With the emergence of the Novel Coronavirus (2019-nCoV), researchers worldwide have started detecting the probable pathogenesis of the disease. The renin-angiotensin system (RAS) and angiotensin-converting enzymes have received a good deal of attention as possible pathways involved in 2019-nCoV pathogenesis. As the experiments seeking to find potential medications acting on these pathways are being conducted in the early phases, having an ecological worldview on the relationship between the prevalence of COVID-19 disease and the genetic differences in the genes involved in the RAS system could be valuable for the field. In this regard, we conducted a meta-analysis study of the prevalence of ACE (I/D) genotype in countries most affected by the COVID-19. In the meta-analysis, 48,758 healthy subjects from 30 different countries were evaluated in 116 studies, using the Comprehensive Meta-analysis software. The I/D allele frequency ratio was pooled by a random-effect model. The COVID-19 prevalence data of death and recovery rates were evaluated as the latitudes for the meta-regression analysis. Our results demonstrated that with the increase of the I/D allele frequency ratio, the recovery rate significantly increased (point estimate: 0.48, CI 95%: 0.05-0.91, p = 0.027). However, there was no significant difference in the case of death rate (point estimate: 1.74, CI 95%: 4.5-1.04, p = 0.22). This ecological perspective coupled with many limitations does not provide a direct clinical relevance between the COVID-19 and RAS system, but it shows potential pathophysiological associations. Our results raise concerns about ethnic and genetic differences that could affect the effectiveness of the currently investigated RAS-associated medications in different regions.

This study demonstrates that human Ad-MSCs act as key regulators of immune tolerance by inhibiting the inflammation. Therefore, they can be attractive candidates for immunomodulatory cell-based therapy in RA.

The gastrointestinal tract is the body’s largest interface between the host and the external environment. People infected with SARS-CoV-2 are at higher risk of microbiome alterations and severe diseases. Recent evidence has suggested that the pathophysiological and molecular mechanisms associated with gastrointestinal complicity in SARS-CoV-2 infection could be explained by the role of angiotensin-converting enzyme-2 (ACE2) cell receptors. These receptors are overexpressed in the gut lining, leading to a high intestinal permeability to foreign pathogens. It is believed that SARS-CoV-2 has a lesser likelihood of causing liver infection because of the diminished expression of ACE2 in liver cells. Interestingly, an interconnection between the lungs, brain, and gastrointestinal tract during severe COVID-19 has been mentioned. We hope that this review on the molecular mechanisms related to the gastrointestinal disorders as well as neurological and hepatic manifestations experienced by COVID-19 patients will help scientists to find a convenient solution for this and other pandemic events.

Background: Although in many studies, the relationship between autoimmune hypothyroidism (Hashimoto) and Vitamin D deficiency was shown, no research has been performed on the role of vitamin D in non-autoimmune hypothyroidism. Methods: This was a case-control study in Endocrinology clinic of Jahrom (south of Iran). The patients with Hashimoto (n = 633) and non-Hashimoto hypothyroidism (n = 305), along with a control group (n = 200) were evaluated. 25(OH) D level, T3 and T4 levels were studied and Anti TPO and Anti TG tests were performed. The results of vitamin D level were analyzed and interpreted using SPSS in terms of the cause of hypothyroidism (immune and non-immune).