Absolute Activated T Lymphocyte Count

**Semantic type:** Laboratory Procedure

**Definition:** The measurement of the number of activated T lymphocytes, which are T lymphocytes that express HLA-DR and do not express CD19, in a cubic millimeter of blood. It is calculated by multiplying 1000 by both the total leukocyte count and the percent of T-cells expressing markers of activation in the differential leukocyte count.

**Synonyms:** - Absolute Activated T Cell Count - Absolute Activated T-Cell Count - Absolute Activated T-Cell Count - Absolute Activated TLYCE - Activated T Lymphocyte to Total Leukocyte per Cubic Millimeter Measurement