Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

TGAB
84382
36-55 years: 142-844 cells/mcL
56-70 years: 58-680 cells/mcL
Reference values have not been established for patients that are 70 years of age.
CD8 RTE %
1 month-17 years: 0.1-1.7%
18-45 years: 0.0-0.6%
>46-70 years: 0.0-0.3%
Reference values have not been established for patients that are 70 years of age.
CD8 RTE Absolute
1 month-17 years: 0.2-4.3 cells/mcL
18-25 years: 0.0-3.4 cells/mcL
26-50 years: 0.0-2.5 cells/mcL
51-70 years: 0.0-0.7 cells/mcL
Reference values have not been established for patients that are 70 years of age.
Clinical References: 1. Douek DC, McFarland RD, Keiser PH, et al: Changes in thymic function
with age and during the treatment of HIV infection. Nature 1998;396:690-694 2. Hazenberg MD,
Verschuren MC, Hamann D, et al: T cell receptor excision circles as markers for recent thymic emigrants:
basic aspects, technical approach, and guidelines for interpretation. J Mol Med 2001;79:631-640 3.
Hassan J, Reen DJ: Human recent thymic emigrants-identification, expansion, and survival
characteristics. J Immunol 2001;167:1970-1976 4. Kimmig S, Przybylski GK, Schmidt CA, et al: Two
subsets of naïve T-helper cells with distinct T-cell receptor excision circle content in human adult
peripheral blood. J Exp Med 2002;195(6):789-794 5. McFarland RD, Douek DC, Koup RA, et al:
Identification of human recent thymic emigrant phenotype. Proc Natl Acad Sci 2000;97(8):4215-4220 6.
Junge S, Kloeckener-Gruissem B, Zufferey R, et al: Correlation between recent thymic emigrants and
CD31+ (PECAM-1) CD4 T-cells in normal individuals during aging and in lymphopenic children. Eur J
Immunol 2007;37:3270-3280 7. Dong X, Hoeltzle MV, Abraham RS: Evaluation of CD4 and CD8 recent
thymic emigrants in healthy adults and children. Unpublished data 2008 8. Duszczyszyn DA, Beck JD,
Antel J, et al: Altered naive CD4 and CD8 T-cell homeostasis in patients with relapsing-remitting
multiple sclerosis: thymic versus peripheral (non-thymic) mechanisms. Clin Exp Immunol
2005;143:305-313
Thyroglobulin Antibody, Serum
Clinical Information: Thyroglobulin autoantibodies bind thyroglobulin (Tg), a major
thyroid-specific protein. Tg plays a crucial role in thyroid hormone synthesis, storage, and release.
Noniodinated Tg is actively transported from thyrocyte cytosol to the thyroid follicular lumen. At the
extracellular apical villae-follicular luminal interface, thyroid peroxidase (TPO) catalyzes the iodination
of tyrosine and thyronine residues of Tg. This is followed by intramolecular coupling of pairs of monoand
diiodotyrosines to form thyroid hormones, predominately thyroxine (T4) or, to lesser degree,
triiodothyronine (T3). The iodinated Tg is stored in the follicular lumen, forming the colloid. For thyroid
hormone release, colloid is reabsorbed at the apical membrane and proteolyzed. Iodinated tyrosine
residues are deiodinated and recycled for synthesis of new Tg molecules, while the bulk of T3 and T4
residues are secreted from the basal membrane into the systemic circulation. Tg is not secreted into the
systemic circulation under normal circumstances. However, follicular destruction through inflammation
(thyroiditis and autoimmune hypothyroidism), hemorrhage (nodular goiter), or rapid disordered growth of
thyroid tissue, as may be observed in Graves disease or follicular cell-derived thyroid neoplasms, can
result in leakage of Tg into the blood stream. This results in the formation of autoantibodies to Tg in some
individuals. The same processes also may result in exposure of other "hidden" thyroid antigens to the
immune system, resulting in the formation of autoantibodies to other thyroid antigens, in particular TPO.
Since anti-Tg and anti-TPO autoantibodies are observed most frequently in autoimmune thyroiditis
(Hashimoto's disease), they were originally considered to be of possible pathogenic significance in this
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