Serum IL-18 levels in tuberculosis: comparison with pneumonia, lung cancer and healthy controls

Evaluation of alpha defensin, IL-1 receptor antagonist, and IL-18 levels in COVID-19 patients with macrophage activation syndrome and acute respiratory distress syndrome

Background

Many laboratory parameters have been associated with morbidity and mortality in SARS‐CoV‐2 (COVID‐19), which emerged in an animal market in Wuhan, China in December 2019 and has infected over 20 million people. This study investigated the relationship between serum interleukin (IL)‐18, IL‐1 receptor antagonist (IL‐1Ra), and alpha defensin levels and the clinical course and prognosis of COVID‐19.

Materials and Methods

This study included 100 patients who were admitted to the chest diseases department and intensive care unit of our hospital and diagnosed with COVID‐19 by real‐time polymerase chain reaction (PCR) of nasopharyngeal swab samples between March 24 and May 31, 2020. The control group consisted of 50 nonsymptomatic health workers with negative real‐time PCR results in routine COVID‐19 screening in our hospital.

Results

Serum alpha defensin, IL‐1Ra, and IL‐18 levels were significantly higher in patients who developed macrophage activation syndrome (MAS) and acute respiratory distress syndrome (ARDS) compared to patients who did not (p < .001 for all). Alpha defensin, IL‐1Ra, and IL‐18 levels were significantly higher in COVID‐19 patients with and without MAS or ARDS when compared to the control group (p < .001 for all). When the 9 patients who died were compared with the 91 surviving patients, IL‐1Ra and IL‐18 levels were found to be significantly higher in the nonsurvivors (p < .001).

Conclusion

Our findings of correlations between alpha defensin and levels of IL‐1Ra and IL‐18, which were previously shown to be useful in COVID‐19 treatment and follow‐up, indicates that it may also be promising in treatment.

Performance of metabonomic serum analysis for diagnostics in paediatric tuberculosis

We applied a metabonomic strategy to identify host biomarkers in serum to diagnose paediatric tuberculosis (TB) disease. 112 symptomatic children with presumptive TB were recruited in The Gambia and classified as bacteriologically-confirmed TB, clinically diagnosed TB, or other diseases. Sera were analysed using ¹H nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Multivariate data analysis was used to distinguish patients with TB from other diseases. Diagnostic accuracy was evaluated using Receiver Operating Characteristic (ROC) curves. Model performance was tested in a validation cohort of 36 children from the UK. Data acquired using ¹H NMR demonstrated a sensitivity, specificity and Area Under the Curve (AUC) of 69% (95% confidence interval [CI], 56-73%), 83% (95% CI, 73-93%), and 0.78 respectively, and correctly classified 20% of the validation cohort from the UK. The most discriminatory MS data showed a sensitivity of 67% (95% CI, 60-71%), specificity of 86% (95% CI, 75-93%) and an AUC of 0.78, correctly classifying 83% of the validation cohort. Amongst children with presumptive TB, metabolic profiling of sera distinguished bacteriologically-confirmed and clinical TB from other diseases. This novel approach yielded a diagnostic performance for paediatric TB comparable to that of Xpert MTB/RIF and interferon gamma release assays.

Use of TBAg/PHA ratio in distinguishing tuberculoma from cancer in solitary pulmonary nodule or mass

INTRODUCTION

Differentiation of tuberculoma from cancer in solitary pulmonary nodule or mass still remains a major challenge in diagnostic laboratories.

OBJECTIVES

The objective of this study is to determine the performance of T-SPOT.TB assay in discriminating these 2 diseases.

METHODS

We prospectively enrolled 331 patients with a solitary pulmonary nodule or mass on computed tomography scans. Conventional tests and T-SPOT.TB assay were simultaneously performed in all participants.

RESULTS

Our results showed that the performance of directly using T-SPOT.TB results in distinguishing tuberculoma from cancer in solitary pulmonary nodule or mass was not satisfactory because of moderate sensitivity and specificity. However, a further calculation of the ratio of TB-specific antigen (TBAg) to phytohemagglutinin (PHA) (TBAg/PHA ratio) of T-SPOT.TB assay may lead to improvement in distinguishing these 2 diseases. If using the threshold value of 0.236, the sensitivity and specificity of the TBAg/PHA ratio in distinguishing tuberculoma from cancer in solitary pulmonary nodule or mass were, respectively, 80.6% and 93.3%. The area under the curve (AUC) of the receiver operating characteristic curve was 0.921 (95% confidence interval, 0.875-0.967). Furthermore, the TBAg/PHA ratio may also be used to distinguish tuberculoma from other benign diseases (AUC: 0.909, sensitivity: 85.07%, specificity: 90%).

CONCLUSIONS

Calculation of the TBAg/PHA ratio might provide a useful non-invasive tool for distinguishing tuberculoma from cancer in patients with a solitary pulmonary nodule or mass in TB-endemic countries.

Lack of Association between Interleukin-18 –607 C/A Gene Polymorphism and Pulmonary Tuberculosis in Zahedan, Southeast Iran

Interleukin-18 (IL-18) plays a critical role in immune response, contributing to the pathogenesis and pathophysiology of infectious diseases. Polymorphisms in the IL-18 genes are known to influence expression levels and may be associated with outcome of infections. The objective of this study was to determine whether the presence of IL-18 polymorphisms –607 A/C (rs1946518) was associated with tuberculosis disease. We investigated the functional polymorphism of IL-18 (rs1946518) in 174 patients with pulmonary tuberculosis (PTB) and 177 healthy subjects. Genotype analysis was done using tetra amplification refractory mutation system-PCR (T-ARMS-PCR). The allelic and genotypic frequencies of the IL-18 polymorphism did not differ significantly between PTB and the controls. Our finding suggests that IL-18 polymorphism (rs1946518) may not be a risk factor for susceptibility to tuberculosis in a sample of Iranian population. Further studies are required to validate our findings.

Unmet needs in respiratory diseases : "You can't know where you are going until you know where you have been"--Anonymous

The care of patients with respiratory diseases has improved vastly in the past 50 years. In spite of that, there are still massive challenges that have not been resolved. Although the incidence of tuberculosis has decreased in the developed world, it is still a significant public health problem in the rest of the world. There are still over 2 million deaths annually from tuberculosis, with most of these occurring in the developing world. Even with the development of new pharmaceuticals to treat tuberculosis, there is no indication that the disease will be eradicated. Respiratory syncytial virus, severe acute respiratory syndrome, and pertussis are other respiratory infectious diseases with special problems of their own, from vaccine development to vaccine coverage. Asthma, one of the most common chronic diseases in children, still accounts for significant mortality and morbidity, as well as high health care costs worldwide. Even in developed countries such as the USA, there are over 4,000 deaths per year. Severe asthma presents a special problem, but the question is whether there can be one treatment pathway for all patients with severe asthma. Severe asthma is a heterogeneous disease with many phenotypes and endotypes. The gene for cystic fibrosis was discovered over 24 years ago. The promise of gene therapy as a cure for the disease has fizzled out, and while new antimicrobials and other pharmaceuticals promise improved longevity and better quality of life, the average life span of a patient with cystic fibrosis is still at about 35 years. What are the prospects for gene therapy in the twenty-first century? Autoimmune diseases of the lung pose a different set of challenges, including the development of biomarkers to diagnose and monitor the disease and biological modulators to treat the disease.

Relationship between single nucleotide polymorphism of interleukin-18 and susceptibility to pulmonary tuberculosis in the Chinese Han population

Interleukin-18 (IL-18) is a multi-functional cytokine capable of inducing either Th1 or Th2 polarization depending on the immunologic milieu. IL-18 may influence the host response to Mycobacterium tuberculosis (M.tb) infection. To investigate the relationship between single nucleotide polymorphisms of the IL-18 and susceptibility to pulmonary tuberculosis in the Chinese Han population, the IL-18 gene was sequenced to detect polymorphisms and to examine the genotype frequencies in 300 patients and 702 healthy controls. DNA sequencing revealed three IL-18 variants: rs1946518, rs5744247, and rs549908. It also revealed that allele A of rs1946518 confers a 1.47-fold increased risk of developing tuberculosis (TB) (P = 0.0001, OR [95%CI] = 1.47 [1.21-1.78]), and that the C allele of rs5744247 confers a 0.77-fold decreased risk of disease (P = 0.01, R [95%CI] = 0.77 [0.632-0.937]). The genotypes rs1946518, rs5744247 and rs549908 were found to be significantly associated with TB. Estimation of the frequencies of haplotypes revealed a potential risk haplotype AGA (P = 0.01, OR [95%CI] = 1.41 [1.15-1.72]) and a protective haplotype CCA (P = 0.01, OR [95%CI] = 0.70 [0.57-0.85]) for TB. The present findings suggest that polymorphisms in the IL-18 gene may affect susceptibility to TB and increase the risk of developing the disease in the Chinese Han population.

Production of TNF-alpha, IL-12(p40) and IL-17 can discriminate between active TB disease and latent infection in a West African cohort

Background

Mycobacterium tuberculosis (MTb) infects approximately 2 billion people world-wide resulting in almost 2 million deaths per year. Determining biomarkers that distinguish different stages of tuberculosis (TB) infection and disease will provide tools for more effective diagnosis and ultimately aid in the development of new vaccine candidates. The current diagnostic kits utilising production of IFN-γ in response to TB antigens can detect MTb infection but are unable to distinguish between infection and disease. The aim of this study was to assess if the use of a longer term assay and the analysis of multiple cytokines would enhance diagnosis of active TB in a TB-endemic population.

Methods

We compared production of multiple cytokines (TNF-α, IFN-γ, IL-10, IL-12(p40), IL-13, IL-17 and IL-18) following long-term (7 days) stimulation of whole-blood with TB antigens (ESAT-6/CFP-10 (EC), PPD or TB10.4) from TB cases (n = 36) and their Mycobacterium-infected (TST+; n = 20) or uninfected (TST−; n = 19) household contacts (HHC).

Results and Conclusions

We found that TNF-α production following EC stimulation and TNF-α and IL-12(p40) following TB10.4 stimulation were significantly higher from TB cases compared to TST+ HHC, while production of IFN-γ and IL-13 were significantly higher from TST+ compared to TST- HHC following PPD or EC stimulation. Combined analysis of TNF-α, IL-12(p40) and IL-17 following TB10.4 stimulation resulted in 85% correct classification into TB cases or TST+ HHC. 74% correct classification into TST+ or TST− HHC was achieved with IFN-γ alone following TB10.4 stimulation (69% following EC) and little enhancement was seen with additional cytokines. We also saw a tendency for TB cases infected with M. africanum to have increased TNF-α and IL-10 production compared to those infected with M. tuberculosis. Our results provide further insight into the pathogenesis of tuberculosis and may enhance the specificity of the currently available diagnostic tests, particularly for diagnosis of active TB.

Suction blister fluid as potential body fluid for biomarker proteins

Early diagnosis is important for effective disease management. Measurement of biomarkers present at the local level of the skin could be advantageous in facilitating the diagnostic process. The analysis of the proteome of suction blister fluid, representative for the interstitial fluid of the skin, is therefore a desirable first step in the search for potential biomarkers involved in biological pathways of particular diseases. Here, we describe a global analysis of the suction blister fluid proteome as potential body fluid for biomarker proteins. The suction blister fluid proteome was compared with a serum proteome analyzed using identical protocols. By using stringent criteria allowing less than 1% false positive identifications, we were able to detect, using identical experimental conditions and amount of starting material, 401 proteins in suction blister fluid and 240 proteins in serum. As a major result of our analysis we construct a prejudiced list of 34 proteins, relatively highly and uniquely detected in suction blister fluid as compared to serum, with established and putative characteristics as biomarkers. We conclude that suction blister fluid might potentially serve as a good alternative biomarker body fluid for diseases that involve the skin.

Induction of serum IL-18 withPropionibacterium acnesand lipopolysaccharide in phagocytic macrophage-inactivated mice

IL-18, an important regulator of immune responses, is expressed in activated macrophages and also in nonimmune cells, such as keratinocytes and epithelial cells. Increased levels of serum IL-18 are reported in patients with a wide variety of diseases, but it is unclear which type of cell is the major source of serum IL-18. Here, we showed that the administration of liposomes encapsulating clodronate (Clo-lip) in mice selectively depleted F4/80(+) phagocytic macrophages in the liver and spleen. Serum levels of mature IL-18 with 18 kDa were increased markedly in mice treated with Propionibacterium acnes and LPS, whereas administration of Clo-lip and gadolinium chloride, another widely used macrophage inactivator, showed no obvious effect on serum IL-18 levels, which were marginal in the liver, lung, and spleen and more pronounced in the intestines, especially in the duodenum. Treatment with P. acnes alone induced IL-18 more than twofold in each organ, and P. acnes and LPS induced a marked increase in IL-18 levels in the liver and spleen but decreased in the intestines. The administration of Clo-lip showed only a marginal effect on the IL-18 levels in these organs. Furthermore, serum levels of liver enzymes and TNF-alpha and liver injury (necrotic change and granuloma formation) induced by P. acnes and LPS were reduced moderately by Clo-lip. These results suggest that phagocytic macrophages do not actively contribute to the induction of serum IL-18 and liver injury in mice treated with P. acnes and LPS.

The relationship between serum endothelin (ET)-1 and wheezing status in the children with Mycoplasma pneumoniae pneumonia

Although Mycoplasma pneumoniae infection is known to be associated with acute wheezing and the exacerbation of asthma, the mechanism by which this pathogen contributes to the development of wheeze-related symptoms is not fully understood. The aim of our study was to examine serum endothelin (ET)-1 and other cytokines in acute M. pneumoniae pneumonia and investigate if there is any relation between these inflammatory mediators and the occurrence of wheezing. We studied 53 patients, aged 3-13 yr, who admitted with pneumonia. These patients were divided into three groups: M. pneumoniae pneumonia with wheeze (n=23) and without wheeze (n=19), and the patients without the evidence of M. pneumoniae infection (n=11). Age-matched controls (n=10) were also studied. The serum concentrations of ET-1, interleukin (IL)-5 and IL-18 were measured using ELISA kits in patient groups and controls. The patients with M. pneumoniae pneumonia had significantly higher serum ET-1 than those without evidence of M. pneumoniae infection. In the presence of M. pneumoniae pneumonia, ET-1 concentrations were significantly higher in the patients with wheeze than those without wheeze. IL-5 and IL-18 in each patient group were higher compared to controls. However, no significant between-group difference was observed. Total serum IgE levels were significantly higher in the patients with M. pneumoniae pneumonia and wheeze than in those without wheeze. A positive correlation was observed between serum ET-1 and total IgE in the patients with M. pneumoniae pneumonia and wheeze. Our results may suggest a role of ET-1 in the occurrence of acute wheezing or exacerbation of asthma associated with M. pneumoniae pneumonia.