Sorted By Test Name - Mayo Medical Laboratories

eference range) to baseline levels or exceeds baseline levels, showing evidence of thymic rebound, which
is consistent with recovery of thymic output and T cell reconstitution. When a patient is being monitored
for thymic recovery posttransplant treatment, this assay requires that a pretransplant (prior to
myeloablative or nonmyeloablative conditioning) or a pretreatment baseline specimen be provided so that
appropriate comparisons can be made between the pre- and posttransplant treatment specimens. Since
there is substantial variability between individuals in TREC counts, the best comparison is made to the
patient's own baseline specimen rather than the reference range (which provides a guideline for TREC
counts for age-matched healthy controls). Additionally, a single TREC measurement has very little value
in discerning thymic reconstitution in patients. Serial measurements 3 months apart for the first year and 6
months apart for the second year following transplant are recommended. For HIV patients on HAART,
TREC measurement can be used for monitoring, along with other laboratory parameters (specified on
page 4, section on Initial Assessment and Monitoring of Therapeutic Response in the Guidelines for the
use of antiretroviral agents in HIV-1 infected adults and adolescents, May 4, 2006, developed by the
DHHS Panel on Antiretroviral Guidelines for Adults and Adolescents - a working group of the Office of
AIDS Research Advisory Council). These guidelines suggest monitoring CD4 count every 3 to 6 months
and, at the same time, the TREC count can be measured as well. A consultative report will be generated
for each patient.
Reference Values:
T & B ABSOLUTE COUNTS
T Cells (CD3)
0-2 months: 2,500-5,500 cells/mcL*
3-5 months: 2,500-5,600 cells/mcL*
6-11 months: 1,900-5,900 cells/mcL*
12-23 months: 2,100-6,200 cells/mcL*
2-5 years: 1,400-3,700 cells/mcL*
6-11 years: 1,200-2,600 cells/mcL*
12-17 years: 1,000-2,200 cells/mcL*
> or =18 years: 582-1,992 cells/mcL
Helper Cells (CD4)
0-2 months: 1,600-4,000 cells/mcL*
3-5 months: 1,800-4,000 cells/mcL*
6-11 months: 1,400-4,300 cells/mcL*
12-23 months: 1,300-3,400 cells/mcL*
2-5 years: 700-2,200 cells/mcL*
6-11 years: 650-1,500 cells/mcL*
12-17 years: 530-1,300 cells/mcL*
> or =18 years: 401-1,532 cells/mcL
Suppressor Cells (CD8)
0-2 months: 560-1,700 cells/mcL*
3-5 months: 590-1,600 cells/mcL*
6-11 months: 500-1,700 cells/mcL*
12-23 months: 620-2,000 cells/mcL*
2-5 years: 490-1,300 cells/mcL*
6-11 years: 370-1,100 cells/mcL*
12-17 years: 330-920 cells/mcL*
> or =18 years: 152-838 cells/mcL
*Shearer WT, Rosenblatt HM, Gelman RS, et al: Lymphocyte subsets in healthy children from birth
through 18 years of age: The Pediatric AIDS Clinical Trials Group P1009 study. J Allergy Clin Immunol
2003;112(5):973-980
TREC, IMMUNE RECONSTITUTION
Pediatrics
6 months-18 years: >801 copies per million peripheral blood mononuclear cells
Reference values have not been established for patients that are less than 5 months of age.
Adults
19-44 years: >227 copies per million CD3 T cells
45-54 years: >111 copies per million CD3 T cells
Current as of January 4, 2013 7:15 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 1685