Antithyroid (Thyroglobulin & Microsomal) Antibodies (ATA)
Introduction
Autoimmunity has been directly associated in the etiology of several reproductive conditions including unexplained infertility and recurrent pregnancy loss. Autoimmune thyroid disorders are characterized by the presence of antithyroid antibodies, specifically antithyroglobulin (ATA) and antithyroid peroxidase (microsomal antibodies, or AMA).
Thyroid autoantibodies have been shown to be independent markers for pregnancies at risk for loss. Women who have antithyroid antibodies miscarry at approximately twice the rate of women who have no antithyroid antibodies. Individual levels of thyroglobulin and thyroid microsomal antibodies are similarly related to the increased miscarriage rate with no evidence of autoantibody specificity.
Approximately 30% of women experiencing recurrent pregnancy loss have one or both antithyroid antibodies. Antithyroid antibodies have also been associated with implantation failure after in vitro fertilization (IVF) and embryo transfer (ET). Endometrial biopsies from women undergoing IVF with antithyroid antibodies show an increase in endometrial activated T cells and cells that secrete more Th1 cytokines and less Th2 cytokines than from women without antithyroid antibodies. An improvement in pregnancy rates after IVF/ET was seen in women with antithyroid antibodies after treatment with intravenous immunoglobulin.
Indication for Testing
All patients that have a history of thyroid abnormalities and/or a history of two or more pregnancy losses or unexplained infertility should be tested for the presence of antithyroid antibodies. Because women having antithyroid antibodies during the first trimester of pregnancy have a 50% chance of either miscarrying or developing thyroid dysfunction in her postpartum period, testing all women during the first trimester has been recommended.
Detection Method
The thyroid antibody test is based on the agglutination of gelatin particles that have been sensitized with thyroglobulin and the thyroid microsomal antigen, extracted and purified from human thyroid tissue. Serum containing specific antibodies will react with the thyroid antigen sensitized colored gelatin particles to form a smooth mat of agglutinated particles in the microtitration tray.
Interpretation of Test Results
Results are obtained by reading the settling patterns of the colored gelatin particles using a tray viewer. Criteria for the observation and evaluation of the reactions are defined in comparison with the patterns of reaction in the Unsensitized Particles Control and Reactive Serum Control. Results are reported as negative, borderline or positive for both antithyroglobulin and anti-microsomal antibodies. A normal value is negative.
| TITER |
RESULT |
| < 1:72 |
Negative |
| 1:72-1:300 |
Borderline |
| > 1:300 |
Positive |
Specimen Collection and Shipping Requirements
- Collect one (1) 10 ml red or tiger top ube.
- Ship at room temperature in prepaid FedEx mailers overnight, next day morning
Turn around Time
Processing of specimens begins immediately upon receipt at our facilities. Results are routinely available within 7 to 10 days and are initially faxed, then mailed to the requesting physician.
Cost
Included in our fees are specimen collection and shipping materials, all courier and shipping charges, telephone and written reports, and consultation with physicians. Please call (312) 274-1928 for pricing information.
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References
Stagnaro-Green A, Roman SH, Cabin RH, El-Harazy E, Alvarez-Marfany M, Davies TF. Detection of at-risk pregnancy by means of highly sensitive assays for thyroid antibodies. JAMA 1990;264:1422-1425.
Glinoer D, Soto, MF Bourdaux P, Lejeune B, Delange F, Lemone M, Kinthaert J, Robyn C, Grun JP, DeNayer P. Pregnancy in patients with mild thyroid antibodies: maternal and neonatal repercussions. J Clin Endocrinol Metab 1991;73:421-427.
Kaider AS, Kaider BD, Janowicz PB, Roussev RG. Immunodiagnostic evaluation in women with reproductive failure. Am J Reprod Immunol 1999;42:335-346.
Sher G, Maassarani G, Zouves C. Feinman M, Sohn S, Matzner W, Chong P, Ching W. The use of combined heparin/aspirin and immunoglobulin G therapy in the treatment of in vitro fertilization patients with antithyroid antibodies. Am J Reprod Immunol 1998;39:223-25.
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