For Ages under 1 Year.
In the setting of infants <12 months of age with a known HIV infection, the revised CDC classification system
[MMWR 1994;43 (No. RR-12): pg 4] has defined three CD4+ T-Lymphocyte categories:
    Category 1: >/= 1,500 cells/mm3 is considered No Evidence of Suppression.
    Category 2: 750-1,499 cells/mm3 is considered Moderate Evidence of Suppression.
    Category 3: < 750 cells/mm3 is considered Severe Suppression.
These categories as well as the clinical setting have been utilized for therapeutic decisions regarding antiretroviral therapy and prophylaxis against infectious agents. Interpretation must always take into account the patient's clinical picture. The CD4+ cell count is one good short term predictor for the development of opportunistic infections. However, the trend in CD4+ cell levels is more important than any single value. In addition, it must be remembered that in interpreting CD4+ counts a component of diurnal variation must always be taken into account. Also, note that CD4+ counts as an isolated test should never be used as a surrogate marker for HIV infection. Finally, the percentage of CD4+ lymphocytes may be useful when interpreted in conjunction with the CD4+ lymphocyte count.

For Ages 1-5 Years.
In the setting of children 1-5 years of age with a known HIV infection, the revised CDC classification system
[MMWR 1994;43 (no. RR-12): pg 4] has defined three CD4+ T-Lymphocyte categories:
    Category 1: >/= 1,000 cells/mm3 is considered No Evidence of Suppression.
    Category 2: 500-999 cells/mm3 is considered Moderate Evidence of Suppression.
    Category 3: < 500 cells/mm3 is considered Severe Suppression.
These categories as well as the clinical setting have been utilized for therapeutic decisions regarding antiretroviral therapy and prophylaxis against infectious agents. Interpretation must always take into account the patient's clinical picture. The CD4+ cell count is one good short-term predictor for the development of opportunistic infections. However, the trend in CD4+ cell levels is more important than any single value. In addition, it must be remembered that in interpreting cd4 counts a component of diurnal variation must always be taken into account. Also, note that CD4+ counts as an isolated test should never be used as a surrogate marker for HIV infection. Finally, the percentage of CD4+ Lymphocyte s may be useful when interpreted in conjunction with the CD4+ Lymphocyte count.

For Ages 6 - 12 Years.
In the setting of children 6-12 years of age with a known HIV infection, the revised CDC classification system
[MMWR 1994;43 (No. RR-12): pg 4] Has defined three CD4+ T-Lymphocyte Categories:
    Category 1: >/= 500 cells/mm3 is considered No Evidence of Suppression.
    Category 2: 200 - 499 cells/mm3 is considered Moderate Evidence of Suppression.
    Category 3: < 200 cells/mm3 is considered Severe Suppression.
These categories as well as the clinical setting have been utilized for therapeutic decisions regarding antiretroviral therapy and prophylaxis against infectious agents. Interpretation must always take into account the patient's clinical picture. The CD4+ cell count is one good short-term predictor for the development of opportunistic infections. However, the trend in CD4+ cell levels is more important than any single value. In addition, it must be remembered that in interpreting CD4+ counts a component of diurnal variation must always be taken into account. Also, note that CD4+ counts as an isolated test should never be used as a surrogate marker for HIV infection. Finally, the percentage of CD4+ Lymphocytes may be useful when interpreted in conjunction with the CD4+ Lymphocyte count.

For ages 12 years and Older
The absolute CD4+ (helper) lymphocyte count is one indicator of immunocompetence.
As a general rule, in patients >12 years of age having CD4+ Lymphocyte levels of:
   > 500 cells/mm3 are considered Immunocompetent.
   400 - 500 cells/mm3 are considered Borderline Immunocompetent.
   200 - 400 cells/mm3 are considered Immunosuppressed.
   < 200 cells/mm3 are considered Immunodeficient.
Interpretation must always take into account the patient's clinical picture. The CD4+ cell count is one good short-term predictor for the development of opportunistic infections. However, the trend in CD4+ cell levels is more important than any single value. In addition, it must be remembered that in interpreting CD4+ counts a component of diurnal variation must always be taken into account. Also, note that CD4+ counts as an isolated test should never be used as a surrogate marker for HIV infection. Finally, the percentage of CD4+ lymphocytes may be useful when interpreted in conjunction With the CD4+ lymphocyte count.