Idiopathic CD4 Lymphocytopenia: A Case Report and Literature Review.

Idiopathic CD4 lymphocytopenia (ICL) is a rare condition where CD4 T cell counts are low, similar to advanced human immunodeficiency virus (HIV) infection but without acquired immunodeficiency syndrome (AIDS)-related symptoms. The cause is unknown, and theories suggest issues with T cell production, survival, migration, or immune system dysregulation. Diagnosis involves ruling out other causes of low CD4 T cells.