{"id":"cd3-t-cells-absolute","name":"CD3+ T Cells, absolute","shortName":"T cells (absolute)","aliases":["Absolute CD3","CD3 Absolute","CD3 Abs Cnt","CD3+ Cells, Absolute","T Cells, Absolute","Absolute CD 3","CD3+ T Cells Absolute","T Cell Count","T Lymphocytes, Absolute","Absolute T Cells","Total T Cells, Absolute","CD3+ T Lymphocytes, Absolute","CD3 Pos. Lymph. Absolute","Absolute CD3+"],"abbreviations":["Abs CD3"],"loinc":[{"code":"8122-4","primary":true}],"specimen":"whole-blood","units":[{"ucum":"/uL","display":"cells/µL"},{"ucum":"10*3/uL","display":"×10³/µL"},{"ucum":"10*9/L","display":"×10⁹/L"},{"ucum":"10*6/L","display":"×10⁶/L"}],"referenceRanges":[{"population":"16+","low":622,"high":2402,"unit":"/uL","unitDisplay":"cells/µL","note":"Labcorp adult interval for CD3+ T cells (test 505370, 95% confidence interval). ARUP Laboratories prints 570 to 2,400 cells/µL for ages 16 to 64 (660 to 2,200 from age 65), which is close to Labcorp's interval. Use the range on your own report. Basic T, B and NK cell counts are the usual first flow cytometry step when an inherited immune problem is suspected, including severe combined immunodeficiency (Salzer 2019).","sources":[{"title":"T- and B-Lymphocyte and Natural Killer Cell Profile (test 505370)","url":"https://www.labcorp.com/tests/505370/t-and-b-lymphocyte-and-natural-killer-cell-profile","publisher":"Labcorp"},{"title":"Lymphocyte Subset Panel 5 - Total Lymphocyte Enumeration (test 0095892)","url":"https://ltd.aruplab.com/Tests/Pub/0095892","publisher":"ARUP Laboratories"},{"title":"Flow Cytometry in the Diagnosis and Follow Up of Human Primary Immunodeficiencies","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC6893889/","publisher":"EJIFCC (International Federation of Clinical Chemistry and Laboratory Medicine)","year":2019}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"How many T cells are in a microliter of blood. T cells are white blood cells that direct and carry out much of the immune response.","url":"https://bloodtesttracker.com/markers/cd3-t-cells-absolute","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}