Clinical Trial Summary
Background:
- Mast cells are responsible for most symptoms of allergic reactions. In some allergic
diseases, it is unusually easy to cause mast cells to release their contents and cause
allergic reactions. In other cases, mast cells grow abnormally and, in rare cases, can
result in tumors. Mast cells also control other parts of the immune system.
- Understanding why mast cells behave abnormally in allergic diseases is important to
finding better ways for diagnosing and treating these potentially life-threatening
disorders.
Objectives:
- To screen mast cells at the genetic and functional levels to characterize abnormalities,
identify mutations, detect carrier states, and/or develop therapies for such disorders.
- To create a library of information about inherited diseases of mast cell homeostasis and
activation, including piebaldism (problems with skin and hair pigmentation), anaphylaxis
(severe allergic reaction), allergies, asthma, atopic dermatitis (eczema), allergic
rhinitis ( hay fever ), food allergies, urticaria/angioedema (hives/swelling),
immunodeficiency diseases, and autoimmune diseases.
Eligibility:
- Patients between the ages of 1 and 80 years who have been referred by a physician and
are known to have or be suspected of having an inherited disorder of mast cells, in
particular patients (and their relatives) with piebaldism, allergies, or anaphylaxis
that is not caused by allergies.
Design:
- Study population will consist of up to 1000 participants in a 5-year period. One third
of the study population will consist of patients; the other two thirds will consist of
biological relatives.
- Evaluation is limited to testing on blood specimens; no treatment will be provided.
- Clinical and research laboratory evaluations of patients will include the following:
- Clinical evaluation and previous laboratory tests as documented in outside medical
records by health care providers. A standard questionnaire will also be administered at
the time of subject enrollment.
- Blood collection for clinical laboratory testing, tailored to each subject s clinical
evaluation where appropriate (5 ml).
- Blood collection for research laboratory testing, tailored to each subject s clinical
evaluation including genetic screening and assessment of mast cell growth and
functioning and storage of additional frozen blood specimens for future studies (up to
an additional 30 ml).
- Evaluations of blood relatives will include the following:
- Clinical evaluation as documented from outside medical records by health care providers
and administration of a standard questionnaire.
- Blood collection where indicated for diagnostic or research purposes.
- After 12 consecutive months on the study, results from initial evaluation will be
reviewed. Subjects with findings deemed to be of continued interest will be contacted
and invited to remain as active participants to this protocol for another year, provided
that they renew their consent to participate.
This protocol is designed to screen subjects (and some family members) with suspected or
identified genetic diseases of allergic inflammation or mast cell homeostasis and activation.
Patients determined by clinical history and initial outside evaluation by their referring
physician to be of interest will be consented and enrolled into this study. Blood specimens,
stored blood products and derivatives, saliva, hair, fingernail clippings, cord blood,
umbilical cord, and/or buccal swabs from such patients and/or their family members will be
obtained for research studies related to understanding the genetic and biochemical bases of
these diseases. Outside medical records may be obtained for chart review to correlate
clinical history to research laboratory testing results. Results will be relayed to the
referring physicians and, where applicable, patients will be referred to other appropriate
NIH protocols for additional clinical evaluation and treatment. The study will enroll up to
1000 subjects and family members.