Test Catalog

Test ID: TIA1    
T-Cell Intracellular Antigen 1 (TIA-1) Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Characterizing neoplasms of cytotoxic T cells or natural killer cells

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

T-cell intracellular antigen 1 (TIA-1) shows a granular cytoplasmic staining pattern due to its presence in cytotoxic granules. It is involved in cytotoxic cell-mediated immune responses. TIA-1 was first identified in cytotoxic T cells; it is also expressed in normal natural killer (NK) cells and granulocytes. TIA-1 antibody is useful in characterizing neoplasms of cytotoxic T cells or NK cells.

Interpretation Provides information to assist in interpretation of the test results

This test does not include pathologist interpretation; only technical performance of the stain. If interpretation is required order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request. Contact 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut within 6 weeks.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Zlobec I, Karamitopoulou E, Terracciano L, et al: TIA-1 cytotoxic granule-associated RNA binding protein improves the prognostic performance of CD8 in mismatch repair-proficient colorectal cancer. PLoS One. 2010 Dec 10;5(12):e14282. doi: 10.1371/journal.pone.0014282

2. Kiyasu J, Aoki R, Tanaka P, et al: FOXP3+ regulatory and TIA-1+ cytotoxic T lymphocytes in HIV-associated Hodgkin lymphoma. Pathol Inter. 2012 Feb;62(2):77-83. doi: 10.1111/j.1440-1827.2011.02754.x

3. Fujimura T, Furudate S, Kambayashi Y, Aiba S: Potential use of Bisphosphonates in Invasive Extramammary Paget's Disease: An Immunohistochemical Investigation. Clin Dev Immunol. 2013 2013:164982. doi: 10.1155/2013/164982