Dynamics of serum cross-neutralization capacity against SARS-CoV-2 Delta variant in convalescent COVID-19 patients.

The magnitude and breadth of the neutralizing antibody response against variants of concern following natural infection would provide valuable insights regarding the immune response induced by severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) infection. Herein, 25 patients were followed at 30 ±7 (Visit 1), 90± 15 (Visit 2), and 180 ± 15 (Visit 3) days post symptom onset (PSO). The neutralization titers against both Wuhan-Hu-1 (WT) and Delta variant were analyzed in parallel along with anti-Spike antibodies (anti-S1/S2 immunoglobulin G [IgG]). The median values of half-maximal neutralization titer (NT50 ) for the WT and Delta variants decreased by 75.8% and 82.2% at Visit 2 and by 85.4% and 81.4% at Visit 3, respectively. At Visit 1, the correlation between the anti-S1/S2 IgG and Nabs titers for the Delta variant was moderate for WT (r = 0.58) and weak for the Delta variant (r = 0.39). However, the correlation coefficient consistently remained above 0.7, with a very strong correlation at Visit 3 for both WT and Delta variants (r = 0.81). The dynamics of anti-S1/S2 IgG antibodies, NT50 , and cross-neutralization index correlated at different time points PSO. Longitudinal analysis of the cross-neutralization capacity of immune sera will inform upon the durability of the immune response against SARS CoV-2 variants.

The Impact of Tocilizumab on Radiological Changes Assessed by Quantitative Chest CT in Severe COVID-19 Patients.

(1) Background: We aimed to analyze the characteristics associated with the in-hospital mortality, describe the early CT changes expressed quantitatively after tocilizumab (TOC), and assess TOC timing according to the oxygen demands. (2) Methods: We retrospectively studied 101 adult patients with severe COVID-19, who received TOC and dexamethasone. The lung involvement was assessed quantitatively using native CT examination before and 7−10 days after TOC administration. (3) Results: The in-hospital mortality was 17.8%. Logistic regression analysis found that interstitial lesions above 50% were associated with death (p = 0.01). The other variables assessed were age (p = 0.1), the presence of comorbidities (p = 0.9), the oxygen flow rate at TOC administration (p = 0.2), FiO2 (p = 0.4), lymphocyte count (p = 0.3), and D-dimers level (p = 0.2). Survivors had a statistically significant improvement at 7−10 days after TOC of interstitial (39.5 vs. 31.6%, p < 0.001), mixt (4.3 vs. 2.3%, p = 0.001) and consolidating (1.7 vs. 1.1%, p = 0.001) lesions. When TOC was administered at a FiO2 ≤ 57.5% (oxygen flow rate ≤ 13 L/min), the associated mortality was significantly lower (4.3% vs. 29.1%, p < 0.05). (4) Conclusions: Quantitative imaging provides valuable information regarding the extent of lung damage which can be used to anticipate the in-hospital mortality. The timing of TOC administration is important and FiO2 could be used as a clinical predictor.

Long-Term Longitudinal Evaluation of Six Commercial Immunoassays for the Detection of IgM and IgG Antibodies against SARS CoV-2.

The number of serological assays for SARS-CoV-2 has skyrocketed in the past year. Concerns have been raised regarding their performance characteristics, depending on the disease severity and the time of the analysis post-symptom onset (PSO). Thus, independent validations using an unbiased sample selection are required for meaningful serology data interpretation. We aimed to assess the clinical performance of six commercially available assays, the seroconversion, and the dynamics of the humoral response to SARS-CoV-2 infection. The study included 528 serum samples from 156 patients with follow-up visits up to six months PSO and 161 serum samples from healthy people. The IgG/total antibodies positive percentage increased and remained above 95% after six months when chemiluminescent immunoassay (CLIA) IgG antiS1/S2 and electro-chemiluminescent assay (ECLIA) total antiNP were used. At early time points PSO, chemiluminescent microparticle immunoassay (CMIA) IgM antiS achieved the best sensitivity. IgM and IgG appear simultaneously in most circumstances, and when performed in parallel the sensitivity increases. The severe and the moderate clinical forms were significantly associated with higher seropositivity percentage and antibody levels. High specificity was found in all evaluated assays, but the sensitivity was variable depending on the time PSO, severity of disease, detection method and targeted antigen.

Pyoderma gangrenosum and suppurative hidradenitis association, overlap or spectrum of the same disease? Case report and discussion.

Suppurative hidradenitis and pyoderma gangrenosum are rare disorders that can be seen isolated or even more rare, as part of different autoinflammatory syndromes: Pyoderma gangrenosum, acne, and hidradenitis suppurativa (PASH), pyoderma gangrenosum, acne, pyogenic arthritis, and hidradenitis suppurativa (PAPASH) or psoriatic arthritis, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PsAPASH). Although they have different clinical features, suppurative hidradenitis and pyoderma gangrenosum seem to share similar pathogenic pathways involving a dysregulated innate immune system, with neutrophilic inflammation, mediated by IL-1ß, controlled by NALP3 inflammasome pathway. We report a case of a 53-year-old male patient previously diagnosed with HS in inguinal-scrotal area that developed rapidly after a traumatic injury on his left anterior calf, a painful inflammatory plaque with pustules on the surface that rapidly progressed (24-48 h) to form ulcers. The lesions ended up healing with a large scarring plaque with cribriform openings, multiple fibrous bridges, open comedones, and double-ended pseudo-comedones. Although the clinical aspect at presentation together with the aspect on the first biopsy were suggestive for pyoderma gangrenosum, the healing aspect is more commonly seen in suppurative hidradenitis. Commonly seen in acne, in the healing phase of suppurative hidradenitis but more rarely in pyoderma gangrenosum, the formation of comedones seem to be a complex process and raise the question if these entities represent in our patient an association, an overlap or the spectrum of the same disease.

Does 'Relationship Intelligence' Make Big Brains in Birds?

Lately, Emery et al. developed a bird-specific modification of the "social brain hypothesis", termed "relationship intelligence hypothesis". Although the idea may be valuable, we doubt that it is supported by sufficient evidence and critically discuss some of the arguments raised by the authors in favour of their new idea.