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Background and purpose: Transient splenial oedema, also known as reversible splenial lesion syndrome (RESLES), is a rare magnetic resonance imaging (MRI) finding that presents as a round or ovoid focal oedema in the posterior corpus callosum, and is associated with a wide range of clinical conditions. The aetiology of RESLES is not fully clear. We aimed to investigate conflicting pathophysiological hypotheses by measuring local glucose metabolism in patients with RESLES.
Methods: We retrospectively analysed patients with RESLES after reductions in antiseizure medications during in-hospital video electroencephalography monitoring. We measured local glucose uptake using positron emission tomography/computed tomography and compared matched cohorts of patients with and without MRI evidence of RESLES using nonparametric tests.
Results: Local glucose metabolism in the splenium of seven patients with RESLES was not significantly different from the glucose metabolism of the seven patients in the matched cohort. This was true using both regular and normalized standardized glucose uptake value calculation methods (p = 0.902 and p = 0.535, respectively).
Conclusion: We found no evidence of local glucose hypometabolism in RESLES, which supports previous pathophysiological considerations that suggest that RESLES is an intercellular, intramyelinic oedema rather than a typical intracellular cytotoxic oedema, which is not reversible.
We aimed to evaluate the factors associated with hemorrhage (HA) of melanoma brain metastases (MBM) after Cyberknife stereotactic radiosurgery (SRS) in the modern era of systemic therapy. A total of 55 patients with 279 MBM were treated in 93 fractions. The median age, SRS dose, radiological follow-up, and time to HA were 60.4 years, 20 Gy, 17.7 months, and 10.7 months, respectively. Radiologically evident HA was documented in 47 (16.8%) metastases. Of the 55 patients, 25 (45.4%) suffered an HA. Among those, HA caused grade 3 toxicity in 10 patients (40%) and grade 1 symptoms in 5 patients (20%). Ten patients (40%) with HA experienced no toxicity. Logistic regression revealed the use of anticoagulants and the administration of systemic therapy within 7/15 days from SRS to be predictive for HA. When considering the HA causing grade 3 symptomatology, only the use of anticoagulants was significant, with the delivery of whole brain radiation therapy (WBRT) before the HA narrowly missing statistical significance. Our retrospective analysis showed that the administration of modern systemic therapy within 7/15 days from SRS may contribute to HA of MBM, though it appears safe, at least concerning grade 3 toxicity. The use of anticoagulants by the time of SRS significantly increased the risk of HA.
Background: The aim of this study was to identify pre-operative parameters able to predict length of stay (LoS) based on clinical data and patient-reported outcome measures (PROMs) from a scorecard database in patients with significant aortic stenosis who underwent TAVI (transfemoral aortic valve implantation). Methods: 302 participants (51.7% males, age range 78.2–84.2 years.) were prospectively recruited. After computing the median LoS value (=6 days, range = 5–8 days), we implemented a decision tree algorithm by setting dichotomized values at median LoS as the dependent variable and assessed baseline clinical variables and PROMs (Clinical Frailty Scale (CFS), EuroQol-5 Dimension-5 Levels (EQ-5D) and Kansas City Cardiomyopathy Questionnaire (KCCQ)) as potential predictors. Results: Among clinical parameters, only peripheral arterial disease (p = 0.029, HR = 1.826) and glomerular filtration rate (GFR, cut-off < 33 mL/min/1.73 m2, p = 0.003, HR = 2.252) were predictive of LoS. Additionally, two PROMs (CFS; cut-off = 3, p < 0.001, HR = 1.324 and KCCQ; cut-off = 30, p = 0.003, HR = 2.274) were strong predictors. Further, a risk score for LoS (RS_LoS) was calculated based on these predictors. Patients with RS_LoS = 0 had a median LoS of 5 days; patients RS_LoS ≥ 3 had a median LoS of 8 days. Conclusions: based on the pre-operative values of the above four predictors, a personalized prediction of LoS after TAVI can be achieved.
Slack (sequence like a Ca2+ -activated K + channel; also termed Slo2.2, Kcnt1, or KNa 1.1) is a Na+ -activated K + channel that is highly expressed in the peripheral and central nervous system. Previous studies have shown that Slack is enriched in the isolectin B4binding, non-peptidergic subpopulation of C-fiber sensory neurons and that Slack controls the sensory input in neuropathic pain. Recent single-cell RNA-sequencing studies suggested that Slack is highly co-expressed with transient receptor potential (TRP) ankyrin 1 (TRPA1) in sensory neurons. By using in situ hybridization and immunostaining we confirmed that Slack is highly co-localized with TRPA1 in sensory neurons, but only to a minor extent with TRP vanilloid 1. Mice lacking Slack globally or conditionally in sensory neurons (SNS-Slack─/─ ), but not mice lacking Slack conditionally in neurons of the spinal dorsal horn (Lbx1-Slack─/─ ), displayed increased pain behavior after intraplantar injection of the TRPA1 activator allyl isothiocyanate. Patch-clamp recordings with cultured primary neurons and in a HEK-293 cell line transfected with TRPA1 and Slack revealed that Slack-dependent K + currents are modulated in a TRPA1-dependent manner. Taken together, these findings highlight Slack as a modulator of TRPA1-mediated activation of sensory neurons.
Furthermore, we investigated the contribution of Slack in the spinal dorsal horn to pain processing. Lbx1-Slack ─/─ mice demonstrated normal basal pain sensitivity and Complete Freund’s Adjuvant-induced inflammatory pain. Interestingly, we observed a significantly increased spared nerve injury (SNI)-induced neuropathic pain hypersensitivity in Lbx1-Slack ─/─ mutants compared to control littermates. Moreover, we tested the effects of pharmacological Slack activation in the SNI model. Systemic and intrathecal, but not intraplantar administration of the Slack opener loxapine significantly alleviated SNI-induced hypersensitivity in control mice, but only slightly in Lbx1Slack ─/─ mice, further supporting the inhibitory function of Slack in spinal dorsal horn neurons in neuropathic pain processing.
Altogether, our data suggest that Slack in sensory neurons controls TRPA1-induced pain, whereas Slack in spinal dorsal horn neurons inhibits peripheral nerve injury induced neuropathic pain. These data provide further insights into the molecular mechanisms of pain sensation.
Druggability Evaluation of the Neuron Derived Orphan Receptor (NOR-1) Reveals Inverse NOR-1 Agonists
(2022)
The neuron derived orphan receptor (NOR-1, NR4A3) is among the least studied nuclear receptors. Its physiological role and therapeutic potential remain widely elusive which is in part due to the lack of chemical tools that can directly modulate NOR-1 activity. To probe the possibility of pharmacological NOR-1 modulation, we have tested a drug fragment library for NOR-1 activation and repression. Despite low hit-rate (<1 %), we have obtained three NOR-1 ligand chemotypes one of which could be rapidly expanded to an analogue comprising low micromolar inverse NOR-1 agonist potency and altering NOR-1 regulated gene expression in a cellular setting. It confirms druggability of the transcription factor and may serve as an early tool to assess the role and potential of NOR-1.
Background & Aims: Liver fibrosis arises from long-term chronic liver injury, accompanied by an accelerated wound healing response with interstitial accumulation of extracellular matrix (ECM). Activated hepatic stellate cells (HSC) are the main source for ECM production. MicroRNA29a (miR-29a) is a crucial antifibrotic miRNA that is repressed during fibrosis, resulting in up-regulation of collagen synthesis.
Methods; Intracellular and extracellular miRNA levels of primary and immortalized myofibroblastic HSC in response to profibrogenic stimulation by transforming growth factor β (TGFβ) or platelet-derived growth factor-BB (PDGF-BB) or upon inhibition of vesicular transport and autophagy processes were determined by quantitative polymerase chain reaction. Autophagy flux was studied by electron microscopy, flow cytometry, immunoblotting, and immunocytochemistry. Hepatic and serum miR-29a levels were quantified by using both liver tissue and serum samples from a cohort of chronic hepatitis C virus patients and a murine CCl4 induced liver fibrosis model.
Results: In our study, we show that TGFβ and PDGF-BB resulted in decrease of intracellular miR-29a and a pronounced increase of vesicular miR-29a release into the supernatant. Strikingly, miR-29a vesicular release was accompanied by enhanced autophagic activity and up-regulation of the autophagy marker protein LC3. Moreover, autophagy inhibition strongly prevented miR-29a secretion and repressed its targets’ expression such as Col1A1. Consistently, hepatic miR-29a loss and increased LC3 expression in myofibroblastic HSC were associated with increased serum miR-29a levels in CCl4-treated murine liver fibrosis and specimens of hepatitis C virus patients with chronic liver disease.
Conclusions: We provide evidence that activation-associated autophagy in HSC induces release of miR-29a, whereas inhibition of autophagy represses fibrogenic gene expression in part through attenuated miR-29a secretion.
Pathologies associated with tissue ischemia/reperfusion (I/R) in highly metabolizing organs such as the brain and heart are leading causes of death and disability in humans. Molecular mechanisms underlying mitochondrial dysfunction during acute injury in I/R are tissue-specific, but their details are not completely understood. A metabolic shift and accumulation of substrates of reverse electron transfer (RET) such as succinate are observed in tissue ischemia, making mitochondrial complex I of the respiratory chain (NADH:ubiquinone oxidoreductase) the most vulnerable enzyme to the following reperfusion. It has been shown that brain complex I is predisposed to losing its flavin mononucleotide (FMN) cofactor when maintained in the reduced state in conditions of RET both in vitro and in vivo. Here we investigated the process of redox-dependent dissociation of FMN from mitochondrial complex I in brain and heart mitochondria. In contrast to the brain enzyme, cardiac complex I does not lose FMN when reduced in RET conditions. We proposed that the different kinetics of FMN loss during RET is due to the presence of brain-specific long 50 kDa isoform of the NDUFV3 subunit of complex I, which is absent in the heart where only the canonical 10 kDa short isoform is found. Our simulation studies suggest that the long NDUFV3 isoform can reach toward the FMN binding pocket and affect the nucleotide affinity to the apoenzyme. For the first time, we demonstrated a potential functional role of tissue-specific isoforms of complex I, providing the distinct molecular mechanism of I/R-induced mitochondrial impairment in cardiac and cerebral tissues. By combining functional studies of intact complex I and molecular structure simulations, we defined the critical difference between the brain and heart enzyme and suggested insights into the redox-dependent inactivation mechanisms of complex I during I/R injury in both tissues.
Introduction: The concurrent presence of both central nervous system (CNS) tumors and multiple sclerosis (MS) poses various diagnostic and therapeutic pitfalls and makes the clinical management of such patients challenging.
Methods: In this retrospective, single-center cohort study, we searched our clinical databases (2006–2019) for patients with concurrent CNS tumors and MS and described their disease courses. Age at diagnosis of the respective disease and probabilities for MS disease activity events (DAEs) with vs. without prior tumor-specific therapy were tested pairwise using t-test for dependent samples and exact binomial test.
Results: N = 16 patients with concurrent CNS tumors and MS were identified. MS diagnosis preceded the CNS oncological diagnosis by an average of 9 years (p = 0.004). More DAEs occurred in patients without prior chemotherapy (83.3%) than in patients with prior chemotherapy (16.7%; p = 0.008). This effect did not reach significance for patients with prior radiation therapy/radiosurgery (66.7% vs. 33.3%, p = 0.238). The average interval between DAEs and the last documented lymphopenia was 32.25 weeks.
Conclusions: This study describes the clinical and demographic features of patients with concurrent CNS tumors and MS and suggests several practical approaches to their clinical management. Our findings suggest that adding a disease-modifying MS therapy to the regimen of patients treated with chemotherapy is necessary only if the patient suffers from a highly active, aggressive course of MS. In view of the lack of prospective trials, individual risk assessments should remain the foundation of the decision on MS treatment in concurrent CNS tumor diseases.
Introduction: Dysphagia is a common and severe symptom of traumatic brain injury (TBI) affecting up to 78% of patients. It is associated with pneumonia, increased morbidity, and mortality. Although subdural hematoma (SDH) accounts for over 50% of TBI, the occurrence of dysphagia in this subtype has not been investigated yet.
Methods: All patients with SDH admitted to the author's institution between the years 2007 and 2020 were included in the study. Patients with SDH and clinical suspicion for dysphagia received a clinical swallowing assessment by a speech and language pathologist (SLP). Furthermore, the severity of dysphagia was rated according to swallowing disorder scale. Functional outcome was evaluated by the Glasgow outcome scale (GOS).
Results: Out of 545 patients with SDH, 71 patients had dysphagia (13%). The prevalence of dysphagia was significantly lower in the surgical arm compared to the conservative arm (11.8 vs. 21.8%; OR 0.23; p = 0.02). Independent predictors for dysphagia were GCS < 13 at admission (OR 4.17; p < 0.001), cardiovascular disease (OR 2.29; p = 0.002), and pneumonia (OR 2.88; p = 0.002), whereas the operation was a protective factor (OR 0.2; p < 0.001). In a subgroup analysis, right-sided SDH was an additional predictor for dysphagia (OR 2.7; p < 0.001). Overall, patients with dysphagia improved significantly under the SLP treatment from the initial diagnosis to hospital discharge (p < 0.01). However, a subgroup of patients with the most severe grade of dysphagia showed no significant improvement. Patients with dysphagia had significantly worse outcomes (GOS 1–3) compared to those without dysphagia (48.8 vs. 26.4%; p < 0.001).
Conclusion: Dysphagia is a frequent symptom in SDH, and the early identification of dysphagia is crucial regarding the initiation of treatment and functional outcome. Surgery is effective in preventing dysphagia and should be considered in high-risked patients.
Mutations in the Von Hippel–Lindau (VHL) gene are the driving force in many forms of clear cell renal cell carcinoma (ccRCC) and promote hypoxia-inducible factor (HIF)-dependent tumor proliferation, metastasis and angiogenesis. Despite the progress that has already been made, ccRCC generally remain resistant to conventional therapies and ccRCC patients suffer from metastasis and acquired resistance, highlighting the need for novel therapeutic options. Cysteinyl leukotriene receptor 1 (CysLTR1) antagonists, like zafirlukast, are administered in bronchial asthma to control eicosanoid signaling. Intriguingly, long-term use of zafirlukast decreases cancer risk and leukotriene receptor antagonists inhibit tumor growth, but the mechanisms still remain unexplored. Therefore, we aim to understand the mechanisms of zafirlukast-mediated cell death in ccRCC cells. We show that zafirlukast induces VHL-dependent and TNFα-independent non-apoptotic and non-necroptotic cell death in ccRCC cells. Cell death triggered by zafirlukast could be rescued with antioxidants and the PARP-1 inhibitor Olaparib, and additionally relies on HIF-2α. Finally, MG-132-mediated proteasome inhibition sensitized VHL wild-type cells to zafirlukast-induced cell death and inhibition of HIF-2α rescued zafirlukast- and MG-132-triggered cell death. Together, these results highlight the importance of VHL, HIF and proteasomal degradation in zafirlukast-induced oxidative cell death with potentially novel therapeutic implications for ccRCC.
Background: Routine human papillomavirus (HPV) testing is performed in cervival cancer and is required for classification of some head and neck cancers. In penile cancer a statement on HPV association of the carcinoma is required. In most cases p16 immunohistochemistry as a surrogate marker is applied in this setting. Since differing clinical outcomes for HPV positive and HPV negative tumors are described we await HPV testing to be requested more frequently by clinicians, also in the context of HPV vaccination, where other HPV subtypes are expected to emerge.
Method: Therefore, a cohort of archived, formalin-fixed paraffin embedded (FFPE) penile neoplasias was stained for p16 and thereafter tested for HPV infection status via PCR based methods. Additionally to Sanger sequencing, we chose LCD-Array technique (HPV 3.5 LCD-Array Kit, Chipron; LCD-Array) for the detection of HPV in our probes expecting a less time consuming and sensitive HPV test for our probes.
Results: We found that LCD-Array is a sensitive and feasible method for HPV testing in routine diagnostics applicable to FFPE material in our cohort. Our cohort of penile carcinomas and carcinomas in situ was associated with HPV infection in 61% of cases. We detected no significant association between HPV infection status and histomorphological tumor characteristics as well as overall survival.
Conclusions: We showed usability of molecular HPV testing on a cohort of archived penile carcinomas. To the best of our knowledge, this is the first study investigating LCD-Array technique on a cohort of penile neoplasias.
Several lines of evidence suggest the ligand-sensing transcription factor Nurr1 as a promising target to treat neurodegenerative diseases. Nurr1 modulators to validate and exploit this therapeutic potential are rare, however. To identify novel Nurr1 agonist chemotypes, we have employed the Nurr1 activator amodiaquine as template for microscale analogue library synthesis. The first set of analogues was based on the 7-chloroquiolin-4-amine core fragment of amodiaquine and revealed superior N-substituents compared to diethylaminomethylphenol contained in the template. A second library of analogues was subsequently prepared to replace the chloroquinolineamine scaffold. The two sets of analogues enabled a full scaffold hop from amodiaquine to a novel Nurr1 agonist sharing no structural features with the lead but comprising superior potency on Nurr1. Additionally, pharmacophore modeling based on the entire set of active and inactive analogues suggested key features for Nurr1 agonists.
Objective: This study was undertaken to calculate epilepsy-related direct, indirect, and total costs in adult patients with active epilepsy (ongoing unprovoked seizures) in Germany and to analyze cost components and dynamics compared to previous studies from 2003, 2008, and 2013. This analysis was part of the Epi2020 study.
Methods: Direct and indirect costs related to epilepsy were calculated with a multicenter survey using an established and validated questionnaire with a bottom-up design and human capital approach over a 3-month period in late 2020. Epilepsy-specific costs in the German health care sector from 2003, 2008, and 2013 were corrected for inflation to allow for a valid comparison.
Results: Data on the disease-specific costs for 253 patients in 2020 were analyzed. The mean total costs were calculated at €5551 (±€5805, median = €2611, range = €274–€21 667) per 3 months, comprising mean direct costs of €1861 (±€1905, median = €1276, range = €327–€13 158) and mean indirect costs of €3690 (±€5298, median = €0, range = €0–€11 925). The main direct cost components were hospitalization (42.4%), antiseizure medication (42.2%), and outpatient care (6.2%). Productivity losses due to early retirement (53.6%), part-time work or unemployment (30.8%), and seizure-related off-days (15.6%) were the main reasons for indirect costs. However, compared to 2013, there was no significant increase of direct costs (−10.0%), and indirect costs significantly increased (p < .028, +35.1%), resulting in a significant increase in total epilepsy-related costs (p < .047, +20.2%). Compared to the 2013 study population, a significant increase of cost of illness could be observed (p = .047).
Significance: The present study shows that disease-related costs in adult patients with active epilepsy increased from 2013 to 2020. As direct costs have remained constant, this increase is attributable to an increase in indirect costs. These findings highlight the impact of productivity loss caused by early retirement, unemployment, working time reduction, and seizure-related days off.
Der Status epilepticus (SE) stellt eine schwerwiegende akute Erkrankung dar, die eine frühzeitige und gezielte Therapie erfordert. Insbesondere der refraktäre SE (RSE) sowie der superrefraktäre SE (SRSE) sind bereits bei jungen Menschen eine interdisziplinäre therapeutische Herausforderung. Bei Patienten in höherem Lebensalter sind hierbei weitere relevante Aspekte zu beachten, die sich einerseits aufgrund einer abweichenden Pharmakokinetik und -dynamik ergeben, andererseits aber auch aus Komorbiditäten, Polypharmazie und möglichen medizinischen Therapielimitationen bzw. Patientenpräferenzen resultieren. Ziel dieses Artikels ist es, diese besonderen Aspekte im Rahmen der SE-Versorgung älterer Menschen aufzuarbeiten und potenzielle Therapiestrategien jenseits der Leitlinie aufzuzeigen. Insbesondere wird hierbei auf alternative Applikationswege und mögliche konservative Eskalationsformen der Therapie eingegangen, die v. a. bei relevant vorerkrankten Patienten von Bedeutung sind, bei denen eine intensivmedizinische Behandlung die ohnehin schon hohe Mortalität des SE im gehobenen Alter weiter erhöhen würde. Mit unterschiedlichen parenteralen Applikationsformen von Benzodiazepinen im SE sowie dem mittlerweile gut beschriebenen Einsatz weiterer Antikonvulsiva wie Brivaracetam, Perampanel, Stiripentol, Topiramat und Zonisamid in RSE und SRSE stehen auch für diese vulnerable Patientengruppe adäquate Therapieoptionen zur Verfügung. Nichtsdestotrotz sollte in der Therapie des SE im gehobenen Alter insbesondere in Anbetracht der per se hohen Mortalität verstärkt auf Patientenpräferenzen und medizinethische Aspekte geachtet werden.
Objective: This study was undertaken to quantify epilepsy-related costs of illness (COI) in Germany and identify cost-driving factors.
Methods: COI were calculated among adults with epilepsy of different etiologies and severities. Multiple regression analysis was applied to determine any epilepsy-related and sociodemographic factors that serve as cost-driving factors.
Results: In total, 486 patients were included, with a mean age of 40.5 ± 15.5 years (range = 18–83 years, 58.2% women). Mean 3-month COI were estimated at €4911, €2782, and €2598 for focal, genetic generalized, and unclassified epilepsy, respectively. The mean COI for patients with drug-refractory epilepsy (DRE; €7850) were higher than those for patients with non-DRE (€4720), patients with occasional seizures (€3596), or patients with seizures in remission for >1 year (€2409). Identified cost-driving factors for total COI included relevant disability (unstandardized regression coefficient b = €2218), poorer education (b = €2114), living alone (b = €2612), DRE (b = €1831), and frequent seizures (b = €2385). Younger age groups of 18–24 years (b = −€2945) and 25–34 years (b = −€1418) were found to have lower overall expenditures. A relevant disability (b = €441), DRE (b = €1253), frequent seizures (b = €735), and the need for specialized daycare (b = €749) were associated with higher direct COI, and poorer education (b = €1969), living alone (b = €2612), the presence of a relevant disability (b = €1809), DRE (b = €1831), and frequent seizures (b = €2385) were associated with higher indirect COI.
Significance: This analysis provides up-to-date COI data for use in further health economics analyses, highlighting the high economic impacts associated with disease severity, disability, and disease-related loss of productivity among adult patients with epilepsy. The identified cost drivers could be used as therapeutic and socioeconomic targets for future cost-containment strategies.
Many countries have restricted public life during the SARS-CoV2 pandemic. As related measures limited the access to sports facilities, this dissertation aimed (1) to examine changes in physical activity (PA) and well-being in affected countries, and (2) to determine the effectiveness of a digital home exercise program in this context.
Part 1 (PA/well-being) of the dissertation was a digital survey administered in 14 countries. Participants reported a 41 - 42% reduction of PA (NPAQ-SF) during restrictions (n=13,503 valid responses). Compliance with international PA guidelines decreased by nearly 19%. Mental well-being declined substantially (n=14,975 responses; 68.1 to 51.9 points on the WHO5 index) and the proportion of individuals at risk of depression tripled (14.2% to 45.2%). Physical well-being (SF-36 Pain) decreased slightly (85.8% to 81.3%). About two thirds (68.1%) of the respondents reported being interested in digital home exercise.
For Part 2 (digital home exercise) of the dissertation, an international multicenter randomized, controlled trial was performed allocating healthy adults (n=763; 33±12 years) to an intervention (IG) or control (CG) group. In contrast to the CG, the IG was offered live-streamed home exercise for four weeks. Subsequently, both groups had access to pre-recorded workouts for another four weeks. Outcomes were measured weekly using validated questionnaires. Mixed-models data analyses revealed an up to 1.65-fold (95% CI: 1.4-1.94; week 1) increase of PA relative to the CG. Moreover, small improvements in exercise motivation (SKK scale), psychological well-being (WHO-5 index), sleep quality (MOS Sleep Scale), and anxiety symptoms (GAD-7 Scale) were observed for IG.
The results of this dissertation suggest that public life restrictions associated with the pandemic had significant adverse effects on movement behavior and well-being. Digital home exercise can help to maintain and/or increase health- beneficial PA and well-being and may hence represent a supportive element of viral containment efforts.
Background: In recent months, Omicron variants of SARS-CoV-2 have become dominant in many regions of the world, and case numbers with Omicron subvariants BA.1 and BA.2 continue to increase. Due to numerous mutations in the spike protein, the efficacy of currently available vaccines, which are based on Wuhan-Hu 1 isolate of SARS-CoV-2, is reduced, leading to breakthrough infections. Efficacy of monoclonal antibody therapy is also likely impaired.
Methods: In our in vitro study using A549-AT cells constitutively expressing ACE2 and TMPRSS2, we determined and compared the neutralizing capacity of vaccine-elicited sera, convalescent sera and monoclonal antibodies against authentic SARS-CoV-2 Omicron BA.1 and BA.2 compared with Delta.
Findings: Almost no neutralisation of Omicron BA.1 and BA.2 was observed using sera from individuals vaccinated with two doses 6 months earlier, regardless of the type of vaccine taken. Shortly after the booster dose, most sera from triple BNT162b2-vaccinated individuals were able to neutralise both Omicron variants. In line with waning antibody levels three months after the booster, only weak residual neutralisation was observed for BA.1 (26%, n = 34, 0 median NT50) and BA.2 (44%, n = 34, 0 median NT50). In addition, BA.1 but not BA.2 was resistant to the neutralising monoclonal antibodies casirivimab/imdevimab, while BA.2 exhibited almost a complete evasion from the neutralisation induced by sotrovimab.
Interpretation: Both SARS-CoV-2 Omicron subvariants BA.1 and BA.2 escape antibody-mediated neutralisation elicited by vaccination, previous infection with SARS-CoV-2, and monoclonal antibodies. Waning immunity renders the majority of tested sera obtained three months after booster vaccination negative in BA.1 and BA.2 neutralisation. Omicron subvariant specific resistance to the monoclonal antibodies casirivimab/imdevimab and sotrovimab emphasizes the importance of genotype-surveillance and guided application.
Funding: This study was supported in part by the Goethe-Corona-Fund of the Goethe University Frankfurt (M.W.) and the Federal Ministry of Education and Research (COVIDready; grant 02WRS1621C (M.W.).
Wastewater-based SARS-CoV-2 epidemiology (WBE) has been established as an important tool to support individual testing strategies. Omicron sub-variants BA.4/5 have spread globally displacing the predeceasing variants. Due to the severe transmissibility and immune escape potential of BA.4/5, early monitoring was required to asses and implement countermeasures in time.
In this study, we monitored the prevalence of SARS-CoV-2 BA.4/5 at six municipal wastewater treatment plants (WWTPs) in the Federal State of North-Rhine-Westphalia (NRW, Germany) in May and June 2022. Initially, L452R-specific primers/probes originally designed for SARS-CoV-2 Delta detection were validated using inactivated authentic viruses and evaluated for their suitability to detect BA.4/5. Subsequently, the assay was used for RT-qPCR analysis of RNA purified from wastewater obtained twice a week at six WWTPs. The occurrence of L452R carrying RNA was detected in early May 2022 and the presence of BA.4/5 was confirmed by variant-specific single nucleotide polymorphism PCR (SNP-PCR) targeting E484A/F486V. Finally, the mutant fractions were quantitatively monitored by digital PCR confirming BA.4/5 as the majority variant by 5th June 2022.
In conclusions, the successive workflow using RT-qPCR, variant-specific SNP-PCR, and RT-dPCR demonstrates the strength of WBE as a versatile tool to rapidly monitor variant spreading independent of individual test capacities.