This observational study aims to better understand Idiopathic CD4+ Lymphocytopenia (ICL), a condition where you have low levels of CD4+ lymphocytes (a type of white blood cell) without a known cause. Researchers want to learn about the natural course of ICL, including changes in CD4+ T cell counts and the development of infections, cancers, or autoimmune diseases. They also want to understand the immune system in people with ICL and identify the underlying causes. You may be eligible if you are 18 or older and have a CD4 count below 300 cells/microliter or less than 20% of total T cells on at least two occasions. The study will measure your CD4 levels at the start and annually to see how they change over time. The study status is currently unclear.

Study design

This is an observational study planning to enroll up to 950 participants, including people with ICL, their blood relatives, and household contacts.

What's involved

Participants will have their blood collected for immunologic, rheumatologic, and genetic testing. You will be followed for a minimum of 4 and a maximum of 20 years, with annual CD4 measurements.

Compensation

Not stated in the trial record.

Follow-up

Participants will be followed for a minimum of 4 and a maximum of 20 years after enrollment.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.