A comparison of zinc metabolism, inflammation, and disease severity in critically ill infected and noninfected adults early after intensive care unit admission

The role of serum zinc and selenium levels in etiology of febrile seizures

BACKGROUND

Febrile seizures (FSs) are the most common form of childhood seizures. Determining the role of trace elements in the pathophysiology of FSs will contribute to the management of FSs by pediatricians.

PURPOSE

This study aimed to investigate the effects of zinc and selenium on the nervous system and how they may influence the risk of FSs.

METHODS

In this case-control study, there were 60 children in the simple FS group and 40 children in the complex FS group. The control groups comprised 50 children with fever but without seizures and 50 healthy children. Blood samples were collected within the first hour after FS.

RESULTS

Zinc and selenium levels were significantly lower in children with fever but without seizures versus healthy children (P<0.001). Serum zinc levels were lower in children with FSs (simple and complex FSs) than in healthy children (P<0.001) but higher than in children with fever but without seizures (P<0.001). Serum selenium levels in children with FSs (simple and complex) were lower than in healthy children but higher than in the children with fever but without seizures. However, these differences were not statistically significant (P>0.05).

CONCLUSION

Serum zinc levels are significantly decreased during infection, whereas they show a statistically significant increase within the first hour after FS activity. This indicates that the body secretes zinc during FSs to restore homeostasis, reduce oxidative stress, and increase the seizure threshold. Therefore, zinc supplementation during febrile periods may effectively prevent FSs in high-risk children.

Zinc Deficiency Reduces Intestinal Secretory Immunoglobulin A and Induces Inflammatory Responses via the Gut-Liver Axis

Nutritional zinc (Zn) deficiency could impair immune function and affect bowel conditions. However, the mechanism by which Zn deficiency affects the immune function of gut-associated lymphoid tissue (GALT) remains unclear. We investigated how Zn deficiency affects the function of GALT and level of secretory IgA (sIgA), a key component of the intestinal immune barrier, its underlying mechanisms, and whether Zn deficiency induces bacterial translocation to the liver. As previous research has indicated that interleukin (IL)-4 administration or Zn supplementation has a beneficial effect on the spleen of Zn-deficient rats, we investigated whether these supplements reverse the GALT immune system. Five-week-old male rats were fed a standard diet, Zn-deficient diet supplemented with saline or IL-4 for 6 weeks, or Zn-deficient diet followed by a standard diet for 4 weeks. Zn deficiency suppressed sIgA secretion in the intestinal tract by affecting GALT function and induced inflammatory responses through bacterial translocation to the liver via the portal vein. Furthermore, IL-4 administration and Zn supplementation in rats with Zn deficiency elicited comparable beneficial effects on GALT function, suggesting that the administration of either IL-4 or Zn could prevent inflammatory response via bacterial translocation to the liver.

Is the Concentration of Trace Elements Zinc, Selenium, Copper, Manganese, and Iron a Predictor of Clinical Outcomes in Critically Ill Trauma Patients?

Trace elements (TE) function as essential micronutrients involved in the biochemical and physiological processes of the human body. We evaluated the baseline serum concentrations of TE as a predictor of clinical outcomes in critically ill trauma patients and monitored the concentrations of TE during the patients intensive care unit (ICU) stay. A total of 89 patients were enrolled. Within the first 24 h of patients' admission, concentrations of TE, zinc (Zn), selenium (Se), copper (Cu), manganese (Mn), and iron (Fe) were measured and monitored on the 5th and 10th day of patients ICU stay. The concentrations of Zn, Se, Cu and Mn were determined from serum using atomic absorption spectrophotometry, whereas the concentration of Fe using the photometric method. ANOVA and logistic regression analyses were used for statistical analysis with the level of significance set at 0.05. At the time of ICU admission, deficiency of Cu was observed in 11 out of 89 (0.13), Zn in 82 (0.92), Se in 5 (0.06) and Fe in 52 (0.58) patients, while excess of Mn was detected in 27 (0.30) and Cu in 3 (0.03) patients. A significant increase of Zn and Cu concentrations was observed from admission to 10th day (P < 0.001 for both), although Zn concentrations did not reach the lower limit of the reference interval. Logistic regression analysis found that only a low concentration of Zn at admission was associated with mechanical ventilation (OR = 0.78; 95%CI: 0.64-0.96; P = 0.018). Furthermore, the concentrations of TE at admission in critically ill trauma patients did not have an impact on the overall length of the ICU and hospital stay, nor on mortality.

Total and Free Zinc Dynamics as Biomarkers for Neurological Impairment in Traumatic Spinal Cord Injury

Background/Objectives: Traumatic spinal cord injury (TSCI) profoundly impacts patients by precipitating a loss of motor and sensory capabilities, largely due to oxidative stress and inflammation during the secondary injury phase. Methods: This investigation explores the diagnostic potential of zinc (Zn) and free zinc (fZn) as biomarkers by analyzing their serum concentration dynamics in 48 TSCI individuals with TSCI, with the aim of correlating these levels with neurological impairment. Serum samples collected at admission, 4 h, 9 h, 12 h, 24 h, and 3 days post-injury were analyzed for total serum Zn and fZn concentrations. The patients were compared to a control group comprised of individuals with vertebral fractures but no neurological deficits. Results: The study revealed injury-specific fluctuations in Zn and fZn levels following TSCI, with significantly lower Zn levels observed post-TSCI compared to controls (p = 0.016). The American Spinal Injury Association (ASIA) Impairment scale (AIS) assessments at admission and three months post-injury showed Zn level differences are linked to neurological recovery (AIS+:1 > AIS+:2, 0 h: p = 0.008; AIS+:0 < AIS+:1, 4 h: p = 0.016), highlighting the critical role of Zn and trace elements in the early remission process after TSCI. Notably, significant differences in fZn levels were detected between the control and TSCI groups (TSCI < Control; 12 h: p = 0.045; 24 h: p = 0.001; 3 d: p = 0.016), with the peak diagnostic performance of fZn at 24 h post-injury, as indicated by an Area Under the ROC Curve (AUC) of 83.84% (CI: 0.698-0.978). Conclusions: These findings underscore the potential of fZn as a biomarker to guide early diagnostic and therapeutic interventions aimed at mitigating secondary injury and enhancing recovery outcomes. This study contributes insights into the dynamics of serum Zn and its importance, holding specific diagnostic properties that could be critically relevant in the early phase of biomarker signature development for TSCI diagnostics and prognosis.

What do we know about micronutrients in critically ill patients? A narrative review

Micronutrient (MN) status alterations (both depletion and deficiency) are associated with several complications and worse outcomes in critically ill patients. On the other side of the spectrum, improving MN status has been shown to be a potential co-adjuvant therapy. This review aims to collect existing data to better guide research in the critical care setting. This narrative review was conducted by the European Society of Intensive Care Medicine Feeding, Rehabilitation, Endocrinology, and Metabolism MN group. The primary objective was to identify studies focusing on individual MNs in critically ill patients, selecting the MNs that appear to be most relevant and most frequently investigated in the last decade: A, B1, B2, B3, B6, folate, C, D, E, copper, iron, selenium, zinc, and carnitine. Given the limited number of interventional studies for most MNs, observational studies were included. For each selected MN, the review summarizes the main form and functions, special needs and risk factors, optimal treatment strategies, pharmacological dosing, and clinical implications all specific to critically ill patients. A rigorous rebalancing of research strategies and priorities is needed to improve clinical practice. An important finding is that high-dose monotherapy of MNs is not recommended. Basal daily needs must be provided, with higher doses in diseases with known higher needs, and identified deficiencies treated. Finally, the review provides a list of ongoing trials on MNs in critically ill patients and identifies a priority list of future research topics.

Effectiveness of Zinc Supplementation for Sepsis Treatment: A Single-Center Retrospective Observational Study

BACKGROUND

Zinc plays an important role in sepsis; however, the effectiveness of zinc supplementation and the appropriate dose remain unclear. This study aimed to verify the effectiveness of zinc supplementation and the appropriate dose in patients with sepsis.

METHODS

This single-center retrospective observational study included 247 patients with sepsis from 1 April 2015 to 31 March 2023 who were receiving ventilatory management. The patients were divided into three groups according to the zinc supplementation dose: <15 mg, 15-50 mg, and ≥50 mg.

RESULTS

The <15 mg, 15-50 mg, and ≥50 mg groups had 28 (19%), six (21%), and 16 deaths (22%) at discharge, with no statistically significant difference (p = 0.36). No statistically significant differences were observed in the length of intensive care unit (ICU) stay (p = 0.06). A higher supplementation dose corresponded with a statistically significant increase in blood zinc concentration in the first week (38.5 ± 16.6 µg/dL, 58.8 ± 19.7 µg/dL, 74.2 ± 22.5 µg/dL, respectively; p < 0.01) but not in the second or third weeks (p = 0.08, 0.19, respectively).

CONCLUSIONS

Zinc supplementation did not reduce the mortality rate or length of ICU stay or contribute to an increased serum zinc concentration. High-dose zinc supplementation may not be effective during acute sepsis.

Zinc Deficiency in Critically Ill Patients: Impact on Clinical Outcome

Background Zinc is a trace element essential for the normal functioning of many vital enzymes and organ systems. Studies examining the rates and degrees of zinc deficiency and its consequences in patients with critical illnesses remain scarce. Materials and methods This is a prospective observational study assessing zinc deficiency in critically ill adult patients admitted to a tertiary care intensive care unit (ICU) and its impact on clinical outcomes. Patients were divided into those with normal (≥ 71 µg/dl) and low (≤ 70 µg/dl) zinc levels. Zinc-deficient patients were further divided into mild, moderate, and severe zinc deficiency groups based on zinc levels of 61-70 µg/dl, 51-60 µg/dl, and below 51 µg/dl, respectively. The primary outcome assessed was ICU mortality, and the secondary outcomes were ICU length of stay (LOS), duration of invasive mechanical ventilation (IMV), acute kidney injury (AKI) at admission, need for non-invasive ventilation (NIV), renal replacement therapy (RRT), or vasopressors during the course of the ICU. Other parameters compared included APACHE (Acute Physiology and Chronic Health Evaluation) II, SOFA (Sequential Organ Failure Assessment) score on day 1, and levels of lactate, procalcitonin, calcium, magnesium, phosphate, and serum albumin. The study also compared the mean zinc levels in patients with low and high SOFA scores (scores up to 7 vs. 8 and above) and low and high APACHE II values (scores up to 15 vs. 16 and above). Results A total of 50 patients were included, of whom 43 (86%) were zinc deficient. Mortality in zinc-deficient and normal zinc-level patients was 33% and 43%, respectively (p = 0.602). Patients with zinc deficiency were also older (mean age 69 vs. 49 years, p = 0.02). There was no difference in secondary outcome parameters, except for more zinc-deficient patients needing RRT. Twenty-six of the zinc-deficient patients had severe zinc deficiency, ten moderate, and seven mild (p = 0.663). ICU mortality was approximately 42%, 10%, and 29% in the severe, moderate, and mild deficiency groups, respectively (p = 0.092). Zinc levels were similar between those with low and high APACHE II scores (mean 47.9 vs. 45.5 µg/dl, p = 0.606) as well as between low and high SOFA scores (mean 47.8 vs. 45.7 µg/dl, p = 0.054). Conclusion The present study suggests that zinc deficiency is very common in critically ill patients but does not correlate with their severity of illness, nor does it lead to a poorer outcome in these patients. However, further studies with a larger cohort of patients would be required to make definitive conclusions.

Identification of ZIP8-induced ferroptosis as a major type of cell death in monocytes under sepsis conditions

Sepsis is a heterogenous syndrome with concurrent hyperinflammation and immune suppression. A prominent feature of immunosuppression during sepsis is the dysfunction and loss of monocytes; however, the major type of cell death contributing to this depletion, as well as its underlying molecular mechanisms, are yet to be identified. In this study, we confirmed the monocyte loss in septic patients based on a pooled gene expression data of periphery leukocytes. Using the collected reference gene sets from databases and published studies, we identified ferroptosis with a greater capacity to distinguish between sepsis and control samples than other cell death types. Further investigation on the molecular drivers, by a genetic algorithm-based feature selection and a weighted gene co-expression network analysis, revealed that zrt-/irt-like protein 8 (ZIP8), encoded by SLC39A8, was closely associated with ferroptosis of monocytes during sepsis. We validated the increase of ZIP8 of monocytes with in vivo and in vitro experiments. The in vitro studies also showed that downregulation of ZIP8 alleviated the lipopolysaccharide-induced lipid peroxidation, as well as restoring the reduction of GPX4, FTH1 and xCT. These findings suggest that ferroptosis might be a key factor in the loss of monocytes during sepsis, and that the heightened expression of ZIP8 may facilitate this progression.

Cellular zinc metabolism and zinc signaling: from biological functions to diseases and therapeutic targets

Zinc metabolism at the cellular level is critical for many biological processes in the body. A key observation is the disruption of cellular homeostasis, often coinciding with disease progression. As an essential factor in maintaining cellular equilibrium, cellular zinc has been increasingly spotlighted in the context of disease development. Extensive research suggests zinc's involvement in promoting malignancy and invasion in cancer cells, despite its low tissue concentration. This has led to a growing body of literature investigating zinc's cellular metabolism, particularly the functions of zinc transporters and storage mechanisms during cancer progression. Zinc transportation is under the control of two major transporter families: SLC30 (ZnT) for the excretion of zinc and SLC39 (ZIP) for the zinc intake. Additionally, the storage of this essential element is predominantly mediated by metallothioneins (MTs). This review consolidates knowledge on the critical functions of cellular zinc signaling and underscores potential molecular pathways linking zinc metabolism to disease progression, with a special focus on cancer. We also compile a summary of clinical trials involving zinc ions. Given the main localization of zinc transporters at the cell membrane, the potential for targeted therapies, including small molecules and monoclonal antibodies, offers promising avenues for future exploration.

The Anti-Oxidative, Anti-Inflammatory, Anti-Apoptotic, and Anti-Necroptotic Role of Zinc in COVID-19 and Sepsis

Zinc is a structural component of proteins, functions as a catalytic co-factor in DNA synthesis and transcription of hundreds of enzymes, and has a regulatory role in protein-DNA interactions of zinc-finger proteins. For many years, zinc has been acknowledged for its anti-oxidative and anti-inflammatory functions. Furthermore, zinc is a potent inhibitor of caspases-3, -7, and -8, modulating the caspase-controlled apoptosis and necroptosis. In recent years, the immunomodulatory role of zinc in sepsis and COVID-19 has been investigated. Both sepsis and COVID-19 are related to various regulated cell death (RCD) pathways, including apoptosis and necroptosis. Lack of zinc may have a negative effect on many immune functions, such as oxidative burst, cytokine production, chemotaxis, degranulation, phagocytosis, and RCD. While plasma zinc concentrations decline swiftly during both sepsis and COVID-19, this reduction is primarily attributed to a redistribution process associated with the inflammatory response. In this response, hepatic metallothionein production increases in reaction to cytokine release, which is linked to inflammation, and this protein effectively captures and stores zinc in the liver. Multiple regulatory mechanisms come into play, influencing the uptake of zinc, the binding of zinc to blood albumin and red blood cells, as well as the buffering and modulation of cytosolic zinc levels. Decreased zinc levels are associated with increasing severity of organ dysfunction, prolonged hospital stay and increased mortality in septic and COVID-19 patients. Results of recent studies focusing on these topics are summarized and discussed in this narrative review. Existing evidence currently does not support pharmacological zinc supplementation in patients with sepsis or COVID-19. Complementation and repletion should follow current guidelines for micronutrients in critically ill patients. Further research investigating the pharmacological mechanism of zinc in programmed cell death caused by invasive infections and its therapeutic potential in sepsis and COVID-19 could be worthwhile.

Metal-organic framework materials promote neural differentiation of dental pulp stem cells in spinal cord injury

Spinal cord injury (SCI) is accompanied by loss of Zn2+, which is an important cause of glutamate excitotoxicity and death of local neurons as well as transplanted stem cells. Dental pulp stem cells (DPSCs) have the potential for neural differentiation and play an immunomodulatory role in the microenvironment, making them an ideal cell source for the repair of central nerve injury, including SCI. The zeolitic imidazolate framework 8 (ZIF-8) is usually used as a drug and gene delivery carrier, which can release Zn2+ sustainedly in acidic environment. However, the roles of ZIF-8 on neural differentiation of DPSCs and the effect of combined treatment on SCI have not been explored. ZIF-8-introduced DPSCs were loaded into gelatin methacryloyl (GelMA) hydrogel and in situ injected into the injured site of SCI rats. Under the effect of ZIF-8, axon number and axon length of DPSCs-differentiated neuro-like cells were significantly increased. In addition, ZIF-8 protected transplanted DPSCs from apoptosis in the damaged microenvironment. ZIF-8 promotes neural differentiation and angiogenesis of DPSCs by activating the Mitogen-activated protein kinase (MAPK) signaling pathway, which is a promising transport nanomaterial for nerve repair.

Zinc levels of patients with a moderate to severe COVID-19 infection at hospital admission and after 4th days of ward hospitalization and their clinical outcome

BACKGROUND

Previous studies associate the disturbance of the Zinc (Zn) status with the severity of the disease and the inflammatory process in the critically ill patient. This decrease in Zn concentrations is an indicator of poor prognosis. Our aim was to evaluate Zn levels at admission and after four days, and to study if lower Zn levels at those days were related to a worse clinical outcome.

MATERIAL AND METHODS

Observational cohort study at a tertiary Hospital. Recruitment period: 09/04/2020-04/24/2021. Clinical information on hypertension, diabetes mellitus (DM), chronic obstructive pulmonary disease (COPD), or bronchial asthma was collected. Obesity was defined as BMI ≥ 30 Kg/m2. Blood extraction was performed at admission and after 4 days. Zn was measured by atomic absorption using a flame method. Worse clinical outcome was defined as death during admission, intensive critical care unit admission or receiving supplemental oxygen through noninvasive or invasive ventilator care.

RESULTS

129 subjects were invited to participate but only 100 subjects completed the survey. According to ROC curve [AUC= 0.63 (95% CI 0.60-0.66)], Zn < 79 μg/dL showed the best performance to detect a worse outcome (Sn=0.85; Sp=0.36). Patients with Zn < 79 μg/dL were older (70 vs 61 y; p = 0.002) with no differences by sex. Most patients presented with fever, dysthermic symptoms and cough, without differences between groups. Pre-existing comorbid conditions did not differ significantly between groups. Less obese subjects were found in the Zn < 79 μg/dL group (21.4 vs 43.3%, p = 0.025). In the univariate analysis, Zn < 79 μg/dL at hospital admission was related to a worse outcome (p = 0.044), but after adjusting for age, C-reactive protein, and obesity there was no difference, but a tendency towards a worse prognosis [OR 2.20 (0.63-7.70), p = 0.215]. Zn levels increased in both groups after 4 days (66.6 vs 73.1 μg/dL at admission, and 72.2 vs 80.5 μg/dL at 4th day), with ns. difference (p = 0.214).

CONCLUSION

Zn < 79 μg/dL at admission for a moderate to severe COVID-19 infection could be related to a worse outcome, although after adjustment for age, C-reactive protein levels and obesity, this Zn level threshold did not show statistically significant difference in the composite end point, but a tendency towards a worse prognosis. In addition, patients with the best clinical evolution showed higher serum Zn levels at 4th day after hospital admission than the patients with a worse prognosis.

Drinking and laboratory biomarkers, and nutritional status characterize the clinical presentation of early-stage alcohol-associated liver disease

Chronic and heavy alcohol consumption is commonly observed in alcohol use disorder (AUD). AUD often leads to alcohol-associated organ injury, including alcohol-associated liver disease (ALD). Approximately 10-20% of patients with AUD progress to ALD. Progression of ALD from the development phase to more advanced states involve the interplay of several pathways, including nutritional alterations. Multiple pathologic processes have been identified in the progression and severity of ALD. However, there are major gaps in the characterization and understanding of the clinical presentation of early-stage ALD as assessed by clinical markers and laboratory measures. Several Institutions and Universities, including the University of Louisville, in collaboration with the National Institutes of Health, have published a series of manuscripts describing early-stage ALD over the past decade. Here, we comprehensively describe early-stage ALD using the liver injury and drinking history markers, and the laboratory biomarkers (with a focus on nutrition status) that are uniquely involved in the development and progression of early-stage ALD.

Assessment of trace elements in critically ill patients with systemic inflammatory response syndrome: A systematic review

BACKGROUND

Zinc (Zn), copper (Cu), and selenium (Se) are involved in immune and antioxidant defense. Their role in systemic inflammatory response syndrome (SIRS) treatment and outcomes remains unclear. This systematic review aimed to describe trace element concentrations in different types of biological samples and their relationship with morbidity and mortality in patients with SIRS.

METHODS

Literature was systematically reviewed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA). The search results were screened and evaluated for eligibility, and data were extracted and summarized in tables and figures.

RESULTS

Most of the 38 included studies evaluated Se (75%), followed by Zn (42%) and Cu (22%). Plasma was the main biological sample evaluated (58%). Thirteen studies found lower plasma/serum concentrations of Zn, Se, and Cu in SIRS patients than in controls upon admission, 11 studies on adults (intensive care unit-ICU) and two in pediatric ICU (PICU). Three ICU studies found no difference in erythrocyte trace element concentrations in patients with SIRS. In all studies, the two main outcomes investigated were organ failure and mortality. In seven ICU studies, patients with lower plasma or serum Zn/Se levels had higher mortality rates. A study conducted in the PICU reported an association between increased Se variation and lower 28-day mortality. In an ICU study, lower erythrocyte selenium levels were associated with higher ICU/hospital mortality, after adjustment. Five ICU studies associated lower plasma/serum Zn/Se levels with higher organ failure scores and one PICU study showed an association between higher erythrocyte Se levels and lower organ dysfunction scores.

CONCLUSION

There was no difference in erythrocyte Se levels in patients with SIRS. Serum/Plasma Zn and serum/plasma/erythrocyte Se are associated with organ dysfunction, mortality, and inflammation. Trace element deficiencies should be diagnosed by erythrocyte, or complementary measurements in the presence of inflammation.

Zinc supplementation in patients with acute myocardial infarction

This single-centre prospective feasibility study (UMIN000030232) evaluated whether zinc supplementation was safe and effective for improving outcomes among patients with acute myocardial infarction (AMI). Within 24 h after successful primary percutaneous coronary intervention, consenting patients with AMI were randomly assigned 1:1 to receive conventional treatment (conventional treatment group) or conventional treatment plus zinc acetate supplementation (zinc supplementation group). The two groups were compared in terms of major adverse cardiovascular events (MACE), and scar size, which was evaluated using cardiac magnetic resonance imaging (CMR) at 4 weeks after discharge. A total of 56 patients underwent randomization (with 26 assigned to the zinc supplementation group and 27 to the conventional treatment group). The two groups had generally similar laboratory findings and clinical characteristics. The two groups also had similar lengths of hospital stay and rates of MACE. Forty of the 53 patients underwent CMR and it revealed that % core zone was numerically lower in the zinc supplementation group than in the conventional treatment group (9.3 ± 6.9% vs. 14.2 ± 9.1%, P = 0.07). This small single-centre study failed to detect a significant reduction in mid-term MACE after AMI among patients who received zinc supplementation.

The Metabolomics of Critical Illness

Critical illness is associated with dramatic changes in metabolism driven by immune, endocrine, and adrenergic mediators. These changes involve early activation of catabolic processes leading to increased energetic substrate availability; later on, they are followed by a hypometabolic phase characterized by deranged mitochondrial function. In sepsis and ARDS, these rapid clinical changes are reflected in metabolomic profiles of plasma and other fluids, suggesting that metabolomics could one day be used to assist in the diagnosis and prognostication of these syndromes. Some metabolites, such as lactate, are already in clinical use and define patients with septic shock, a high-mortality subtype of sepsis. Larger-scale metabolomic profiling may ultimately offer a tool to identify subgroups of critically ill patients who may respond to therapy, but further work is needed before this type of precision medicine is readily employed in the clinical setting.

The relationship between nutrition and the immune system

Nutrition plays an essential role in the regulation of optimal immunological response, by providing adequate nutrients in sufficient concentrations to immune cells. There are a large number of micronutrients, such as minerals, and vitamins, as well as some macronutrients such as some amino acids, cholesterol and fatty acids demonstrated to exert a very important and specific impact on appropriate immune activity. This review aims to summarize at some extent the large amount of data accrued to date related to the modulation of immune function by certain micro and macronutrients and to emphasize their importance in maintaining human health. Thus, among many, some relevant case in point examples are brought and discussed: (1) The role of vitamin A/all-trans-retinoic-acids (ATRA) in acute promyelocytic leukemia, being this vitamin utilized as a very efficient therapeutic agent via effective modulation of the immune function (2) The involvement of vitamin C in the fight against tumor cells via the increase of the number of active NK cells. (3) The stimulation of apoptosis, the suppression of cancer cell proliferation, and delayed tumor development mediated by calcitriol/vitamin D by means of immunity regulation (4) The use of selenium as a cofactor to reach more effective immune response to COVID vaccination (5). The crucial role of cholesterol to regulate the immune function, which is demonstrated to be very sensitive to the variations of this macronutrient concentration. Other important examples are reviewed as well.

Zinc in Human Health and Infectious Diseases

During the last few decades, the micronutrient zinc has proven to be an important metal ion for a well-functioning immune system, and thus also for a suitable immune defense. Nowadays, it is known that the main cause of zinc deficiency is malnutrition. In particular, vulnerable populations, such as the elderly in Western countries and children in developing countries, are often affected. However, sufficient zinc intake and homeostasis is essential for a healthy life, as it is known that zinc deficiency is associated with a multitude of immune disorders such as metabolic and chronic diseases, as well as infectious diseases such as respiratory infections, malaria, HIV, or tuberculosis. Moreover, the modulation of the proinflammatory immune response and oxidative stress is well described. The anti-inflammatory and antioxidant properties of zinc have been known for a long time, but are not comprehensively researched and understood yet. Therefore, this review highlights the current molecular mechanisms underlying the development of a pro-/ and anti-inflammatory immune response as a result of zinc deficiency and zinc supplementation. Additionally, we emphasize the potential of zinc as a preventive and therapeutic agent, alone or in combination with other strategies, that could ameliorate infectious diseases.

The relationship between zinc deficiency and infectious complications in patients with hepatitis B virus-related acute-on-chronic liver failure

BACKGROUND

The prevalence of zinc deficiency is high in patients with chronic liver disease, but few studies have hitherto explored the relationship between the serum zinc level and hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF). This study aimed to assess the association between zinc deficiency and infectious complications, and model for end-stage liver disease (MELD) score in patients with HBV-related ACLF.

METHODS

Patients with HBV-related ACLF from the Department of Infectious Diseases of the Third Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between January 2019 and December 2019 were retrospectively analysed in this study. Their demographic, clinical, and laboratory data were retrieved from the hospital information system and analysed. The Student's t-test was used for normally distributed continuous variables between two groups and the Chi-square test was used for categorical data. Univariate and multivariate logistic regression analyses were applied to identify independent parameters.

RESULTS

A total of 284 patients were included in this study, including 205 liver cirrhosis and 79 non-cirrhosis patients. The proportion of patients with zinc deficiency was the highest (84.5%), followed by subclinical zinc deficiency (14.1%) and normal zinc level (1.4%). Patients in the zinc deficiency group had a higher MELD score than the subclinical zinc deficiency or normal zinc group (P = 0.021). Age, total bilirubin, and serum zinc level were independent factors for infection (Ps < 0.05). The serum zinc level in patients without complications at admission was significantly higher than that in patients with complications (P = 0.004). Moreover, the serum zinc level in patients with prothrombin time activity (PTA) of <20% was significantly lower than that in patients with 20% ≤ PTA < 30% (P = 0.007) and that in patients with 30% ≤ PTA < 40% (P < 0.001).

CONCLUSIONS

Zinc deficiency is common in patients with HBV-related ACLF. Zinc deficiency is closely associated with infectious complications and MELD score in patients with HBV-related ACLF.

Investigating hypozincemia and validity of plasma zinc measurements in infected patients

Hypozincemia is a well-known phenomenon in patients with infection caused by the activation of the acute phase response (APR). Zn status is still based upon plasma Zn levels in venous blood samples. Recent trials have questioned the validity of this measurement in infected patients. The aim of this study was to assess plasma levels of Zn, albumin and Zinc-binding capacity in patients during and following infection. Furthermore, to assess if an assay for albumin-corrected Zn could potentially replace or add knowledge to existing tools for assessment of Zinc-status. A prospective clinical observational trial was conducted. Associations between P-Zn, -Albumin, -Albumin-corrected Zn and Zn binding capacity were analyzed. Analyzes were based upon two venous blood samples drawn during and following infection, respectively. Twenty-three patients admitted to a medical ward showing paraclinical signs of infection were included in the study. Significantly lower levels of Zn and albumin were found during infection compared with the levels post-infection. These findings corresponded to the changes found in Zn binding capacity. About 52% of patients were deemed Zn deficient by plasma Zn levels during infection but after applying the correction for P-Albumin, all patients were found to be within normal ranges of Zn levels. Furthermore, we found no statistically significant difference between albumin-corrected Zn during infection and P-Zn post-infection. The new assay was found to accurately estimate the 'true' Zn levels in infected patients. Based on our findings, we propose albumin-corrected P-Zn as a promising new tool, which may result in more precise diagnostics and treatment.

Proinflammatory cytokines levels in sepsis and healthy volunteers, and tumor necrosis factor-alpha associated sepsis mortality: A systematic review and meta-analysis

BACKGROUND

Sepsis is a global health challenge associated with significant morbidity and mortality. Detrimental sepsis effects are attributed to excessive inflammation or a "cytokine storm." However, anti-inflammation therapies have failed to lower sepsis mortality. We aim to characterize levels of key inflammatory cytokines in patients with sepsis and compare levels with those in healthy individuals and relate tumor necrosis factor (TNF) α levels to patient characteristics and outcomes.

METHODS

We performed a systematic review and meta-analysis. Medline, Embase, Cochrane Library, and Web of Science Core Collection databases were searched between 1985 and May 2020. Analysis was restricted to studies in English. We included randomized controlled trials (RCTs), controlled trials, cohort studies, case series, and cross-sectional studies that reported mean levels of cytokines in the circulation thought to be relevant for sepsis pathogenesis. We also evaluated concentrations of these cytokines in healthy individuals. The Quality in Prognosis Studies tool was used to assess the methodological quality of included studies. We extracted summary data from published reports. Data analyses were performed using a random-effects model to estimate pooled odds ratios (OR) with 95% confidence intervals for cytokine levels and mortality. This systematic review is registered in PROSPERO (CRD42020179800).

FINDINGS

We identified 3654 records, and 104 studies were included with a total of 3250 participants. The pooled estimated mean TNFα concentration in sepsis patients was 58.4 pg/ml (95% Confidence Interval or CI 39.8-85.8 pg/ml), and in healthy individuals was 5.5 pg/ml (95% CI 3.8-8.0 pg/ml). Pooled estimate means for IL-1β and IFN-γ in sepsis patients were 21.8 pg/ml and 63.3 pg/ml, respectively. Elevated TNFα concentrations associated with increased 28-day sepsis mortality (p = 0.001). In subgroup analyses, we did not detect an association between TNFα levels and sepsis source, sepsis severity, or sequential organ failure assessment (SOFA) score. A TNF-α cutoff level ≥14.7 pg/ml separated sepsis patients from healthy individuals with a sensitivity of 82.6%, a specificity of 91.7%, and a likelihood ratio of 9.9.

INTERPRETATION

Sepsis mean TNFα concentration is increased approximately 10-fold compared to mean concentration in healthy individuals, and TNFα associated with sepsis mortality but not sepsis severity. The concept that elevated cytokines cause sepsis should be revisited in the context of these data.

FUNDING

None.

The emerging roles of next-generation metabolomics in critical care nutrition

Critical illness leads to millions of deaths worldwide each year, with a significant surge due to the COVID-19 pandemic. Patients with critical illness are frequently associated with systemic metabolic disorders and malnutrition. The idea of intervention for critically ill patients through enteral and parenteral nutrition has been paid more and more attention gradually. However, current nutritional therapies focus on evidence-based practice, and there have been lacking holistic approaches for nutritional support assessment. Metabolomics is a well-established omics technique in system biology that enables comprehensive profiling of metabolites in a biological system and thus provides the underlying information expressed and modulated by all other omics layers. In recent years, with the development of high-resolution and accurate mass spectrometry, metabolomics entered a new "generation", promoting its broader applications in critical care nutrition. In this review, we first described the technological development and milestones of next-generation metabolomics in the past 20 years. We then discussed the emerging roles of next-generation metabolomics in advancing our understanding of critical care nutrition, such as nutritional deficiency risk evaluation, metabolic mechanisms of nutritional therapies, and novel nutrition target identification.

The Impact of Zinc Supplementation on Critically Ill Patients With Acute Kidney Injury: A Propensity Score Matching Analysis

Background

Zinc is an essential trace element involved in multiple metabolic processes. Acute kidney injury (AKI) is associated with low plasma zinc, but outcomes with zinc supplementation in critically ill patients with AKI remain unknown. Our objective was to investigate the effectiveness of zinc supplementation in this patient population.

Methods

Critically ill patients with AKI were identified from the Medical Informative Mart for Intensive Care IV database. Prosperity score matching (PSM) was applied to match patients receiving zinc treatment to those without zinc treatment. The association between zinc sulfate use and in-hospital mortality and 30-day mortality, need for renal replacement therapy (RRT), and length of stay was determined by logistic regression and Cox proportional hazards modeling.

Results

A total of 9,811 AKI patients were included in the study. PSM yielded 222 pairs of patients who received zinc treatment and those who did not. Zinc supplementation was associated with reduced in-hospital mortality (HR = 0.48 (95% CI: 0.28, 0.83) P = 0.009) and 30-day mortality (HR = 0.51 (95% CI, 0.30, 0.86) P = 0.012). In the subgroup analysis, zinc use was associated with reduced in-hospital mortality in patients with stage 1 AKI and those with sepsis.

Conclusions

Zinc supplementation was associated with improved survival in critically ill patients with AKI. The supplementation was especially effective in those with stage 1 AKI and sepsis. These results need to be verified in randomized controlled trials.

Free Zinc as a Predictive Marker for COVID-19 Mortality Risk

Free zinc is considered to be the exchangeable and biological active form of zinc in serum, and is discussed to be a suitable biomarker for alterations in body zinc homeostasis and related diseases. Given that coronavirus disease 2019 (COVID-19) is characterized by a marked decrease in total serum zinc, and clinical data indicate that zinc status impacts the susceptibility and severity of the infection, we hypothesized that free zinc in serum might be altered in response to SARS-CoV-2 infection and may reflect disease severity. To test this hypothesis, free zinc concentrations in serum samples of survivors and nonsurvivors of COVID-19 were analyzed by fluorometric microassay. Similar to the reported total serum zinc deficit measured by total reflection X-ray fluorescence, free serum zinc in COVID-19 patients was considerably lower than that in control subjects, and surviving patients displayed significantly higher levels of free zinc than those of nonsurvivors (mean ± SD; 0.4 ± 0.2 nM vs. 0.2 ± 0.1 nM; p = 0.0004). In contrast to recovering total zinc concentrations (r = 0.706, p < 0.001) or the declining copper−zinc ratio (r = −0.646; p < 0.001), free zinc concentrations remained unaltered with time in COVID-19 nonsurvivors. Free serum zinc concentrations were particularly low in male as compared to female patients (mean ± SD; 0.4 ± 0.2 nM vs. 0.2 ± 0.1 nM; p = 0.0003). This is of particular interest, as the male sex is described as a risk factor for severe COVID-19. Overall, results indicate that depressed free serum zinc levels are associated with increased risk of death in COVID-19, suggesting that free zinc may serve as a novel prognostic marker for the severity and course of COVID-19.

Zinc deficiency as a possible risk factor for increased susceptibility and severe progression of Corona Virus Disease 19

The importance of Zn for human health becomes obvious during Zn deficiency. Even mild insufficiencies of Zn cause alterations in haematopoiesis and immune functions, resulting in a proinflammatory phenotype and a disturbed redox metabolism. Although immune system malfunction has the most obvious effect, the functions of several tissue cell types are disturbed if Zn supply is limiting. Adhesion molecules and tight junction proteins decrease, while cell death increases, generating barrier dysfunction and possibly organ failure. Taken together, Zn deficiency both weakens the resistance of the human body towards pathogens and at the same time increases the danger of an overactive immune response that may cause tissue damage. The case numbers of Corona Virus Disease 19 (COVID-19) are still increasing, which is causing enormous problems for health systems and economies. There is an urgent need to reduce both the number of severe cases and the resulting deaths. While therapeutic options are still under investigation, and first vaccines have been approved, cost-effective ways to reduce the likelihood of or even prevent infection, and the transition from mild symptoms to more serious detrimental disease, are highly desirable. Nutritional supplementation might be an effective option to achieve these aims. In this review, we discuss known Zn deficiency effects in the context of an infection with Severe Acute Respiratory Syndrome-Coronavirus-2 and its currently known pathogenic mechanisms and elaborate on how severe pre-existing Zn deficiency may pre-dispose patients to a severe progression of COVID-19. First published clinical data on the association of Zn homoeostasis with COVID-19 and registered studies in progress are listed.

Impact of Inherited Genetic Variants on Critically Ill Septic Children

Sepsis remains an important source of morbidity and mortality in children, despite the development of standardized care. In the last decades, there has been an increased interest in genetic and genomic approaches to early recognition and development of treatments to manipulate the host inflammatory response. This review will present a summary of the normal host response to infection and progression to sepsis, followed by highlighting studies with a focus on gene association studies, epigenetics, and genome-wide expression profiling. The susceptibility (or outcome) of sepsis in children has been associated with several polymorphisms of genes broadly involved in inflammation, immunity, and coagulation. More recently, gene expression profiling has been focused on identifying novel biomarkers, pathways and therapeutic targets, and gene expression-based subclassification. Knowledge of a patient’s individual genotype may, in the not-too-remote future, be used to guide tailored treatment for sepsis. However, at present, the impact of genomics remains far from the bedside of critically ill children.

The Prognostic Value of Serum Zinc Levels in Acutely Hospitalized Patients: a Systematic Review

Several small studies have identified possible associations between low serum zinc levels and worse outcomes in patients acutely hospitalized for a variety of diseases. This study systematically evaluated all published literature to determine whether serum zinc might independently predict important outcomes in hospitalized patients. PubMed, Embase, and Cochrane Libraries databases were searched from 1970 to 2019 to identify all citations having the keyword "zinc" with hospital outcomes. Studies were included if they measured the association between serum zinc levels in non-electively hospitalized patients with survival, length of stay, or unplanned readmission. Data were double-abstracted to evaluate the association between zinc levels and these outcomes. Our search returned 1091 citations of which 12 studies met the inclusion criteria. Studies were small (median 112.5 patients) using unspecified sampling methods. Seven studies were restricted to critically ill patients. Mean zinc levels ranged from 27.5 to 85.3 μg/dL. Baseline mean zinc levels were significantly lower (p < 0.05) in patients who eventually died in 1 of 7 studies. Five of seven studies found significantly increased risk of death in hospital with lower zinc levels. Associations between zinc levels and critical care or hospital length of stay were unclear. In 1 study, lower zinc levels were associated with a significantly increased risk of unplanned readmission. Current studies measuring the association between serum zinc levels and outcomes in acutely hospitalized patients are limited by their sample sizes, select patient populations, and limited statistical analyses. The association of zinc levels with hospital patient outcomes is unclear.

Serum zinc and copper in people with COVID-19 and zinc supplementation in parenteral nutrition

Objectives

Zinc and copper are important to protect cells from oxidative stress and to enhance immunity. An association between low zinc levels and the severity of acute respiratory distress syndrome has been shown for people with COVID-19. We aimed to study serum zinc and copper concentrations in people with severe COVID-19 and zinc supplementation in parenteral nutrition (PN).

Methods

Thirty-five people with COVID-19 in need of PN were studied in a retrospective design. Serum samples were collected at three time points: at the start of PN, between 3 and 7 d after, and at the end of PN.

Results

Participants were on PN for a mean of 14 d, with a mean (± SD) daily supplemental zinc of 14.8 ± 3.7 mg/d. Serum zinc increased during PN administration from 98.8 ± 22.8 to 114.1 ± 23.3 µg/dL (Wilks’ λ = 0.751, F = 5.459, P = 0.009). Conversely, serum copper did not vary from baseline (107.9 ± 34.2 µg/dL) to the end of the study (104.5 ± 37.4 µg/dL, Wilks’ λ = 0.919, F = 1.453, P = 0.248). Serum zinc within the first week after starting PN and at the end of PN inversely correlated with total hospital stay (r = −0.413, P = 0.014, and r = −0.386, P = 0.022, respectively). Participants in critical condition presented lower serum copper (z = 2.615, P = 0.007). Mortality was not associated with supplemental zinc or with serum zinc or copper concentrations at any time of the study (P > 0.1 for all analyses).

Conclusions

Serum zinc concentrations during PN support were inversely associated with length of hospital stay but not with mortality. Serum copper concentrations were lower in participants in critical condition but not associated with prognosis.

Micronutrients in Sepsis and COVID-19: A Narrative Review on What We Have Learned and What We Want to Know in Future Trials

Sepsis remains the leading cause of mortality in hospitalized patients, contributing to 1 in every 2–3 deaths. From a pathophysiological view, in the recent definition, sepsis has been defined as the result of a complex interaction between host response and the infecting organism, resulting in life-threatening organ dysfunction, depending on microcirculatory derangement, cellular hypoxia/dysoxia driven by hypotension and, potentially, death. The high energy expenditure driven by a high metabolic state induced by the host response may rapidly lead to micronutrient depletion. This deficiency can result in alterations in normal energy homeostasis, free radical damage, and immune system derangement. In critically ill patients, micronutrients are still relegated to an ancillary role in the whole treatment, and always put in a second-line place or, frequently, neglected. Only some micronutrients have attracted the attention of a wider audience, and some trials, even large ones, have tested their use, with controversial results. The present review will address this topic, including the recent advancement in the study of vitamin D and protocols based on vitamin C and other micronutrients, to explore an update in the setting of sepsis, gain some new insights applicable to COVID-19 patients, and to contribute to a pathophysiological definition of the potential role of micronutrients that will be helpful in future dedicated trials.

Low Zinc Levels at Admission Associates with Poor Clinical Outcomes in SARS-CoV-2 Infection

BACKGROUND

Zinc is an essential micronutrient that impacts host-pathogen interplay at infection. Zinc balances immune responses, and also has a proven direct antiviral action against some viruses. Importantly, zinc deficiency (ZD) is a common condition in elderly and individuals with chronic diseases, two groups with an increased risk for severe severe coronavirus disease 2019 (COVID-19) outcomes. We hypothesize that serum zinc content (SZC) influences COVID-19 disease progression, and thus might represent a useful biomarker.

METHODS

We ran an observational cohort study with 249 COVID-19 patients admitted in Hospital del Mar. We have studied COVID-19 severity and progression attending to SZC at admission. In parallel, we have studied severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) replication in the Vero E6 cell line modifying zinc concentrations.

FINDINGS

Our study demonstrates a correlation between serum zinc levels and COVID-19 outcome. Serum zinc levels lower than 50 µg/dL at admission correlated with worse clinical presentation, longer time to reach stability, and higher mortality. Our in vitro results indicate that low zinc levels favor viral expansion in SARS-CoV-2 infected cells.

INTERPRETATION

Low SZC is a risk factor that determines COVID-19 outcome. We encourage performing randomized clinical trials to study zinc supplementation as potential prophylaxis and treatment with people at risk of zinc deficiency.

Interleukin-4 Administration or Zinc Supplementation Is Effective in Preventing Zinc Deficiency-Induced Hemolytic Anemia and Splenomegaly

Nutritional zinc deficiency aggravates inflammation, subsequently causing anemia and splenomegaly in rats; however, the mechanism underlying such splenomegaly remains poorly understood. Therefore, in this study, we aimed to elucidate the mechanisms underlying the splenomegaly and anemia occurring in zinc-deficient rats and investigate whether these effects of zinc deficiency could be reversed by interleukin (IL)-4 administration or zinc supplementation. Five-week-old male Sprague-Dawley rats were fed a standard diet; fed a zinc-deficient diet (n = 7 each) and injected with saline or IL-4; or fed a zinc-deficient diet for 6 weeks followed by a standard diet for 4 weeks thereafter. White blood cells, segmented neutrophils, platelets, CD4⁺ T cells, CD11b/c⁺ granulocytes, CINC/GRO⁺ cells, and myeloperoxidase-positive cells in the blood and spleen of the zinc-deficient rats were significantly higher than those in all the other groups. Conversely, red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, lymphocytes, and CD8⁺ T cells in the blood of the zinc-deficient rats were significantly lower than those in the other groups. Furthermore, serum aspartate aminotransferase, lactate dehydrogenase, indirect bilirubin concentrations, and erythrocyte osmotic fragility in the zinc-deficient rats were significantly higher than those in the other groups. Moreover, zinc deficiency significantly decreased the GATA1 protein levels in the spleen. Collectively, these results indicate that zinc deficiency aggravates the inflammatory response and causes hemolytic anemia and splenomegaly. Importantly, IL-4 administration and zinc supplementation can reverse the zinc deficiency-induced hemolytic anemia and splenomegaly.

Intra-nasal zinc level relationship to COVID-19 anosmia and type 1 interferon response: A proposal

Anosmia is common among COVID-19 patients and anosmia assessment is proposed to be useful in the early diagnosis and prognosis of patients. Data on the pathogenesis of anosmia during COVID-19 suggest potential olfactory nerve involvement. Zinc is an essential micronutrient that regulates the immune responses, and zinc deficiency is known to induce anosmia and ageusia. We previously proposed that a drop in nasal zinc level is a normal nasal immune response to acute viral infections, including SARS-CoV-2 infection, and play a role in the pathogenesis of anosmia. The drop in the local zinc level in response to SARS-CoV-2 may lead to lower type 1 interferons and shift toward Th2 immune responses; if prolonged, it may lead to increased viral replication and more severe disease. In people who are at risk for baseline systemic zinc deficiency, such as the elderly and those with chronic diseases such as, chronic lung disease, diabetes, cardiovascular disease, and cancer, SARS-CoV-2 infection-induced drop in nasal zinc level may be more severe and prolonged and lead to an insufficient anti-viral nasal immune response and control the spread of the virus systemically and to the lungs. A better understanding of the clinical implications of baseline systemic zinc deficiency on anosmia and nasal immune responses may allow the development of new treatment strategies to slow down or stop the systemic invasion of SARS-CoV-2.

Preventing the development of severe COVID-19 by modifying immunothrombosis

BACKGROUND

COVID-19-associated acute respiratory distress syndrome (ARDS) is associated with significant morbidity and high levels of mortality. This paper describes the processes involved in the pathophysiology of COVID-19 from the initial infection and subsequent destruction of type II alveolar epithelial cells by SARS-CoV-2 and culminating in the development of ARDS.

MAIN BODY

The activation of alveolar cells and alveolar macrophages leads to the release of large quantities of proinflammatory cytokines and chemokines and their translocation into the pulmonary vasculature. The presence of these inflammatory mediators in the vascular compartment leads to the activation of vascular endothelial cells platelets and neutrophils and the subsequent formation of platelet neutrophil complexes. These complexes in concert with activated endothelial cells interact to create a state of immunothrombosis. The consequence of immunothrombosis include hypercoagulation, accelerating inflammation, fibrin deposition, migration of neutrophil extracellular traps (NETs) producing neutrophils into the alveolar apace, activation of the NLRP3 inflammazome, increased alveolar macrophage destruction and massive tissue damage by pyroptosis and necroptosis Therapeutic combinations aimed at ameliorating immunothrombosis and preventing the development of severe COVID-19 are discussed in detail.

Prediction of survival odds in COVID-19 by zinc, age and selenoprotein P as composite biomarker

SARS-CoV-2 infections cause the current coronavirus disease (COVID-19) pandemic and challenge the immune system with ongoing inflammation. Several redox-relevant micronutrients are known to contribute to an adequate immune response, including the essential trace elements zinc (Zn) and selenium (Se). In this study, we tested the hypothesis that COVID-19 patients are characterised by Zn deficiency and that Zn status provides prognostic information. Serum Zn was determined in serum samples (n = 171) collected consecutively from patients surviving COVID-19 (n = 29) or non-survivors (n = 6). Data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study were used for comparison. Zn concentrations in patient samples were low as compared to healthy subjects (mean ± SD; 717.4 ± 246.2 vs 975.7 ± 294.0 μg/L, P < 0.0001). The majority of serum samples collected at different time points from the non-survivors (25/34, i.e., 73.5%) and almost half of the samples collected from the survivors (56/137, i.e., 40.9%) were below the threshold for Zn deficiency, i.e., below 638.7 μg/L (the 2.5th percentile in the EPIC cohort). In view that the Se status biomarker and Se transporter selenoprotein P (SELENOP) is also particularly low in COVID-19, we tested the prevalence of a combined deficit, i.e., serum Zn below 638.7 μg/L and serum SELENOP below 2.56 mg/L. This combined deficit was observed in 0.15% of samples in the EPIC cohort of healthy subjects, in 19.7% of the samples collected from the surviving COVID-19 patients and in 50.0% of samples from the non-survivors. Accordingly, the composite biomarker (SELENOP and Zn with age) proved as a reliable indicator of survival in COVID-19 by receiver operating characteristic (ROC) curve analysis, yielding an area under the curve (AUC) of 94.42%. We conclude that Zn and SELENOP status within the reference ranges indicate high survival odds in COVID-19, and assume that correcting a diagnostically proven deficit in Se and/or Zn by a personalised supplementation may support convalescence.

Assessment of Plasma Zinc and Total Leukocyte Count in Calves Experimentally Infected with Mannheimia haemolytica

Mannheimia haemolytica is the main bacterial pathogen isolated in bovine respiratory disease (BRD), a common disease affecting calves before weaning. Previous research has shown that experimental infection with bovine herpesvirus 1, a respiratory virus, decreases plasma zinc (Zn) levels. However, changes in plasma Zn concentrations in calves experimentally infected with M. haemolytica have not been studied thus far. The objective of this study was to evaluate the effect of experimental infection with M. haemolytica on plasma Zn concentration in calves. Total leukocyte count and bovine respiratory disease (BRD) clinical score were also evaluated. We conducted a 6-day trial in 14 male Holstein calves randomly assigned to one of two groups, experimental (EG, n = 8) and control (CG, n = 6). Animals in EG were intrabronchially inoculated with M. haemolytica (6.5 × 10⁶ CFU/mL) on day 0 of the trial. Plasma Zn levels were affected by time, treatment, and time by treatment interaction, being lower in EG compared with CG on days 1, 2, and 3. Differences in total leukocyte count were significant on day 1, observing a tendency on day 3. BRD clinical score differed between groups, being higher in EG throughout the trial. We conclude that experimental M. haemolytica infection reduced plasma Zn concentration in clinically ill calves, suggesting that the clinical condition of animals (healthy/ill) should be considered to better interpret plasma Zn values.

Zinc Supplementation Modulates NETs Release and Neutrophils' Degranulation

Zinc plays an important physiological role in the entire body, especially in the immune system. It is one of the most abundant microelements in our organism and an essential component of enzymes and antibacterial proteins. Zinc levels were reported to be correlated with the intensity of innate immunity responses, especially those triggered by neutrophils. However, as the results are fragmentary, the phenomenon is still not fully understood and requires further research. In this study, we aimed to perform a comprehensive assessment and study the impact of zinc on several basic neutrophils’ functions in various experimental setups. Human and murine neutrophils were preincubated in vitro with zinc, and then phagocytosis, oxidative burst, degranulation and release of neutrophil extracellular traps (NETs) were analyzed. Moreover, a murine model of zinc deficiency and zinc supplementation was introduced in the study and the functions of isolated cells were thoroughly studied. We showed that zinc inhibits NETs release as well as degranulation in both human and murine neutrophils. Our study revealed that zinc decreases NETs release by inhibiting citrullination of histone H3. On the other hand, studies performed in zinc-deficient mice demonstrated that low zinc levels result in increased release of NETs and enhanced neutrophils degranulation. Overall, it was shown that zinc affects neutrophils’ functions in vivo and in vitro. Proper zinc level is necessary to maintain efficient functioning of the innate immune response.

Association Between Low Zinc Levels and Severity of Acute Respiratory Distress Syndrome by New Coronavirus SARS-CoV-2

BACKGROUND

We verify the prevalence of low zinc levels among critically ill patients infected by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the intensive care unit (ICU) who required invasive mechanical ventilation, as well as its association with severity of acute respiratory distress syndrome (ARDS).

METHODS

This is an observational study composed of patients admitted to the ICU. Demographics, anthropometric data for calculating body mass index (BMI), and laboratory data were obtained at admission: blood count, ferritin, arterial blood gas, serum zinc levels, and C-reactive protein. Also, arterial oxygen tension (PaO₂ ) divided by fractional inspired oxygen (FiO₂ ) was calculated by the first arterial blood gas after intubation. A diagnosis of severe ARDS was determined if the PaO₂ /FiO₂ ratio was ≤100 mm Hg. Low zinc levels were established if zinc levels were <70 μg/dL.

RESULTS

A total of 269 patients met inclusion criteria; 51.3% were men; median age was 74 (66-81) years; 91.1% (245 of 269) were elderly. The median BMI was 30.1 (24.7-32.1) kg/m² , with 59.9% (161 of 269) of patients having overweight and obesity. The prevalence of low zinc levels was 79.6% (214 of 269) and severe ARDS was 56.5% (152 of 269). There was an association of low zinc levels and severe ARDS (odds ratio [OR], 14.4; 95% CI, 6.2-33.5; P < .001), even after adjusting for baseline variables (OR, 15.4; 95% CI, 6.5-36.3; P < .001).

CONCLUSION

Critically ill patients infected by SARS-CoV-2 with severe ARDS have a high prevalence of low serum zinc levels.

The Role of Micronutrients in Support of the Immune Response against Viral Infections

Viral infections are a leading cause of morbidity and mortality worldwide, and the importance of public health practices including handwashing and vaccinations in reducing their spread is well established. Furthermore, it is well known that proper nutrition can help support optimal immune function, reducing the impact of infections. Several vitamins and trace elements play an important role in supporting the cells of the immune system, thus increasing the resistance to infections. Other nutrients, such as omega-3 fatty acids, help sustain optimal function of the immune system. The main aim of this manuscript is to discuss of the potential role of micronutrients supplementation in supporting immunity, particularly against respiratory virus infections. Literature analysis showed that in vitro and observational studies, and clinical trials, highlight the important role of vitamins A, C, and D, omega-3 fatty acids, and zinc in modulating the immune response. Supplementation with vitamins, omega 3 fatty acids and zinc appears to be a safe and low-cost way to support optimal function of the immune system, with the potential to reduce the risk and consequences of infection, including viral respiratory infections. Supplementation should be in addition to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19).

An alloy of zinc and innate immunity: Galvanising host defence against infection

Innate immune cells such as macrophages and neutrophils initiate protective inflammatory responses and engage antimicrobial responses to provide frontline defence against invading pathogens. These cells can both restrict the availability of certain transition metals that are essential for microbial growth and direct toxic concentrations of metals towards pathogens as antimicrobial responses. Zinc is important for the structure and function of many proteins, however excess zinc can be cytotoxic. In recent years, several studies have revealed that innate immune cells can deliver toxic concentrations of zinc to intracellular pathogens. In this review, we discuss the importance of zinc status during infectious disease and the evidence for zinc intoxication as an innate immune antimicrobial response. Evidence for pathogen subversion of this response is also examined. The likely mechanisms, including the involvement of specific zinc transporters that facilitate delivery of zinc by innate immune cells for metal ion poisoning of pathogens are also considered. Precise mechanisms by which excess levels of zinc can be toxic to microorganisms are then discussed, particularly in the context of synergy with other antimicrobial responses. Finally, we highlight key unanswered questions in this emerging field, which may offer new opportunities for exploiting innate immune responses for anti-infective development.

The pathophysiology of SARS-CoV-2: A suggested model and therapeutic approach

In this paper, a model is proposed of the pathophysiological processes of COVID-19 starting from the infection of human type II alveolar epithelial cells (pneumocytes) by SARS-CoV-2 and culminating in the development of ARDS. The innate immune response to infection of type II alveolar epithelial cells leads both to their death by apoptosis and pyroptosis and to alveolar macrophage activation. Activated macrophages secrete proinflammatory cytokines and chemokines and tend to polarise into the inflammatory M1 phenotype. These changes are associated with activation of vascular endothelial cells and thence the recruitment of highly toxic neutrophils and inflammatory activated platelets into the alveolar space. Activated vascular endothelial cells become a source of proinflammatory cytokines and reactive oxygen species (ROS) and contribute to the development of coagulopathy, systemic sepsis, a cytokine storm and ARDS. Pulmonary activated platelets are also an important source of proinflammatory cytokines and ROS, as well as exacerbating pulmonary neutrophil-mediated inflammatory responses and contributing to systemic sepsis by binding to neutrophils to form platelet-neutrophil complexes (PNCs). PNC formation increases neutrophil recruitment, activation priming and extraversion of these immune cells into inflamed pulmonary tissue, thereby contributing to ARDS. Sequestered PNCs cause the development of a procoagulant and proinflammatory environment. The contribution to ARDS of increased extracellular histone levels, circulating mitochondrial DNA, the chromatin protein HMGB1, decreased neutrophil apoptosis, impaired macrophage efferocytosis, the cytokine storm, the toll-like receptor radical cycle, pyroptosis, necroinflammation, lymphopenia and a high Th17 to regulatory T lymphocyte ratio are detailed.

The Potential Impact of Zinc Supplementation on COVID-19 Pathogenesis

During the current corona pandemic, new therapeutic options against this viral disease are urgently desired. Due to the rapid spread and immense number of affected individuals worldwide, cost-effective, globally available, and safe options with minimal side effects and simple application are extremely warranted. This review will therefore discuss the potential of zinc as preventive and therapeutic agent alone or in combination with other strategies, as zinc meets all the above described criteria. While a variety of data on the association of the individual zinc status with viral and respiratory tract infections are available, study evidence regarding COVID-19 is so far missing but can be assumed as was indicated by others and is detailed in this perspective, focusing on re-balancing of the immune response by zinc supplementation. Especially, the role of zinc in viral-induced vascular complications has barely been discussed, so far. Interestingly, most of the risk groups described for COVID-19 are at the same time groups that were associated with zinc deficiency. As zinc is essential to preserve natural tissue barriers such as the respiratory epithelium, preventing pathogen entry, for a balanced function of the immune system and the redox system, zinc deficiency can probably be added to the factors predisposing individuals to infection and detrimental progression of COVID-19. Finally, due to its direct antiviral properties, it can be assumed that zinc administration is beneficial for most of the population, especially those with suboptimal zinc status.

Neurological symptoms due to Coronavirus disease 2019

In this review, we focus on summarizing everything that is known about the neurological effects of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2). It has been shown that Coronavirus Disease 2019 (Covid-19) may result in neuromuscular disorders or damage to nerves outside of the brain and spinal cord, which may lead to weakness, numbness, and pain. Published literature has stated that SARS-COV-1 may infect the central nervous system and due to its similarities to SARS-COV-2, we suspect that SARS-COV-2 has the same potential. We conclude that Covid-19 has neurological manifestations. Further research should be done in this field to understand the full extent of this virus.

Zinc and respiratory tract infections: Perspectives for COVID‑19 (Review)

In view of the emerging COVID‑19 pandemic caused by SARS‑CoV‑2 virus, the search for potential protective and therapeutic antiviral strategies is of particular and urgent interest. Zinc is known to modulate antiviral and antibacterial immunity and regulate inflammatory response. Despite the lack of clinical data, certain indications suggest that modulation of zinc status may be beneficial in COVID‑19. In vitro experiments demonstrate that Zn2+ possesses antiviral activity through inhibition of SARS‑CoV RNA polymerase. This effect may underlie therapeutic efficiency of chloroquine known to act as zinc ionophore. Indirect evidence also indicates that Zn2+ may decrease the activity of angiotensin‑converting enzyme 2 (ACE2), known to be the receptor for SARS‑CoV‑2. Improved antiviral immunity by zinc may also occur through up‑regulation of interferon α production and increasing its antiviral activity. Zinc possesses anti‑inflammatory activity by inhibiting NF‑κB signaling and modulation of regulatory T‑cell functions that may limit the cytokine storm in COVID‑19. Improved Zn status may also reduce the risk of bacterial co‑infection by improving mucociliary clearance and barrier function of the respiratory epithelium, as well as direct antibacterial effects against S. pneumoniae. Zinc status is also tightly associated with risk factors for severe COVID‑19 including ageing, immune deficiency, obesity, diabetes, and atherosclerosis, since these are known risk groups for zinc deficiency. Therefore, Zn may possess protective effect as preventive and adjuvant therapy of COVID‑19 through reducing inflammation, improvement of mucociliary clearance, prevention of ventilator‑induced lung injury, modulation of antiviral and antibacterial immunity. However, further clinical and experimental studies are required.

Dietary micronutrients in the wake of COVID-19: an appraisal of evidence with a focus on high-risk groups and preventative healthcare

Existing micronutrient deficiencies, even if only a single micronutrient, can impair immune function and increase susceptibility to infectious disease. Certain population groups are more likely to have micronutrient deficiencies, while certain disease pathologies and treatment practices also exacerbate risk, meaning these groups tend to suffer increased morbidity and mortality from infectious diseases. Optimisation of overall nutritional status, including micronutrients, can be effective in reducing incidence of infectious disease. Micronutrient deficiencies are rarely recognised but are prevalent in the UK, as well as much more widely, particularly in high-risk groups susceptible to COVID-19. Practitioners should be aware of this fact and should make it a consideration for the screening process in COVID-19, or when screening may be difficult or impractical, to ensure blanket treatment as per the best practice guidelines. Correction of established micronutrient deficiencies, or in some cases assumed suboptimal status, has the potential to help support immune function and mitigate risk of infection. The effects of and immune response to COVID-19 share common characteristics with more well-characterised severe acute respiratory infections. Correction of micronutrient deficiencies has proven effective in several infectious diseases and has been shown to promote favourable clinical outcomes. Micronutrients appear to play key roles in mediating the inflammatory response and such effects may be enhanced through correction of deficiencies. Many of those at highest risk during the COVID-19 pandemic are also populations at highest risk of micronutrient deficiencies and poorer overall nutrition. Correction of micronutrient deficiencies in established COVID-19 infection may contribute to supporting immune response to infection in those at highest risk. There is a need for further research to establish optimal public health practice and clinical intervention regimens.

Nutritional Support in Coronavirus 2019 Disease

The epidemic that broke out in Chinese Wuhan at the beginning of 2020 presented how important the rapid diagnosis of malnutrition (elevating during intensive care unit stay) and the immediate implementation of caloric and protein-balanced nutrition care are. According to specialists from the Chinese Medical Association for Parenteral and Enteral Nutrition (CSPEN), these activities are crucial for both the therapy success and reduction of mortality rates. The Chinese have published their recommendations including principles for the diagnosis of nutritional status along with the optimal method for nutrition supply including guidelines when to introduce education approach, oral nutritional supplement, tube feeding, and parenteral nutrition. They also calculated energy demand and gave their opinion on proper monitoring and supplementation of immuno-nutrients, fluids and macronutrients intake. The present review summarizes Chinese observations and compares these with the latest European Society for Clinical Nutrition and Metabolism guidelines. Nutritional approach should be an inseparable element of therapy in patients with COVID-19.

Hypozincaemia is associated with severity of aneurysmal subarachnoid haemorrhage: a retrospective cohort study

BACKGROUND

Hypozincaemia may develop in critically ill patients, including those with acute brain injury in the early phase after hospital admission. The aim of this study was to investigate the prevalence of hypozincaemia after aneurysmal subarachnoid haemorrhage (aSAH) and its association with delayed cerebral ischemia and functional outcome.

METHODS

We retrospectively analysed a cohort of 384 patients with SAH admitted to the Neurointensive Care Unit at Rigshospitalet, Copenhagen, Denmark, in whom at least one measurement of plasma zinc concentration was done during the hospital stay. Hypozincaemia was defined as at least one measurement of plasma zinc below 10 μmol/L. Potential associations between hypozincaemia, demographic variables and functional outcome after aSAH were analysed in multivariable logistic regression models.

RESULTS

Hypozincaemia was observed in 67% (n = 257) of all patients and occurred within 7 days in more than 95% of all hypozincaemic patients. In a multivariable model, severe SAH (WFNS 3-5; OR 4.2, CI 2.21-8.32, p < 0.001) and Sequential Organ Failure Assessment (SOFA) score on the day of admission (OR 1.24, CI 1.11-1.40, p < 0.001) were independently associated with hypozincaemia. In another multivariable model, hypozincaemia was independently associated with an unfavourable outcome (defined as a modified Rankin Scale score from 3 to 6) (OR 1.97, CI 1.06-3.68, p = 0.032), as was age (OR 1.03, CI 1.01-1.05, p = 0.015), SOFA score on the day of admission (OR 1.14, CI 1.02-1.29, p = 0.02), a diagnosis of delayed cerebral ischaemia (OR 4.06, CI 2.29-7.31, p < 0.001) and a clinical state precluding assessment for delayed cerebral ischaemia (OR 15.13, CI 6.59-38.03, p < 0.001).

CONCLUSION

Hypozincaemia occurs frequently after aSAH, is associated with a higher disease severity and independently contributes to an unfavourable outcome.

Inflammation Adjustment by Two Methods Decreases the Estimated Prevalence of Zinc Deficiency in Malawi

Serum zinc concentration (SZC) is used widely to assess population-level zinc status. Its concentration decreases during inflammatory responses, which can affect the interpretation of the results. This study aimed to re-estimate the prevalence of zinc deficiency in Malawi based on the 2015-2016 Malawi Micronutrient Survey (MNS) data, by adjusting SZC measures with markers of inflammation. SZC and inflammation data from 2760 participants were analysed. Adjustments were made using: (1) The Internal Correction Factor (ICF) method which used geometric means, and (2) The Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) method, which used linear regression. Mean SZC values increased significantly when adjustments were made by either ICF or BRINDA (p < 0.001). The national prevalence of zinc deficiency decreased from 62% to 59%, after ICF adjustment, and to 52% after BRINDA adjustment. ICF and BRINDA values of SZC were highly correlated (p < 0.001, r = 0.99), but a Bland-Altman plot showed a lack of agreement between the two methods (bias of 2.07 µg/dL). There was no association between the adjusted SZC and stunting, which is a proxy indicator for zinc deficiency. Inflammation adjustment of SZC, using ICF or BRINDA, produces lower estimates of zinc deficiency prevalence, but the lack of agreement between the adjustment methods warrants further research. Furthermore, the lack of association between SZC and stunting highlights the need to explore other biomarkers and proxies of population zinc assessment. This study demonstrates the importance of considering inflammatory confounders when reporting SZC, to ensure accuracy and to support policy decision making.

Zinc Concentration Dynamics Indicate Neurological Impairment Odds after Traumatic Spinal Cord Injury

Traumatic Spinal Cord Injury (TSCI) is debilitating and often results in a loss of motor and sensory function caused by an interwoven set of pathological processes. Oxidative stress and inflammatory processes are amongst the critical factors in the secondary injury phase after TSCI. The essential trace element Zinc (Zn) plays a crucial role during this phase as part of the antioxidant defense system. The study aims to determine dynamic patterns in serum Zn concentration in patients with TSCI and test for a correlation with neurological impairment. A total of 42 patients with TSCI were enrolled in this clinical observational study. Serum samples were collected at five different points in time after injury (at admission, and after 4 h, 9 h, 12 h, 24 h, and 3 days). The analysis of the serum Zn concentrations was conducted by total reflection X-ray fluorescence (TXRF). The patients were divided into two groups—a study group S (n = 33) with neurological impairment, including patients with remission (G1, n = 18) and no remission (G0, n = 15) according to a positive AIS (American Spinal Injury Association (ASIA) Impairment Scale) conversion within 3 months after the trauma; and a control group C (n = 9), consisting of subjects with vertebral fractures without neurological impairment. The patient data and serum concentrations were examined and compared by non-parametric test methods to the neurological outcome. The median Zn concentrations in group S dropped within the first 9 h after injury (964 µg/L at admission versus 570 µg/L at 9 h, p < 0.001). This decline was stronger than in control subjects (median of 751 µg/L versus 729 µg/L, p = 0.023). A binary logistic regression analysis including the difference in serum Zn concentration from admission to 9 h after injury yielded an area under the curve (AUC) of 82.2% (CI: 64.0–100.0%) with respect to persistent neurological impairment. Early Zn concentration dynamics differed in relation to the outcome and may constitute a helpful diagnostic indicator for patients with spinal cord trauma. The fast changes in serum Zn concentrations allow an assessment of neurological impairment risk on the first day after trauma. This finding supports strategies for improving patient care by avoiding strong deficits via adjuvant nutritive measures, e.g., in unresponsive patients after trauma.

Bioinformatics Analysis Identifies Hub Genes and Molecular Pathways Involved in Sepsis-Induced Myopathy

BACKGROUND Sepsis-induced myopathy (SIM) is a complication of sepsis that results in prolonged mechanical ventilation, long-term functional disability, and increased patient mortality. This study aimed to use bioinformatics analysis to identify hub genes and molecular pathways involved in SIM, to identify potential diagnostic or therapeutic biomarkers. MATERIAL AND METHODS The Gene Expression Omnibus (GEO) database was used to acquire the GSE13205 expression profile. The differentially expressed genes (DEGs) in cases of SIM and healthy controls, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using the limma R/Bioconductor software package and clusterProfiler package in R, respectively. The protein-protein interaction (PPI) network data of DEGs was retrieved using the STRING database and analyzed using the Molecular Complex Detection (MCODE) Cytoscape software plugin. RESULTS A total of 196 DEGs were obtained in SIM samples compared with healthy samples, including 93 upregulated genes. The DEGs were significantly upregulated in mineral absorption, and the interleukin-17 (IL-17) signaling pathway and 103 down-regulated genes were associated with control of the bile secretion signaling pathway. A protein-protein interaction (PPI) network was constructed with 106 nodes and 192 edges. The top two important clusters were selected from the PPI by MCODE analysis. There were 16 hub genes with a high degree of connectivity in the PPI network that were selected, including heme oxygenase 1 (HMOX1), nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (NQO1), and metallothionein (MT)-1E. CONCLUSIONS Bioinformatics network analysis identified key hub genes and molecular mechanisms in SIM.

The Effect of Zinc on Post-neurosurgical Wound Healing: A Review

The aim of this article is to explore neurosurgeons' knowledge and understanding of the physiology of zinc and provide current information about the role zinc plays in post-neurological wound healing. We review several medical journals and bring together the most updated information related to lesion-healing after surgery.