Inefficient tissue immune response against MPXV in an immunocompromised mpox patient.

The recent outbreak of monkeypox virus (MPXV) was unprecedented in its size and distribution. Those living with uncontrolled HIV and low CD4 T cell counts might develop a fulminant clinical mpox course with increased mortality, secondary infections, and necrotizing lesions. Fatal cases display a high and widespread MPXV tissue burden. The underlying pathomechanisms are not fully understood. We report here the pathological findings of an MPXV-driven abscess in gastrocnemius muscle requiring surgery in an immunocompromised patient with severe mpox. Presence of virus particles and infectivity were confirmed by electron microscopy, expansion microscopy, and virus culture, respectively. MPXV tissue distribution by immunohistochemistry (IHC) showed a necrotic core with infection of different cell types. In contrast, at the lesion rim fibroblasts were mainly infected. Immune cells were almost absent in the necrotic core, but were abundant at the infection rim and predominantly macrophages. Further, we detected high amounts of alternatively activated GPNMB+-macrophages at the lesion border. Of note, macrophages only rarely colocalized with virus-infected cells. Insufficient clearance of infected cells and infection of lesion-associated fibroblasts sustained by the abundance of profibrotic macrophages might lead to the coalescing of lesions and the severe and persistent clinical mpox course observed in immunocompromised patients.

Delayed Induction of Noninflammatory SARS-CoV-2 Spike-Specific IgG4 Antibodies Detected 1 Year After BNT162b2 Vaccination in Children.

Humoral immune responses after BNT162b2 vaccination are predominantly composed of immunoglobulin (Ig) G1 and IgG3 subclass antibodies. As previously described in adults, S1-specific and receptor-binding domain-specific IgG4 levels increase significantly 1 year after the second BNT162b2 vaccination in children 5-11 years of age. Understanding mRNA vaccine-specific IgG4 responses in all age groups is crucial as more mRNA vaccines will reach licensure in the coming years.

Method for Quantitative HDV RNA Detection: I, Manual Workflow (Serum and Liver Tissue) and II, Fully Automated High Throughput Workflow for Diagnostic Use.

The hepatitis delta virus (HDV) is a small RNA virus (1700 base pairs), which uses the surface proteins of the hepatitis B virus (HBV) as an envelope. Accurate and reliable quantitative detection of HDV RNA is central for scientific and translational clinical research or diagnostic purposes. However, HDV poses challenges for nucleic acid amplification techniques: (1) the circular genome displays high intramolecular base pairing; (2) high content of cytosine and guanine; and (3) enormous genomic diversity among the eight known HDV genotypes (GTs). Here, we provide step-by-step instructions for (A) a manual workflow to perform a quantitative HDV reverse transcription (RT)-PCR from serum and liver tissue and (B) a quantitative HDV RT-PCR assay with whole process control to be used for serum or plasma samples run on a fully automated system. Both assays target the conserved ribozyme region and demonstrate inclusivity for all eight HDV GTs. The choice of assay depends on the experimental needs and equipment availability. While the former is ideal for scientific research laboratories, the latter provides a useful tool in the field of translational research or diagnostics.

Analytical and clinical validation of a novel, laboratory-developed, modular multiplex-PCR panel for fully automated high-throughput detection of 16 respiratory viruses.

BACKGROUND: Viral respiratory Infections pose a health risk, especially to vulnerable patient populations. Effective testing programs can detect and differentiate these infections at an early stage, which is particularly important for high-risk clinical departments. The objective of this study was to develop and validate a multiplex PCR-panel for 16 different respiratory viruses on a fully-automated high-throughput platform. METHODS: Three multiplex-PCR assays were designed to run on the cobas5800/6800/8800 systems, consolidating 16 viral targets: RESP1: SARS-CoV-2, influenza-A/B, RSV; RESP2: hMPV, hBoV, hAdV, rhino-/ENV; RESP3: HPIV-1-4, hCoV-229E, hCoV-NL63, hCoV-OC43, hCoV-HKU1. Analytic performance was evaluated using digital-PCR based standards and international reference material. Clinical performance was determined by comparing results from clinical samples with reference assays. RESULTS: Analytical sensitivity (i.e. lower limit of detection (LoD), 95 % probability of detection) was determined as follows: SARS-CoV-2: 29.3 IU/ml, influenza-A: 179.9 cp/ml, influenza-B: 333.9 cp/ml and RSV: 283.1 cp/ml. LoDs of other pathogens ranged between 9.4 cp/ml (hCoV-NL63) and 21,419 cp/ml (HPIV-2). Linearity was verified over 4-7 log-steps with pooled standard differentials (SD) ranging between 0.18-0.70ct. Inter-/intra-run variability (precision) was assessed for all targets over 3 days. SDs ranged between 0.13-0.74ct. Positive agreement in clinical samples was 99.4 % and 95 % for SARS-CoV-2 and influenza-A respectively. Other targets were in the 80-100 % range. Negative agreement varied between 96.3-100 %. DISCUSSION: Lab-developed tests are a key factor for effective clinical diagnostics. The multiplex panel presented in this study demonstrated high performance and provides an easily scalable high-throughput solution for respiratory virus testing, e.g. for testing in high-risk patient populations.

Immunity against measles, mumps, rubella, and varicella among homeless individuals in Germany - A nationwide multi-center cross-sectional study.

Introduction: Homeless individuals suffer a high burden of vaccine-preventable infectious diseases. Moreover, they are particularly susceptible to adverse infection outcomes with limited access to the health care system. Data on the seroprevalence of measles, mumps, rubella, and varicella within this cohort are missing. Methods: The seroprevalence of measles, mumps, rubella, and varicella was determined within the homeless population in Germany. Predictors of lacking immune protection were determined using multivariable logistic regression analysis. Results: Homeless individuals in Germany (n = 611) showed a seroprevalence of 88.5% (95% CI: 85.8-91.0) for measles, 83.8% (95% CI: 80.6-86.6) for mumps, 86.1% (95% CI: 83.1-88.7) for rubella, and 95.7% (95% CI 93.8-97.2) for varicella. Measles seroprevalences declined from individuals born in 1965 to individuals born in 1993, with seroprevalences not compatible with a 95% threshold in individuals born after 1980. For mumps, seroprevalences declined from individuals born in 1950 to individuals born in 1984. Here, seroprevalences were not compatible with a 92% threshold for individuals born after 1975. Seronegativity for measles, mumps and rubella was associated with age but not with gender or country of origin. Discussion: Herd immunity for measles and mumps is not achieved in this homeless cohort, while there was sufficient immune protection for rubella and varicella. Declining immune protection rates in younger individuals warrant immunization campaigns also targeting marginalized groups such as homeless individuals. Given that herd immunity thresholds are not reached for individuals born after 1980 for measles, and after 1975 for mumps, vaccination campaigns should prioritize individuals within these age groups.

Analytical and clinical validation of a multiplex PCR assay for detection of Neisseria gonorrhoeae and Chlamydia trachomatis including simultaneous LGV serotyping on an automated high-throughput PCR system.

For effective infection control measures for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), a reliable tool for screening and diagnosis is essential. Here, we aimed to establish and validate a multiplex PCR assay on an automated system using a dual-target approach for the detection of CT/NG and differentiation between lymphogranuloma venereum (LGV) and non-LGV from genital and extra-genital specimens. Published primer/probe sets (CT: pmpH, cryptic plasmid; NG: porA, opa) were modified for the cobas 5800/6800/8800. Standards quantified by digital PCR were used to determine linearity and lower limit of detection (LLoD; eSwab, urine). For clinical validation, prospective samples (n = 319) were compared with a CE-marked in vitro diagnostics (CE-IVD) assay. LLoDs ranged from 21.8 to 244 digital copies (dcp)/mL and 10.8 to 277 dcp/mL in swab and urine, respectively. A simple linear regression analysis yielded slopes ranging from -4.338 to -2.834 and Pearson correlation coefficients from 0.956 to 0.994. Inter- and intra-run variability was <0.5 and <1 cycle threshold (ct), respectively. No cross-reactivity was observed (n = 42). Clinical validation showed a sensitivity of 94.74% (95% confidence interval (CI): 87.23%-97.93%) and 95.51% (95% CI: 89.01%-98.24%), a specificity of 99.59% (95% CI: 97.71%-99.98%) and 99.57% (95% CI: 97.58%-99.98%), positive predictive values of 89.91% (estimated prevalence: 3.7%; 95% CI: 80.91%-95.6%) and 88.61% (estimated prevalence: 3.4%; 95% CI: 80.18%-94.34%), and negative predictive values of 99.81% (95% CI: 98.14%-100%) and 99.85% (95% CI: 98.14%-100%) for the detection of CT and NG, respectively. In conclusion, we established a dual-target, internally controlled PCR on an automated system for the detectiwon of CT/NG from genital and extra-genital specimens. Depending on local regulations, the assay can be used as a screening or a confirmatory/typing assay.IMPORTANCEChlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) represent a major global health burden, with the World Health Organization estimating that >128 million and >82 million people, respectively, were newly infected in 2020. For effective infection control measures, a reliable tool for sensitive diagnosis and screening of CT/NG is essential. We established a multiplex PCR assay for the detection of CT/NG and simultaneous discrimination between lymphogranuloma venereum (LGV) and non-LGV strains, which has been validated for genital and extra-genital specimens on a fully automated system. To increase assay sensitivity, a dual-target approach has been chosen for both pathogens. This strategy reduces false-positive results in oropharyngeal swabs due to the detection of commensal N. species that may harbor NG DNA fragments targeted in the PCR due to horizontal gene transmission following previous infection. In sum, the established assay provides a powerful tool for use as either a screening/diagnostic or a typing/confirmatory assay.

Blocking viral entry with bulevirtide reduces the number of HDV-infected hepatocytes in human liver biopsies.

BACKGROUND & AIMS: Bulevirtide (BLV) is a first-in-class entry inhibitor and the only approved treatment for patients chronically infected with HDV in Europe. We aimed to investigate the efficacy of BLV treatment in paired liver biopsies obtained at baseline and after 24 or 48 weeks of treatment. METHODS: We performed a combined analysis of 126 paired liver biopsies derived from three clinical trials. In the phase II clinical trial MYR202, patients with chronic hepatitis D were randomised to receive 24 weeks of BLV at 2 mg, 5 mg or 10 mg/day. Patients in MYR203 (phase II) and MYR301 (phase III) received 48 weeks of BLV at 2 mg or 10 mg/day. Tenofovir disoproxil fumarate monotherapy or delayed treatment served as comparators. Virological parameters and infection-related host genes were assessed by qPCR and immunohistochemistry. RESULTS: At week 24, median intrahepatic HDV RNA decline from baseline was 0.9Log10 with 2 mg (n = 7), 1.1Log10 with 5 mg (n = 5) and 1.4 Log10 with 10 mg (n = 7) of BLV. At week 48, median reductions were 2.2Log10 with 2 mg (n = 27) and 2.7Log10 with 10 mg (n = 37) of BLV, while HDV RNA levels did not change in the comparator arms. Notably, a drastic decline in the number of hepatitis delta antigen-positive hepatocytes and a concomitant decrease in transcriptional levels of inflammatory chemokines and interferon-stimulated genes was determined in all BLV-treatment arms. Despite the abundance of HBsAg-positive hepatocytes, replication and covalently closed circular DNA levels of the helper virus HBV were low and remained unaffected by BLV treatment. CONCLUSION: Blocking viral entry diminishes signs of liver inflammation and promotes a strong reduction of HDV infection within the liver, thus suggesting that some patients may achieve HDV cure with long-term treatment. IMPACT AND IMPLICATIONS: Chronic infection with HDV causes the most severe form of viral hepatitis, affecting approximately 12 million people worldwide. The entry inhibitor bulevirtide (BLV) is the only recently approved anti-HDV drug, which has proven efficacious and safe in clinical trials and real-word data. Here, we investigated paired liver biopsies at baseline and after 24 or 48 weeks of treatment from three clinical trials to understand the effect of the drug on viral and host parameters in the liver, the site of viral replication. We found that BLV treatment strongly reduces the number of HDV-infected cells and signs of liver inflammation. This data implies that blocking viral entry ameliorates liver inflammation and that prolonged treatment regimens might lead to HDV cure in some patients. This concept will guide the further development of therapeutic strategies and combination treatments for patients with CHD. CLINICAL TRIAL NUMBERS: NCT03546621, NCT02888106, NCT03852719.

Adaptation and validation of a quantitative vanA/vanB DNA screening assay on a high-throughput PCR system.

Vancomycin resistant enterococci (VRE) are a leading cause of ICU-acquired bloodstream infections in Europe. The bacterial load in enteral colonization may be associated with a higher probability of transmission. Here, we aimed to establish a quantitative vanA/vanB DNA real-time PCR assay on a high-throughput system. Limits of detection (LOD), linear range and precision were determined using serial bacterial dilutions. LOD was 46.9 digital copies (dcp)/ml for vanA and 60.8 dcp/ml for vanB. The assay showed excellent linearity between 4.7 × 101 and 3.5 × 105 dcp/ml (vanA) and 6.7 × 102 and 6.7 × 105 dcp/ml (vanB). Sensitivity was 100% for vanA and vanB, with high positive predictive value (PPV) for vanA (100%), but lower PPV for vanB (34.6%) likely due to the presence of vanB DNA positive anerobic bacteria in rectal swabs. Using the assay on enriched VRE broth vanB PPV increased to 87.2%. Quantification revealed median 2.0 × 104 dcp/ml in PCR positive but VRE culture negative samples and median 9.1 × 104 dcp/ml in VRE culture positive patients (maximum: 107 dcp/ml). The automated vanA/B_UTC assay can be used for vanA/vanB detection and quantification in different diagnostic settings and may support future clinical studies assessing the impact of bacterial load on risk of infection and transmission.

Obesity and diabetes mellitus are associated with SARS-CoV-2 outcomes without influencing signature genes of extrapulmonary immune compartments at the RNA level.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is responsible for eliciting Coronavirus disease 2019 (COVID-19) still challenges healthcare services worldwide. While many patients only suffer from mild symptoms, patients with some pre-existing medical conditions are at a higher risk for a detrimental course of disease. However, the underlying mechanisms determining disease course are only partially understood. One key factor influencing disease severity is described to be immune-mediated. In this report, we describe a post-mortem analysis of 45 individuals who died from SARS-CoV-2 infection. We could show that although sociodemographic factors and premedical conditions such as obesity and diabetes mellitus reduced survival time in our cohort, they were not associated with changes in the expression of immune-related signature genes at the RNA level in the blood, the gut, or the liver between these different groups. Our data indicate that obesity and diabetes mellitus influence SARS-CoV-2-related mortality, without influencing the extrapulmonary gene expression of immunity-related signature genes at the RNA level.

High Clinical Manifestation Rate in an Imported Outbreak of Hepatitis E Genotype 1 Infection in a German Group of Travellers Returning from India

Abstract: Background. There are only few reports about travel-associated, imported tropical hepatitis E virus (HEV) genotype 1 infections within Western travellers. We describe the clinical course of a single outbreak of hepatitis E in a German travellers group returning from India and compare the results of two commercial HEV-seroassays. Material and methods. After identifying hepatitis E in an index patient returning from a journey to India all 24 members of this journey were tested for anti-HEV-IgG and IgM using two commercial seroassays (Wantai and Mikrogen), for HEV-RNA by PCR and HEV-Ag by an antigen-assay (Wantai). Results. 5/24 (21%) individuals were viraemic with viral loads between 580-4,800,000 IU/mL. Bilirubin and ALT levels in these patients ranged from 1.3-14.9 mg/dL (mean 7.3 mg/dL, SD 5.6 mg/dL) and 151-4,820 U/L (mean 1,832U/L, SD 1842U/L), respectively and showed significant correlations with viral loads (r = 0.863, p < 0.001; r = 0.890, p < 0.001). No risk factor for food-borne HEV-transmission was identified. All viraemic patients (5/5) tested positive for anti-HEV-IgG and IgM in the Wantai-assay but only 4/5 in the Mikrogen-assay. Wantai-HEV-antigen-assay was negative in all patients. Six months later all previously viraemic patients tested positive for anti-HEV-IgG and negative for IgM in both assays. However, two non-viremic individuals who initially tested Wantai-IgM-positive stayed positive indicating false positive results. Conclusions. Despite the exact number of exposed individuals could not be determined HEV genotype 1 infections have a high manifestation rate of more than 20%.The Wantai-antigen-test failed, the Wantai-IgMrapid-test and the Mikrogen-IgM-recomblot showed a better performance but still they cannot replace real-time PCR for diagnosing ongoing HEV-infections.