NCT00001406 · National Institute of Allergy and Infectious Diseases (NIAID)
Activation and Function of Eosinophils in Conditions With Blood or Tissue Eosinophilia
What this study is about
This study will investigate how, why and under what conditions eosinophils (a type of white blood cell) become activated and will examine their function in immune reactions. Eosinophil counts often rise in response to allergies, asthma, and parasitic worm infections. They can also go up in uncommon autoimmune conditions and, rarely, in association with tumors.
View original scientific description
This study will investigate how, why and under what conditions eosinophils (a type of white blood cell) become activated and will examine their function in immune reactions. Eosinophil counts often rise in response to allergies, asthma, and parasitic worm infections. They can also go up in uncommon autoimmune conditions and, rarely, in association with tumors. Elevated levels of these cells is called eosinophilia. Usually, eosinophilia causes no apparent symptoms, but in rare cases there may be local swelling and itching, allergic lung problems, heart disease or nerve damage caused by the release of toxic substances in these cells into body tissues. Patients 1 to 100 years of age with eosinophil counts greater than 750/ml or an abnormal accumulation of eosinophils in the skin or body tissues may be eligible for this study. All participants will have a thorough medical history, physical examination and blood tests. Depending on the person's age and symptoms, other diagnostic tests may be done, including specialized studies of the eye, lungs, skin, bone marrow, nerves or heart. This is not a treatment study, and no experimental treatments will be offered. Patients who require treatment will receive standard medical care. Certain other procedures may be requested solely for research purposes. All participants will be asked to donate extra blood for laboratory studies investigating how immune cells and other immune substances in the blood act to stimulate a rise in eosinophils. In addition, some participants may undergo one or more of the following: * Annual Follow-up evaluations - Physical examinations and blood tests to evaluate changes in the patient's condition and eosinophil counts over time. * Bone marrow biopsy and aspiration will be recommended during the initial evaluation, and in certain patients at other times when it is important to look directly at the newly developing cells in the bone marrow. For this procedure an area of skin and bone is anesthetized with xylocaine (an anesthetic similar to that used by dentists), and a very sharp needle is used to sample the bone marrow for evaluation. Bone marrow biopsy and aspiration can have side effects of pain and/or bleeding into the skin and soft tissues at the site of the procedure. Rarely the area at the biopsy site can become infected, and is treated with antibiotics. * Genetic testing: Some of the blood drawn from you as part of this study will be used for genetic tests. Genetic tests can help researchers study how health or illness is passed on to you by your parents or from you to your children. Any genetic information collected or discovered about you or your family will be confidential. * Leukapheresis (only patients 18 years and older) to collect large numbers of certain cells - In this procedure, whole blood is collected through a needle placed in an arm vein. The blood circulates through a machine that separates it into its components. The white cells are then removed and the rest of the blood is returned to the body, either through the same needle used to draw the blood or through a second needle placed in the other arm....
Primary outcome measures
To understand the mechanisms driving eosinophilia and disease pathogenesis in patients with a wide range of eosinophilic disorders
Time frame: Ongoing assessment
Identification and characterization of clinical and genetic variants of hypereosinophilic syndromes.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- To be eligible to participate in this study, an individual must meet all of the following criteria:
- Stated willingness to comply with all study procedures and availability for the duration of the study
- Male or female, aged 1-100
- Ability of subject (or Legally Authorized Representative (LAR)) to understand and sign a written informed consent document Eosinophilic Patients only:
- Documented peripheral blood count \>1500/mm3, tissue eosinophilia (abnormal accumulation of eosinophils in the skin or other body tissues) or suspected eosinophilic end organ involvement
- Primary (non-NIH) physician for routine medical care Relatives only:
- Extended family member of an eosinophilic participant on this protocol
Exclusion criteria
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Any condition(s) or diagnosis, physical and/or psychological, that the investigator feels precludes the patient from participation in the study. Relatives only:
- Females must not be pregnant
Where
- Bethesda, Maryland
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 10, 2026 · Source of record for eligibility and locations