As part of a major project to investigate protective and diagnostic immune markers against tuberculosis (TB), we measured antibody isotype responses to Mycobacterium tuberculosis (Mtb) antigens (LAM, ...Rv2031, and HBHA) in cohorts of 149 pulmonary tuberculosis patients (PTBP), 148 household contacts (HHCs), and 68 community controls (CCs) in an endemic setting. ELISA was used to measure levels of IgA, IgG, and IgM from sera of cohorts at baseline, and at 6 and 12 months from entry. The results show that there were significant differences in IgA, IgG, and IgM responses to the different antigens and in the three cohorts. At baseline, the level of IgM against RV2031 and LAM did not vary between cohorts, but the levels of IgA and IgG against Rv2031 were significantly higher in PTB patients than HHCs and CCs, followed by HHCs, and the lowest in CCs. In patients, there was a significant variation in antibody responses before and after chemotherapy. The levels of IgA and IgG against HBHA, and IgA against Rv2031 decreased significantly and remained low, while IgA and IgG against LAM increased significantly and remained high following chemotherapy. However, the levels of IgM against Rv2031 and LAM increased at 6 months but decreased again at 12 months. IgM against HBHA did not show any significant variation before and after chemotherapy. Similarly, there were also significant variations in antibody responses in HHCs over time. Our results show that there are significant variations in IgA, IgG and IgM responses to the different antigens and in the three cohorts, implying that not all antibody isotype responses are markers of clinical TB. In addition, the current and previous studies consistently show that IgA and IgG against Rv2031 discriminate between clinical disease, Mtb-infected and non-infected individuals.
Novel vaccines are needed to control tuberculosis (TB), the bacterial infectious disease that together with malaria and HIV is worldwide responsible for high levels of morbidity and mortality. TB can ...result from the reactivation of an initially controlled latent infection by
Mycobacterium tuberculosis (
Mtb).
Mtb proteins for which a possible role in this reactivation process has been hypothesized are the five homologs of the resuscitation-promoting factor of
Micrococcus luteus, namely
Mtb Rv0867c (
rpfA), Rv1009 (
rpfB), Rv1884c (
rpfC), Rv2389c (
rpfD) and Rv2450c (
rpfE). Analysis of the immune recognition of these 5 proteins following
Mtb infection or
Mycobacterium bovis BCG vaccination of mice showed that Rv1009 (rpfB) and Rv2389c (rpfD) are the most antigenic in the tested models. We therefore selected rpfB and rpfD for testing their vaccine potential as plasmid DNA vaccines. Elevated cellular immune responses and modest but significant protection against intra-tracheal
Mtb challenge were induced by immunization with the
rpfB encoding DNA vaccine. The results indicate that rpfB is the most promising candidate of the five rpf-like proteins of
Mtb in terms of its immunogenicity and protective efficacy and warrants further analysis for inclusion as an antigen in novel TB vaccines.
Perfluoroalkyl substances (PFAS) are man-made fluorinated chemicals, widely used in various types of consumer products, resulting in their omnipresence in human populations. The aim of this study was ...to describe current PFAS levels in European teenagers and to investigate the determinants of serum/plasma concentrations in this specific age group.
PFAS concentrations were determined in serum or plasma samples from 1957 teenagers (12–18 years) from 9 European countries as part of the HBM4EU aligned studies (2014–2021). Questionnaire data were post-harmonized by each study and quality checked centrally. Only PFAS with an overall quantification frequency of at least 60% (PFOS, PFOA, PFHxS and PFNA) were included in the analyses. Sociodemographic and lifestyle factors were analysed together with food consumption frequencies to identify determinants of PFAS exposure. The variables study, sex and the highest educational level of household were included as fixed factors in the multivariable linear regression models for all PFAS and each dietary variable was added to the fixed model one by one and for each PFAS separately.
The European exposure values for PFAS were reported as geometric means with 95% confidence intervals (CI): PFOS 2.13 μg/L (1.63–2.78), PFOA (0.97 μg/L (0.75–1.26)), PFNA 0.30 μg/L (0.19–0.45) and PFHxS 0.41 μg/L (0.33–0.52). The estimated geometric mean exposure levels were significantly higher in the North and West versus the South and East of Europe. Boys had significantly higher concentrations of the four PFAS compared to girls and significantly higher PFASs concentrations were found in teenagers from households with a higher education level. Consumption of seafood and fish at least 2 times per week was significantly associated with 21% (95% CI: 12–31%) increase in PFOS concentrations and 20% (95% CI: 10–31%) increase in PFNA concentrations as compared to less frequent consumption of seafood and fish. The same trend was observed for PFOA and PFHxS but not statistically significant. Consumption of eggs at least 2 times per week was associated with 11% (95% CI: 2–22%) and 14% (95% CI: 2–27%) increase in PFOS and PFNA concentrations, respectively, as compared to less frequent consumption of eggs. Significantly higher PFOS concentrations were observed for participants consuming offal (14% (95% CI: 3–26%)), the same trend was observed for the other PFAS but not statistically significant. Local food consumption at least 2 times per week was associated with 40% (95% CI: 19–64%) increase in PFOS levels as compared to those consuming local food less frequently.
This work provides information about current levels of PFAS in European teenagers and potential dietary sources of exposure to PFAS in European teenagers. These results can be of use for targeted monitoring of PFAS in food.
Abstract
Understanding the mechanisms and impact of booster vaccinations are essential in the design and delivery of vaccination programs. Here we show that a three dose regimen of a synthetic ...peptide vaccine elicits an accruing CD8
+
T cell response against one SARS-CoV-2 Spike epitope. We see protection against lethal SARS-CoV-2 infection in the K18-hACE2 transgenic mouse model in the absence of neutralizing antibodies, but two dose approaches are insufficient to confer protection. The third vaccine dose of the single T cell epitope peptide results in superior generation of effector-memory T cells and tissue-resident memory T cells, and these tertiary vaccine-specific CD8
+
T cells are characterized by enhanced polyfunctional cytokine production. Moreover, fate mapping shows that a substantial fraction of the tertiary CD8
+
effector-memory T cells develop from re-migrated tissue-resident memory T cells. Thus, repeated booster vaccinations quantitatively and qualitatively improve the CD8
+
T cell response leading to protection against otherwise lethal SARS-CoV-2 infection.
Interferon-γ release assays (IGRA) with Resuscitation promoting factor (Rpf) proteins enhanced tuberculosis (TB) screening and diagnosis in adults but have not been evaluated in children. Children ...often develop paucibacillary TB and their immune response differs from that of adults, which together affect TB disease diagnostics and immunodiagnostics. We assessed the ability of Rpf to identify infection among household TB-exposed children in The Gambia and investigated their ability to discriminate Mycobacterium tuberculosis complex (MTBC) infection from active TB disease in children.
Detailed clinical investigations were done on 93 household TB-exposed Gambian children and a tuberculin skin test (TST) was administered to asymptomatic children. Venous blood was collected for overnight stimulation with ESAT-6/CFP-10-fusion protein (EC), purified protein derivative and RpfA, B, C, D and E. Interferon gamma (IFN-γ) production was measured by ELISA in supernatants and corrected for the background level. Infection status was defined by IGRA with EC and TB disease by mycobacterial confirmation and/or clinical diagnosis. We compared IFN-γ levels between infected and uninfected children and between infected and TB diseased children using a binomial logistic regression model while correcting for age and sex. A Receiver Operating Characteristics analysis was done to find the best cut-off for IFN-γ level and calculate sensitivity and specificity.
Interferon gamma production was significantly higher in infected (IGRA+, n = 45) than in uninfected (IGRA-, n = 20) children after stimulation with RpfA, B, C, and D (P = 0.03; 0.007; 0.03 and 0.003, respectively). Using RpfB and D-specific IFN-γ cut-offs (33.9 pg/mL and 67.0 pg/mL), infection was classified with a sensitivity-specificity combination of 73-92% and 77-72% respectively, which was similar to and better than 65-75% for TST. Moreover, IFN-γ production was higher in infected than in TB diseased children (n = 28, 5 bacteriologically confirmed, 23 clinically diagnosed), following RpfB and D stimulation (P = 0.02 and 0.03, respectively).
RpfB and RpfD show promising results for childhood MTBC infection screening, and both performed similar to and better than the TST in our study population. Additionally, both antigens appear to discriminate between infection and disease in children and thus warrant further investigation as screening and diagnostic antigens for childhood TB.
Mycobacterium tuberculosis DosR regulon-encoded antigens are highly immunogenic in M. tuberculosis-infected humans and are associated with latent tuberculosis infection. We have investigated the ...hypothesis that infection with or exposure to nontuberculous mycobacteria (NTM) can induce cross-reactive immunity to M. tuberculosis DosR regulon-encoded antigens since responsiveness has been observed in non-M. tuberculosis-exposed but purified protein derivative-responsive individuals. M. tuberculosis DosR regulon-encoded antigen-specific T-cell responses were studied in peripheral blood mononuclear cells (PBMCs) of NTM-infected/exposed individuals. BLASTP was used to determine the presence of M. tuberculosis DosR regulon-encoded protein orthologs among environmental mycobacteria and nonmycobacteria. Significant gamma interferon production was observed in PBMCs from NTM-infected/exposed individuals in response to M. tuberculosis DosR regulon-encoded antigens. DosR regulon-encoded protein orthologs were prominently present in tuberculous and environmental mycobacteria and surprisingly also in nonmycobacteria. The ubiquitous presence of the highly conserved DosR master regulator protein Rv3133c suggests that this is a general adaptive bacterial response regulator. We report a first series of M. tuberculosis antigens to which cross-reactive immunity is induced by NTM infection/exposure. The high conservation of M. tuberculosis DosR regulon-encoded antigens most likely enables them to induce cross-reactive T-cell responses.
Background
Portal vein embolization (PVE) is performed to reduce the risk of liver failure and subsequent mortality after major liver resection. Although a cut‐off value of 2·7 per cent per min per ...m2 has been used with hepatobiliary scintigraphy (HBS) for future remnant liver function (FRLF), patients with perihilar cholangiocarcinoma (PHC) potentially benefit from an additional cut‐off of 8·5 per cent/min (not corrected for body surface area). Since January 2016 a more liberal approach to PVE has been adopted, including this additional cut‐off for HBS of 8·5 per cent/min. The aim of this study was to assess the effect of this approach on liver failure and mortality.
Methods
This was a single‐centre retrospective study in which consecutive patients undergoing liver resection under suspicion of PHC in 2000–2015 were compared with patients treated in 2016–2019, after implementation of the more liberal approach. Primary outcomes were postoperative liver failure (International Study Group of Liver Surgery grade B/C) and 90‐day mortality.
Results
Some 191 patients with PHC underwent liver resection. PVE was performed in 6·4 per cent (9 of 141) of the patients treated in 2000–2015 and in 32 per cent (16 of 50) of those treated in 2016–2019. The 90‐day mortality rate decreased from 16·3 per cent (23 of 141) to 2 per cent (1 of 50) (P = 0·009), together with a decrease in the rate of liver failure from 19·9 per cent (28 of 141) to 4 per cent (2 of 50) (P = 0·008). In 2016–2019, 24 patients had a FRLF greater than 8·5 per cent/min and no liver failure or death occurred, suggesting that 8·5 per cent/min is a reliable cut‐off for patients with suspected
PHC.
Conclusion
The major decrease in liver failure and mortality rates in recent years and the simultaneous increased use of PVE suggests an important role for PVE in reducing adverse outcomes after surgery for
PHC.
Antecedentes
La embolización de la vena porta (portal vein embolization, PVE) se realiza para reducir el riesgo de insuficiencia hepática y de mortalidad asociada después de una resección hepática mayor. Aunque con la gammagrafía hepato‐biliar (hepato‐biliary scintigraphy, HBS) se ha utilizado un punto de corte de 2,7%/min/m2 para la función hepática remanente futura (future remnant liver function, FRLF), los pacientes con colangiocarcinoma perihilar (perihilar cholangiocarcinoma, PHC) se beneficiarían potencialmente de un punto de corte adicional de 8,5%/min (no corregido para el área de superficie corporal). Desde enero de 2016, se adoptó un enfoque más liberal para la PVE, incluyendo este punto de corte adicional para la HBS de 8,5%/min. El objetivo de este estudio fue evaluar el efecto de este enfoque sobre la insuficiencia hepática y la mortalidad.
Métodos
Se trata de un estudio retrospectivo de un solo centro, en el que los pacientes consecutivos sometidos a resección hepática por sospecha de PHC entre 2000‐2016 se compararon con los pacientes tratados entre 2016‐2019, después de la implementación de un enfoque más liberal. Los objetivos primarios fueron la insuficiencia hepática postoperatoria (ISGLS grado B/C) y la mortalidad a los 90 días.
Resultados
Un total de 191 pacientes con PHC se sometieron a resección hepática. Se realizó PVE en el 6% (9/141) de los pacientes antes de 2016 y en el 32% (16/50) de los pacientes después de 2016. La mortalidad disminuyó del 16% (23/141) al 2% (1/50) (P = 0,009), junto con una disminución de la insuficiencia hepática del 20% (28/141) al 4% (2/50) (P = 0,008). Después de 2016, 20 pacientes tuvieron un FRLF > 8,5%/min y no se produjo insuficiencia hepática o mortalidad, lo que sugiere que el 8,5%/min es un punto de corte fiable para los pacientes con sospecha de PHC.
Conclusión
La disminución marcada de la insuficiencia hepática y de la mortalidad en los últimos años y el aumento simultáneo del uso de la PVE, sugiere que la PVE ha jugado un importante papel en el descenso de los resultados adversos después de la cirugía para el PHC.
The use of portal vein embolization (PVE) in patients undergoing major liver resection for perihilar cholangiocarcinoma at the authors' centre increased from 6·4 per cent in 2000–2015 to 32 per cent in 2016–2019. This increased use of PVE coincided with a major decrease in the postoperative liver failure rate, from 19·9 to 4 per cent, and a decrease in the 90‐day mortality rate, from 16·3 to 2 per cent. Using hepatobiliary scintigraphy, an additional cut‐off for future remnant liver function of 8·5 per cent/min (not corrected for body surface area) correlated with safe liver resection in patients with suspected perihilar cholangiocarcinoma.
Portal vein embolization decreases rates of liver failure and mortality
Interferon-gamma release assays based on region of difference 1 antigens have improved diagnosis of latent tuberculosis infection (LTBI). However, these tests cannot discriminate between recently ...acquired infection (higher risk of progression to active tuberculosis) and remote LTBI. The objective of the present study was to evaluate the T-cell interferon-gamma responses to Mycobacterium tuberculosis DosR-regulon-encoded antigens (latency antigens) compared with QuantiFERON TB-Gold In-Tube (QFT-GIT) in subjects at different stages of tuberculosis. A total of 16 individuals with remote LTBI and 23 with recent infection were studied; 15 controls unexposed to M. tuberculosis and 50 patients with active tuberculosis and 45 with cured tuberculosis were also analysed. The results indicated that subjects with remote LTBI showed significantly higher whole-blood interferon-gamma responses to M. tuberculosis latency antigen Rv2628 than did individuals with recent infection, active tuberculosis and controls (p<0.003), whereas no significant differences between these groups were found for other latency antigens tested (Rv2626c, Rv2627c, Rv2031c and Rv2032). The proportion of responders to Rv2628 was five-fold higher among QFT-GIT-positive-individuals with remote infection than among those with recently acquired infection. These data suggest that responses to M. tuberculosis latency antigen Rv2628 may associate with immune-mediated protection against tuberculosis. In contact-tracing investigations, these preliminary data may differentiate recent (positive QFT-GIT results without responses to Rv2628) from remote infection (positive to both tests).
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