Pulmonary Tuberculosis Individuals Research Articles

Modelling of tuberculosis dynamics incorporating indirect transmission of contaminated environment and infectivity of smear-negative individuals: A case study for Xinjiang, China

Xinjiang has been one of the high incidence areas of pulmonary tuberculosis (PTB) in China. Besides being infected by direct contacting with active PTB individuals (direct infection), the susceptible would be infected because of the exposure to the environment contaminated by Mycobacterium tuberculosis (indirect infection). Active PTB individuals include not only the smear-positive PTB (PTB+) but also the smear-negative PTB (PTB–) who are infectious due to their ability to release tiny Mycobacterium tuberculosis particles even in the absence of visible Mycobacterium tuberculosis in sputum. By taking account of direct/indirect infection and the difference between PTB+ and PTB– individuals in transmission capability, a periodic dynamical PTB transmission model is proposed. The model is fitted to the newly monthly PTB+ and PTB– cases in Xinjiang from 2008 to 2017 by Markov Chain Monte Carlo algorithm. Moreover, global sensitivity analysis is constructed to address the uncertainty of some key parameters by using Latin hypercube sampling and partial rank correlation coefficient methods. Basic reproduction number R0 for PTB transmission in Xinjiang is estimated to be 2.447 (95% CrI:(1.203, 3.844)), indicating that PTB has been prevalent in Xinjiang over the study period. Our results suggest that reducing the direct/indirect transmission rates, early screening, isolating and treating the latent, PTB+ and PTB– individuals, and enhancing the clearance of Mycobacterium tuberculosis in the environment could more effectively control PTB transmission in Xinjiang. The model fits the reported PTB data well and achieves acceptable prediction accuracy. We believe that our model can provide heuristic support for controlling PTB transmission in Xinjiang.

High-Dose Rifampicin Mediated Systemic Alterations of Cytokines, Chemokines, Growth Factors, Microbial Translocation Markers, and Acute-Phase Proteins in Pulmonary Tuberculosis.

High-dose rifampicin (HDR) is now undergoing clinical trials to improve the efficacy of anti-tuberculosis treatment (ATT). However, the influence of HDR in the modulation of different cytokines, chemokines/growth factors, microbial translocation markers (MTMs), and acute-phase proteins (APPs) in pulmonary tuberculosis (PTB) is not well known. PTB individuals were separated into three different arms (R10, R25, and R35) based on their rifampicin dosage. We examined the circulating levels of Type 1, Type 2, pro-inflammatory/regulatory cytokines, chemokines/growth factors, MTMs, and APPs at baseline and after completion of the second month of ATT by ELISA. The baseline levels of cytokines, chemokines/growth factors, MTMs, and APPs did not (except IL-5, IL-6, IL-17A, MCP-1, MIP-1β, GCSF, SAA, ⍺2 MG, Hp) significantly differ between the study individuals. However, at the second month, the plasma levels of Type 1 (TNFα and IFNγ), Type 2 (IL-4, IL-5, and IL-13), pro-inflammatory/regulatory cytokines (IL-6, IL-17A, IL-10, and GMCSF), and APPs were significantly decreased in R35 regimen- compared to R25 and/or R10 regimen-treated PTB individuals. In contrast, the plasma levels of IL-2, IL-8, MCP-1, MIP-1β, GSF, and MTMs were significantly increased in the R35 regimen compared to R25 and/or R10 regimen-treated PTB individuals. Overall, our data reveal that HDR could potentially be beneficial for host immunity by altering different immune and inflammatory markers.

Association of CYP2R1 gene polymorphisms in pulmonary tuberculosis

The CYP2R1 gene express the enzyme 25-hydroxylase, involved in the synthesis of major circulating vitamin D metabolite 25-hydroxyvitaminD [25(OH)D]. CYP2R1 gene variants have been reported to be associated with altered 25(OH)D level and associated with the development of active disease including tuberculosis (TB). The aim of the present study was to understand the association of rs10741657 (G/A) and rs2060793(A/G) CYP2R1 gene polymorphisms with tuberculosis susceptibility/protection in 104 Healthy controls (HCs) and 105 pulmonary tuberculosis (PTB) patients and to understand the influence of gene variants on 25(OH)D levels in South Indian population. Genotyping was performed by polymerase chain reaction trailed by restriction fragment length polymorphism (PCR-RFLP) method. Plasma samples were used for 25(OH)D level estimation by ELISA method. In rs10741657, under a dominant model (GG vs AG + AA), “AG” and “AA” genotypes as well as in rs2060793 under an overdominant model (GA vs GG + AA), “GA” genotype were significantly associated with protection to pulmonary tuberculosis. Based on sex, rs10741657 “AG” was significantly associated with protection and “GG” was significantly associated with susceptibility to TB in males. A sufficient vitamin D level was found with rs10741657 “AA” and “AG” genotypes and “GG” genotype associated with 81.8% of vitamin D deficiency in PTB individuals. In conclusion, rs10741657 “AG” and “AA” genotypes were associated with higher 25(OH)D levels and protection to TB. The lower 25(OH)D levels associated with rs10741657 “GG” genotype individuals may be recommended for higher vitamin D supplementation for better outcome from the disease. Further studies with large sample size are needed to confirm this study finding.

Altered systemic levels of acute phase proteins in tuberculous lymphadenitis and modulation after treatment.

BackgroundPulmonary tuberculosis (PTB) is characterized by elevated levels of acute phase proteins (APPs), but their association with tuberculous lymphadenitis (TBL) is poorly studied.MethodsWe examined the systemic levels of APPs (alpha-2-macroglobulin [⍺-2MG], serum amyloid A [SAA], C-reactive protein [CRP] and haptoglobin [Hp]) in TBL, PTB, latent tuberculosis (LTB) and healthy controls (HC) at baseline and in TBL after the completion of anti-tuberculosis treatment (ATT). We have also examined the association of these proteins with lymph node (LN) size, culture grade and multiple versus single LN involvement.ResultsTBL individuals exhibited increased systemic levels of ⍺-2MG, SAA, CRP and Hp in comparison to HCs and increased CRP levels in comparison to LTB individuals. TBL individuals also exhibited decreased systemic levels of Hp compared to PTB individuals. APPs were not significantly associated with LN size, LN involvement and culture grade, indicating a lack of association with disease severity. Following ATT, post-treatment levels of ⍺-2MG, CRP and Hp were significantly diminished compared to pre-treatment levels.ConclusionTBL disease is characterized by altered levels of APPs at baseline and modulated following treatment, indicating the presence of systemic inflammation.

Strongyloides stercoralis Coinfection Is Associated With Greater Disease Severity, Higher Bacterial Burden, and Elevated Plasma Matrix Metalloproteinases in Pulmonary Tuberculosis.

Helminths and tuberculosis (TB) largely overlap at the population level. Whether helminth infections influence disease severity and bacterial burdens in TB is not well understood. This study was conducted to examine the disease severity in a cohort of pulmonary TB (PTB) individuals with (Ss+) or without (Ss-) seropositivity for Strongyloides stercoralis infection. Ss+ was associated with increased risk of cavitation (odds ratio [OR], 4.54; 95% confidence interval [CI], 2.33-9.04; P < .0001) and bilateral lung involvement (OR, 5.97; 95% CI, 3.03-12.09; P < .0001) in PTB individuals. Ss+ was also associated with higher bacterial burdens (OR, 7.57; 95% CI, 4.18-14.05; P < .0001) in PTB individuals. After multivariate analysis adjusting for covariates, Ss+ was still associated with greater risk of cavitation (adjusted OR [aOR], 3.99; 95% CI, 1.73-9.19; P = .0014), bilateral lung involvement (aOR, 4.09; 95% CI, 1.78-9.41; P = .0011), and higher bacterial burden (aOR, 9.32; 95% CI, 6.30-13.96; P < .0001). Finally, Ss+ was also associated with higher plasma levels of matrix metalloproteinases ([MMP]-1, -2, -7, -8, and -9) in PTB individuals. Therefore, our data demonstrate that coexistent Ss infection is associated with greater disease severity and higher bacterial burden in PTB. Our data also demonstrate enhanced plasma levels of MMPs in coinfected individuals, suggesting a plausible biological mechanism for these effects.

Matrix Metalloproteinases and Tissue Inhibitors of Metalloproteinases Are Potential Biomarkers of Pulmonary and Extra-Pulmonary Tuberculosis.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) are potential regulators of tuberculosis (TB) pathology. Whether they are candidates for non-sputum-based biomarkers for pulmonary TB (PTB) and extra-pulmonary TB (EPTB) is not fully understood. Hence, to examine the association of MMPs and TIMPs with PTB and EPTB, we have measured the circulating levels of MMPs (MMP-1, 2, 3, 7, 8, 9, 12, and 13) and TIMPs (TIMP-1, 2, 3, and 4) in PTB, EPTB and compared them with latent tuberculosis (LTB) or healthy control (HC) individuals. We have also assessed their circulating levels before and after the completion of anti-tuberculosis treatment (ATT). Our data describes that systemic levels of MMP-1, 8, 9, 12 were significantly increased in PTB compared to EPTB, LTB, and HC individuals. In contrast, MMP-7 was significantly reduced in PTB compared to EPTB individuals. Likewise, the systemic levels of MMP-1, 7, 13 were significantly increased in EPTB in comparison to LTB and HC individuals. In contrast, MMP-8 was significantly reduced in EPTB individuals compared to LTB and HC individuals. In addition, the systemic levels of TIMP-1, 2, 3 were significantly diminished and TIMP-4 levels were significantly enhanced in PTB compared to EPTB, LTB, and HC individuals. The circulating levels of TIMP-2 was significantly reduced and TIMP-3 was significantly elevated in EPTB individuals in comparison with LTB and HCs. Some of the MMPs (7, 8, 9, 12, 13 in PTB and 1, 7, 8, 9 in EPTB) and TIMPs (1, 2, 3, 4 in PTB and 4 in EPTB) were significantly modulated upon treatment completion. ROC analysis showed that MMP-1, 9 and TIMP-2, 4 could clearly discriminate PTB from EPTB, LTB and HCs and MMP-13 and TIMP-2 could clearly discriminate EPTB from LTB and HCs. Additionally, multivariate analysis also indicated that these alterations were independent of age and sex in PTB and EPTB individuals. Therefore, our data demonstrates that MMPs and TIMPs are potential candidates for non-sputum-based biomarkers for differentiating PTB and EPTB from LTB and HC individuals.

Heightened systemic levels of anti-inflammatory cytokines in pulmonary tuberculosis and alterations following anti-tuberculosis treatment

BackgroundPro-inflammatory cytokines are markers of disease severity and bacterial burden in pulmonary tuberculosis (PTB). However, the association of Type 2, regulatory and other anti-inflammatory cytokines with disease severity and bacterial burden in PTB is not well understood. Aims/methodologyTo examine the association of anti-inflammatory cytokines with PTB, we examined the plasma levels of Type 2 (IL-4, IL-5, IL-13), regulatory (IL-10, TGFβ) and other anti-inflammatory (IL-19, IL-27, IL-37) cytokines in individuals with PTB, latent TB (LTB) or healthy controls (HC). We also examined the plasma levels of these cytokines in PTB individuals following anti-tuberculosis therapy (ATT). ResultsPTB individuals exhibited significantly higher plasma levels of IL-4, IL-13, IL-10, IL-19 and IL-27 in comparison to LTB and HC individuals and of TGFβ in comparison to HC individuals. In contrast, PTB individuals exhibited significantly lower plasma levels of IL-5 and IL-37 in comparison to both LTB and HC individuals. PTB individuals with bilateral or cavitary disease did not exhibit significantly different plasma levels of these cytokines in comparison to those with unilateral or non-cavitary disease nor did the cytokines exhibit any significant relationship with bacterial burdens. Finally, following ATT, the plasma levels of IL-4, IL-5 and IL-10 were significantly decreased, while the plasma levels of IL-13 and IL-37 were significantly increased in PTB individuals. ConclusionTherefore, our data demonstrate that PTB is associated with altered levels of Type 2, regulatory and other anti-inflammatory cytokines, some of which are altered followed chemotherapy. Our data also reveal that anti-inflammatory cytokines are not markers of disease severity or bacterial burden in PTB. Elevations in anti-inflammatory cytokines might help prevent the detrimental effects of pro-inflammatory responses in PTB.

Plasma chemokines are biomarkers of disease severity, higher bacterial burden and delayed sputum culture conversion in pulmonary tuberculosis

Plasma cytokines are biomarkers of disease extent and mycobacterial burden in pulmonary tuberculosis (PTB). Whether chemokines can perform the same role in PTB is not known. We examined the plasma levels of chemokines in individuals with PTB, latent TB (LTB) or healthy controls (HC) and their association with disease severity and mycobacterial burdens in PTB. We also examined the chemokines in PTB individuals at the end of anti-tuberculous chemotherapy (ATT). PTB individuals exhibited significantly higher levels of CCL1, CCL3, CXCL1, CXCL2, CXCL9 and CXCL10 in comparison to LTB and/or HC individuals. PTB individuals with bilateral or cavitary disease displayed significantly elevated levels of CCL1, CCL3, CXCL1, CXCL10 and CXCL11 compared to those with unilateral or non-cavitary disease and also exhibited a significant positive relationship with bacterial burdens. In addition, PTB individuals with slower culture conversion displayed significantly elevated levels of CCL1, CCL3, CXCL1 and CXCL9 at the time of PTB diagnosis and prior to ATT. Finally, the chemokines were significantly reduced following successful ATT. Our data demonstrate that PTB is associated with elevated levels of chemokines, which are partially reversed followed chemotherapy. Our data demonstrate that chemokines are markers of disease severity, predicting increased bacterial burden and delayed culture conversion in PTB.

Diminished type 1 and type 17 cytokine expressing - Natural killer cell frequencies in tuberculous lymphadenitis

Tuberculous lymphadenitis (TBL) is associated with the expansion of CD4+ and CD8+ T cells expressing Type 1 and Type 17 cytokines in the peripheral blood. However, the expression pattern of cytokine producing natural killer (NK) cells in both the peripheral blood and affected lymph nodes i.e. site of infection in TBL have not been examined. Hence, we have analyzed the baseline and mycobacterial antigen specific NK cell cytokine frequencies in whole blood of TBL and pulmonary tuberculosis (PTB) individuals. We have also examined the NK cell frequencies before and after treatment completion and in peripheral blood versus affected lymph nodes (LN) of TBL individuals. TBL is characterized by diminished frequencies of NK cells expressing Type 1 (IFNγ, TNFα), Type 17 (IL-17F) cytokines compared to PTB individuals upon antigen-specific stimulation. In contrast, TBL individuals did not exhibit any significant differences in the frequencies of NK cells expressing Type 1 and Type 17 cytokines upon completion of anti-tuberculosis treatment. LN of TBL is associated with altered frequencies of NK cells expressing Type 17 (increased IL-17F and decreased IL-22) cytokines when compared to peripheral blood. Thus, we conclude that TBL individuals are characterized by diminished frequencies of NK cells expressing Type 1/Type 17 cytokines.

Altered circulating levels of B cell growth factors and their modulation upon anti-tuberculosis treatment in pulmonary tuberculosis and tuberculous lymphadenitis.

B cell activating factor/a proliferation-inducing ligand (BAFF/APRIL) are members of the tumor necrosis factor alpha (TNF) α family of ligands, which are essential for B cell survival, development, and modulation of the immune system. To examine the association of circulating levels of BAFF and APRIL with pulmonary tuberculosis (PTB) and tuberculous lymphadenitis (TBL), we measured the systemic levels of APRIL and BAFF in individuals with PTB, TBL, latent tuberculosis (LTB) and healthy controls (HC). Further, we also examined the pre and post-treatment plasma levels of above-mentioned parameters in PTB and TBL individuals upon completion of anti-TB chemotherapy. Next, the association of these cytokines either with extent of disease, disease severity, bacterial burden in PTB and lymph node culture grade or the lymph node size in TBL was also assessed. Finally, ROC analysis was performed to examine the discrimination capacity of APRIL and BAFF between PTB or TBL with LTB. Our study revealed significantly diminished plasma levels of APRIL in PTB and higher plasma levels of BAFF in both PTB and TBL individuals compared to LTB and HC. Furthermore, we observed a significant increase in APRIL levels in TBL and significantly decreased plasma levels of BAFF in both PTB and TBL after the completion of successful anti-TB treatment. There was no statistically positive relationship between BAFF and APRIL levels and the extent of disease, disease severity and bacterial burden in PTB. In TBL, there was a significant correlation between APRIL (but not BAFF) levels with lymph node culture grades. In contrast, APRIL in PTB and BAFF in TBL were able to clearly discriminate from LTB in ROC analysis. In summary, our results showed altered levels of BAFF/APRIL and their modulation upon chemotherapy, suggesting that these cytokines might be involved in the immune-modulation of TB infection.

Altered Systemic Adipokine Levels in Pulmonary Tuberculosis and Changes following Treatment.

Pulmonary tuberculosis (PTB) is associated with modulation of levels of adipokines, specifically adiponectin and leptin, but the effect of standard antituberculosis treatment (ATT) on the systemic levels of adiponectin, resistin, and leptin has not been well explored. To identify the association of adipokines with PTB and their relationship with disease severity and bacterial burden, we measured the levels of adiponectin, resistin, and leptin in PTB individuals and compared them with latent tuberculosis (LTB) and healthy control (HC) individuals. Pulmonary tuberculosis was characterized by diminished circulating levels of adiponectin and leptin and heightened circulating levels of resistin in comparison to that in LTB and HC individuals. However, PTB with bilateral or cavitary disease did not exhibit any increased systemic levels of these adipokines in comparison with those with unilateral or non-cavitary disease, respectively. In addition, none of the adipokines exhibited a positive correlation with bacterial burdens, but adiponectin alone exhibited a negative correlation with body mass index in PTB individuals. Finally, on successful completion of ATT, PTB individuals exhibited significantly increased levels of adiponectin and leptin and significantly decreased levels of resistin. Therefore, our data identify an important association of systemic adipokine levels with PTB disease and its alteration following ATT.

Diminished circulating plasma and elevated lymph node culture supernatant levels of IL-10 family cytokines in tuberculous lymphadenitis

BackgroundIL-10 family cytokines are associated with the host immune response to pulmonary tuberculosis (PTB), but their association with host response in tuberculous lymphadenitis (TBL) is not known. MethodsHence, we examined the circulating levels of the whole panel of IL-10 family cytokines in TBL (n = 44) and compared them to the levels in PTB (n = 44) and healthy control (HC, n = 44) individuals. We also assessed the pre and post-treatment cytokine levels in TBL individuals following the completion of anti-tuberculosis treatment (ATT). Next, we also compared the levels of IL-10 family cytokine in circulation versus lymph node (LN) culture supernatants in a subset of TBL individuals (n = 22). Finally, we also measured the levels of IL-10 family cytokines in tuberculosis antigen (purified protein derivative, PPD) stimulated and unstimulated LN culture supernatants. ResultsTBL individuals exhibit significantly decreased levels of IL-10, IL-19, IL-20, IL-24, IL-28B and IL-29 in the circulation when compared to PTB (except IL-10) and HC (except IL-20 and IL-28B) and significantly increased levels of IL-22 when compared to PTB individuals. Following ATT, TBL individuals exhibit significantly elevated levels of IL-10, IL-19, IL-20, IL-24, IL-28B and IL-29 and significantly diminished levels of IL-26. Similarly, TBL individuals also exhibited significantly increased levels of IL-10, IL-19, IL-20, IL-24, IL-28A and IL-29 in LN culture supernatants compared to plasma and significantly decreased levels of IL-22. This was associated with enhanced levels of IL-19, IL-20, IL-24, IL-28B and IL-29 upon PPD stimulation of LN cultures. ConclusionsTherefore, we demonstrate that TBL is associated with significantly diminished plasma and elevated LN culture supernatant levels of most of the IL-10 family cytokines. This to our knowledge is the first comprehensive examination of IL-10 family cytokines in TBL.

Heightened Systemic Levels of Neutrophil and Eosinophil Granular Proteins in Pulmonary Tuberculosis and Reversal following Treatment.

Granulocytes are activated during Mycobacterium tuberculosis infection and act as immune effector cells, and granulocyte responses are implicated in tuberculosis (TB) pathogenesis. Plasma levels of neutrophil and eosinophil granular proteins provide an indirect measure of degranulation. In this study, we wanted to examine the levels of neutrophil and eosinophil granular proteins in individuals with pulmonary tuberculosis (PTB) and to compare them with the levels in individuals with latent TB (LTB). Hence, we measured the plasma levels of myeloperoxidase (MPO), neutrophil elastase, proteinase 3, major basic protein (MBP), eosinophil-derived neurotoxin (EDN), eosinophil cationic protein (ECP), and eosinophil peroxidase (EPX) in these individuals. Finally, we also measured the levels of all of these proteins in PTB individuals following antituberculosis treatment (ATT). Our data reveal that PTB individuals are characterized by significantly higher plasma levels of MPO, elastase, proteinase 3, as well as MBP and EDN in comparison to those in LTB individuals. Our data also reveal that ATT resulted in the reversal of all of these changes, indicating an association with TB disease. Finally, our data show that the systemic levels of MPO and proteinase 3 can significantly discriminate PTB from LTB individuals. Thus, our data suggest that neutrophil and eosinophil granular proteins could play a potential role in the innate immune response and, therefore, the pathogenesis of pulmonary TB.

Tuberculous Lymphadenitis Is Associated with Enhanced Baseline and Antigen-Specific Induction of Type 1 and Type 17 Cytokines and Reduced Interleukin-1β (IL-1β) and IL-18 at the Site of Infection.

Tuberculous lymphadenitis (TBL) is characterized by an expansion of Th1 and Th17 cells with altered serum levels of proinflammatory cytokines. However, the cytokine profile at the site of infection, i.e., the affected lymph nodes, has not been examined in detail. To estimate the baseline and mycobacterial antigen-stimulated concentrations of type 1, type 17, and other proinflammatory cytokines in patients with TBL (n = 14), we examined both the baseline and the antigen-specific concentrations of these cytokines before and after chemotherapy and compared them with those in individuals with pulmonary tuberculosis (PTB) (n = 14). In addition, we also compared the cytokine responses in whole blood and those in the lymph nodes of TBL individuals. We observed significantly enhanced baseline and antigen-specific levels of type 1 cytokines (gamma interferon [IFN-γ] and tumor necrosis factor alpha [TNF-α]) and a type 17 cytokine (interleukin-17 [IL-17]) and significantly diminished baseline and antigen-specific levels of proinflammatory cytokines (IL-1β and IL-18) in the whole blood of TBL individuals compared to those in the whole blood of PTB individuals. Moreover, we also observed a pattern of baseline and antigen-specific cytokine production at the site of infection (lymph node) similar to that in the whole blood of TBL individuals. Following standard antituberculosis (anti-TB) treatment, we observed alterations in the baseline and/or antigen-specific levels of IFN-γ, TNF-α, IL-1β, and IL-18. TBL is therefore characterized by enhanced baseline and antigen-specific production of type 1 and type 17 cytokines and reduced baseline and antigen-specific production of IL-1β and IL-18 at the site of infection.

Coincident pre-diabetes is associated with dysregulated cytokine responses in pulmonary tuberculosis.

BackgroundCytokines play an important role in the pathogenesis of pulmonary tuberculosis (PTB) - Type 2 diabetes mellitus co-morbidity. However, the cytokine interactions that characterize PTB coincident with pre-diabetes (PDM) are not known.MethodsTo identify the influence of coincident PDM on cytokine levels in PTB, we examined circulating levels of a panel of cytokines in the plasma of individuals with TB-PDM and compared them with those without PDM (TB-NDM).ResultsTB-PDM is characterized by elevated circulating levels of Type 1 (IFNγ, TNFα and IL-2), Type 17 (IL-17A and IL-17F) and other pro-inflammatory (IL-1β, IFNβ and GM-CSF) cytokines. TB-PDM is also characterized by increased systemic levels of Type 2 (IL-5) and regulatory (IL-10 and TGFβ) cytokines. Moreover, TB antigen stimulated whole blood also showed increased levels of pro-inflammatory (IFNγ, TNFα and IL-1β) cytokines as well. However, the cytokines did not exhibit any significant correlation with HbA1C levels or with bacterial burdens.ConclusionOur data reveal that pre-diabetes in PTB individuals is characterized by heightened cytokine responsiveness, indicating that a balanced pro and anti - inflammatory cytokine milieu is a feature of pre-diabetes - TB co-morbidity.

Role of pre-Xpert® screening using chest X-ray in early diagnosis of smear-negative pulmonary tuberculosis.

In a sub-district level hospital in South India, the proportion of patients with abnormal chest X-ray (CXR) was evaluated among smear-negative, Xpert® MTB/RIF (Xpert) positive individuals with pulmonary tuberculosis (PTB) symptoms; 384 smear-negative PTB individuals with PTB symptoms and without a history of anti-tuberculosis treatment underwent CXR and Xpert testing of one sputum specimen. Of 378 individuals with both Xpert and CXR results available, 14 were positive for Mycobacterium tuberculosis. Of these, 13 (92.9%) had an abnormal CXR and one was normal. This study highlights the usefulness of CXR before Xpert testing, which needs further validation.

Altered CD8+ T cell frequency and function in tuberculous lymphadenitis

CD8(+) T cells secreting Type1 and Type 17 cytokines and cytotoxic molecules play a major role in immunity and protection against pulmonary tuberculosis (PTB), although their role in tuberculous lymphadenitis (TBL) is not well known. To identify the distribution and function of CD8(+) T cells expressing Type1, Type 2 and Type 17 cytokines and cytotoxic molecules in TBL, we examined baseline and mycobacterial-antigen specific immune responses in the whole blood of individuals with PTB and compared them with TBL. TBL is characterized by elevated frequencies of baseline and mycobacterial-antigen stimulated CD8(+) T cells expressing Type 1 (IL-2 and TNFα) and Type 17 (IL-17A and IL-17F) cytokines in comparison to PTB individuals. In contrast, TBL individuals exhibited diminished frequency of CD8(+) T cells expressing perforin, granzyme B and CD107a. The blockade of IL-1R and IL-6R during antigenic stimulation resulted in significantly diminished frequencies of CD8(+) T cells expressing Type 1 and Type 17 cytokines in TBL. Therefore, our data suggest that TBL is characterized by an IL-1 and IL-6 dependent expansion of CD8(+) T cells expressing Type 1 and Type 17 cytokines as well as altered frequencies of cytotoxic molecules, reflecting an important association of these cells with the pathogenesis of TBL.

IL-10 Dependent Suppression of Type 1, Type 2 and Type 17 Cytokines in Active Pulmonary Tuberculosis

BackgroundAlthough Type 1 cytokine responses are considered protective in pulmonary tuberculosis (PTB), their role as well as those of Type 2, 17 and immunoregulatory cytokines in tuberculous lymphadenitis (TBL) and latent tuberculosis (LTB) have not been well studied.Aim and MethodsTo identify cytokine responses associated with pulmonary tuberculosis (TB), TB lymphadenitits and latent TB, we examined mycobacterial antigen-specific immune responses of PTB, TBL and LTB individuals. More specifically, we examined ESAT-6 and CFP-10 induced Type 1, Type 2 and Type 17 cytokine production and their regulation using multiplex ELISA.ResultsPTB individuals exhibited a significantly lower baseline as well as antigen-specific production of Type 1 (IFNγ, TNFα and IL-2); Type 2 (IL-4) and Type 17 (IL-17A and IL-17F) cytokines in comparison to both TBL and LTB individuals. TBL individuals exhibited significantly lower antigen-specific IFNγ responses alone in comparison to LTB individuals. Although, IL-10 levels were not significantly higher, neutralization of IL-10 during antigen stimulation resulted in significantly enhanced production of IFNγ, IL-4 and IL-17A in PTB individuals, indicating that IL-10 mediates (at least partially) the suppression of cytokine responses in PTB.ConclusionPulmonary TB is characterized by an IL-10 dependent antigen-specific suppression of Type 1, Type 2 and Type 17 cytokines, reflecting an important association of these cytokines in the pathogenesis of active TB.