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

2 Years
Open (Enrolling)
Idiopathic CD4+ Lymphocytopenia, Cryptococcal Meningitis, Warts

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Trial Information

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

Idiopathic CD4+ lymphocytopenia (ICL) is a disorder characterized by decreased numbers of
circulating CD4+ T lymphocytes in the absence of known causes of CD4+ lymphocytopenia. ICL
is defined as an absolute CD4+ T cell count of less than 300 cells/mL in a patient with no
human immunodeficiency virus infection or known immunodeficiency syndrome. The causes and
frequency of the disorder remain unknown. The condition is typically diagnosed when patients
present with a serious infection. In this natural history protocol, we will evaluate
patients with CD4+ T cell counts below 300 cells/microL. We propose to follow 100 patients
for a minimum of 4 and maximum of 10 years, with a particular focus on the association
between ICL and autoimmune disease. We will collect blood for immunologic, rheumatologic,
and genetic testing in an effort to identify and understand the underlying defects that
cause ICL and follow its course in a cohort of patients who will receive best standard
therapy for opportunistic infections.

Inclusion Criteria


To be eligible for this study, patients must satisfy all of the following inclusion

- Age greater than or equal to 2 years

- Absolute CD4 count < 300 cells/microL or < 20% of total T cells in children greater
than or equal to 6 years old and adults on at least two occasions at least 6 weeks
apart; or CD4+ percentage < 20% of normal on 2 occasions at least 6 weeks apart in
children < 6 years old

- Ongoing care by a referring primary care physician

- Willingness to allow storage of blood and tissue samples for future analysis


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 ELISA and Western blot and/or viral load testing

- Known underlying immunodeficiency syndrome

- 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.

Type of Study:


Study Design:

Time Perspective: Prospective

Principal Investigator

Kathryn J Sowerwine, M.D.

Investigator Role:

Principal Investigator

Investigator Affiliation:

National Institute of Allergy and Infectious Diseases (NIAID)


United States: Federal Government

Study ID:




Start Date:

March 2009

Completion Date:

Related Keywords:

  • Idiopathic CD4+ Lymphocytopenia
  • Cryptococcal Meningitis
  • Warts
  • Idiopathic Lymphocytopenia
  • Opportunistic Infection
  • Immunodeficiency Syndrome
  • Autoimmune Disease
  • CD4+ Lymphocytes
  • Idiopathic CD4 Lymphocytopenia
  • Lymphopenia
  • Meningitis
  • Meningitis, Cryptococcal



National Institutes of Health Clinical Center, 9000 Rockville Pike Bethesda, Maryland  20892