Etiology, Pathogenesis, and Natural History of Idiopathic CD4+ Lymphocytopenia

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.

Conditions

Idiopathic CD4+ Lymphocytopenia, Cryptococcal Meningitis, Warts

Study Overview

Study Details

Study overview

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.

Etiology, Pathogenesis, and Natural History of Idiopathic CD4+ Lymphocytopenia

Etiology, Pathogenesis, and Natural History of Idiopathic CD4+ Lymphocytopenia

Condition
Idiopathic CD4+ Lymphocytopenia
Intervention / Treatment

-

Contacts and Locations

Bethesda

National Institutes of Health Clinical Center, Bethesda, Maryland, United States, 20892

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

For general information about clinical research, read Learn About Studies.

Eligibility Criteria

  • 1. 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
  • 2. Known underlying immunodeficiency syndrome other than ICL
  • 3. Evidence of active malignancy
  • 4. Receipt of medications, herbal substances, or biologic agents known to diminish the CD4+ count within 30 days of when the CD4+ lymphocytopenia was detected
  • 5. Any condition that in the judgment of the investigators would place the subject at undue risk or compromise the results of the study.

Ages Eligible for Study

18 Years to

Sexes Eligible for Study

ALL

Accepts Healthy Volunteers

Yes

Collaborators and Investigators

National Institute of Allergy and Infectious Diseases (NIAID),

Irini Sereti, M.D., PRINCIPAL_INVESTIGATOR, National Institute of Allergy and Infectious Diseases (NIAID)

Study Record Dates

N/A