Federated learning for diagnosis of age-related macular degeneration.

This paper presents a federated learning (FL) approach to train deep learning models for classifying age-related macular degeneration (AMD) using optical coherence tomography image data. We employ the use of residual network and vision transformer encoders for the normal vs. AMD binary classification, integrating four unique domain adaptation techniques to address domain shift issues caused by heterogeneous data distribution in different institutions. Experimental results indicate that FL strategies can achieve competitive performance similar to centralized models even though each local model has access to a portion of the training data. Notably, the Adaptive Personalization FL strategy stood out in our FL evaluations, consistently delivering high performance across all tests due to its additional local model. Furthermore, the study provides valuable insights into the efficacy of simpler architectures in image classification tasks, particularly in scenarios where data privacy and decentralization are critical using both encoders. It suggests future exploration into deeper models and other FL strategies for a more nuanced understanding of these models' performance. Data and code are available at https://github.com/QIAIUNCC/FL_UNCC_QIAI.

Hybrid immunity shifts the Fc-effector quality of SARS-CoV-2 mRNA vaccine-induced immunity

Despite the robust immunogenicity of SARS-CoV-2 mRNA vaccines, emerging data reveal enhanced neutralizing antibody and T cell cross-reactivity among individuals that previously experienced COVID-19, pointing to a hybrid immune advantage with infection-associated immune priming. Beyond neutralizing antibodies and T cell immunity, mounting data point to a potential role for additional antibody effector functions, including opsinophagocytic activity, in the resolution of symptomatic COVID-19. Whether hybrid immunity modifies the Fc-effector profile of the mRNA vaccine-induced immune response remains incompletely understood. Thus, here we profiled the SARS-CoV-2 specific humoral immune response in a group of individuals with and without prior COVID-19. As expected, hybrid Spike-specific antibody titers were enhanced following the primary dose of the mRNA vaccine, but were similar to those achieved by naive vaccinees after the second mRNA vaccine dose. Conversely, Spike-specific vaccine-induced Fc-receptor binding antibody levels were higher after the primary immunization in individuals with prior COVID-19, and remained higher following the second dose compared to naive individuals, suggestive of a selective improvement in the quality, rather than the quantity, of the hybrid humoral immune response. Thus, while the magnitude of antibody titers alone may suggest that any two antigen exposures - either hybrid immunity or two doses of vaccine alone - represent a comparable prime/boost immunologic education, we find that hybrid immunity offers a qualitatively improved antibody response able to better leverage Fc effector functions against conserved regions of the virus.

A role for Nucleocapsid-specific antibody function in Covid-19 Convalescent plasma therapy

COVID-19 convalescent plasma (CCP), a passive polyclonal antibody therapeutic, has exhibited mixed results in the treatment of COVID-19. Given that the therapeutic effect of CCP may extend beyond the ability of SARS-CoV-2-specific antibody binding and neutralization to influence the evolution of the endogenous antibody response, we took a systematic and comprehensive approach to analyze SARS-CoV-2 functional antibody profiles of participants in a randomized controlled trial of CCP treatment of individuals hospitalized with COVID-19 pneumonia where CCP was associated with both decreased mortality and improved clinical severity. Using systems serology, we found that the clinical benefit of CCP is related to a shift towards reduced inflammatory Spike (S) responses and enhanced Nucleocapsid (N) humoral responses. We found CCP had the greatest clinical benefit in participants with low pre-existing anti-SARS-CoV-2 antibody function, rather than S or N antibody levels or participant demographic features. Further, CCP induced immunomodulatory changes to recipient humoral profiles persisted for at least two months, marked by the selective evolution of anti-inflammatory Fc-glycan profiles and persistently expanded nucleocapsid-specific humoral immunity following CCP therapy. Together, our findings identify a novel mechanism of action of CCP, suggest optimal patient characteristics for CCP treatment, identify long-last immunomodulatory effects of CCP, and provide guidance for development of novel N-focused antibody therapeutics for severe COVID-19 hyperinflammation.

Vaccination with SARS-CoV-2 Spike Protein and AS03 Adjuvant Induces Rapid Anamnestic Antibodies in the Lung and Protects Against Virus Challenge in Nonhuman Primates

Adjuvanted soluble protein vaccines have been used extensively in humans for protection against various viral infections based on their robust induction of antibody responses. Here, soluble prefusion-stabilized spike trimers (preS dTM) from the severe acute respiratory syndrome coronavirus (SARS-CoV-2) were formulated with the adjuvant AS03 and administered twice to nonhuman primates (NHP). Binding and functional neutralization assays and systems serology revealed that NHP developed AS03-dependent multi-functional humoral responses that targeted multiple spike domains and bound to a variety of antibody FC receptors mediating effector functions in vitro. Pseudovirus and live virus neutralizing IC50 titers were on average greater than 1000 and significantly higher than a panel of human convalescent sera. NHP were challenged intranasally and intratracheally with a high dose (3x106 PFU) of SARS-CoV-2 (USA-WA1/2020 isolate). Two days post-challenge, vaccinated NHP showed rapid control of viral replication in both the upper and lower airways. Notably, vaccinated NHP also had increased spike-specific IgG antibody responses in the lung as early as 2 days post challenge. Moreover, vaccine-induced IgG mediated protection from SARS-CoV-2 challenge following passive transfer to hamsters. These data show that antibodies induced by the AS03-adjuvanted preS dTM vaccine are sufficient to mediate protection against SARS-CoV-2 and support the evaluation of this vaccine in human clinical trials.

Adjuvanting a subunit SARS-CoV-2 nanoparticle vaccine to induce protective immunity in non-human primates

The development of a portfolio of SARS-CoV-2 vaccines to vaccinate the global population remains an urgent public health imperative. Here, we demonstrate the capacity of a subunit vaccine under clinical development, comprising the SARS-CoV-2 Spike protein receptor binding domain displayed on a two-component protein nanoparticle (RBD-NP), to stimulate robust and durable neutralizing antibody (nAb) responses and protection against SARS-CoV-2 in non-human primates. We evaluated five different adjuvants combined with RBD-NP including Essai O/W 1849101, a squalene-in-water emulsion; AS03, an alpha-tocopherol-containing squalene-based oil-in-water emulsion used in pandemic influenza vaccines; AS37, a TLR-7 agonist adsorbed to Alum; CpG 1018-Alum (CpG-Alum), a TLR-9 agonist formulated in Alum; or Alum, the most widely used adjuvant. All five adjuvants induced substantial nAb and CD4 T cell responses after two consecutive immunizations. Durable nAb responses were evaluated for RBD-NP/AS03 immunization and the live-virus nAb response was durably maintained up to 154 days post-vaccination. AS03, CpG-Alum, AS37 and Alum groups conferred significant protection against SARS-CoV-2 infection in the pharynges, nares and in the bronchoalveolar lavage. The nAb titers were highly correlated with protection against infection. Furthermore, RBD-NP when used in conjunction with AS03 was as potent as the prefusion stabilized Spike immunogen, HexaPro. Taken together, these data highlight the efficacy of the RBD-NP formulated with clinically relevant adjuvants in promoting robust immunity against SARS-CoV-2 in non-human primates.

The utility of endovenous cyanoacrylate glue ablation for incompetent saphenous veins in the setting of venous leg ulcers.

OBJECTIVE: Patients with venous leg ulcers (VLUs) represent the worse spectrum of chronic venous insufficiency (CVI). The Early Venous Reflux Ablation (EVRA) landmark trial published in 2018 demonstrated that early endovenous intervention results in faster healing of VLUs. We describe our post-EVRA experience using endovenous cyanoacrylate glue ablation (ECGA) to treat superficial venous reflux on an early basis and assess its efficacy and safety in the setting of VLUs. METHODS: There were 37 patients (39 legs, 43 truncal veins) with 43 discrete venous ulcers who underwent ECGA for CVI symptoms and VLUs. They received compression therapy and regular dressings for the VLUs postoperatively and were reviewed at 1 week, 3 months, 6 months, and 12 months after the procedure. Postoperative healing time for VLUs and complications were recorded along with the patient's satisfaction and postprocedure pain scores. RESULTS: The venous ulcers were all <30 cm2 before ECGA. The mean time for VLU healing from operation was 73.6 ± 21.9 days, and the primary occlusion rate of the CVI at both 1 week and 3 months was 100%. No major adverse events were observed except for one case of deep venous thrombosis. There was significant improvement in the revised Venous Clinical Severity Score postoperatively from 11 ± 1.63 (baseline) to 5.6 ± 1.37 (P < .001) at 3-month follow-up (on a scale of 0 to 27, with the severity of symptoms at a maximal 27). The visual analog scale scores for pain were low postoperatively, decreasing from a preoperative score of 6.84 ± 1.42 to 2.72 ± 1.59 (P < .001) at the 3-month follow-up (on a scale of 1-10, with 10 being the most severe pain). The median time to return to normal activities was 7 days (interquartile range, 5-7 days). CONCLUSIONS: ECGA together with compression therapy for VLUs is both safe and effective in this population of Asian patients. ECGA for patients with VLUs has excellent patient acceptability, minimal morbidity, and low recanalization rates at 12 months. Larger extensive studies and longer follow-up periods are required to validate the preliminary outcomes of this paper, and if it is proven to significantly improve ulcer healing rates, this will change the way we approach chronic venous ulceration.

Transverse myelitis masquerading as cauda equina syndrome, stroke and cervical myelopathy.

Transverse myelitis is an uncommon but well-defined neurological syndrome. However, a high index of suspicion is needed to diagnose this condition, especially when it occurs in concomitance with preexisting spinal canal stenosis. We report our patient, a 48 year old male, who initially presented to our spine clinic with acute onset unilateral lower limb weakness associated with urinary retention, which was suspected to be cauda equina syndrome due to a prolapsed intervertebral disc. However, initial magnetic resonance (MR) imaging showed only mild spinal canal stenosis from L2-L5 and C3- C6 levels; thus, the possibility of cauda equina syndrome was ruled out. A few days later, patient developed ipsilateral upper limb weakness giving an impression of hemiparesis due to stroke. However, imaging of brain returned normal. There was still a dilemma whether symptoms could be due to cervical myelopathy as there was mild cervical cord compression with early myelomalacia changes, but the findings were subtle to come to a definite conclusion. Subsequently, patient desaturated and required ventilatory support. Repeat MR imaging of the cervical spine revealed T2 hyperintensities spanning multiple levels in the cervical cord which highlighted the possibility of transverse myelitis and the diagnosis was clinched after a CSF analysis. Despite the debilitating effects, patient responded well to corticosteroid therapy and gradually recovered. This case is reported to highlight the diagnostic dilemma and the rapid progression of transverse myelitis that demands timely medical intervention to avoid permanent disabilities.