EPIC Study

Study Name

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

Study Number

09-I-0102

Goal of Study

The primary objective of this study is to further characterize the natural history of idiopathic CD4 lymphocytopenia (ICL) while also investigating the genetic, environmental, and immunologic features of the condition. During your participation in this study, we will be collecting your blood in order to study the numbers and function of your CD4 lymphocytes and other immune cells. We will also be studying your microbiome (the community or group of organisms or germs that live on the skin or inside the body.)

ICL is a condition where a person has a decreased number of a type of white blood cells called CD4 lymphocytes. The immune system contains white blood cells that fight against infections and low levels of CD4 lymphocytes may make a person more likely to develop opportunistic infections (infections that occur when the immune system is not working well). We do not know what causes ICL. We do not fully understand why some ICL patients develop opportunistic infections while other ICL patients do not. Some patients with ICL develop autoimmune disorders. An autoimmune disorder is caused by the immune system's inability to recognize the body's own cells and tissues, and thus treats them as an invading organism by attacking them. We do not know why patients with ICL develop autoimmune disorders more frequently than healthy individuals.

Study Regimen

About 200 ICL patients (ages 18 and up) will take part in this study along with about 100 blood relatives and 100 household contacts of ICL subjects. Study visits will include physical exams, blood tests, and genetic testing, among other procedures. Participants will be seen annually, for up to 10 years. Volunteers will be compensated.

Eligibility Criteria

  • You are age 18 years or older
  • You have a documented history of Idiopathic CD4 Lymphocytopenia (ICL) with a t-cell count of <300 at least twice, at least six weeks apart
  • You are HIV-negative
  • You have a primary care provider
  • You do not have any difficulty having blood drawn
  • You do not have any form of cancer
  • If female, you are not currently breast feeding, pregnant, or planning to get pregnant in the near future
  • You agree to have genetic testing