Test Background Enumeration of peripheral blood T-cells (CD3, CD4, CD8), B-cells (CD19) and NK cells (CD56). Other lymphocyte surface markers can also be enumerated. HIV positive patients may have reduced T-helper (CD4) lymphocytes or a reduced T-helper: T-suppressor (CD8) cell ratio, usually in conjunction with an absolute lymphocytopenia. This test is now recommended as an early indicator of the development of AIDS in HIV positive subjects. It is not specific for HIV infection and other viral conditions, non-Hodgkin’s Lymphoma, SLE and sarcoidosis may also be associated with a low count.
Clinical Indications Early indicator of the development of AIDS in HIV positive subjects.
Reference RangeAdult ranges (>18 years) CD3+ T lymphocytes Percentage 55-83 CD3+ T lymphocytes Absolute 700-2100 CD3+/CD4+ T lymphocyte Percentage 28-57 CD3+/CD4+ T lymphocyte Absolute 300-1400 CD3+/CD8+ T lymphocyte Percentage 10-39 CD3+/CD8+ T lymphocyte Absolute 200-900 CD19+ B lymphocyte Percentage 6-19 CD19+ B lymphocyte Absolute 100-500 CD3-/CD16-CD56+ NK cells Percentage 7-31 CD3-/CD16-CD56+ NK cells Absolute 90-600 Absolute Lymphocytes 1000-2800 NB values for children vary according to age
Sample Required EDTA (lavender top) Do not separate or refrigerate Test within 24 hours Please label ‘risk specimen’ if HIV positive
Sample Volume 3 mL
Turnaround Time 3 days
NotesPlease discuss with the Immunology laboratory on ext. 10130.