On the role of bacterial metalloproteases in COVID-19 associated cytokine storm.

The cytokine release syndrome or cytokine storm, which is the hyper-induction of inflammatory responses has a central role in the mortality rate of COVID-19 and some other viral infections. Interleukin-6 (IL-6) is a key player in the development of cytokine storms. Shedding of interleukin-6 receptor (IL-6Rα) results in the accumulation of soluble interleukin-6 receptors (sIL-6R). Only relatively few cells express membrane-bound IL-6Rα. However, sIL-6R can act on potentially all cells and organs through the ubiquitously expressed gp130, the coreceptor of IL-6Rα. Through this, so-called trans-signaling, IL-6-sIL-6R is a powerful factor in the development of cytokine storms and multiorgan involvement. Some bacteria (e.g., Serratia marcescens, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes), commonly considered to cause co-infections during viral pneumonia, can directly induce the shedding of membrane receptors, including IL-6Rα, or enhance endogenous shedding mechanisms causing the increase of sIL-6R level. Here we hypothesise that bacteria promoting shedding and increase the sIL-6R level can be an important contributing factor for the development of cytokine storms. Therefore, inhibition of IL-6Rα shedding by drastically reducing the number of relevant bacteria may be a critical element in reducing the chance of a cytokine storm. Validation of this hypothesis can support the consideration of the prophylactic use of antibiotics more widely and at an earlier stage of infection to decrease the mortality rate of COVID-19. Video abstract.

The Esophageal Adenocarcinoma Epidemic Has Reached Hungary: A Multicenter, Cross-Sectional Study.

BACKGROUND: The epidemiology of esophageal cancer has changed dramatically over the past 4 decades in many Western populations. We aimed to understand the Hungarian epidemiologic trends of esophageal squamous cell cancer (SCC) and adenocarcinoma (AC). METHODS: We performed a cross-sectional study using data from esophageal cancer patients diagnosed between 1992 and 2018 at eight tertiary referral centers in four major cities of Hungary. We retrospectively identified cases in the electronic databases of each center and collected data on gender, age at diagnosis, year of diagnosis, specialty of the origin center, histological type, and localization of the tumor. Patients were grouped based on the two main histological types: AC or SCC. For statistical analysis, we used linear regression models, chi-square tests, and independent sample t tests. RESULTS: We extracted data on 3,283 patients with esophageal cancer. Of these, 2,632 were diagnosed with either of the two main histological types; 737 had AC and 1,895 SCC. There was no significant difference in the gender ratio of the patients between AC and SCC (80.1 vs 81.8% males, respectively; p = 0.261). The relative incidence of AC increased over the years (p < 0.001, b = 1.19 CI: 0.84-1.54). AC patients were older at diagnosis than SCC patients (64.37 ± 11.59 vs 60.30 ± 10.07 years, p < 0.001). The age of patients at the diagnosis of primary esophageal cancer increased over time (p < 0.001, R = 0.119). CONCLUSIONS: The rapid increase in the relative incidence of AC and simultaneous decrease of the relative incidence of SCC suggest that this well-established Western phenomenon is also present in Hungary.