Discovery of highly neutralizing human antibodies targeting Pseudomonas aeruginosa.

Drug-resistant Pseudomonas aeruginosa (PA) poses an emerging threat to human health with urgent need for alternative therapeutic approaches. Here, we deciphered the B cell and antibody response to the virulence-associated type III secretion system (T3SS) in a cohort of patients chronically infected with PA. Single-cell analytics revealed a diverse B cell receptor repertoire directed against the T3SS needle-tip protein PcrV, enabling the production of monoclonal antibodies (mAbs) abrogating T3SS-mediated cytotoxicity. Mechanistic studies involving cryoelectron microscopy identified a surface-exposed C-terminal PcrV epitope as the target of highly neutralizing mAbs with broad activity against drug-resistant PA isolates. These anti-PcrV mAbs were as effective as treatment with conventional antibiotics in vivo. Our study reveals that chronically infected patients represent a source of neutralizing antibodies, which can be exploited as therapeutics against PA.

Use of Sotrovimab in 14 Children with COVID-19: A Single-center Experience.

Children affected by coronavirus disease 2019 (COVID-19) with preexisting comorbidities are at risk of complications. Monoclonal antibodies prevent severe COVID-19 courses in adults but data on children are scarce. Here we report on the use of Sotrovimab in 14 children at risk of severe disease treated at the University of Cologne Children's Hospital. Tolerability was good and no infusion-related reactions were seen.

Validation of the Asthma Severity Scoring System (ASSESS) in the ALLIANCE Cohort.

BACKGROUND: The Asthma Severity Scoring System (ASSESS) quantifies asthma severity in adolescents and adults. Scale performance in children younger than 12 years is unknown. OBJECTIVE: To validate the ASSESS score in the All Age Asthma Cohort and explore its use in children younger than 12 years. METHODS: Scale properties, responsiveness, and known-group validity were assessed in 247 children (median age, 11 years; interquartile range, 8-13 years) and 206 adults (median age, 52 years; interquartile range, 43-63 years). RESULTS: Overall, measures of internal test consistency and test-retest reliability were similar to the original data of the Severe Asthma Research Program. Cronbach α was 0.59 in children aged 12 to 18 years and 0.73 in adults, reflecting the inclusion of multiple and not-always congruent dimensions to the ASSESS score, especially in children. Analysis of known-group validity confirmed the discriminatory power, because the ASSESS score was significantly worse in patients with poor asthma control, exacerbations, and increased salbutamol use. In children aged 6 to 11 years, test-retest reliability was inferior compared with that in adults and adolescents (Cronbach α, 0.27) mostly because of a less lung function impairment in children with asthma of this age group. Known-group validity, however, confirmed good discriminative power regarding severity-associated variables similar to adolescents and adults. CONCLUSIONS: Test-retest reliability and validity of the ASSESS score was confirmed in the All Age Asthma Cohort. In children aged 6 to 11 years, internal consistency was inferior compared with that in older patients with asthma; however, test validity was good and thus encourages age-spanning usage of the ASSESS score in all patients 6 years or older.

Quality Control of Nitrogen Multiple Breath Washout in a Multicenter Pediatric Asthma Study.

BACKGROUND: Nitrogen multiple breath washout (N2MBW) is a lung function test increasingly used in small airway diseases. Quality criteria have not yet been globally implemented and time-consuming retrospective overreading is necessary. Little data has been published on children with recurrent wheeze or asthma from multicentered studies. METHODS: Children with wheeze or asthma and healthy controls were included in the longitudinal All Age Asthma Cohort (ALLIANCE). To assess ventilation inhomogeneity, N2MBW tests were performed in five centers from 2013 until 2020. All N2MBW tests were centrally overread by one center. Multiple washout procedures (trials) at the visit concluded to one test occasion. Tests were accepted if trials were technically sound (started correctly, terminated correctly, no leak, regular breathing pattern) and repeatable within one test occasion. Signal misalignment was retrospectively corrected. Factors that may impact test quality were analyzed, such as experience level. RESULTS: N2MBW tests of n=561 participants were analyzed leading to n=949 (68.3%) valid tests of n=1,390 in total. Inter-center test acceptability ranged from 27.6% to 77.8%. End-of-test criterion and leak were identified to be the most common reasons for rejection. Data loss and uncorrectable signal misalignment led to rejection of 58% of trials in one center. In preschool children, significant improvement of test acceptability was found longitudinally (χ2(8)=18.6; p=0.02). CONCLUSION: N2MBW is feasible in a multicenter asthma study in children. However, the quality of this time-consuming procedure is dependent on experience level of staff in preschool children and still requires retrospective overreading for all age groups.

Clinical Aspects of the Subsequent SARS-CoV-2 Waves in Children from 2020 to 2022-Data from a Local Cohort in Cologne, Germany (n = 21,635).

Almost two and a half years after the appearance of the first cases of SARS-CoV-2 in December 2019, more than 500 million people have been infected with SARS-CoV-2 and over 6 million have died of it worldwide. In terms of the pediatric cohort, it already became evident at an early stage that the infection causes milder symptoms in children and rarely runs a fatal course. OBJECTIVE: This work presents data gathered over a period of over two years in patients between the age of 0 and 18 years. The aim is to provide information on the clinical aspects of the five different SARS-CoV-2 waves. METHODS: Between 13 March 2020 and 22 April 2022, all nucleic acid amplification tests (NAATs) of children who received a swab for SARS-CoV-2 at our clinic were included. Data were collected on standardized questionnaires. The analysis of the data was anonymized and retrospective. RESULTS: We investigated 21,635 NAATs, of which 1028 of the tests were positive (4.8%). The highest rate of positive results was observed in the fifth wave (541/2.292 NAATs (23.6%)). Most of the children who were hospitalized were hospitalized in wave three (22.9%). The availability of a vaccine was followed by a decrease in positive NAATs in the corresponding age group thereafter. CONCLUSIONS: These data underline the fact that children infected with SARS-CoV-2, regardless of which VOC, are often only mildly affected. Vaccinations seem to remain the key to avoid massive numbers of infected people and a potential collapse of the healthcare systems.

Effective high-throughput RT-qPCR screening for SARS-CoV-2 infections in children.

Systematic SARS-CoV-2 testing is a valuable tool for infection control and surveillance. However, broad application of high sensitive RT-qPCR testing in children is often hampered due to unpleasant sample collection, limited RT-qPCR capacities and high costs. Here, we developed a high-throughput approach ('Lolli-Method') for SARS-CoV-2 detection in children, combining non-invasive sample collection with an RT-qPCR-pool testing strategy. SARS-CoV-2 infections were diagnosed with sensitivities of 100% and 93.9% when viral loads were >106 copies/ml and >103 copies/ml in corresponding Naso-/Oropharyngeal-swabs, respectively. For effective application of the Lolli-Method in schools and daycare facilities, SEIR-modeling indicated a preferred frequency of two tests per week. The developed test strategy was implemented in 3,700 schools and 698 daycare facilities in Germany, screening over 800,000 individuals twice per week. In a period of 3 months, 6,364 pool-RT-qPCRs tested positive (0.64%), ranging from 0.05% to 2.61% per week. Notably, infections correlated with local SARS-CoV-2 incidences and with a school social deprivation index. Moreover, in comparison with the alpha variant, statistical modeling revealed a 36.8% increase for multiple (≥2 children) infections per class following infections with the delta variant. We conclude that the Lolli-Method is a powerful tool for SARS-CoV-2 surveillance and can support infection control in schools and daycare facilities.

T2-high asthma phenotypes across lifespan.

RATIONALE: In adults, personalised asthma treatment targets patients with type 2 (T2)-high and eosinophilic asthma phenotypes. It is unclear whether such classification is achievable in children. OBJECTIVES: To define T2-high asthma with easily accessible biomarkers and compare resulting phenotypes across all ages. METHODS: In the multicentre clinical All Age Asthma Cohort (ALLIANCE), 1125 participants (n=776 asthmatics, n=349 controls) were recruited and followed for 2 years (1 year in adults). Extensive clinical characterisation (questionnaires, blood differential count, allergy testing, lung function and sputum induction (in adults)) was performed at baseline and follow-ups. Interleukin (IL)-4, IL-5 and IL-13 were measured after stimulation of whole blood with lipopolysaccharide (LPS) or anti-CD3/CD28. MEASUREMENTS AND MAIN RESULTS: Based on blood eosinophil counts and allergen-specific serum IgE antibodies, patients were categorised into four mutually exclusive phenotypes: "atopy-only", "eosinophils-only", "T2-high" (eosinophilia + atopy) and "T2-low" (neither eosinophilia nor atopy). The T2-high phenotype was found across all ages, even in very young children in whom it persisted to a large degree even after 2 years of follow-up. T2-high asthma in adults was associated with childhood onset, suggesting early origins of this asthma phenotype. In both children and adults, the T2-high phenotype was characterised by excessive production of specific IgE to allergens (p<0.0001) and, from school age onwards, by increased production of IL-5 after anti-CD3/CD28 stimulation of whole blood. CONCLUSIONS: Using easily accessible biomarkers, patients with T2-high asthma can be identified across all ages delineating a distinct phenotype. These patients may benefit from therapy with biologicals even at a younger age.

Morbidity of Respiratory Syncytial Virus (RSV) Infections: RSV Compared With Severe Acute Respiratory Syndrome Coronavirus 2 Infections in Children Aged 0-4 Years in Cologne, Germany.

The aim of this retrospective analysis was to provide information on how infections with respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) differ in symptoms, clinical course, outcome, and utilization of hospital care. We investigated 748 polymerase chain reaction results from symptomatic children aged 0-4 years in Cologne, Germany. One hundred sixty-nine patients tested positive for RSV (22.6%) and 24 children for SARS-CoV-2 (3.2%). Symptomatic patients with RSV infection were hospitalized significantly longer. RSV-positive patients needed oxygen supplementation significantly more often as well as high-flow therapy. With regard to care efforts, RSV-infected patients put higher pressure on the hospital and utilized more hospital resources.

The Alpha Variant (B.1.1.7) of SARS-CoV-2 in Children: First Experience from 3544 Nucleic Acid Amplification Tests in a Cohort of Children in Germany.

In May 2021, the Alpha variant (B.1.1.7) of SARS-CoV-2 was found in 91% of the SARS-CoV-2 cases in Germany. Not much is known about the symptoms, courses of disease, and infectiousness in pediatric patients with the Alpha variant. OBJECTIVE: The aim of this retrospective analysis was to gain information on the infection with the Alpha variant in children and adolescents. METHODS: Between 12 January 2021 and 3 June 2021, all nucleic acid amplification tests (NAATs) of children who received a swab for SARS-CoV-2 were included. Data were collected on standardized questionnaires. The analysis of data was anonymized and retrospective. RESULTS: We investigated 3544 NAATs; 95 children were tested positive (2.7%) for SARS-CoV-2. For the sub-analysis, 65 children were analyzed. In 59 children, the Alpha variant was found (90.8%), and 54.2% (n = 32/59) were symptomatic. The most common symptoms were fever, cough, and rhinitis. The median Ct value was 24.0 (min 17.0; max 32.7). CONCLUSIONS: We can underline early findings that children are still less effected by SARS-CoV-2 infection with the spread of the Alpha variant. We found no evidence that children infected with the Alpha variant showed more severe symptoms or suffered from a more severe clinical course than those infected with the wild type.