Exosomes, and the potential for exosome-based interventions against COVID-19.

Since late 2019, the world has been devastated by the coronavirus disease 2019 (COVID-19) induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with more than 760 million people affected and ∼seven million deaths reported. Although effective treatments for COVID-19 are currently limited, there has been a strong focus on developing new therapeutic approaches to address the morbidity and mortality linked to this disease. An approach that is currently being investigated is the use of exosome-based therapies. Exosomes are small, extracellular vesicles that play a role in many clinical diseases, including viral infections, infected cells release exosomes that can transmit viral components, such as miRNAs and proteins, and can also include receptors for viruses that facilitate viral entry into recipient cells. SARS-CoV-2 has the ability to impact the formation, secretion, and release of exosomes, thereby potentially facilitating or intensifying the transmission of the virus among cells, tissues and individuals. Therefore, designing synthetic exosomes that carry immunomodulatory cargo and antiviral compounds are proposed to be a promising strategy for the treatment of COVID-19 and other viral diseases. Moreover, exosomes generated from mesenchymal stem cells (MSC) might be employed as cell-free therapeutic agents, as MSC-derived exosomes can diminish the cytokine storm and reverse the suppression of host anti-viral defences associated with COVID-19, and boost the repair of lung damage linked to mitochondrial activity. The present article discusses the significance and roles of exosomes in COVID-19, and explores potential future applications of exosomes in combating this disease. Despite the challenges posed by COVID-19, exosome-based therapies could represent a promising avenue for improving patient outcomes and reducing the impact of this disease.

Hepatitis C infection seroprevalence in pregnant women worldwide: a systematic review and meta-analysis.

Background: Monitoring progress towards the WHO global target to eliminate hepatitis C virus (HCV) infection by 2030, entails reliable prevalence estimates for HCV infection in different populations. Little is known about the global burden of HCV infection in pregnant women. Here, for the first time to our knowledge, we estimated the global and regional seroprevalence of HCV antibody (Ab) and determinants in pregnant women. Methods: In this systematic review and meta-analysis study, we searched PubMed/MEDLINE, Web of Science, Embase, Scopus, and SciELO databases for peer-reviewed observational studies between January 1, 2000 and April 1, 2023, without language or geographical restrictions. Pooled global seroprevalence (and 95% confidence interval, CI) were estimated using random-effects meta-analysis and seroprevalences were categorised according to World Health Organization regions and subregions, publishing year, countries' income and human development index (HDI) levels. We used sensitivity analysis to assess the effect of four large sample size studies on pooled global prevalence through the "leave-one-out" method. We also investigated the association of potential risk factors with HCV seropositivity in pregnant women by subgroup and meta-regression analyses. The Protocol was registered in PROSPERO CRD42023423259. Findings: We included 192 eligible studies (208 datasets), with data for 148,509,760 pregnant women from 53 countries. The global seroprevalence of HCV Ab in pregnant women was 1.80% (95% CI, 1.72-1.89%) and 3.29% (3.01-3.57%) in overall and sensitivity analyses, respectively. The seroprevalence was highest in the Eastern Mediterranean region (6.21%, 4.39-8.29%) and lowest in the Western Pacific region (0.75%, 0.38-1.22%). Subgroup analysis indicated that the seroprevalence of HCV Ab among pregnant women was significantly higher for those with opioid use disorder (51.94%, 95% CI: 37.32-66.39) and HIV infection (4.34%, 95% CI: 2.21-7.06%) than for the general population of pregnant women (1.08%, 95% CI: 1.02-1.15%), as confirmed by multivariable meta-regression (p < 0.001). A significant decreasing trend was observed with increasing human development index levels. Other important risk factors for HCV seropositivity included older age, lower educational levels, poly sexual activity, history of blood transfusion, hospitalization, surgery, abortion and sexual transmitted diseases, having scarification/tattoo or piercing, and testing hepatitis B positive. Interpretation: This meta-analysis showed relatively high burden of exposure to HCV infection (2.2-5.3 million) in pregnant women globally. However, due to substantial heterogeneity between studies, our estimates might be different than the true seroprevalence. Our findings highlighted the need to expand HCV screening for women of reproductive age or during pregnancy, particularly in countries with high prevalence; as well as for more studies that assess safety of existing therapeutic drugs during pregnancy or potentially support development of drugs for pregnant women. Funding: There was no funding source for this study.

Chlamydia pneumonia infection and risk of multiple sclerosis: A meta-analysis.

BACKGROUND: The role of infectious agents, including Chlamydia pneumoniae (Cpn), in the development of multiple sclerosis (MS), is still a matter of major contention. OBJECTIVE: This meta-analysis study aimed to assess the actual involvement of Cpn in MS development. METHODS: We undertook a search of international scientific databases to identify eligible studies. We used a random-effects meta-analysis model (REM) to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Heterogeneity was calculated using the I2 statistic. Sensitivity and subgroup analyses were applied to assess the effects of study characteristics and socio-demographic variables on the pooled OR. RESULTS: We identified 37 studies comprising 51 datasets that satisfied the inclusion criteria. Considering diagnostic methods for Cpn, 26 and 25 datasets used PCR- and serological-based methods, respectively. In PCR-based datasets, REM showed a significant positive association between Cpn infection and the development of MS (OR, 5.29; 95% CI, 3.12-8.97), while a non-significant positive association was achieved in serological-based datasets (OR, 1.34; 95% CI, 0.88-2.03). In subgroup analyses on PCR-based datasets, results were significant for both CSF (OR, 5.70) and serum (OR, 4.84) samples; both healthy (OR, 16.11) and hospital-based (OR, 2.88) controls; and both moderate (OR, 5.14) and high (OR, 5.48) quality studies. In serological-based datasets, only those that used CSF samples yielded significant results (OR, 3.41). CONCLUSIONS: Our findings verify the significant positive relationship between Cpn infection and MS. We advocate prospective cohort studies with lifelong follow-ups and also experimental studies to better understand the role of Cpn in MS development.

Primary cardiac synovial sarcoma presenting with brain metastases.

Primary cardiac synovial sarcoma is a very rare primary cardiac tumor that usually arises in the right side of the heart. Brain metastases in primary cardiac sarcomas are not uncommon. Because of the wild nature of these tumors, they usually have poor outcomes. This study describes a 29-year-old female who presented with blurred vision, headache, nausea, vomiting and brain lesions in the radiologic study. Incidentally, two-dimensional echocardiography revealed a left atrial lesion. The patient underwent emergency cardiac surgery to resect the left atrial mass that arose from the atrial free wall and pulmonary veins. The diagnosis of the lesion was primary synovial sarcoma in the histopathologic examination.

Tumors that usually arises in the right side of the heart are very rare. These tumors can spread to other parts like brain. Because of the wild nature of these tumors, they usually have poor results. This study describes a 29-year-old female who comes to the hospital with vision problems, headache, nausea, vomiting and brain masses in the imaging. In addition, there was a mass on the left side of her heart. The patient underwent emergency heart surgery to resect the mass that arose from the heart wall and lung veins. The nature of the lesion was primary synovial sarcoma in the pathologic examination.