Epidemiological and Cytokine Profile of Patients with Pulmonary and Extrapulmonary Tuberculosis in a Population of the Brazilian Amazon

Abstract

Several factors are associated with the development of different clinical forms of tuberculosis (TB). The present study evaluated epidemiological variables and cytokine levels in samples from 89 patients with TB (75 with pulmonary TB and 14 with extrapulmonary TB) and 45 controls. Cytokines were measured by flow cytometry (Human Th1/Th2/Th17 Cytometric Bead Array kit). The TB group had a higher frequency of individuals who were 39 years of age or older, married, with primary education or illiterate and had a lower family income (p < 0.05). All individuals with extrapulmonary TB reported that they were not working, and the main reasons were related to disease symptoms or treatment. The levels of IFN-γ (OR = 4.06) and IL-4 (OR = 2.62) were more likely to be elevated in the TB group (p = 0.05), and IFN-γ levels were lower in patients with extrapulmonary TB compared to those with pulmonary TB (OR = 0.11; p = 0.0050). The ROC curve was applied to investigate the diagnostic accuracy of IFN-γ levels between the different clinical forms of tuberculosis, resulting in high AUC (0.8661; p < 0.0001), sensitivity (93.85%) and specificity median (65.90%), suggesting that IFN-γ levels are useful to differentiate pulmonary TB from extrapulmonary TB. The dysregulation of pro- and anti-inflammatory cytokine levels represent a risk for the development of TB and contribute to the pathogenesis of the disease, especially variation in IFN-γ levels, which may determine protection or risk for extrapulmonary TB.

Association of Cytokine Gene Polymorphisms and Their Impact on Active and Latent Tuberculosis in Brazil’s Amazon Region

“…Other studies have observed an association of the wild-type genotype and allele with TB in different populations [32][33][34]. IFN-γ is fundamental to the protective immune response against Mtb, which is mediated by CD4 + Th1 cells [35]. This cytokine has a major impact on the physiology of infected macrophages and on the biology of phagosomes [36].…”

Factors Associated With Extrapulmonary Tuberculosis in Southeastern Mexico: A Case-Control Study

“…Although EPTB+ is less contagious due to its characteristics, it can eventually spread to the lungs and become infectious (PTB+), which represents a latent threat to public health and global TB control [ 10 ]. EPTB+ also results in a significant number of hospitalizations, longer in-hospital time, and higher costs compared to PTB+, generating a significant impact on patients' lives [ 30 ]. In addition, the clinical and symptomatological characteristics of EPTB+ can vary according to the organ or tissue affected, so both the general and specific manifestations of the disease must be considered.…”