NCT00867269 · National Institute of Allergy and Infectious Diseases (NIAID)
Etiology, Pathogenesis, and Natural History of Idiopathic CD4+ Lymphocytopenia
What this study is about
Background: * Idiopathic CD4+ lymphocytopenia (ICL) is a condition in which there is a decreased level of CD4+ lymphocytes (a type of white blood cell), which can lead to opportunistic infections or autoimmune disorders and diseases. Objectives: * To characterize the natural history with regard to CD4+ T cell count and onset of infection, malignancy, and autoimmunity.
View original scientific description
Background: * Idiopathic CD4+ lymphocytopenia (ICL) is a condition in which there is a decreased level of CD4+ lymphocytes (a type of white blood cell), which can lead to opportunistic infections or autoimmune disorders and diseases. Objectives: * To characterize the natural history with regard to CD4+ T cell count and onset of infection, malignancy, and autoimmunity. * To describe the immunological status of patients affected by ICL while providing the best possible standard therapy to eradicate opportunistic infections. * To establish the timeline of CD4 lymphocytopenia, with particular focus on defining subgroups of patients according to the decline, stabilization, or rise of CD4+ T cell counts over time. * To characterize the opportunistic infections that occur in ICL patients at microbiologic and molecular levels. * To characterize the immunophenotype and possible genetic immunodeficiency causes of ICL. * To determine whether measurable immunologic parameters correlate with the development of opportunistic infections or other comorbidities such as lymphoma in patients with ICL. * To determine whether there is any association between ICL and autoimmunity. * To determine CD4+ T cell turnover, survival, functionality, and cytokine responsiveness in ICL patients. Eligibility: * Patients 2 years of age and older with an absolute CD4 count less than 300 in children 6 years or older and adults or less than 20% of T cells in children younger than 6 on two occasions at least 6 weeks apart. * Patients with negative results of HIV testing by ELISA, Western Blot, and viral load. * Patients must not have underlying immunodeficiency conditions, be receiving cytotoxic chemotherapy (anti-cancer drugs that kill cells), or have cancer. Design: * At the initial visit to the National Institutes of Health, the following evaluations will be conducted: * Personal and family medical histories. * Physical examination, including rheumatology evaluation and other consultations as medically indicated (e.g., dermatology, pulmonology, ophthalmology, imaging studies). * Blood samples for analysis of red and white blood cell counts, liver function, immune hormones, and antibody and autoantibody levels, white blood cell growth and function, and DNA. * Urinalysis and urine pregnancy testing for female patients of childbearing age. * Evaluation and treatment of active infections as medically indicated, including biopsies, buccal swabs, pulmonary function tests, and imaging studies. * Follow-up visits will take place approximately every 12 months or more frequently if indicated, and will continue for a minimum of 4 years and a maximum of 10 years. * Evaluations at follow-up will include blood samples (i.e., CBC with differential, biochemical profile, HIV testing, etc.) and urinalysis and rheumatology consults.
Primary outcome measures
CD4 <300/microliters or < 20% of total T cells and their blood
Time frame: Baseline and annually
To further characterize the natural history of ICL while also investigating the genetic, environmental, and immunologic features of the condition.
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 for this study, patients must satisfy all of the following inclusion criteria:
- Age greater than or equal to 18 years
- Absolute CD4 count \< 300 cells/microL or \< 20% of total T cells on at least two occasions at least 6 weeks apart
- Ongoing care by a referring primary care physician
- Willingness to allow storage of blood and tissue samples for future analysis ICL PARTICPANT
Exclusion criteria
- Patients will be ineligible for this study if they satisfy any of the following criteria:
- Known infection with HIV-1, HIV-2, or human T-cell lymphotropic viruses (HTLV-1 or HTLV-2) as demonstrated by enzyme-linked immunosorbent assay (ELISA) and western blot and/or viral load testing
- Known underlying immunodeficiency syndrome other than ICL
- Evidence of active malignancy
- Receipt of medications, herbal substances, or biologic agents known to diminish the CD4+ count within 30 days of when the CD4+ lymphocytopenia was detected
- Any condition that in the judgment of the investigators would place the subject at undue risk or compromise the results of the study. BLOOD RELATIVE INCLUSION CRITERIA: To be eligible for study participation as a blood relative, subjects must be greater than or equal to 18 years of age and be a blood relative of an individual who meets or has met the CDC criteria for ICL. HOUSEHOLD CONTACT INCLUSION CRITERIA: To be eligible for study participation as a household contact, subjects must be greater than or equal to18 years of age and live within the same household as an ICL subjects participating in this protocol. Blood relatives who are household contacts are eligible to participate.
Where
- Bethesda, Maryland
Related conditions & keywords
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