Indian Journal of Drugs in Dermatology

LETTER TO EDITOR
Year
: 2016  |  Volume : 2  |  Issue : 2  |  Page : 105--106

Tuberculin purified protein derivative immunotherapy in the treatment of viral warts


Mahmood Dhahir Al-Mendalawi 
 Department of Paediatrics, Al Kindy College of Medicine, Baghdad University, Baghdad, Iraq

Correspondence Address:
Mahmood Dhahir Al-Mendalawi
Department of Paediatrics, Al-Kindy College of Medicine, Baghdad University, P.O. Box 55302, Baghdad Post Office, Baghdad
Iraq




How to cite this article:
Al-Mendalawi MD. Tuberculin purified protein derivative immunotherapy in the treatment of viral warts.Indian J Drugs Dermatol 2016;2:105-106


How to cite this URL:
Al-Mendalawi MD. Tuberculin purified protein derivative immunotherapy in the treatment of viral warts. Indian J Drugs Dermatol [serial online] 2016 [cited 2020 Aug 7 ];2:105-106
Available from: http://www.ijdd.in/text.asp?2016/2/2/105/196173


Full Text

Sir,

I read with interest the study by Nimbalkar et al. on the tuberculin purified protein derivative (PPD) immunotherapy in the treatment of viral warts. [1] The authors found that such treatment modality was safe, simple to perform, not very painful, inexpensive with minimal side effects, effective with good cure rate in the treatment of single and multiple warts, equally effective at injected and warts at distant site, and prevents recurrence of warts with completely clearance. [1] I presume that the implication of that treatment modality in the clinical field should be taken cautiously. This is based on the following point. It is obvious that tuberculosis (TB) is a major public health problem in India which accounts for nearly one-fifth of the global TB burden. Although India has been gaining success in eliminating TB, the disease still kills 1000 people daily. [2] Latent TB is serious as it serves as a potential reservoir for future active TB. Thus, the identification and treatment of latent TB in those at the highest risk for progression is an essential component of TB control program worldwide. It is well-known that tuberculin skin test (TST) and interferon-gamma release assay (IGRA) are two essential tests incorporated in the diagnostic algorithm of TB, particularly the latent TB. Several guidelines have recommended a two-step testing procedure, notably TST followed by IGRA for the diagnosis of latent TB. Great concerns have been raised on the correlation between prior TST exposure and subsequent IGRA. The TST usually involves multiple antigens of tuberculin PPD, including the antigens used in IGRA. Exposure to these antigens by means of a TST might elicit an immune response that could lead to the false-positive result in a subsequent IGRA, thus limiting the validity of IGRA in individuals in whom these tests are sequentially done. Reviewing the literature on the effect of a previous TST on the result of the subsequent IGRA revealed generally distressing results. For example, a systematic review on that issue has shown that although the effect of TST on IGRA results was likely to be inconsequential in IGRA-positive participants and in IGRA-negative participants, the interpretation of results might be confounded by a preceding TST if administered more than 3 days before an IGRA. [3] A set of Italian researchers have shown that TST did not influence the outcome of subsequent IGRA testing in individuals with negative TST results, but it could boost the interferon-gamma response in participants sensitized to TB antigens and not detected by IGRA. [4] However, a set of Korean researchers obviously pointed out that the agreement between the results of the TST and the IGRA was low, and interferon-gamma level could be influenced by the TST, in the TST-positive population, when a follow-up IGRA was performed 2-4 weeks later. [5] I, therefore, presume that inquiry about antecedent tuberculin PPD exposure for the treatment of viral warts should be taken into consideration during interpreting the results of IGRA in individuals with suspected TB in India.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Nimbalkar A, Pande S, Sharma R, Borkar M. Tuberculin purified protein derivative immunotherapy in the treatment of viral warts. Indian J Drugs Dermatol 2016;2:19-23.
2Theng YL, Chandra S, Goh LY, Lwin MO, Foo S. Exploratory qualitative study for community management and control of tuberculosis in India. Acta Trop 2014;132:98-105.
3van Zyl-Smit RN, Zwerling A, Dheda K, Pai M. Within-subject variability of interferon-g assay results for tuberculosis and boosting effect of tuberculin skin testing: A systematic review. PLoS One 2009;4:e8517.
4Sauzullo I, Massetti AP, Mengoni F, Rossi R, Lichtner M, Ajassa C, et al. Influence of previous tuberculin skin test on serial IFN-g release assays. Tuberculosis (Edinb) 2011;91:322-6.
5Choi JC, Shin JW, Kim JY, Park IW, Choi BW, Lee MK. The effect of previous tuberculin skin test on the follow-up examination of whole-blood interferon-gamma assay in the screening for latent tuberculosis infection. Chest 2008;133:1415-20.