Thymic Dysfunction and Atrophy in COVID-19 Disease Complicated by Inflammation, Malnutrition and Cachexia.

Background: The current COVID-19 pandemic has put millions of people, especially children at risk of protein-energy malnutrition (PEM) by pushing them into poverty and disrupting the global food supply chain. The thymus is severely affected by nutritional deficiencies and is known as a barometer of malnutrition. Aim: The present commentary provides a novel perspective on the role of malnutrition-induced thymic dysfunction, involution and atrophy on the risk and severity of disease in children during the COVID-19 pandemic. Methods: A review of pertinent indexed literature including studies examining the effects of malnutrition on the thymus and immune dysfunction in COVID-19. Results: Protein-energy malnutrition and micronutrient deficiencies of zinc, iron and vitamin A are known to promote thymic dysfunction and thymocyte loss in children. Malnutrition- and infection-induced thymic atrophy and immune dysfunction may increase the risk of first, progression of COVID-19 disease to more severe forms including development of multisystem inflammatory syndrome in children (MIS-C); second, slow the recovery from COVID-19 disease; and third, increase the risk of other infections. Furthermore, malnourished children may be at increased risk of contracting SARS-CoV-2 infection due to socioeconomic conditions that promote viral transmission amongst contacts and create barriers to vaccination. Conclusion: National governments and international organizations including WHO, World Food Program, and UNICEF should institute measures to ensure provision of food and micronutrients for children at risk in order to limit the health impact of the ongoing COVID-19 pandemic.

Cytokines and Chemokines in Cancer Cachexia and Its Long-Term Impact on COVID-19.

Cancer cachexia remains a serious public health concern worldwide, particularly as cancer rates rise. Treatment is endangered, and survival is reduced, because this illness is commonly misdiagnosed and undertreated. Although weight loss is the most evident sign of cachexia, there are other early metabolic and inflammatory changes that occur before the most obvious symptoms appear. Cachexia-related inflammation is induced by a combination of factors, one of which is the release of inflammation-promoting chemicals by the tumor. Today, more scientists are beginning to believe that the development of SARS-CoV-2 (COVID-19) related cachexia is similar to cancer-related cachexia. It is worth noting that patients infected with COVID-19 have a significant inflammatory response and can develop cachexia. These correlations provide feasible reasons for the variance in the occurrence and severity of cachexia in human malignancies, therefore, specific therapeutic options for these individuals must be addressed based on disease types. In this review, we highlighted the role of key chemokines, cytokines, and clinical management in relation to cancer cachexia and its long-term impact on COVID-19 patients.

Can chloroquine/hydroxychloroquine prove efficient in cancer cachexia? A hypothesis in the era of COVID-19.

Cancer cachexia (CC) is a progressive loss of muscle mass (with or without a decrease of adipose tissue). Gradual deterioration of the patient's fitness is resistant to nutritional intervention. The biochemical foundation of observed catabolism, detrimental protein, and energy balance is complex. However, the generalized inflammatory response plays a vital role. It is a kind of cytokine storm, which involves increased activity of TNF-α, IL-1, IL-6, and INF-γ. Pharmacological treatment of cachexia consists mainly of progestagens and glucocorticosteroids. Still, the assessment of new options limiting the harmful impact of cachexia could be beneficial. Chloroquine (CQ) and hydroxychloroquine (HCQ) are old antimalarial agents endowed with immunomodulatory properties. Being potent autophagy inhibitors, they could lead to a form of intracellular starvation in both cytokine-releasing cells and cancer cells, thus limiting the harmful impact of CC. CQ and HCQ are also efficient in particular connective tissue disorders. They have gained special attention since the World Health Organization announced the coronavirus disease 2019 (COVID-19) pandemic. According to initial reports, people with a severe inflammatory reaction showed significant benefits. Possibly they could not be attributed to the antiviral activity alone. It is worth noting that the cytokine storm in COVID-19, connective tissue disorders, and cancer cachexia share some similarities. Therefore, we hypothesize that low doses of CQ/HCQ may prove efficient in cancer cachexia.

Weight loss, malnutrition, and cachexia in COVID-19: facts and numbers.

Patients with COVID-19 disease are prone to develop significant weight loss and clinical cachexia. Three reports with altogether 589 patients that reported on weight loss and cachexia in COVID-19 were identified. Disease severity of patients and the timing of the assessment during the disease course in these patients were variable-65 patients (11%) were intensive care treated at the time of assessment, and 183 (31%) were cared for in sub-intensive or intermediate care structures. The frequency of weight loss ≥5% (that defines cachexia) was 37% (range 29-52%). Correlates of weight loss occurrence were reported to be raised C-reactive protein levels, impaired renal function status, and longer duration of COVID-19 disease. Underweight status by WHO criteria (BMI < 18.5 kg/m2 ) was only observed in 4% of patients analysing data from seven studies with 6661 patients. Cachexia assessment in COVID-19 needs assessment of weight loss. COVID-19 associated cachexia is understood to affect muscle and fat tissue as is also seen in many other chronic illness-associated forms of cachexia. There are many factors that can contribute to body wasting in COVID-19, and they include loss of appetite and taste, fever and inflammation, immobilization, as well as general malnutrition, catabolic-anabolic imbalance, endocrine dysfunction, and organ-specific complications of COVID-19 disease such as cardiac and renal dysfunction. Treatment of COVID-19 patients should include a focus on nutritional support and rehabilitative exercise whenever possible. Specific anti-cachectic therapies for COVID-19 do not exist, but constitute a high medical need to prevent long-term disability due to acute COVID-19 disease.

Can COVID-19 be a risk for cachexia for patients during intensive care? Narrative review and nutritional recommendations.

Although increased weight, and particularly obesity, has been associated with a more severe clinical course of COVID-19 and risk of fatality, the course of the illness can lead to prolonged length of stay. Changes in nutritional status and weight loss during hospitalisation are largely reported in some populations, but still not explored in COVID-19 patients. Considering that patients with COVID-19 show an increased inflammatory response, other signs and symptoms, which can lead to weight and muscle loss, should be monitored. The aim of this article was to establish possible connections between COVID-19, prolonged hospitalisation and muscle wasting, as well as to propose nutritional recommendations for the prevention and treatment of cachexia, through a narrative review. Identification of risk and presence of malnutrition should be an early step in general assessment of all patients, with regard to more at-risk categories including older adults and individuals suffering from chronic and acute disease conditions, such as COVID-19. The deterioration of nutritional status, and consequently cachexia, increases the risk of mortality and needs to be treated with attention as other complications. There is, however, little hard evidence of nutritional approaches in assisting COVID-19 treatment or its management including cachexia.