment in this study
Use of beta blockers
Inability to provide informed consent
Inability or refusal to undergo a bone marrow biopsy and aspirate
History of HIV positive or other known immunodeficiency
History or evidence of chronic Hepatitis B and/or C infection
Known cause for anaphylaxis
Contacts and Locations| Contact: Patient Recruitment and Public Liaison Office | (800) 411-1222 | prpl@mail.cc.nih.gov |
| Contact: TTY | 1-866-411-1010 |
| United States, Maryland | |
| National Institutes of Health Clinical Center, 9000 Rockville Pike | Recruiting |
| Bethesda, Maryland, United States, 20892 | |
More Information
| Study ID Numbers: | 080184, 08-I-0184 |
| Study First Received: | July 19, 2008 |
| Last Updated: | December 24, 2008 |
| ClinicalTrials.gov Identifier: | NCT00719719 |
| Health Authority: | United States: Federal Government |
|
Mast Cell Tryptase Bone Marrow |
Hives Adult Anaphylaxis |
|
Hypersensitivity Anaphylaxis Hypersensitivity, Immediate Urticaria |
|
Immune System Diseases |
