The formation of a scar after
Mycobacterium bovis
Bacillus Calmette-Guérin
(
BCG) vaccination influences the effectiveness of protection against
Mycobacterium tuberculosis
(MTB) infection. The innate immunity plays a critical role both in the pathophysiology of tuberculosis (TB) and BCG vaccination protection mechanism. Parts of innate immunity: macrophages, dendritic cells, and neutrophils, have microbial recognition surface receptors called Toll-like receptors (TLR) 2 and 4. The objective of this study is to compare the serum levels of TLR2 and TLR4 in BCG-vaccinated pediatric patients with pulmonary and extrapulmonary TB. This cross-sectional study included children aged less than 18 years old with contracted TB disease and had received BCG vaccination. The subjects were recruited by convenience sampling from both outpatient and inpatient care at Bhakti Medicare and Jakarta Islamic Hospital, from November 2018 to December 2019. Serum TLR2 and TLR4 levels measured using ELISA of the two groups of subjects: children with pulmonary TB (PTB) and extrapulmonary TB (EPTB), were then compared. The presence of BCG scars was included in the analysis. Independent T-test, ANOVA test, and Kolmogorov-Smirnov normality tests on the SPSS program were used to statistically analyze the results. Serum TLR2 and TLR4 levels were higher in EPTB group, but the difference was not significant (TLR2 p = 0.758 and TLR4 p = 0.646, respectively). Subjects with BCG scars in both groups have significantly higher serum TLR2 and TLR4 levels than those without BCG scars in the EPTB group (EPTB p = 0.001 and p = 0.004, respectively); (PTB p < 0.001 and p < 0.001, respectively). BCG vaccination and MTB infection stimulate better innate immune response in EPTB than in PTB and serum TLR2 and TLR4 levels in those with BCG scars were higher when compared to those without BCG scars.
Background
The ability of
Mycobacterium tuberculosis
to survive intracellularly, provides a cellular adaptive immune response played by specific T cells to defend against tuberculosis. The adaptive immune response to Bacillus of Calmette and Guerin (BCG) immunization is responded to by B cells, T Follicular B helper, T regulatory, restriction CD1, CD8
+
, CD4
+
, Th1, Th2, and Th17. BCG immunization can cause a tuberculin test reaction to being positive. The tuberculin test is a method for diagnosing TB infection and for screening individuals for latent infection and assessing the rate of TB infection in a given population.
Methods
a nested case-control survey was conducted on patients with a diagnosis of TB and parents 0–18 years of age from 3 hospitals in Indonesia during September–November 2019 with a total sample of 69 people undergoing clinical examinations, supporting and diagnosing subjects, blood sampling 1–2 cc for examination mRNA gene Treg, Treg, CD 4+, and CD 8+, then centrifuged at 3000 rpm for 10 min to support blood cells and serum.
Results
There was a significant relationship between expression of mRNA gene Treg with TST (p = 0,000), Treg with TST (p = 0,000), and CD4
+
with TST (p = 0,000). Meanwhile, CD8 + was not significantly associated with TST (p = 0.118).
Conclusions
It is necessary to check the expression of mRNA gene Treg, Treg, CD4
+
, and CD8
+
with more samples to find the mean value that shows the protective value of further TB.
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