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CD4 Cell Count

  • CD4 cells are a subset of T lymphocytes (helper T cells), which are part of the body’s defense against fungal, viral, and parasitic infections and exhibit some control over neoplastic growth.
  • The normal CD4 cell count range is approximately 500 – 1500 cells/mm³.
  • A drop in CD4 cell count indicates immune system deterioration.
  • A CD4 cell count below 200 cells/mm³ is considered severe immune suppression.
  • When the CD4 cell count drops below 200 cells/mm³, a patient will start to receive prophylaxis against certain opportunistic infections, such as Pneumocystis jerovecil pneumonia, formerly called Pneumocystis carinii pneumonia (PCP).
  • A CD4 cell count below 200 cells/mm³ is a definition of AIDS.
  • The development of oral lesions is associated with a decreased CD4 cell count.

HIV infection stage, based on age-specific CD+ T-lymphocyte count or CD4+ T-lymphopcyte percentage of total lymphocyte count#

Age on date of CD4 T-lymphocyte test
<1 year1-5 years6 years through adult
3 <750 <26 <500 <22 <200 <14
The stage is based primarily on the CD4+ T-lymphocyte count; the CD4+ T-lymphocyte count takes precedence over the CD4 T-lymphocyte percentage, and the percentage is considered only if the count is missing.

Related Pages#