Identification of circulating monocytes as producers of tuberculosis disease biomarker C1q.

Tuberculosis (TB) is a prevalent disease causing an estimated 1.6 million deaths and 10.6 million new cases annually. Discriminating TB disease from differential diagnoses can be complex, particularly in the field. Increased levels of complement component C1q in serum have been identified as a specific and accessible biomarker for TB disease but the source of C1q in circulation has not been identified. Here, data and samples previously collected from human cohorts, a clinical trial and a non-human primate study were used to identify cells producing C1q in circulation. Cell subset frequencies were correlated with serum C1q levels and combined with single cell RNA sequencing and flow cytometry analyses. This identified monocytes as C1q producers in circulation, with a pronounced expression of C1q in classical and intermediate monocytes and variable expression in non-classical monocytes.

Radiological and long-term clinical response to elexacaftor/tezacaftor/ivacaftor in people with cystic fibrosis with advanced lung disease.

INTRODUCTION: A triple combination of CFTR modulators ELE/TEZ/IVA (elexacaftor/tezacaftor/ivacaftor, Trikafta™) has been evaluated in clinical trials for people with cystic fibrosis (pwCF) and was approved to the European and US market. During registration and settling reimbursement in Europe, it could be requested on a compassionate use basis, for patients with advanced lung disease (ppFEV1 < 40). AIM: The aim of this study is to evaluate 2 years of experience with the clinical and radiological response of ELE/TEZ/IVA in pwCF in a compassionate use setting. METHODS: pwCF who started ELE/TEZ/IVA in a compassionate use setting were prospectively followed with assessment of spirometry, BMI, chest CT, CFQ-R and sweat chloride concentration (SCC) before start and after 3 months. Furthermore, spirometry, sputum cultures, and BMI were repeated after 1, 6, 12, 18, and 24 months. RESULTS: Eighteen patients were eligible for this evaluation, nine with F508del/F508del genotype (eight of whom were using dual CFTR modulators) and nine with F508del/minimal function mutation. After 3 months, mean change in SCC was -44.9 (p ≤ 0.001), together with significant improvement in CT (change in Brody score: -28.27 p ≤ 0.001) and CFQ-R results (change in respiratory domain: +18.8, p = 0.002). After 24 months, ppFEV1 change was +8.89 (p = 0.002), BMI had improved by +1.53 kg/m2 (p ≤ 0.001) and exacerbation rate declined from 5.94 in 24 months before start to 1.17 (p ≤ 0.001) in the 24 months after. CONCLUSION: pwCF with advanced lung disease experience relevant clinical benefit after 2 years of treatment with ELE/TEZ/IVA in a compassionate use setting. Structural lung damage, quality of life, exacerbation rate, and BMI improved significantly with treatment. Gain in ppFEV1 is lower compared to the phase III trials that included younger patients with moderately affected lung function.

Epidemiology and management of nontuberculous mycobacterial disease in people with cystic fibrosis, the Netherlands.

BACKGROUND: Nontuberculous mycobacteria (NTM) are opportunistic, difficult to treat pathogens. With increasing prevalence of NTM infections in people with cystic fibrosis (pwCF) and the improved life expectancy, the burden is expected to grow. METHODS: We assessed the epidemiology and management of NTM isolation and disease in pwCF in the Netherlands using a survey and retrospective, case-controlled data from the Dutch CF Registry. We determined the isolation prevalence, treatment and outcomes from 2013-2019. RESULTS: NTM isolation prevalence increased from 1.0% to 3.6% (2013-2019). This was a single NTM isolation in 53.7% of the adults and 60.0% of the children. M. abscessus and M. avium complex (MAC) were most frequent (47.1 and 30.9%). Of the treated pwCF, 48.5% attained culture conversion of M. abscessus; 54.5% for MAC. Children with an NTM isolation showed more infections with S. maltophilia and/or A. fumigatus (p < 0.001) compared to controls. In the year prior to NTM isolation, children in the NTM group had a lower mean FEV1% predicted (81.5 ± 16.7 vs. 88.6 ± 15.3, p = 0.024), while adults in the NTM group had more IV antibiotic days compared to controls (60 vs. 17, p = 0.047). In the following years, FEV1% predicted declined faster in pwCF with NTM than the control group (children: -3.8% vs. -1.6%, p = 0.023; adults: -0.7% and 0.4%, ns). CONCLUSIONS: The isolation prevalence of 3.6%, poor treatment outcomes and associated lung function decline emphasize that NTM pulmonary disease (NTM-PD) is a significant health issue among pwCF in the Netherlands. Its prevention and treatment require increased attention.

Serum Biomarker Profile Including CCL1, CXCL10, VEGF, and Adenosine Deaminase Activity Distinguishes Active From Remotely Acquired Latent Tuberculosis.

Introduction: There is an urgent medical need to differentiate active tuberculosis (ATB) from latent tuberculosis infection (LTBI) and prevent undertreatment and overtreatment. The aim of this study was to identify biomarker profiles that may support the differentiation between ATB and LTBI and to validate these signatures. Materials and Methods: The discovery cohort included adult individuals classified in four groups: ATB (n = 20), LTBI without prophylaxis (untreated LTBI; n = 20), LTBI after completion of prophylaxis (treated LTBI; n = 20), and healthy controls (HC; n = 20). Their sera were analyzed for 40 cytokines/chemokines and activity of adenosine deaminase (ADA) isozymes. A prediction model was designed to differentiate ATB from untreated LTBI using sparse partial least squares (sPLS) and logistic regression analyses. Serum samples of two independent cohorts (national and international) were used for validation. Results: sPLS regression analyses identified C-C motif chemokine ligand 1 (CCL1), C-reactive protein (CRP), C-X-C motif chemokine ligand 10 (CXCL10), and vascular endothelial growth factor (VEGF) as the most discriminating biomarkers. These markers and ADA(2) activity were significantly increased in ATB compared to untreated LTBI (p ≤ 0.007). Combining CCL1, CXCL10, VEGF, and ADA2 activity yielded a sensitivity and specificity of 95% and 90%, respectively, in differentiating ATB from untreated LTBI. These findings were confirmed in the validation cohort including remotely acquired untreated LTBI participants. Conclusion: The biomarker signature of CCL1, CXCL10, VEGF, and ADA2 activity provides a promising tool for differentiating patients with ATB from non-treated LTBI individuals.

Management of Individual Patient Expectations When Starting with Highly Effective CFTR Modulators.

Highly effective CFTR modulators such as elexacaftor/tezacaftor/ivacaftor (ELE/TEZ/IVA will become available for an increasing number of people with cystic fibrosis (pwCF) in the near future. Before the start of this therapy, many questions may arise concerning the expected effects. We assembled the currently available data from the literature about ELE/TEZ/IVA that focused on commonly asked questions from patients. Overall, the literature so far presents a very hopeful prospect of effects, not only on lung function, but also on nutritional status, sinonasal symptoms and quality of life. The effects in patients with pwCF with severe lung damage are also favorable. Treatment is generally well tolerated. In some cases, patient-derived cell models can help in predicting the effects for individual patients.

Whole Blood Mycobacterial Growth Assays for Assessing Human Tuberculosis Susceptibility: A Systematic Review and Meta-Analysis.

Background: Whole blood mycobacterial growth assays (WBMGA) quantify mycobacterial growth in fresh blood samples and may have potential for assessing tuberculosis vaccines and identifying individuals at risk of tuberculosis. We evaluated the evidence for the underlying assumption that in vitro WBMGA results can predict in vivo tuberculosis susceptibility. Methods: A systematic search was done for studies assessing associations between WBMGA results and tuberculosis susceptibility. Meta-analyses were performed for eligible studies by calculating population-weighted averages. Results: No studies directly assessed whether WBMGA results predicted tuberculosis susceptibility. 15 studies assessed associations between WBMGA results and proven correlates of tuberculosis susceptibility, which we divided in two categories. Firstly, WBMGA associations with factors believed to reduce tuberculosis susceptibility were statistically significant in all eight studies of: BCG vaccination; vitamin D supplementation; altitude; and HIV-negativity/therapy. Secondly, WBMGA associations with probable correlates of tuberculosis susceptibility were statistically significant in three studies of tuberculosis disease, in a parasitism study and in two of the five studies of latent tuberculosis infection. Meta-analyses for associations between WBMGA results and BCG vaccination, tuberculosis infection, tuberculosis disease and HIV infection revealed consistent effects. There was considerable methodological heterogeneity. Conclusions: The study results generally showed significant associations between WBMGA results and correlates of tuberculosis susceptibility. However, no study directly assessed whether WBMGA results predicted actual susceptibility to tuberculosis infection or disease. We recommend optimization and standardization of WBMGA methodology and prospective studies to determine whether WBMGA predict susceptibility to tuberculosis disease.

Positive predictive value of ELISpot in BAL and pleural fluid from patients with suspected pulmonary tuberculosis.

BACKGROUND: The aim of this study was to evaluate the positive predictive value (PPV) of ELISpot in bronchoalveolar lavage (BAL) and pleural fluid for the diagnosis of active tuberculosis (TB) in real-life clinical practice, together with the added value of a cut-off >1.0 for the ratio between the extra-sanguineous and systemic interferon-gamma responses in positive samples. METHODS: A retrospective, single-centre study was performed. Patients with positive ELISpot in BAL and pleural fluid were included. RESULTS: The PPV for TB in patients with positive ELISpot in BAL (n = 40) was 64.9%, which increased to 82.6% for the ESAT-6 panel and 71.4% for the CFP-10 panel after the introduction of a cut-off >1.0 for the ratio between the BAL and blood interferon-gamma responses. In patients with positive ELISpot in pleural fluid (n = 16), the PPV for TB was 85.7%, which increased to 91.7% for the ESAT-6 panel and 92.3% for the CFP-10 panel after the introduction of a cut-off >1.0 for the ratio between the pleural fluid and blood interferon-gamma responses. CONCLUSIONS: This report describes the PPV of ELISpot in BAL and pleural fluid for the diagnosis of active TB in real-life clinical practice. The results indicate the possibility of an increase of the PPV using a cut-off >1.0 for the ratio between the extra-sanguineous and systemic interferon-gamma responses. Further studies are needed to underline this ratio-approach and to evaluate the full diagnostic accuracy of ELISpot in extra-sanguineous fluids like BAL and pleural fluid.

Sarcoidosis and Purified Protein Derivative reactivity.

BACKGROUND: The possible association between (tuberculous and nontuberculous) mycobacterial infections and sarcoidosis is still a matter of dispute. Using diagnostic tests for specific T-cell responses, this association can be investigated in an innovative manner. OBJECTIVE: To measure the T-cell responsiveness to the purified protein derivative (PPD) antigen in blood and broncho-alveolar lavage (BAL) fluid in patients with sarcoidosis and patients with other causes of interstitial lung disease. It was hypothesized that if a mycobacterial infection of the lung is of importance for the development of sarcoidosis, T-cell responsiveness towards the PPD antigen would be increased in patients with sarcoidosis when compared to patients with other causes of interstitial lung disease. METHODS: A single-center study was conducted which included patients with and without sarcoidosis. Venous blood was collected and BAL was performed for, inter alia, Interferon Gamma Release Assay´s (IGRA) with different stimulating antigens, including PPD, ESAT-6, CFP-10 and, as a control, Epstein-Barr virus (EBV). RESULTS: A total of 118 patients were included. There is no difference between PPD reactivity in BAL fluid in patients with or without sarcoidosis. In patients without sarcoidosis, ELISpot PPD in blood shows more reactivity compared to patients with sarcoidosis, although this difference is not significant. ELISpot EBV and TB results are not significant different between both groups. CONCLUSION: These results provide no evidence for the involvement of different mycobacteria in the pathogenesis of sarcoidosis.

Tuberculosis during TNF-α inhibitor therapy, despite screening.

As part of a prospective study on the safety of TNF-α inhibitor therapy after screening for and treatment of latent tuberculosis infection (LTBI), we report two patients who developed active tuberculosis (TB) infection during TNF-α inhibitor therapy, despite negative screening for LTBI. The clinical history is suggestive of a primary infection acquired during travelling to TB-endemic countries. In this lesson of the month we would like to highlight the risk of travelling to TB-endemic areas in patients treated with TNF-α inhibitor therapy. Screening for latent tuberculosis infection is not enough to prevent tuberculosis in patients treated with TNF-α inhibitor therapy.

Proteins involved in extracellular matrix dynamics are associated with respiratory syncytial virus disease severity.

Severity of respiratory syncytial virus (RSV) infection ranges widely. To what extent the local immune response is involved in RSV disease pathogenesis and which markers of this response are critical in determining disease severity is still a matter of debate. The local immune response was studied in nasopharyngeal aspirates (NPAs) during RSV infection. 47 potential markers of disease severity were analysed in a screening cohort of RSV-infected infants with mild disease at home (n = 8), hospitalised infants (n = 10) and infants requiring mechanical ventilation (n = 7). Results were confirmed in a cohort of infants hospitalised for RSV infection (n = 200). Finally, genetic validation was studied in a cohort of infants hospitalised for RSV infection (n = 465) and healthy controls (n = 930). The concentration of TIMP-1 (tissue inhibitor of metalloproteinase) was higher in the NPAs of hospitalised infants compared with the NPAs of infants at home (1,199 versus 568 ng · mL(-1); p<0.0001). Similar results were found for matrix metalloproteinase (MMP)-3 (765 versus 370 pg · mL(-1); p = 0.004). MMP-3 was confirmed as a marker of disease severity in a larger cohort and MMP3 gene polymorphism rs522616 was associated with severe RSV infection (OR 0.82, p<0.05). In conclusion, extracellular matrix proteinases play an important role in the pathogenesis of RSV bronchiolitis.