COVID-19 severity and thrombo-inflammatory response linked to ethnicity

Although there is strong evidence that SARS-CoV-2 infection is associated with adverse outcomes in certain ethnic groups, the association of disease severity and risk factors such as comorbidities and biomarkers with racial disparities remains undefined. This retrospective study between March 2020 and February 2021 explores COVID-19 risk factors as predictors for patients’ disease progression through country comparison. Disease severity predictors in Germany and Japan were cardiovascular-associated comorbidities, dementia, and age. We adjusted age, sex, body mass index, and history of cardiovascular disease comorbidity in the country cohorts using a propensity score matching (PSM) technique to reduce the influence of differences in sample size and the surprisingly young, lean Japanese cohort. Analysis of the 170 PSM pairs confirmed that 65.29% of German and 85.29% of Japanese patients were in the uncomplicated phase. More German than Japanese patients were admitted in the complicated and critical phase. Ethnic differences were identified in patients without cardiovascular comorbidities. Japanese patients in the uncomplicated phase presented a suppressed inflammatory response and coagulopathy with hypocoagulation. In contrast, German patients exhibited a hyperactive inflammatory response and coagulopathy with hypercoagulation. These differences were less pronounced in patients in the complicated phase or with cardiovascular diseases. Coagulation/fibrinolysis-associated biomarkers rather than inflammatory-related biomarkers predicted disease severity in patients with cardiovascular comorbidities: platelet counts were associated with severe illness in German patients. In contrast, high D-dimer and fibrinogen levels predicted disease severity in Japanese patients. Our comparative study indicates that ethnicity influences COVID-19-associated biomarker expression linked to the inflammatory and coagulation (thrombo-inflammatory) response. Future studies will be necessary to determine whether these differences contributed to the less severe disease progression observed in Japanese COVID-19 patients compared with those in Germany

The importance of Protein Kinase C isoforms PKCα and PKCβ for the acetylcholine-induced Calcium Signal in the native murine pancreatic β-cells

Titelblatt und Inhaltsverzeichnis Einleitung Material und Methoden Ergebnisse Diskussion LiteraturverzeichnisZusammenfassend konnten wir mit Hilfe der drei untersuchten Maus- Modelle mit PKCα-, PKCβ\- und PKCα-/PKCβ-Defizienz die Beteiligung der beiden Isozyme am ACh-vermittelten intrazellulären Ca2+-Signal in den insulinsezernierenden β-Zellen nachweisen. Hierbei zeigte es sich eine Kombination aus hemmenden, aber auch fördernden Einflüssen dieser PKCIsoformen auf das Ca2+-Signal, wobei vor allem der Einstrom des Ca2+ aus dem extrazellulären Raum beeinträchtigt wurde. Die Freisetzung der Ca2+- Ionen aus den intrazellulären Speichern blieb in unseren Experimenten in allen knock-out-Modellen unbeeinträchtigt. Während die PKCα-Defizienz nur zu einer leichten Verminderung des ACh-bedingten Ca2+-Signals in der Plateau-Phase führte, kam es in den PKCβ-/- β-Zellen zu deutlicher Vergrößerung des Ca2+-Signals nach ACh-Stimulation. Die PKCβ- Defizienz führte hierbei vor allem zur Vermehrung des Ca2+-Einstroms über die spannungsunabhängigen Ca2+-Kanäle, wie in der Versuchsreihe mit Thapsigargin- Blockade der intrazellulären Ca2+-ATPasen nachgewiesen werden konnte. Die PKCβ scheint vorwiegend eine hemmende Wirkung auf den Ca2+-Einstrom auszuüben. Die PKCαβ-/- β-Zellen zeigten eine signifikante Erhöhung des Initial-Peaks nach ACh-Stimulation, der vermehrte Ca2+-Einstrom über spannungsunabhängige Kanäle konnte in den PKCαβ-/- β-Zellen nicht nachgewiesen werden. Während in den PKCα-/- und PKCβ-/- β-Zellen der Ca2+-Einstrom über CaVKanäle nach der Depolarisation der Zellmembran unverändert blieb, zeigten die PKCαβ-/- β-Zellen eine deutliche Verminderung des Ca2+-Einstroms über CaV (CaV 1.2, CaV 1.3) nach der Depolarisation der Zellmembran mit K+- Ionen. Offensichtlich verfügen die cPKC-Enzyme β-Zelle über die Möglichkeit, einander zu kompensieren. Dennoch handelt es sich um Enzyme mit spezifischer Funktion. Die weitere Erforschung dieser Zusammenhänge würde zum besseren Verständnis der physiologischen aber auch der pathophysiologischen Vorgänge in der β-Zelle führen und langfristig auch neue Möglichkeiten zur Entwicklung nächster Generationen unterschiedlicher Antidiabetika führen, die zur Behandlung vom Diabetes Typ 2 beitragen könnten.PKCα-, PKCβ\- and PKCαβ-deficient mice were used to establish the importance of classical PKC isoforms for the intracellular calcium signaling in pancreatic β-cells. PKC-deficient β-cells showed distinct isoform-dependent changes in calcium signaling, especially the calcium influx through the membrane calcium channels. The intracellular calcium stores were not affected. PKCα deficiency caused minimal decrease in calcium influx in the second phase of intracellular calcium signal due to acetylcholine stimulation. PKCβ deficiency, however, induced increased global calcium influx in acetylcholine associated calcium signaling. Especially the voltage-independent calcium channels (SOC) showed increased influx, as detected by thapsigargin treatment in β-cells. The PKCβ isoform appears to be involved into a negative feedback mechanism of calcium signal regulation due to acetylcholine stimulation. Global cPKC deficiency (PKCαβ-knockout) caused increased initial calcium signal in acetylcholine-treated β-cells. Additionally, global calcium influx through voltage-dependent calcium channels (CaV) was significantly decreased. Therefore, the classical PKC isoforms are able to compensate each other in CaV channel regulation. The better understanding of mechanisms underlying the physiological and pathophysiological regulation in the β-cell is absolutely necessary for future development of novel therapy strategies for type 2 diabetes

Use of monoclonal antibody therapy for nosocomial SARS-CoV-2 infection in patients at high risk for severe COVID-19: experience from a tertiary-care hospital in Germany

Additional treatment options for coronavirus disease (COVID-19) are urgently needed, particularly for populations at high risk of severe disease. This cross-sectional, retrospective study characterized the outcomes of 43 patients with nosocomial severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection with and without treatment using monoclonal SARS-CoV-2 spike antibodies (bamlanivimab or casirivimab/imdevimab). Our results indicate that treatment with monoclonal antibodies results in a significant decrease in disease progression and mortality when used for asymptomatic patients with early SARS-CoV-2 infection

Self-sampling versus health care professional-guided swab collection for SARS-CoV-2 testing

Purpose!#!To evaluate the diagnostic reliability and practicability of self-collected oropharyngeal swab samples for the detection of SARS-CoV-2 infection as self-sampling could enable broader testing availability and reduce both personal protective equipment and potential exposure.!##!Methods!#!Hospitalized SARS-CoV-2-infected patients were asked to collect two oropharyngeal swabs (SC-OPS1/2), and an additional oropharyngeal swab was collected by a health care professional (HCP-OPS). SARS-CoV-2 PCR testing for samples from 58 participants was performed, with a 48-h delay in half of the self-collected samples (SC-OPS2). The sensitivity, probability of concordance, and interrater reliability were calculated. Univariate and multivariate analyses were performed to assess predictive factors. Practicability was evaluated through a questionnaire.!##!Results!#!The test sensitivity for HCP-OPS, SC-OPS1, and SC-OPS2 was 88%, 78%, and 77%, respectively. Combining both SC-OPS results increased the estimated sensitivity to 88%. The concordance probability between HCP-OPS and SC-OPS1 was 77.6% and 82.5% between SC-OPS1 and SC-OPS2, respectively. Of the participants, 69% affirmed performing future self-sampling at home, and 34% preferred self-sampling over HCP-guided testing. Participants with both positive HCP-OPS1 and SC-OPS1 indicating no challenges during self-sampling had more differences in viral load levels between HCP-OPS1 and SC-OPS1 than those who indicated challenges. Increasing disease duration and the presence of anti-SARS-CoV-2-IgG correlated with negative test results in self-collected samples of previously confirmed SARS-CoV-2 positive individuals.!##!Conclusion!#!Oropharyngeal self-sampling is an applicable testing approach for SARS-CoV-2 diagnostics. Self-sampling tends to be more effective in early versus late infection and symptom onset, and the collection of two distinct samples is recommended to maintain high test sensitivity

SARS-CoV-2 serology increases diagnostic accuracy in CT-suspected, PCR-negative COVID-19 patients during pandemic

Background!#!In the absence of PCR detection of SARS-CoV-2 RNA, accurate diagnosis of COVID-19 is challenging. Low-dose computed tomography (CT) detects pulmonary infiltrates with high sensitivity, but findings may be non-specific. This study assesses the diagnostic value of SARS-CoV-2 serology for patients with distinct CT features but negative PCR.!##!Methods!#!IgM/IgG chemiluminescent immunoassay was performed for 107 patients with confirmed (group A: PCR + ; CT ±) and 46 patients with suspected (group B: repetitive PCR-; CT +) COVID-19, admitted to a German university hospital during the pandemic's first wave. A standardized, in-house CT classification of radiological signs of a viral pneumonia was used to assess the probability of COVID-19.!##!Results!#!Seroconversion rates (SR) determined on day 5, 10, 15, 20 and 25 after symptom onset (SO) were 8%, 25%, 65%, 76% and 91% for group A, and 0%, 10%, 19%, 37% and 46% for group B, respectively; (p < 0.01). Compared to hospitalized patients with a non-complicated course (non-ICU patients), seroconversion tended to occur at lower frequency and delayed in patients on intensive care units. SR of patients with CT findings classified as high certainty for COVID-19 were 8%, 22%, 68%, 79% and 93% in group A, compared with 0%, 15%, 28%, 50% and 50% in group B (p < 0.01). SARS-CoV-2 serology established a definite diagnosis in 12/46 group B patients. In 88% (8/9) of patients with negative serology > 14 days after symptom onset (group B), clinico-radiological consensus reassessment revealed probable diagnoses other than COVID-19. Sensitivity of SARS-CoV-2 serology was superior to PCR > 17d after symptom onset.!##!Conclusions!#!Approximately one-third of patients with distinct COVID-19 CT findings are tested negative for SARS-CoV-2 RNA by PCR rendering correct diagnosis difficult. Implementation of SARS-CoV-2 serology testing alongside current CT/PCR-based diagnostic algorithms improves discrimination between COVID-19-related and non-related pulmonary infiltrates in PCR negative patients. However, sensitivity of SARS-CoV-2 serology strongly depends on the time of testing and becomes superior to PCR after the