T-Cell Subsets, Naive, Memory and Activated
Method Description Describes how the test is performed and provides a method-specific reference
This flow cytometric assay quantitates the following CD4 and CD8 T-cell subsets: naive (global and CD62L+), memory (global, central, and effector memory), and activated (CD4+25+ and MHC class II-positive) T cells. EDTA anticoagulated blood is incubated with antibodies to various T-cell markers (ie, CD3, CD4, CD8, CD45RO, CD45RA, HLADR, CD27, CD62L, CD25, and CD28). After RBC lysis, the sample is washed to remove any unbound antibodies prior to analysis on a BD FACS Cantoinstrument. The assay uses 4 antibody tubes for data acquisition and analysis is performed as 3 panels. Each T-cell subset is expressed as a percentage of total CD4+ or CD8 T cells. Only the CD3 T cells are expressed as a percentage of total lymphocytes. The absolute counts for the T-cell subsets are derived from flow cytometry analysis of whole blood using monoclonal antibodies to identify CD45, CD3, CD4, and CD8. CD14 is used to exclude monocytes, thereby improving accuracy and enhancing the purity of the lymphocyte population. The assay is a 5-color, lyse-no wash procedure and the absolute counts are calculated from internal bead standards. The T-cell subsets panel is linked to the TCD4 test (TCD4 / CD4 Count for Immune Monitoring, Blood) within the experiment and, therefore, the CD3, CD4, and CD8 T-cell reference ranges are provided within the TCD4 assay. The results for the other T-cell subsets are interpreted using a reference range derived from data of normal healthy adult and pediatric donors. Isotype controls are used in each assay to measure background fluorescence of the samples. A normal, healthy control is also included in each experiment to ensure the optimal performance of the assay.(Unpublished Mayo information)
PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday
Do not send specimen after Thursday. Specimen must be received by 10 a.m. on Friday.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test