Reinfection risk of novel coronavirus (COVID-19): A systematic ‎review of current evidence

BACKGROUNDThere is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients.AIMTo summarize the recent findings and reports of CoVID-19 reinfection in patients previously reCoVered from the disease.METHODSThis study was a systematic review of current evidence conducted in August 2020. The authors studied the probable reinfection risk of novel coronavirus (CoVID-19). We performed a systematic search using the keywords in online databases. The investigation adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the reliability and validity of this study and results.RESULTSWe reviewed 31 studies. Eight studies described reCoVered patients with reinfection. Only one study reported reinfected patients who died. In 26 studies, there was no information about the status of the patients. Several studies indicated that reinfection is not probable and that post-infection immunity is at least temporary and short.CONCLUSIONBased on our review, we concluded that a positive polymerase chain reaction retest could be due to several reasons and should not always be considered as reinfection or reactivation of the disease. Most relevant studies in positive retest patients have shown relative and probably temporary immunity after the reCoVery of the disease.     

Therapeutic potential of silymarin as a natural iron‐chelating agent in β‐thalassemia intermedia

Abnormal iron accumulation in vital organs is one of the major complications of β‐thalassemia intermedia (β‐TI). Silymarin, a flavonolignan isolated from Silybum marianum, significantly decreases the serum ferritin levels of β‐TI patients. This finding suggests silymarin as a safe and effective natural iron‐chelating agent for the treatment of iron‐overloaded conditions.     

Worldwide prevalence of microbial agents’ coinfection among COVID‐19 patients: A comprehensive updated systematic review and meta‐analysis

BackgroundTo provide information about pathogens’ coinfection prevalence with SARS‐CoV‐2 could be a real help to save patients’ lives. This study aims to evaluate the pathogens’ coinfection prevalence among COVID‐19 patients.MethodIn order to find all of the relevant articles, we used systematic search approach. Research‐based databases including PubMed, Web of Science, Embase, and Scopus, without language restrictions, were searched to identify the relevant bacterial, fungal, and viral coinfections among COVID‐19 cases from December 1, 2019, to August 23, 2021. In order to dig deeper, other scientific repositories such as Medrxiv were probed.ResultsA total of 13,023 studies were found through systematic search. After thorough analysis, only 64 studies with 61,547 patients were included in the study. The most common causative agents of coinfection among COVID‐19 patients were bacteria (pooled prevalence: 20.97%; 95% CI: 15.95–26.46; I ²: 99.9%) and less frequent were virus coinfections (pooled prevalence: 12.58%; 95% CI: 7.31–18.96; I ²: 98.7%). The pooled prevalence of fungal coinfections was also 12.60% (95% CI: 7.84–17.36; I ²: 98.3%). Meta‐regression analysis showed that the age sample size and WHO geographic region did not influenced heterogeneity.ConclusionWe identified a high prevalence of pathogenic microorganism coinfection among COVID‐19 patients. Because of this rate of coinfection empirical use of antibacterial, antifungal, and antiviral treatment are advisable specifically at the early stage of COVID‐19 infection. We also suggest running simultaneously diagnostic tests to identify other microbiological agents’ coinfection with SARS‐CoV‐2.     

The incidence of berry aneurysm in the Iranian population: an autopsy study

Intracranial berry aneurysms are the most common kind of aneurysms in the brain, and are caused by head trauma in 1% of cases. They may remain asymptomatic for a long time or may rupture and cause intracranial hemorrhage. These aneurysms are associated with a high mortality rate. A definitive diagnosis can be made by angiography or autopsy. We studied the cadavers of 425 people who passed away accidentally. The number and location of berry aneurysms were recorded. Twelve cases (2.82%) were found to have a single berry aneurysm and two (0.47%) had multiple aneurysms. The aneurysms had a tendency to occur in the frontal half of the Circle of Willis and in approximation of the bifurcation of arteries. The main characteristics of cases of berry aneurysm in the Iranian population were in agreement with that reported in previous Western studies.     

Combination of fluticasone propionate and salmeterol potentiates the suppression of cigarette smoke-induced IL-8 production by macrophages

Cigarette smoke is the major risk factor for the development of chronic obstructive pulmonary disease (COPD). Macrophages are suggested to orchestrate the chronic inflammatory response and tissue destruction associated with COPD by secreting interleukin (IL)-8, a major neutrophil chemoattractant. The combination of inhaled corticosteroids and long-acting beta(2)-adrenoceptor agonists are increasingly used as maintenance therapy in patients with COPD. The aim of this study was to determine whether combined fluticasone propionate, a corticosteroid, and salmeterol, a long-acting beta(2)-adrenoceptor agonist, can suppress IL-8 production by human macrophages. To mimic resident macrophages in the lung, human monocytes were cultured for 5 days in medium containing Granulocyte Macrophage Colony Stimulating Factor (GM-CSF) and Macrophage Colony Stimulating Factor (M-CSF). In human Monocyte-Derived Macrophages, we found that cigarette smoke medium strongly enhanced IL-8 release in a time- and concentration-dependent manner. IL-8 release by cigarette smoke was significantly suppressed in a concentration-dependent manner by fluticasone and salmeterol. Coincubation of the drugs potentiated the inhibitory effect on cigarette smoke medium-induced IL-8 production and longer preincubation times resulted in more IL-8 inhibition. Interestingly, preincubation of cells with suboptimal concentration of salmeterol for 4 h before fluticasone administration for 30 min potentiates the inhibitory effect of fluticasone on IL-8 release. In conclusion, combination therapy may provide benefits over monotherapy for the treatment of COPD patients.     

Expression of recombinant parvalbumin from wolf-herring fish and determination of its IgE-binding capability

In this study, we produced the recombinant form of parvalbumin from wolf-herring fish and determined its IgE reactivity. Parvalbumin cDNA was sub-cloned into pET28 and expressed in Escherichia coli BL-21. The immunoreactivities of the recombinant and native parvalbumins were compared, and the effect of calcium binding was determined by sera from 25 fish-allergic patients. ELISA and Western blotting confirmed similar IgE-reactivities of the recombinant and native proteins and confirmed that this phenomenon is highly dependent on calcium binding. The recombinant protein was 94.5% similar to carp parvalbumin (Cyp c1). Approximately 72% of patients reacted strongly with recombinant parvalbumin, 80% of them reacted with the native form and only 56% showed IgE reactivity with crude extract. Because the IgE-binding capacity of recombinant wolf-herring parvalbumin is retained and is highly similar to Cyp c1, the wild and hypoallergenic forms of this allergen could be used for diagnosis and immunotherapy of fish allergy, respectively.