Idiopathic CD4+ Lymphocytopenia - Diagnosis

Diagnosis

The mandatory criteria for diagnosis of idiopathic CD4+ lymphocytopenia include:

• Low numbers of CD4+ cells, on two or more measurements over at least six weeks:
  • CD4 cell count less than 300 cells per microliter, or
  • Less than 20% of T lymphocytes are CD4+
• Lack of laboratory evidence of HIV infection
• Absence of any alternative explanation for the CD4 lymphocytopenia

A one-time finding of low CD4+ cells is usually associated with a recent infection and resolves on its own. Alternative explanations for the low CD4 counts include conditions such as blood cancers (aleukemia), treatment with chemotherapy, immunosuppressive medications, or other medications that suppress or kill T cells, infections, and problems with blood production.

All criteria must be fulfilled for a diagnosis of ICL. Additionally, if these findings are present, but combined with other significant findings, such as anemia or thrombocytopenia, then other diagnoses must be considered.