Absolute Lymphocytes

Absolute Lymphocyte Count (ALC) measures the total number of lymphocytes (T cells, B cells, NK cells) per volume of blood (WBC count x Lymphocyte %). Low ALC (lymphopenia, <1000 cells/uL) can indicate viral infections (like HIV, COVID-19), immune deficiencies, malnutrition, or stress (high cortisol), and is associated with increased mortality risk. High ALC (lymphocytosis) is common in viral infections (like mono) or certain leukemias/lymphomas.