Indian Journal of Ophthalmology

LETTER TO THE EDITOR
Year
: 2021  |  Volume : 69  |  Issue : 1  |  Page : 180--181

Tuberculin sensitivity test in uveitis: Immunological perspectives


Manish Jain1, Yashik Bansal2,  
1 Department of Ophthalmology, VCSG Government Institute of Medical Science and Research, Srinagar, Uttarakhand, India
2 Department of Microbiology, VCSG Government Institute of Medical Science and Research, Srinagar, Uttarakhand, India

Correspondence Address:
Dr. Manish Jain
Department of Ophthalmology, VCSG Government Institute of Medical Science and Research, Srinagar - 246 174, Uttarakhand
India




How to cite this article:
Jain M, Bansal Y. Tuberculin sensitivity test in uveitis: Immunological perspectives.Indian J Ophthalmol 2021;69:180-181


How to cite this URL:
Jain M, Bansal Y. Tuberculin sensitivity test in uveitis: Immunological perspectives. Indian J Ophthalmol [serial online] 2021 [cited 2021 Feb 27 ];69:180-181
Available from: https://www.ijo.in/text.asp?2021/69/1/180/303321


Full Text



Dear Editor,

We laud Rathinam et al. for bringing out a much needed review on immunological tests in Uveitis.[1] Granulomatous inflammations constitute a significant chunk of uveitis, both in peripheral and referral practices. We share additional immunological perspectives on Tuberculin sensitivity test (TST).

Despite being a common test, many healthcare workers misinterpret moderate positive response as tuberculosis and initiate antitubercular drugs even as many cases of ocular tuberculosis are immunologically driven. Similarly, a negative test is taken as anergy leading to the diagnosis of sarcoidosis. As such, a positive test merely suggests a past exposure to mycobacterial antigens and adequate cell mediated immunity (CMI).

In addition, many patients tend to have serial TSTs before finding their way to a tertiary center. This enhances the subsequent size of induration, just as past/ongoing steroid therapy would reduce it. Inadvertent boosting of tubercular hypersensitivity has aggravated inflammation leading to irreversible visual loss.[2]

The peripheral anergy in sarcoidosis is a result a compartmentalization, whereby monocytes are actively recruited at the site of active inflammation.[3] Anergy, earlier considered a result of steroid responsive suppressor T-cells, is mediated by monocytes through prostglandin (PGE2) & interleukin 1 and is amenable to drugs such as indomethacin and steroids [Figure 1].[4] Positive TST in a case of sarcoidosis could imply reversal of anergy or concurrent tuberculosis. Unlike “in vitro” tests such as Interferon-γ release assays, conversion, reversal, and booster effects are unique to TST.[5]{Figure 1}

In summary, positive/negative TST can be compatible with both sarcoidosis and tuberculosis depending upon the CMI. Paucibacillary and military tuberculosis should be seen as a continuum akin to tuberculoid, indeterminate, and lepromatous leprosy. History of past TST and steroid treatment is crucial in the interpretation and the rare, but serious risk to visual functions should be borne in mind.[5]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Rathinam SR, Tugal-Tutkun I, Agarwal M, Rajesh V, Egriparmak M, Patnaik G. Immunological tests and their interpretation in uveitis. Indian J Ophthalmol 2020;68:1737-48.
2Yen MY, Liu JH. Bilateral optic neuritis following bacille Calmette-Guérin (BCG) vaccination. J Clin Neuroophthalmol 1991;11:246-9.
3Hudspith BN, Flint KC, Geraint-James D, Brostoff J, Johnson NM. Lack of immune deficiency in sarcoidosis: Compartmentalisation of the immune response. Thorax 1987;42:250-5.
4Hudspith BN, Brostoff J, McNicol MW, Johnson NM. Anergy in sarcoidosis: The role of interleukin-1 and prostaglandins in the depressed in vitro lymphocyte response. Clin Exp Immunol 1984;57:324-30.
5Nayak S, Acharjya B. Mantoux test and its interpretation. Indian Dermatol Online J 2012;3:2-6.