Collaborative Stage

Note 1: The CD4 cell count is used to monitor how well the immune system is working in a patient who is Human Immunodeficiency Virus (HIV) positive. A blood test measures the number of CD4 T-cells in each microliter (ul) of blood. The measurement may also be in CD4 cells per cubic millimeter of blood. One microliter (ul) is equivalent to 1 cubic millimeter of fluid. A low CD4 count (less than 200) indicates a weakened immune system. For Kaposi Sarcoma patients, a CD4 count lower than 200 is a poor risk factor.
Note 2: Record the CD4 count at the time of the Kaposi Sarcoma diagnosis as documented in the patient record. If the CD4+ count is 980 or greater use code 980. If the test is done but the actual value is not available or not stated, use code 997.
Note 3: If the patient is HIV negative, use code 987.
Note 4: Record the actual value of the CD4 count as documented in the patient record. If the actual CD4+ count is 980 or greater, use code 980.

Code	Description
001-979	CD4 count 001-979/cubic millimeter or microliter (ul) of blood (Exact count of CD4 cells)
980	CD4 count 980 or greater/cubic millimeter or microliter (ul) of blood
987	Not applicable: Patient is HIV negative
988	Not applicable: Information not collected for this case (May include cases converted from code 888 used in CSv1 for "Not applicable" or when the item was not collected. If this item is required to derive T, N, M, or any stage, use of code 988 may result in an error.)
990	CD4 count less than 200, NOS CD4 count stated to be low CD4 count stated to be poor risk
991	CD4 count greater than or equal to 200, NOS CD4 count stated to be normal CD4 count stated to good risk
997	Test ordered, results not in chart
998	Test not done (test not ordered and not performed)
999	Unknown or no information Not documented in patient record

CS Site-Specific Factor 4
CD4 Cell Count