The EliSpot (Interferon-Gamma-Test):
To make statements on the activities of the immune system on a cellular basis, the EliSpot can be used. This test procedure is also known as Interferon-Gamma-Test. Contrary to other available Lymphocyte-Transformation-Tests (LTT) on the applied market, the EliSpot is a standardised and disclosed test principal. It is acknowledged and approved by the FDA (American authority that controls and authorises methods of testing) to diagnose tuberculosis (1). It was tested and considered “efficient”. It is also used in Germany.
When using the EliSpot for other infections (borrelia, EBV, chlamydia…), only other antigens are used (not antigens from mycobacterium tuberculosis but f.e. from antigens from borrelia, EBV, chlamydia…etc.). This is the only difference. Otherwise, it’s the same test-principle.
Moreover, EliSpots have also been used in transplant medicine.
Right now there is also research and factual discussion (Universitiy of Cologne, and Berlin Charite) about usage of cellular test-systems with T cells for mold infections (Aspergillus, Mucorales) (3).
Of course, we are hoping for further developments and improvements and cinical studies but for now, this standardised EliSpot gives us useful additional information on the activities of the (cellular) immune system of the infected person. It is very important for the practice that we can get the answer how active the infection is. The antibodies can not give as the answer. There is complete agreement on that.
For instance, it would be interesting to achieve a differentiation between active cytotoxic T-cells and T-memory-cells in order to more accurately evaluate the activity of the infection. Studies are currently in progress. A new study was published on Febuary 12th 2015 showing the benefits for the therapeutic approach to determinate the two cytokines Gamma-Interferon and Interleukin-2, by EliSpot Assay in patients with acute and chronic Q-fever, also a tick-borne disease (2).
(1) T-Cell-Spot/IGRA has been approved by the FDA in May 2011 for M. tuberculosis; TB EliSpot (TSpot TB) von Oxford Immunotech, Quellennachweis: www.fda.com PMA (premarket approval) nr. P070006
(2) Teske Schoffelen, Marjolijn C. Wegdam-Blans, Anne Ammerdorffer, Marjolijn J. H. Pronk, Yvonne E. P. Soethoudt, Mihai G. Netea, Jos W. M. van der Meer, Chantal P. Bleeker-Rovers and Marcel van Deuren: “Specific in vitro interferon-gamma and IL-2 production as biomarkers during treatment of chronic Q fever “, Frontiers in Microbiology | Infectious Diseases, February 2015 | Volume 6 | Article 93 | 2
(3) P. Bacher et al.:” Fungus-specific CD4(+) T cells for rapid identification of invasive pulmonary mold infection (Paywall)”, Am J Respir Crit Care Med., doi: 10.1164/rccm.201407-1235LE;2015
An interesting article, too: Werner Kempf et al.: “Cutaneous borreliosis associated with T-cell-predominant infiltrates: A diagnostic challange”, J Am Acad Dermatol; http//dx.doi.org/10.1016/j.jaad.2014.12.014
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