Treatment of MDR, Pre-XDR, XDR, and Rifampicin-Resistant Tuberculosis or in Case of Intolerance to at Least Rifampicin in Austria, Germany, and Switzerland.

Based on the assessment of new evidence, the World Health Organization (WHO) updated its guidelines for the treatment of drug-resistant tuberculosis (TB) in December 2022. The new recommendations and the latest study data made it necessary to update the existing guideline on the treatment of at least rifampicin-resistant TB (RR-TB) for the German-speaking countries, replacing the respective chapters of the treatment guidelines published in 2022. A shortened treatment of proven RR-TB and multidrug-resistant TB for at least 6 months using the fixed and non-modifiable drug combination of bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaLM) is now also recommended for Austria, Germany, and Switzerland under certain conditions considering the existing barriers for the implementation of the new treatment regimen. For the treatment of pre-extensively drug-resistant (pre-XDR-) TB, an individualized treatment for 18 months continues to be the primary recommendation. The non-modifiable drug combination of bedaquiline, pretomanid, and linezolid (BPaL) may be used alternatively in selected pre-XDR-TB cases, provided that all prerequisites are met. The necessary requirements for using BPaLM and BPaL are presented in detail in this amendment to the consensus-based TB treatment guideline for adult patients.

[Treatment of MDR, pre-XDR, XDR and rifampicin resistant tuberculosis or in case of intolerance to at least rifampicin in Austria, Germany and Switzerland - Amendment dated 19.09.2023 to the Sk2-Guideline: Tuberculosis in adulthood of the German Central Committee against Tuberculosis (DZK) on behalf of the German Respiratory Society (DGP)]. / Therapie bei MDR-, prä-XDR-, XDR-Tuberkulose und Rifampicin-Resistenz oder bei Medikamentenunverträglichkeit gegenüber mindestens Rifampicin.

In December 2022, based on the assessment of new evidence, the World Health Organization (WHO) updated its guidelines for the treatment of drug-resistant tuberculosis (TB). The evaluation of both, these recommendations, and the latest study data, makes it necessary to update the existing guidelines on the treatment of at least rifampicin-resistant tuberculosis for the German-speaking region, hereby replacing the respective chapters. A shortened MDR-TB treatment of at least 6 month using the fixed and non-modifiable drug combination of bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaLM) is now also recommended for Germany, Austria, and Switzerland under certain conditions. This recommendation applies to TB cases with proven rifampicin resistance, including rifampicin monoresistance. For treatment of pre-extensively drug resistant TB (pre-XDR-TB), an individualized treatment for 18 months adjusted to resistance data continues to be the primary recommendation. The non-modifiable drug combination of bedaquiline, pretomanid, and linezolid (BPaL) may be used alternatively in pre-XDR TB if all prerequisites are met. The necessary prerequisites for the use of BPaLM and BPaL are presented in this amendment to the S2k guideline for 'Tuberculosis in adulthood'.

[Tuberculosis in adulthood - The Sk2-Guideline of the German Central Committee against Tuberculosis (DZK) and the German Respiratory Society (DGP) for the diagnosis and treatment of adult tuberculosis patients]. / Tuberkulose im Erwachsenenalter.

In Germany tuberculosis is a rare disease and usually well treatable. Worldwide it is one of the most common infectious diseases with approximately 10 million new cases every year. Even with low incidences in Germany, tuberculosis is an important differential diagnosis especially due to international developments and migration movements. With a decreasing experience there's a continuous demand on accurate and up-to-date information. This guideline covers all aspects of microbiological diagnostics, basic principles of standard therapy, treatment of extrapulmonary tuberculosis, management of side effects, special features of diagnosis and treatment of resistant tuberculosis, and treatment in TB-HIV coinfection. Also, it explains when treatment in specialized centers is required, aspects of care and legal regulations and the diagnosis and preventive therapy of latent tuberculosis infection. The update of the S2k guideline "Tuberculosis in Adults" is intended to serve as a guideline for prevention, diagnosis, and treatment of tuberculosis for all those involved in tuberculosis care and to help meet the current challenges in dealing with tuberculosis in Germany.

T-cells of invasive candidiasis patients show patterns of T-cell-exhaustion suggesting checkpoint blockade as treatment option.

OBJECTIVE: Recent data imply that strengthening host immunity by checkpoint inhibition improves outcome in invasive fungal infections (IFI), particularly in candidiasis. METHODS: To assess T-cell exhaustion in this context, we compared peripheral blood mononuclear cells (PBMCs) and serum samples of patients with invasive Candida albicans infection (IC, n = 21) to PBMCs or tumor-infiltrating lymphocytes (TILs) from cancer patients (n = 14) and PBMCs of healthy controls (n = 20). Type and differentiation of lymphocytes and expression of 29 immune-regulatory molecules were analyzed by flow cytometry. C. albicans specific responses were assessed by FluoroSpot (n = 8) and antibody measurement (n = 14). RESULTS: Fractions and phenotypes of lymphocyte subsets in PBMCs of IC patients were similar compared to PBMCs of controls, while they were different in TILs. PBMCs of patients with IC showed increased expression of immune-checkpoint molecules. The pattern of upregulated molecules was similar to TILs, but not present in PBMCs of control cancer patients. Fractions of T-cells expressing PD-1 and TIGIT were higher in IC patients that died. FluoroSpot analysis showed a Candida-specific IFN-y or IL-2 response in 5/8 patients, enhanced by addition of nivolumab in vitro. CONCLUSIONS: Together with preclinical data and preliminary evidence of clinical efficacy in mucormycosis, our results support clinical evaluation of immune-checkpoint inhibition in IFI treatment. TRIAL REGISTRATION: NCT04533087; retrospectively registered on August 31, 2020.

Publisher Correction: Tumor-necrosis factor impairs CD4+ T cell-mediated immunological control in chronic viral infection.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Analyzing candidemia guideline adherence identifies opportunities for antifungal stewardship.

Candidemia epidemiology varies significantly by region; thus, local data are essential for evidence-based decision-making in prophylaxis and treatment. Current management strategies are derived from large randomized controlled trials mostly executed in large high-volume tertiary care centers. Results may not be entirely transferable to smaller hospitals. This study investigates epidemiology, diagnosis, and treatment standards in six hospitals in the Cologne metropolitan area (number of inhabitants approx. one million). We assessed adherence to the current guideline of the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and the Infectious Diseases Society of America (IDSA) using the EQUAL Candida Score of the European Confederation of Medical Mycology (ECMM). Data were documented by trained medical students as part of an integrated research and teaching concept at the University of Cologne. Between January 2014 and June 2017, 77 patients had candidemia, corresponding to an incidence of 0.2 cases/1000 admissions. While 55 patients were enrolled, 22 patients were excluded due to incompletely retrievable health records. Fluconazole monotherapy was the preferred first-line treatment in cases with Candida albicans infection (21/29). A central vascular catheter was present in 40 patients and was removed in 17 (43%) during treatment. Overall mortality at 30 days was 44%. Patients reached a mean EQUAL Candida Score of 9.9 (range 8-14), which was well below the maximum score of 22 for perfect guideline adherence. In summary, management of candidemia differed from current European recommendations. It remains unclear to what extent enhanced adherence would improve patient outcome. Larger prospective studies need to answer that question.

[Fulminant sepsis after Capnocytophaga canimorsus infection]. / Fulminante Sepsis nach Capnocytophaga-canimorsus-Infektion.

Capnocytophaga canimorsus is a Gram-negative bacterium present in the oral cavities of cats and dogs. It is known for its capability to cause life-threatening sepsis following a dog bite, especially in immunocompromised patients. We report the case of a 67-year-old man who suffered from septic shock and multiorgan failure presumably following contamination of a pre-existing minor skin lesion by canine saliva. The purpose of this report is to raise awareness of Capnocytophaga canimorsus among physicians when faced with a patient presenting with fulminant septic shock and Gram-negative bacteremia, who has been exposed to dogs.

[Tuberculosis Guideline for Adults - Guideline for Diagnosis and Treatment of Tuberculosis including LTBI Testing and Treatment of the German Central Committee (DZK) and the German Respiratory Society (DGP)]. / S2k-Leitlinie: Tuberkulose im Erwachsenenalter.

Since 2015 a significant increase in tuberculosis cases is notified in Germany, mostly due to rising numbers of migrants connected to the recent refugee crisis. Because of the low incidence in previous years, knowledge on tuberculosis is more and more limited to specialized centers. However, lung specialist and healthcare workers of other fields have contact to an increasing number of tuberculosis patients. In this situation, guidance for the management of standard therapy and especially for uncommon situations will be essential. This new guideline on tuberculosis in adults gives recommendations on diagnosis, treatment, prevention and prophylaxis. It provides a comprehensive overview over the current knowledge, adapted to the specific situation in Germany. The German Central Committee against Tuberculosis (DZK e. V.) realized this guideline on behalf of the German Respiratory Society (DGP). A specific guideline for tuberculosis in the pediatrics field will be published separately. Compared to the former recommendations of the year 2012, microbiological diagnostics and therapeutic drug management were given own sections. Chapters about the treatment of drug-resistant tuberculosis, tuberculosis in people living with HIV and pharmacological management were extended. This revised guideline aims to be a useful tool for practitioners and other health care providers to deal with the recent challenges of tuberculosis treatment in Germany.

Repurposing QuantiFERON for Detection of Neutralizing Interferon-γ Autoantibodies in Patients With Nontuberculous Mycobacterial Infections.

Nontuberculous mycobacterial infections due to autoantibodies targeting interferon-γ are an emerging medical problem. However, case finding is hampered due to highly complex diagnostic procedures not available in routine laboratories. We show that QuantiFERON assays can be exploited as a simple screening tool that may facilitate adequate and timely treatment.

Low prevalence of DHFR and DHPS mutations in Pneumocystis jirovecii strains obtained from a German cohort.

BACKGROUND: Pneumocystis pneumonia (PCP) is an opportunistic and potentially life-threatening infection of immunocompromised individuals. A combination of trimethoprim-sulfamethoxazole is widely used for prophylaxis and treatment of PCP. Polymorphisms in the drug targets, the dihydropteroate synthase (DHPS) or the dihydrofolate reductase (DHFR) are presumably a reason for treatment failure. METHODS: We retrospectively examined the prevalence of DHPS and DHFR mutations in Pneumocystis jirovecii isolates obtained from HIV-infected and non-HIV-infected PCP patients. DHFR and DHPS genes were amplified using semi-nested PCR followed by sequencing. Obtained data were correlated with clinical findings. RESULTS: Sequencing of the DHPS gene was achieved in 81 out of 128 isolates (63%), the DHFR-gene was successfully sequenced in 96 isolates (75%). The vast majority of DHFR and DHPS sequences were either wild-type or showed synonymous single nucleotide polymorphisms. Only one sample contained a double mutation at DHPS codon 55 and codon 57 which was associated with treatment failure in some studies. No linkage of treatment failure to a DHFR or DHPS genotype was observed. In our cohort, 35 of 95 Patients (37%) were HIV-positive and 60 (63%) were HIV-negative. The overall mortality rate was 24% with a much higher rate among non-HIV patients. CONCLUSION: DHPS and DHFR mutations exist but are infrequent in our cohort. The contribution of gene polymorphisms to treatment failure needs further research. In immunocompromised HIV-negative patients PCP is associated with high mortality rates. Prophylactic treatment is warranted in this patient subset.

LL37:DNA complexes provide antimicrobial activity against intracellular bacteria in human macrophages.

As part of the innate host response neutrophils release neutrophil extracellular traps (NETs), protein:DNA complexes that contain a number of antimicrobial peptides (AMPs), such as cathelicidin. Human cathelicidin in its active form, LL37, has potent antimicrobial activity against bacteria. However, whether LL37 derived from NETs contributes to antimicrobial activity against intracellular pathogens remains unclear. Here, we report that NETs induced by mycobacteria contain cathelicidin. Human macrophages internalized NET-bound cathelicidin, which is transported to lysosomal compartments. Furthermore, using a model of in vitro-generated LL37:DNA complexes we found that LL37 derived from such complexes attacks mycobacteria in macrophage phagolysosomes resulting in antimicrobial activity. Taken together, our results suggest a mechanism by which LL37 in complex with DNA contributes to host defence against intracellular bacteria in human macrophages.

Imatinib Triggers Phagolysosome Acidification and Antimicrobial Activity against Mycobacterium bovis Bacille Calmette-Guérin in Glucocorticoid-Treated Human Macrophages.

Glucocorticoids are extensively used to treat inflammatory diseases; however, their chronic intake increases the risk for mycobacterial infections. Meanwhile, the effects of glucocorticoids on innate host responses are incompletely understood. In this study, we investigated the direct effects of glucocorticoids on antimycobacterial host defense in primary human macrophages. We found that glucocorticoids triggered the expression of cathelicidin, an antimicrobial critical for antimycobacterial responses, independent of the intracellular vitamin D metabolism. Despite upregulating cathelicidin, glucocorticoids failed to promote macrophage antimycobacterial activity. Gene expression profiles of human macrophages treated with glucocorticoids and/or IFN-γ, which promotes induction of cathelicidin, as well as antimycobacterial activity, were investigated. Using weighted gene coexpression network analysis, we identified a module of highly connected genes that was strongly inversely correlated with glucocorticoid treatment and associated with IFN-γ stimulation. This module was linked to the biological functions autophagy, phagosome maturation, and lytic vacuole/lysosome, and contained the vacuolar H(+)-ATPase subunit a3, alias TCIRG1, a known antimycobacterial host defense gene, as a top hub gene. We next found that glucocorticoids, in contrast with IFN-γ, failed to trigger expression and phagolysosome recruitment of TCIRG1, as well as to promote lysosome acidification. Finally, we demonstrated that the tyrosine kinase inhibitor imatinib induces lysosome acidification and antimicrobial activity in glucocorticoid-treated macrophages without reversing the anti-inflammatory effects of glucocorticoids. Taken together, we provide evidence that the induction of cathelicidin by glucocorticoids is not sufficient for macrophage antimicrobial activity, and identify the vacuolar H(+)-ATPase as a potential target for host-directed therapy in the context of glucocorticoid therapy.

High Intracellular Concentrations of Posaconazole Do Not Impact on Functional Capacities of Human Polymorphonuclear Neutrophils and Monocyte-Derived Macrophages In Vitro.

Posaconazole is a commonly used antifungal for the prophylaxis and treatment of invasive fungal infections. We previously demonstrated that the intracellular concentration of posaconazole in peripheral blood mononuclear cells (PBMCs) and polymorphonuclear neutrophils (PMNs) was greatly increased compared to the plasma concentration. As these professional phagocytes are crucial to combat fungal infections, we set out to investigate if and how, beneficial or deleterious, this high loading of intracellular posaconazole impacts the functional capacities of these cells. Here, we show that high intracellular concentrations of posaconazole do not significantly impact PMN and monocyte-derived macrophage function in vitro In particular, killing capacity and cytoskeletal features of PMN, such as migration, are not affected, indicating that these cells serve as vehicles for posaconazole to the site of infection. Moreover, since posaconazole as such slowed the germination of Aspergillus fumigatus conidia, infected neutrophils released less reactive oxygen species (ROS). Based on these findings, we propose that the delivery of posaconazole by neutrophils to the site of Aspergillus species infection warrants control of the pathogen and preservation of tissue integrity at the same time.

Tumor-necrosis factor impairs CD4(+) T cell-mediated immunological control in chronic viral infection.

Persistent viral infections are characterized by the simultaneous presence of chronic inflammation and T cell dysfunction. In prototypic models of chronicity--infection with human immunodeficiency virus (HIV) or lymphocytic choriomeningitis virus (LCMV)--we used transcriptome-based modeling to reveal that CD4(+) T cells were co-exposed not only to multiple inhibitory signals but also to tumor-necrosis factor (TNF). Blockade of TNF during chronic infection with LCMV abrogated the inhibitory gene-expression signature in CD4(+) T cells, including reduced expression of the inhibitory receptor PD-1, and reconstituted virus-specific immunity, which led to control of infection. Preventing signaling via the TNF receptor selectively in T cells sufficed to induce these effects. Targeted immunological interventions to disrupt the TNF-mediated link between chronic inflammation and T cell dysfunction might therefore lead to therapies to overcome persistent viral infection.

Selection of an HLA-C*03:04-Restricted HIV-1 p24 Gag Sequence Variant Is Associated with Viral Escape from KIR2DL3+ Natural Killer Cells: Data from an Observational Cohort in South Africa.

BACKGROUND: Viruses can evade immune surveillance, but the underlying mechanisms are insufficiently understood. Here, we sought to understand the mechanisms by which natural killer (NK) cells recognize HIV-1-infected cells and how this virus can evade NK-cell-mediated immune pressure. METHODS AND FINDINGS: Two sequence mutations in p24 Gag associated with the presence of specific KIR/HLA combined genotypes were identified in HIV-1 clade C viruses from a large cohort of infected, untreated individuals in South Africa (n = 392), suggesting viral escape from KIR+ NK cells through sequence variations within HLA class I-presented epitopes. One sequence polymorphism at position 303 of p24 Gag (TGag303V), selected for in infected individuals with both KIR2DL3 and HLA-C*03:04, enabled significantly better binding of the inhibitory KIR2DL3 receptor to HLA-C*03:04-expressing cells presenting this variant epitope compared to the wild-type epitope (wild-type mean 18.01 ± 10.45 standard deviation [SD] and variant mean 44.67 ± 14.42 SD, p = 0.002). Furthermore, activation of primary KIR2DL3+ NK cells from healthy donors in response to HLA-C*03:04+ target cells presenting the variant epitope was significantly reduced in comparison to cells presenting the wild-type sequence (wild-type mean 0.78 ± 0.07 standard error of the mean [SEM] and variant mean 0.63 ± 0.07 SEM, p = 0.012). Structural modeling and surface plasmon resonance of KIR/peptide/HLA interactions in the context of the different viral sequence variants studied supported these results. Future studies will be needed to assess processing and antigen presentation of the investigated HIV-1 epitope in natural infection, and the consequences for viral control. CONCLUSIONS: These data provide novel insights into how viruses can evade NK cell immunity through the selection of mutations in HLA-presented epitopes that enhance binding to inhibitory NK cell receptors. Better understanding of the mechanisms by which HIV-1 evades NK-cell-mediated immune pressure and the functional validation of a structural modeling approach will facilitate the development of novel targeted immune interventions to harness the antiviral activities of NK cells.

Increased Frequency of CD49b/LAG-3(+) Type 1 Regulatory T Cells in HIV-Infected Individuals.

In HIV-1 infection elevated serum levels of interferon-α (IFN-α) and interleukin-10 (IL-10) are associated with immune hyperactivation and disease progression. Recently, coexpression of CD49b and LAG-3 was shown to identify Type 1 regulatory T (Tr1) cells, which secrete large amounts of the immunosuppressive cytokine IL-10. We analyzed the frequency of CD49b/LAG-3(+) Tr1 cells in the peripheral blood of HIV-infected individuals at different stages of the disease. We found increased levels of CD49b/LAG-3(+) Tr1 cells as well as IL-10 in HIV patients. With disease progression, Tr1 cells negatively correlate with frequency of plasmacytoid dendritic cells (pDCs), the main producers of IFN-α. However, elevated IL-10 levels could not be ascribed to the CD49b/LAG-3(+)Tr1 cell population. Moreover, we showed in vitro that IFN-α leads to an upregulation of IL-10 as well as CD49b/LAG-3(+) Tr1 cell counts in healthy controls, recapitulating effects observed in vivo during HIV infection. Our results suggest that overexpression of IFN-α during HIV infection drives the generation of CD49b/LAG-3(+) Tr1 cells and the immunosuppressive cytokine IL-10. Furthermore, it remains unclear whether elevated IL-10 levels are beneficial or detrimental in regard to disease progression.

The cysteine desulfurase IscS of Mycobacterium tuberculosis is involved in iron-sulfur cluster biogenesis and oxidative stress defence.

The complex multiprotein systems for the assembly of protein-bound iron-sulfur (Fe-S) clusters are well defined in Gram-negative model organisms. However, little is known about Fe-S cluster biogenesis in other bacterial species. The ISC (iron-sulfur cluster) operon of Mycobacterium tuberculosis lacks several genes known to be essential for the function of this system in other organisms. However, the cysteine desulfurase IscSMtb (Rv number Rv3025c; Mtb denotes M. tuberculosis) is conserved in this important pathogen. The present study demonstrates that deleting iscSMtb renders the cells microaerophilic and hypersensitive to oxidative stress. Moreover, the ∆iscSMtb mutant shows impaired Fe-S cluster-dependent enzyme activity, clearly indicating that IscSMtb is associated with Fe-S cluster assembly. An extensive interaction network of IscSMtb with Fe-S proteins was identified, suggesting a novel mechanism of sulfur transfer by direct interaction with apoproteins. Interestingly, the highly homologous IscS of Escherichia coli failed to complement the ∆iscSMtb mutant and showed a less diverse protein-interaction profile. To identify a structural basis for these observations we determined the crystal structure of IscSMtb, which mirrors adaptations made in response to an ISC operon devoid of IscU-like Fe-S cluster scaffold proteins. We conclude that in M. tuberculosis IscS has been redesigned during evolution to compensate for the deletion of large parts of the ISC operon.

Longitudinal analysis of distribution and function of plasmacytoid dendritic cells in peripheral blood and gut mucosa of HIV infected patients.

Aberrant activation of plasmacytoid dendritic cells (pDCs) with excessive production of interferon alpha (IFNα) represents one of the hallmarks of immune activation during chronic phase of human immunodeficiency virus (HIV) infection. A number of studies have shown that disruption of mucosal integrity in the gut is a cause of persistent immune activation. However, little is known about the role that pDCs play in this process, and our current understanding comes from the simian immunodeficiency virus macaque model. Thus, in the present study we sought to investigate the frequency and function of pDCs in peripheral blood and gut samples from HIV-infected individuals before and 6 months after initiation of antiretroviral therapy (ART). We show that circulating pDCs were depleted in ART-naive HIV+ patients, and upregulated the gut-homing receptor CD103 compared with uninfected controls. By converse, pDCs accumulated in the terminal ileum of ART-naive HIV individuals compared with controls. Baseline levels of IFNα production and markers of immune activation in gut samples of ART-naive HIV subjects were elevated. All these parameters declined after 6 months of ART. Our results suggest that in chronic HIV infection, pDCs migrate from peripheral blood to the gut-associated lymphatic tissue, where they may contribute to immune activation.

Incorporation of antigens into viral capsids augments immunogenicity of adeno-associated virus vector-based vaccines.

Genetic modification of adeno-associated virus (AAV) capsids has previously been exploited to redirect viral tropism. Here we demonstrate that engineering of AAV capsids as scaffolds for antigen display augments antigen-specific immunogenicity. Combining antigen display with vector-mediated overexpression resulted in a single-shot prime-boost vaccine. This new class of vaccines induced immune responses significantly faster and an IgG antibody pool of higher avidity than conventional vectors, highlighting the potency of capsid modification in vaccine development.