The impact of obesity on the immune response to infection

Risk factors for tuberculous or nontuberculous spondylitis after percutaneous vertebroplasty or kyphoplasty in patients with osteoporotic vertebral compression fracture: A case-control study

Objectives

The contributing factors for spondylitis after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) remain unclear. Here, we sought to investigate the factors affecting spondylitis occurrence after PVP/PKP. We also compared the clinical characteristics between patients with tuberculous spondylitis (TS) and nontuberculous spondylitis (NTS) following vertebral augmentation.

Methods

Literature searches (from January 1, 1982 to October 16, 2020) using MEDLINE, EMBASE, Google Scholar and Web of science databases were conducted to identify eligible studies according to predefined criteria. The local database was also retrospectively reviewed to include additional TS and NTS patients at our center.

Results

Thirty studies from the literature and 11 patients from our local institute were identified, yielding a total of 23 TS patients and 50 NTS patients for analysis. Compared with NTS group, patients in the TS group were more likely to have a history of trauma before PVP/PKP treatment. Univariate analyses of risk factors revealed pulmonary tuberculosis and diabetes were significant factors for TS after PVP/PKP. Analyzing NTS, we found obesity, a history of preoperative trauma, urinary tract infection, diabetes and multiple surgical segments (≥2) were significantly associated with its occurrence following PVP/PKP treatment. Multivariate logistic analyses showed a history of pulmonary tuberculosis and diabetes were independent risk factors for TS after PVP/PKP, while diabetes and the number of surgically treated segments independently influenced NTS development.

Conclusions

A history of pulmonary tuberculosis and diabetes were independent risk factors for TS. For NTS, diabetes and the number of surgically treated segments significantly influenced the occurrence of postoperative spinal infection. These data may be helpful for guiding risk stratification and preoperative prevention for patients, thereby reducing the incidence of vertebral osteomyelitis after PVP/PKP.

Factors associated with an unfavorable clinical course in hospitalized patients with pelvic inflammatory disease: a retrospective cohort study of 117 patients from a Japanese academic institution

Background

This study aimed to determine the factors associated with an unfavorable clinical course (emergency surgery and/or prolonged hospitalization) in patients requiring hospitalization owing to pelvic inflammatory disease (PID).

Methods

A retrospective study was performed on 117 patients diagnosed with PID who were admitted to our hospital between January 2014 and December 2018. Multivariate regression analysis was conducted to determine the factors associated with emergency surgical intervention, and prolonged hospitalization in a subgroup of successful expectant management (n = 93).

Results

The average age (mean ± standard deviation) of the patients was 41.2 ± 12.5 years; 16 (13.7%) were postmenopausal; 81 patients (69.2%) complicated with a tubo-ovarian abscess (TOA) of which 59 (72.9%) had an ovarian endometrioma; and 19 patients (16.2%) had a history of various intrauterine manipulations. Emergency surgery was performed in 24 patients (20.5%), and patients with TOA underwent emergency surgery more often than did patients without TOA (25.9% vs. 8.3%, p = 0.03), and TOA was associated with longer length of hospital stay (17.1 days vs. 8.0 days, p = 0.01). Smoking, postmenopausal status, past medical history of PID, and high C-reactive protein (CRP) level at admission were significantly associated with emergency surgery. In patients with successful expectant management, obesity (body mass index ≥ 30) and high WBC and CRP level at admission were significantly associated with prolonged hospitalization.

Conclusions

Of the patients requiring hospitalization owing to PID, TOA was associated with both emergency surgery and prolonged hospital stay. Patients with increased inflammatory markers and obesity should be considered to be at a high risk for unfavorable clinical course in the management of PID.

Dynamic risk prediction of BK polyomavirus reactivation after renal transplantation

Purpose

To construct a dynamic prediction model for BK polyomavirus (BKV) reactivation during the early period after renal transplantation and to provide a statistical basis for the identification of and intervention for high-risk populations.

Methods

A retrospective study of 312 first renal allograft recipients was conducted between January 2015 and March 2022. The covariates were screened using univariable time-dependent Cox regression, and those with P<0.1 were included in the dynamic and static analyses. We constructed a prediction model for BKV reactivation from 2.5 to 8.5 months after renal transplantation using dynamic Cox regression based on the landmarking method and evaluated its performance using the area under the curve (AUC) value and Brier score. Monte-Carlo cross-validation was done to avoid overfitting. The above evaluation and validation process were repeated in the static model (Cox regression model) to compare the performance. Two patients were presented to illustrate the application of the dynamic model.

Results

We constructed a dynamic prediction model with 18 covariates that could predict the probability of BKV reactivation from 2.5 to 8.5 months after renal transplantation. Elder age, basiliximab combined with cyclophosphamide for immune induction, acute graft rejection, higher body mass index, estimated glomerular filtration rate, urinary protein level, urinary leukocyte level, and blood neutrophil count were positively correlated with BKV reactivation, whereas male sex, higher serum albumin level, and platelet count served as protective factors. The AUC value and Brier score of the static model were 0.64 and 0.14, respectively, whereas those of the dynamic model were 0.79 ± 0.05 and 0.08 ± 0.01, respectively. In the cross-validation, the AUC values of the static and dynamic models decreased to 0.63 and 0.70 ± 0.03, respectively, whereas the Brier score changed to 0.11 and 0.09 ± 0.01, respectively.

Conclusion

Dynamic Cox regression based on the landmarking method is effective in the assessment of the risk of BKV reactivation in the early period after renal transplantation and serves as a guide for clinical intervention.

Associations of sarcopenia with graft failure and mortality in patients undergoing living donor liver transplantation

Recent studies have reported that sarcopenia influences morbidity and mortality in surgical patients. However, few studies have investigated the associations of sarcopenia with short-term and long-term graft failure in recipients after living donor liver transplantation (LDLT). In this study, we investigated the associations between sarcopenia and graft failure/mortality in patients undergoing LDLT. We retrospectively examined 2816 recipients who underwent LDLT between January 2008 and January 2018. Cox regression analysis was performed to evaluate the associations between sarcopenia and graft failure/mortality in recipients at 60 days, 180 days, and 1 year and overall. Sarcopenia in the recipient was significantly associated with 60-day graft failure (adjusted hazard ratio [HR], 1.98; 95% confidence interval [CI], 1.09-3.61; p = 0.03), 180-day graft failure (HR, 1.85; 95% CI, 1.19-2.88; p = 0.01), 1-year graft failure (HR, 1.45; 95% CI, 1.01-2.17; p = 0.05), and overall graft failure (HR, 1.42; 95% CI, 1.08-1.87; p = 0.01). In addition, recipient sarcopenia was associated with 180-day mortality (HR, 1.88; 95% CI, 1.17-3.01; p = 0.01), 1-year mortality (HR, 1.53; 95% CI, 1.01-2.29; p = 0.04), and overall mortality (HR, 1.43; 95% CI, 1.08-1.90; p = 0.01). Preoperative sarcopenia was associated with high rates of graft failure and mortality in LDLT recipients. Therefore, preoperative sarcopenia may be a strong predictor of the surgical prognosis in LDLT recipients.

Saroglitazar ameliorates monosodium glutamate-induced obesity and associated inflammation in Wistar rats: Plausible role of NLRP3 inflammasome and NF- κB

OBJECTIVES

Inflammation is the major progenitor of obesity and associated metabolic disorders. The current study investigated the modulatory role of saroglitazar on adipocyte dysfunction and associated inflammation in monosodium glutamate (MSG) obese Wistar rats.

MATERIALS AND METHODS

The molecular docking simulation studies of saroglitazar and fenofibrate were performed on the ligand-binding domain of NLRP3 and NF- κB. Under in vivo study, neonatal pups received normal saline or MSG (4 g/kg, SC) for 7 alternate days after birth. After keeping for 42 days as such, animals were divided into seven groups: Normal control; MSG control; MSG + saroglitazar (2 mg/kg); MSG + saroglitazar (4 mg/kg); saroglitazar (4 mg/kg) per se; MSG + fenofibrate (100 mg/kg); fenofibrate (100 mg/kg) per se. Drug treatments were given orally, from the 42^nd to 70^th day. On day 71, blood was collected and animals were sacrificed for isolation of liver and fat pads.

RESULTS

In silico study showed significant binding of saroglitazar and fenofibrate against NLRP3 and NF- κB. Saroglitazar significantly reduced body weight, body mass index, Lee's index, fat pad weights, adiposity index, decreased serum lipids, interleukin-1β (IL-1β), tumor necrosis factor-α(TNF-α), interleukin-6 (IL-6), leptin, insulin, blood glucose, HOMA-IR values, oxidative stress in the liver and increased hepatic low-density lipoprotein receptor levels. Histopathological analysis of the liver showed decreased inflammation and vacuolization, and reduced adipocyte cell size. Immunohistochemical analysis showed suppression of NLRP3 in epididymal adipocytes and NF- κB expression in the liver.

CONCLUSION

Saroglitazar ameliorated obesity and associated inflammation via modulation of NLRP3 inflammasome and NF- κB in MSG obese Wistar rats.

Pre-existing comorbidities shape the immune response associated with severe COVID-19

BACKGROUND

Comorbidities are risk factors for the development of severe COVID-19. However, to which extent an underlying comorbidity influences the immune response to SARS-CoV-2 remains unknown.

OBJECTIVE AND METHODS

High-throughput, high-dimensional single-cell-mapping of peripheral blood leukocytes and algorithm-guided analysis were employed to investigate the complex interrelations of comorbidities, the immune response and patient outcome in COVID-19.

RESULTS

We discovered characteristic immune signatures associated not only with severe COVID-19, but also with the underlying medical condition. Different factors of the metabolic syndrome (obesity-hypertension-diabetes) affected distinct immune populations, thereby additively increasing the immune dysregulatory effect when present in a single patient. Patients with disorders affecting the lung or heart together with factors of metabolic syndrome clustered together, while immune disorder and chronic kidney disease displayed a distinct immune profile in COVID-19. Particularly SARS-CoV-2-infected patients with pre-existing chronic kidney disease were characterized by the highest number of altered immune signatures of both lymphoid and myeloid immune branches. This overall major immune dysregulation could be the underlying mechanism for the estimated odds ratio of 16.3 for severe COVID-19 in this burdened cohort.

CONCLUSION

The combinatorial systematic analysis of COVID-19 patient immune signatures, comorbidities, and patient outcomes provides the mechanistic immunological underpinnings of comorbidity-driven patient risk and uncovered comorbidity-driven immune signatures.

Influence of Nutritional Status and Physical Exercise on Immune Response in Metabolic Syndrome

Metabolic Syndrome (MetS) is a cluster of metabolic alterations mostly related to visceral adiposity, which in turn promotes glucose intolerance and a chronic systemic inflammatory state, characterized by immune cell infiltration. Such immune system activation increases the risk of severe disease subsequent to viral infections. Strong correlations between elevated body mass index (BMI), type-2-diabetes and increased risk of hospitalization after pandemic influenza H1N1 infection have been described. Similarly, a correlation between elevated blood glucose level and SARS-CoV-2 infection severity and mortality has been described, indicating MetS as an important predictor of clinical outcomes in patients with COVID-19. Adipose secretome, including two of the most abundant and well-studied adipokines, leptin and interleukin-6, is involved in the regulation of energy metabolism and obesity-related low-grade inflammation. Similarly, skeletal muscle hormones—called myokines—released in response to physical exercise affect both metabolic homeostasis and immune system function. Of note, several circulating hormones originate from both adipose tissue and skeletal muscle and display different functions, depending on the metabolic context. This review aims to summarize recent data in the field of exercise immunology, investigating the acute and chronic effects of exercise on myokines release and immune system function.

Sex Differences Distinctly Impact High-Fat Diet-Induced Immune Dysfunction in Wistar Rats

BACKGROUND

Immune function is altered during obesity. Moreover, males and females across different species demonstrate distinct susceptibility to several diseases. However, less is known regarding the interplay between high-fat diet (HFD) and sex in the context of immune function.

OBJECTIVES

The objective was to determine sex differences on immune function in response to an HFD compared with a control low-fat diet (LFD) in Wistar rats.

METHODS

At 5 wk of age, male and female Wistar rats were randomly assigned to 1 of 2 diets for 9 wk: ad libitum control LFD (20 kcal% fat, 53 kcal% carbohydrate, and 27 kcal% protein) or HFD (50 kcal% fat, 23 kcal% carbohydrate, and 27 kcal% protein). At 13 wk of age, rats were killed and splenocytes were isolated. Immune cell subsets were determined by flow cytometry. Immune cell function was determined by measuring the ex vivo cytokine production following stimulation with mitogens. Two-factor ANOVA was used to assess the main effect of sex, diet, and their interaction.

RESULTS

Males gained more weight than females (410 ± 46 vs. 219 ± 45 g), independently of diet (P-sex < 0.01). The HFD led to a lower production of IL-2 while increasing the production of IL-10 (both P-diet ≤ 0.05), independently of sex. HFD-fed females had increased production of cytokines (IL-2 and IL-6) after stimulation with phorbol 12-myristate 13-acetate plus ionomycin (PMA+I), as well as a higher T-helper (Th) 1:Th2 balance compared with HFD-fed males (all P < 0.05). Males fed the HFD had significantly lower production of IL-2 upon stimulation compared with all other groups.

CONCLUSIONS

Female Wistar rats developed a milder obesity phenotype and maintained enhanced cytokine production compared with males fed the HFD. Sex differences modulate immune function in the context of high-fat feeding and it should be considered in research design to establish personalized health-related recommendations.

Combined exposure to maternal high-fat diet and neonatal lipopolysaccharide disrupts stress-related signaling but normalizes spatial memory in juvenile rats

Both neonatal infections and exposure to maternal obesity are inflammatory stressors in early life linked to increased rates of psychopathologies related to mood and cognition. Epidemiological studies indicate that neonates born to mothers with obesity have a higher likelihood of developing neonatal infections, however effects on offspring physiology and behavior resulting from the combination of these stressors have yet to be investigated. The aim of this study was to explore immediate and persistent phenotypes resulting from neonatal lipopolysaccharide (nLPS) administration in rat offspring born to dams consuming a high-fat diet (HFD). Neural transcript abundance of genes involved with stress regulation and spatial memory were examined alongside related behaviors. At the juvenile age point, unlike offspring exposed to maternal HFD (mHFD) or nLPS alone, offspring with combined exposure to mHFD + nLPS displayed altered transcript abundances of stress-related genes in the ventral hippocampus (HPC) in a manner conducive to potentiating stress responses. For memory-related phenotypes, juveniles exposed to mHFD + nLPS exhibited normalized spatial memory and levels of memory-related gene expression in the dorsal HPC similar to control diet offspring, while control diet + nLPS, and mHFD offspring exhibited reduced levels of memory-related gene expression and impaired spatial memory. These findings suggest that dual exposure to unique inflammatory stressors in early life can disrupt neural stress regulation but normalize spatial memory processes.

The Role of Diet and Gut Microbiota in Regulating Gastrointestinal and Inflammatory Disease

Diet is an important lifestyle factor that is known to contribute in the development of human disease. It is well established that poor diet plays an active role in exacerbating metabolic diseases, such as obesity, diabetes and hypertension. Our understanding of how the immune system drives chronic inflammation and disease pathogenesis has evolved in recent years. However, the contribution of dietary factors to inflammatory conditions such as inflammatory bowel disease, multiple sclerosis and arthritis remain poorly defined. A western diet has been associated as pro-inflammatory, in contrast to traditional dietary patterns that are associated as being anti-inflammatory. This may be due to direct effects of nutrients on immune cell function. Diet may also affect the composition and function of gut microbiota, which consequently affects immunity. In animal models of inflammatory disease, diet may modulate inflammation in the gastrointestinal tract and in other peripheral sites. Despite limitations of animal models, there is now emerging evidence to show that anti-inflammatory effects of diet may translate to human gastrointestinal and inflammatory diseases. However, appropriately designed, larger clinical studies must be conducted to confirm the therapeutic benefit of dietary therapy.

Obesity and Leptin Resistance in the Regulation of the Type I Interferon Early Response and the Increased Risk for Severe COVID-19

Obesity, and obesity-associated conditions such as hypertension, chronic kidney disease, type 2 diabetes, and cardiovascular disease, are important risk factors for severe Coronavirus disease-2019 (COVID-19). The common denominator is metaflammation, a portmanteau of metabolism and inflammation, which is characterized by chronically elevated levels of leptin and pro-inflammatory cytokines. These induce the “Suppressor Of Cytokine Signaling 1 and 3” (SOCS1/3), which deactivates the leptin receptor and also other SOCS1/3 sensitive cytokine receptors in immune cells, impairing the type I and III interferon early responses. By also upregulating SOCS1/3, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 adds a significant boost to this. The ensuing consequence is a delayed but over-reactive immune response, characterized by high-grade inflammation (e.g., cytokine storm), endothelial damage, and hypercoagulation, thus leading to severe COVID-19. Superimposing an acute disturbance, such as a SARS-CoV-2 infection, on metaflammation severely tests resilience. In the long run, metaflammation causes the “typical western” conditions associated with metabolic syndrome. Severe COVID-19 and other serious infectious diseases can be added to the list of its short-term consequences. Therefore, preventive measures should include not only vaccination and the well-established actions intended to avoid infection, but also dietary and lifestyle interventions aimed at improving body composition and preventing or reversing metaflammation.

No obesity paradox in patients with community-acquired pneumonia - secondary analysis of a randomized controlled trial

Background

Obesity is associated with an increased risk for several chronic conditions and mortality. However, there are data in support of beneficial outcome in acute medical conditions such as community-acquired pneumonia (CAP), termed “obesity paradox”. The aim of this study was to test the association of BMI with clinical outcomes in a large randomized clinical trial of patients hospitalized with CAP.

Design and Methods

In total, 773 patients hospitalized with CAP were included in this study. Patients were stratified into four groups according to their baseline BMI (underweight <18.5, normal weight 18.5–25, overweight 25–30, and obese >30 kg/m²). The primary endpoint was time to clinical stability (TTCS). Secondary endpoints included 30-day mortality, ICU admission rate, CAP complications, and duration of antibiotic treatment.

Results

BMI and TTCS had a U-shaped association with shortest TTCS among patients at an overweight BMI of 28 kg/m². In patients with obesity, there was a trend towards reduced hazards to reach clinical stability when compared to patients with normal weight (HR 0.82; 95%CI, 0.67–1.02; p = 0.07). In underweight BMI group TTCS was prolonged by 1 day (HR 0.63; 95%CI, 0.45–0.89; p = 0.008). There was no difference in mortality or ICU admission rates between BMI groups (p > 0.05). While in the underweight BMI group the total duration of antibiotic treatment was prolonged by 2.5 days (95%CI, 0.88–4.20, p = 0.003), there was no difference in patients with obesity.

Conclusions

The overweight BMI group had shortest time to clinical stability. While underweight patients face adverse clinical outcomes, there is neither beneficial, nor adverse outcome in patients with obesity hospitalized for CAP.

ClinicalTrials.gov (registration no. NCT00973154).

Increased Surgical Site Subcutaneous Fat Thickness Is Associated with Infection after Posterior Cervical Fusion

Background: Previous literature has associated increased body mass index (BMI) with risk of surgical site infection (SSI) after posterior cervical fusion (PCF) surgery. However, few studies have examined the association between local adiposity and risk of SSI, re-admission, and re-operation after PCF. Local adiposity is easily measured on pre-operative magnetic resonance imaging (MRI) and may act as a more accurate predictor compared with BMI. Patients and Methods: Subjects undergoing PCF from 2013-2018 at a single institution were identified retrospectively. Posterior cervical subcutaneous fat thickness, paraspinal muscle thickness, and lamina-to-skin distance measurements were obtained from computed tomography (CT) or MRI scans. Subjects with active infection, malignancy, or revision procedures were excluded. Results: Two hundred five patients were included with 20 developing SSIs. Subjects with SSIs had a longer fusion construct (4.90 vs. 3.71 levels; p = 0.001), higher Elixhauser comorbidity index (ECI; 2.05 vs. 1.34; p = 0.045), had a history of diabetes mellitus (30% vs. 10.8%; p = 0.026), higher subcutaneous fat thickness (30.5 vs. 23.6 mm; p = 0.013), and higher lamina-to-skin distance (66.4 vs. 57.9 mm; p = 0.027). Subcutaneous fat thickness (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.10]; p = 0.026) and lamina-to-skin distance (OR, 1.05; 95% CI, 1.01-1.09]; p = 0.014) were associated with SSI in multivariable analysis. A subcutaneous fat thickness cutoff value of 23.2 mm had 90% sensitivity and 54.1% specificity for prediction of SSI. There was no association need for re-admission or re-operation. Conclusions: Increased posterior cervical fat may increase the risk of SSI after PCF. Pre-operative advanced imaging may be a valuable tool for assisting with patient counseling, optimization, and risk stratification.

Patients with Obesity and a History of Metformin Treatment Have Lower Influenza Mortality: A Retrospective Cohort Study

Background: Obesity is a risk factor for the development of influenza by leading to a chronic inflammatory state and T-cell dysfunction. Based upon preclinical research, metformin has influenza activity by restoring T-cell function and improving the immune response. Objective: We aimed to evaluate the potential drug repurposing of metformin for the management of influenza among patients with obesity utilizing national claims data in an electronic health record database. Methods: The VA Informatics and Computing Infrastructure (VINCI) was utilized to obtain individual-level information on demographics, administrative claims, and pharmacy dispensation. A cohort was created among individuals with laboratory confirmed diagnosis of influenza with a diagnosis of fever, cough, influenza, or acute upper respiratory infection in an outpatient setting. The study outcome was death after diagnosis of influenza. Cohorts were formed using diabetes status and metformin exposure prior to a positive influenza diagnosis. Hazard ratios for mortality were estimated using a cox proportional hazards model adjusting for baseline covariates and a sub-analysis was conducted utilizing propensity score matching. A greedy nearest neighbor algorithm was utilized to match 1 to 1 non-metformin diabetic controls and non-diabetic controls to diabetic patients receiving metformin. Results: A total of 3551 patients met the inclusion criteria and were evaluated in our study. The cohorts consisted of 1461 patients in the non-diabetic cohort, 1597 patients in the diabetic / metformin cohort, and 493 patients in the diabetic no metformin cohort. Compared to non-diabetic patients, diabetic patients with metformin had a lower rate of death (aHR 0.78, 95% CI 0.609–0.999). There was not a statistical difference between the non-diabetic patients and the diabetic patients without metformin (aHR 1.046, 95% CI 0.781–1.400). The propensity score matched cohorts revealed consistent results with the primary analysis. Conclusion: Our results demonstrated patients with obesity and a history of metformin treatment have lower influenza mortality.

The Interplay of Obesity, Dyslipidemia and Immune Dysfunction: A Brief Overview on Pathophysiology, Animal Models, and Nutritional Modulation

Obesity has emerged as a leading global health concern. It is characterized by chronic low-grade inflammation, which impairs insulin signaling, lipid metabolism and immune function. Recent findings from animal and clinical studies have begun to elucidate the underlying mechanisms of immune dysfunction seen in the context of obesity. Here, we provide a brief review on the current understanding of the interplay between obesity, dyslipidemia and immunity. We also emphasize the advantages and shortcomings of numerous applicable research models including rodents and large animal swine that aim at unraveling the molecular basis of disease and clinical manifestations. Although there is no perfect model to answer all questions at once, they are often used to complement each other. Finally, we highlight some emerging nutritional strategies to improve immune function in the context of obesity with a particular focus on choline and foods that contains high amounts of choline.

Adipose tissue microenvironments during aging: Effects on stimulated lipolysis

Adipose tissue is a critical organ for nutrient sensing, energy storage and maintaining metabolic health. The failure of adipose tissue homeostasis leads to metabolic disease that is seen during obesity or aging. Local metabolic processes are coordinated by interacting microenvironments that make up the complexity and heterogeneity of the adipose tissue. Catecholamine-induced lipolysis, a critical pathway in adipocytes that drives the release of stored triglyceride as free fatty acid after stimulation, is impaired during aging. The impairment of this pathway is associated with a failure to maintain a healthy body weight, core body-temperature during cold stress or mount an immune response. Along with impairments in aged adipocytes, aging is associated with an accumulation of inflammation, immune cell activation, and increased dysfunction in the nervous and lymphatic systems within the adipose tissue. Together these microenvironments support the initiation of stimulated lipolysis and the transport of free fatty acid under conditions of metabolic homeostasis. However, during aging, the defects in these cellular systems result in a reduction in ability to stimulate lipolysis. This review will focus on how the immune, nervous and lymphatic systems interact during tissue homeostasis, review areas that are impaired with aging and discuss areas of research that are currently unclear.

Predictors of postendoscopic retrograde cholangiopancreatography associated cholangitis: a retrospective cohort study

BACKGROUND

Post-ERCP cholangitis (endoscopic retrograde cholangiopancreatography) and associated sepsis can be lifethreatening. Despite the wealth of studies on post-ERCP pancreatitis risk factors, there is limited data on post-ERCP cholangitis. This study aimed to investigate the rates, predictors, and outcomes of post-ERCP cholangitis.

METHODS

A retrospective review of 452 ERCP cases performed by a single endoscopist at a tertiary center between March 2019 and February 2021 was performed. Patient-related, organizational and periprocedural factors that could affect post-ERCP cholangitis were evaluated. Predictors of post-ERCP cholangitis were determined by multivariable analysis.

RESULTS

The post-ERCP cholangitis rate was 19.5%. Cholangiocarcinoma (OR 15.72, CI 2.43-101.55, p = 0.004), the American Society of Anesthesiologist Score (ASA) (OR 2.87, CI 1.14-7.21, p = 0.024), an increase in bilirubin after ERCP (OR 1.81 CI 1.01-3.22, p = 0.043), body mass index (OR 1.15, CI 1.00-1.33, p = 0.04) and procedure duration (OR 1.02, CI 1.00-1.05, p = 0.049) were predictors of post-ERCP cholangitis. Biliary stone extraction using a balloon was found to be protective against cholangitis (OR 0.18, CI 0.05-0.60, p = 0.005). Sepsis rate related to post-ERCP cholangitis was 2.4% and death 1%.

The Influence of Obesity and Weight Loss on the Bioregulation of Innate/Inflammatory Responses: Macrophages and Immunometabolism

Obesity is characterized by low-grade inflammation and more susceptibility to infection, particularly viral infections, as clearly demonstrated in COVID-19. In this context, immunometabolism and metabolic flexibility of macrophages play an important role. Since inflammation is an inherent part of the innate response, strategies for decreasing the inflammatory response must avoid immunocompromise the innate defenses against pathogen challenges. The concept “bioregulation of inflammatory/innate responses” was coined in the context of the effects of exercise on these responses, implying a reduction in excessive inflammatory response, together with the preservation or stimulation of the innate response, with good transitions between pro- and anti-inflammatory macrophages adapted to each individual’s inflammatory set-point in inflammatory diseases, particularly in obesity. The question now is whether these responses can be obtained in the context of weight loss by dietary interventions (low-fat diet or abandonment of the high-fat diet) in the absence of exercise, which can be especially relevant for obese individuals with difficulties exercising such as those suffering from persistent COVID-19. Results from recent studies are controversial and do not point to a clear anti-inflammatory effect of these dietary interventions, particularly in the adipose tissue. Further research focusing on the innate response is also necessary.

Impact of prior bariatric surgery on risk and severity of COVID-19 infection: A meta-analysis of observational studies

BACKGROUND

The association of prior bariatric surgery (BS) with infection rate and prognosis of coronavirus disease 2019 (COVID-19) remains unclear. We conducted a meta-analysis of observational studies to address this issue.

METHODS

We searched databases including MEDLINE, Embase, and CENTRAL from inception to May, 2022. The primary outcome was risk of mortality, while secondary outcomes included risk of hospital/intensive care unit (ICU) admission, mechanical ventilation, acute kidney injury (AKI), and infection rate.

RESULTS

Eleven studies involving 151,475 patients were analyzed. Meta-analysis showed lower risks of mortality [odd ratio (OR)= 0.42, 95% CI: 0.27-0.65, p < 0.001, I² = 67%; nine studies; 151,113 patients, certainty of evidence (COE):moderate], hospital admission (OR=0.56, 95% CI: 0.36-0.85, p = 0.007, I² =74.6%; seven studies; 17,810 patients; COE:low), ICU admission (OR=0.5, 95% CI: 0.37-0.67, p < 0.001, I² =0%; six studies; 17,496 patients, COE:moderate), mechanical ventilation (OR=0.52, 95% CI: 0.37-0.72, p < 0.001, I² =57.1%; seven studies; 137,992 patients, COE:moderate) in patients with prior BS (BS group) than those with obesity without surgical treatment (non-BS group). There was no difference in risk of AKI (OR=0.74, 95% CI: 0.41-1.32, p = 0.304, I² =83.6%; four studies; 129,562 patients, COE: very low) and infection rate (OR=1.05, 95% CI: 0.89-1.22, p = 0.572, I² =0%; four studies; 12,633 patients, COE:low) between the two groups. Subgroup analysis from matched cohort studies demonstrated associations of prior BS with lower risks of mortality, ICU admission, mechanical ventilation, and AKI.

CONCLUSION

Our results showed a correlation between prior BS and less severe COVID-19, which warrants further investigations to verify.

Metabolic and functional impairment of CD8+ T cells from the lungs of influenza-infected obese mice

Obesity is an independent risk factor for morbidity and mortality in response to influenza infection. However, the underlying mechanisms by which obesity impairs immunity are unclear. Herein, we investigated the effects of diet-induced obesity on pulmonary CD8+ T cell metabolism, cytokine production, and transcriptome as a potential mechanism of impairment during influenza virus infection in mice. Male C57BL/6J lean and obese mice were infected with sub-lethal mouse-adapted A/PR/8/34 influenza virus, generating a pulmonary anti-viral and inflammatory response. Extracellular metabolic flux analyses revealed pulmonary CD8+ T cells from obese mice, compared with lean controls, had suppressed oxidative and glycolytic metabolism at day 10 post-infection. Flow cytometry showed the impairment in pulmonary CD8+ T cell metabolism with obesity was independent of changes in glucose or fatty acid uptake, but concomitant with decreased CD8+ GrB+ IFNγ+ populations. Notably, the percent of pulmonary effector CD8+ GrB+ IFNγ+ T cells at day 10 post-infection correlated positively with total CD8+ basal extracellular acidification rate and basal oxygen consumption rate. Finally, next-generation RNA sequencing revealed complex and unique transcriptional regulation of sorted effector pulmonary CD8+ CD44+ T cells from obese mice compared to lean mice following influenza infection. Collectively, the data suggest diet-induced obesity increases influenza virus pathogenesis, in part, through CD8+ T cell-mediated metabolic reprogramming and impaired effector CD8+ T cell function.

Impact of methotrexate and adalimumab on immune function of patients with psoriasis

Patients with psoriasis are commonly treated with methotrexate or biologics. We examined the immune response in a whole blood assay (TruCulture®) to assess the effect of methotrexate and adalimumab. Twenty patients with psoriasis were included and cytokine levels following stimulation with LPS, R848, HKCA, PolyIC, or a blank were investigated before and after 3-6 months of treatment with methotrexate or adalimumab and in patients who had received adalimumab > 5 years. Methotrexate only induced minor changes in the cytokine responses, whereas adalimumab affected a wide range of cytokines important for the immune defense towards microorganisms. In the long-term adalimumab treated group, the cytokine levels were almost equivalent to the short-term adalimumab-treated group. Overall, methotrexate was not associated with cytokine suppression. Short and long-term treatment with adalimumab lowered multiple cytokines involved in the immune defense equally emphasizing the need to continuously be aware of the risk of infections in these patients. This article is protected by copyright. All rights reserved.

Pandemics of the 21st Century: The Risk Factor for Obese People

The number of obese adults and children is increasing worldwide, with obesity now being a global epidemic. Around 2.8 million people die annually from clinical overweight or obesity. Obesity is associated with numerous comorbid conditions including hypertension, cardiovascular disease, type 2 diabetes, hypercholesterolemia, hypertriglyceridemia, nonalcoholic fatty liver disease, and cancer, and even the development of severe disease after infection with viruses. Over the past twenty years, a number of new viruses has emerged and entered the human population. Moreover, influenza (H1N1)pdm09 virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have caused pandemics. During pandemics, the number of obese patients presents challenging and complex issues in medical and surgical intensive care units. Morbidity amongst obese individuals is directly proportional to body mass index. In this review, we describe the impact of obesity on the immune system, adult mortality, and immune response after infection with pandemic influenza virus and SARS-CoV-2. Finally, we address the effect of obesity on vaccination.

Obesity in the Critical Care Setting

The prevalence of obesity continues to rise and is caused by many factors. Obesity places patients at risk for high blood pressure, diabetes, heart disease, and cancer. Although obesity in the normal population is associated with increased morbidity and mortality, obesity in critically ill patients has lower mortality. This is referred to as the obesity paradox, and although not fully understood, involves several mechanisms that demonstrate a protective factor in critically ill obese patients. However, despite the benefit, the management of critically ill obese patients faces many challenges.

Obesity and Postoperative Complications Following Ankle Arthrodesis: A Propensity Score Matched Analysis

Obese patients undergoing orthopedic procedure have been reported to have higher rates of postoperative complications, but the published associations have numerous confounders. This study aims to evaluate the independent effect of obesity on postoperative complications and hospital utilization following ankle arthrodesis. A database review of a Medicare database was performed on patients less than 85 years old who underwent ankle arthrodesis between 2005 and 2014. Patient cohorts were defined using International Classification of Diseases-9 coding for body mass index (BMI)-obese (30-40 kg/m²), and morbidly obese (>40 kg/m²). Normal BMI patients were defined as those without the respect codes for obesity (30-40 kg/m²), morbidly obese (>40 kg/m²), or underweight (<19 kg/m²). All groups were propensity score matched by demographics and comorbidities. Outcomes of interest included 90-day major and minor medical complications, and hospital burden. Morbid obesity was associated with an increased risk of acute kidney injury (4.4% vs 2.4%, OR 1.94, 95% CI 1.37-2.74, p < .001), urinary tract infection (5.2% vs 3.2%, OR 1.66, 95% CI 1.21-2.25, p = .001), readmission (13.6% vs 10.8%, OR 1.33, 95% CI 1.10-1.61, p = .003), and overall minor complications (16.0% vs 11.8%, OR 1.44, 95% CI 1.19-1.74, p < .001) compared to normal BMI patients, and an increased risk for acute kidney injury (4.4% vs 1.9%, OR 2.25, 95% CI 1.32-3.97, p = .003) compared to obese patients. Obesity was not associated with increased medical complications (p > .05). While morbid obesity was associated with an increase in the postoperative complications, obesity was not associated with any increase in postoperative complications following ankle arthrodesis.

Flower lose, a cell fitness marker, predicts COVID-19 prognosis

Risk stratification of COVID-19 patients is essential for pandemic management. Changes in the cell fitness marker, hFwe-Lose, can precede the host immune response to infection, potentially making such a biomarker an earlier triage tool. Here, we evaluate whether hFwe-Lose gene expression can outperform conventional methods in predicting outcomes (e.g., death and hospitalization) in COVID-19 patients. We performed a post-mortem examination of infected lung tissue in deceased COVID-19 patients to determine hFwe-Lose's biological role in acute lung injury. We then performed an observational study (n = 283) to evaluate whether hFwe-Lose expression (in nasopharyngeal samples) could accurately predict hospitalization or death in COVID-19 patients. In COVID-19 patients with acute lung injury, hFwe-Lose is highly expressed in the lower respiratory tract and is co-localized to areas of cell death. In patients presenting in the early phase of COVID-19 illness, hFwe-Lose expression accurately predicts subsequent hospitalization or death with positive predictive values of 87.8-100% and a negative predictive value of 64.1-93.2%. hFwe-Lose outperforms conventional inflammatory biomarkers and patient age and comorbidities, with an area under the receiver operating characteristic curve (AUROC) 0.93-0.97 in predicting hospitalization/death. Specifically, this is significantly higher than the prognostic value of combining biomarkers (serum ferritin, D-dimer, C-reactive protein, and neutrophil-lymphocyte ratio), patient age and comorbidities (AUROC of 0.67-0.92). The cell fitness marker, hFwe-Lose, accurately predicts outcomes in COVID-19 patients. This finding demonstrates how tissue fitness pathways dictate the response to infection and disease and their utility in managing the current COVID-19 pandemic.

The composition of human vaginal microbiota transferred at birth affects offspring health in a mouse model

Newborns are colonized by maternal microbiota that is essential for offspring health and development. The composition of these pioneer communities exhibits individual differences, but the importance of this early-life heterogeneity to health outcomes is not understood. Here we validate a human microbiota-associated model in which fetal mice are cesarean delivered and gavaged with defined human vaginal microbial communities. This model replicates the inoculation that occurs during vaginal birth and reveals lasting effects on offspring metabolism, immunity, and the brain in a community-specific manner. This microbial effect is amplified by prior gestation in a maternal obesogenic or vaginal dysbiotic environment where placental and fetal ileum development are altered, and an augmented immune response increases rates of offspring mortality. Collectively, we describe a translationally relevant model to examine the defined role of specific human microbial communities on offspring health outcomes, and demonstrate that the prenatal environment dramatically shapes the postnatal response to inoculation.

Pediatric Obesity-Related Asthma: The Role of Nutrition and Nutrients in Prevention and Treatment

Childhood obesity rates have dramatically risen in numerous countries worldwide. Obesity is likely a factor in increased asthma risk, which is already one of the most widespread chronic respiratory pathologies. The pathogenic mechanism of asthma risk has still not yet been fully elucidated. Moreover, the role of obesity-related inflammation and pulmonary overreaction to environmental triggers, which ultimately result in asthma-like symptoms, and the importance of dietary characteristics is well recognized. Diet is an important adjustable element in the asthma development. Food-specific composition of the diet, in particular fat, sugar, and low-quality nutrients, is likely to promote the chronic inflammatory state seen in asthmatic patients with obesity. An unbalanced diet or supplementation as a way to control asthma more efficiently has been described. A personalized dietary intervention may improve respiratory symptoms and signs and therapeutic response. In this narrative review, we presented and discussed more recent literature on asthma associated with obesity among children, focusing on the risk of asthma among children with obesity, asthma as a result of obesity focusing on the role of adipose tissue as a mediator of systemic and local airway inflammation implicated in asthma regulation, and the impact of nutrition and nutrients in the development and treatment of asthma. Appropriate early nutritional intervention could possibly be critical in preventing and managing asthma associated with obesity among children.

The evaluation of factors affecting antibody response after administration of the BNT162b2 vaccine: a prospective study in Japan

The aim of this study was to evaluate the antibody reaction after administration of the BNT162b2 vaccine, and to reveal the factors that affect antibody production. This prospective study was carried out in the Association of EISEIKAI Medical and Healthcare Corporation Minamitama Hospital, in Tokyo, Japan, from April 15, 2021 to June 09, 2021. All our hospital's workers who were administered the BNT162b2 vaccine as part of a routine program were included in this study. We calculated the anti-SARS-CoV-2 spike-specific antibody titter (1) before vaccination, (2) 7 to 20 days after the first vaccination, and (3) A total of 7 to 20 days after the second vaccination. The low-antibody titer group (LABG) was defined as the group having less than 25 percentiles of antibody titer. Univariate and Multivariate logistic regression analysis were performed to ascertain the effects of factors on the likelihood of LABG. A total of 374 participants were eventually included in our study, and they were divided into 94 LABG and 280 non-LABG. All samples showed significant antibody elevation in the second antibody test, with a mean value of 3,476 U/mL. When comparing the LABG and non-LABG groups, the median age, blood sugar, and HbA1c were significantly higher in the LABG group. The rates of participants with low BMI (<18.5) and high BMI (>30) were significantly higher in the LABG group. The proportion of chronic lung disease, hypertension, diabetes, dyslipidemia, autoimmune disease, and cancer were significantly higher in the LABG group. Although there was no significant difference confirmed with respect to the exercise hours per day, the proportion of participants that did not perform outdoor exercises was significantly higher in the LABG group. The time interval between the second vaccination and the second antibody test, and between the first and the second vaccination was significantly longer in the non-LABG group. In the multivariate logistic regression analysis, older than 60 years, the past history of hypertension, HbA1c higher than 6.5%, and lack of outdoor exercises were significant suppressors of antibody responses, whereas the length of days from the first to the second vaccination longer than 25 days promoted a significant antibody response. Again, our single-center study demonstrates that older than 60 years, hypertension, HbA1c higher than 6.5%, and lack of outdoor exercises were significant suppressors of antibody responses, whereas the length of days from the first to the second vaccination longer than 25 days promoted a significant antibody response. Evidence from multi-center studies is needed to develop further vaccination strategies.

Mechanisms by Which Obesity Promotes Acute Graft-Versus-Host Disease in Mice

The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by the occurrence of acute and chronic graft-versus-host disease (GVHD). We have recently demonstrated that obesity results in exacerbated acute gastrointestinal GVHD in both mouse models and clinical outcomes due to increased pro-inflammatory cytokine responses and microbiota alterations. We therefore wanted to delineate the role of the various parameters in obesity, adiposity, effects of high-fat (HF) diet, and the role of microbiome on GVHD pathogenesis, by taking advantage of a mouse strain resistant to diet-induced obesity (DIO). Female BALB/c mice are resistant to DIO phenotype with approximately 50% becoming DIO under HF diets. The DIO-susceptible recipients rapidly succumb to acute gut GVHD, whereas the DIO-resistant recipient littermates, which do not become obese, are partially protected from GVHD, indicating that being on HF diet alone contributes to but is not the primary driver of GVHD. Microbiome assessment revealed restricted diversity in both cohorts of mice, but coprophagy normalizes the microbiota in mice housed together. We then individually housed DIO-resistant, DIO-susceptible, and lean control mice. Notably, each of the individually housed groups demonstrates marked restricted diversity that has been shown to occur from the stress of single housing. Despite the restricted microbiome diversity, the GVHD pathogenesis profile remains consistent in the group-housed mice, with the lean control single-housed mice exhibiting no acute GVHD and DIO-resistant recipients showing again partial protection. These results demonstrate that the deleterious effects of obesity on acute gut GVHD are critically dependent on adiposity with the HF diet also playing a lesser role, and the microbiome alterations with obesity instead appear to fuel ongoing acute GVHD processes.

Impact of bariatric surgery on the risk of hospitalization due to influenza virus infection

BACKGROUND

Obesity independently increases the risk of hospitalization due to viral respiratory infections, including influenza virus and, more recently, severe acute respiratory syndrome coronavirus 2. As an independent risk factor, obesity impairs the immune response to viral infections and decreases the effectiveness of immunizations.

OBJECTIVES

Using influenza as a proxy, we aimed to determine the impact of bariatric surgery (BaS) on the risk of hospitalization due to viral respiratory infections.

SETTING

Academic hospital, United States.

METHODS

National (Nationwide) Inpatient Sample data collected from 2010 to 2015 were examined. Patients were classified as treatment and control groups. Treatment subjects were defined as patients with a history of BaS and control subjects as patients with a body mass index ≥35 kg/m² and without a history of BaS. Any hospitalization with influenza as a primary diagnosis was identified. Univariate analysis and multivariate regression models were performed to assess the differences between groups.

RESULTS

A total of 2,300,845 subjects were reviewed, of which 2,004,804 were control subjects and 296,041 were treated patients. Univariate analysis showed that the hospitalization rate in the treatment group was significantly lower than in the control group (.007% versus .019%, P < .0001), which was confirmed after adjusting for covariables (control versus treatment: odds ratio = 2.21, P = .0010).

CONCLUSIONS

BaS may decrease the risk of hospitalization due to influenza, but further prospective studies are needed to confirm these results. We also suggest that these results should be translated into the development of similar studies to determine the impact of BaS on the incidence and severity of the coronavirus disease 2019.

Association between body mass index and urinary tract infection: a systematic review and meta-analysis of observational cohort studies

BACKGROUND AND OBJECTIVE

Very few studies have investigated the relationship between body mass index (BMI) and risk of urinary tract infection (UTI), and conclusions from these available studies have been inconsistent. To resolve this inconsistency, we performed a systematic review and meta-analysis to precisely examine the association between BMI and UTI.

METHODS

This meta-analysis was performed based on the PRISMA recommendations. PubMed, Web of Science, Scopus, Embase, and Google Scholar databases were searched for all published observational studies that reported the risk of UTI based on BMI categories up to March 2020.

RESULTS

Fourteen (n = 14) articles comprising 19 studies in different populations met our inclusion criteria. The overall analysis showed a significant increased risk of UTI in subjects affected by obesity vs. individuals without obesity (RR = 1.45; 95% CI: 1.28 - 1.63; I² = 94%), and a non-significant increased risk of UTI in subjects who were overweight (RR = 1.03; 95% CI: 0.98 - 1.10; I² = 49.6%) and underweight (RR = 0.99; 95% CI: 0.81 - 21; I² = 0.0%) when compared to subjects who had normal weight. In the stratified analysis, we showed that obesity increased the risk of UTI in females (RR = 1.63; 95% CI: 1.38 - 1.93) and in subjects below 60 years old (RR = 1.53; 95% CI: 1.33 - 1.75).

CONCLUSION

This systematic review and meta-analysis recognized a significant relationship between BMI and incidence of UTI in obese vs. non-obese subjects, as well as in females and in individuals below 60 years old.

Radiographic spine adipose index: an independent risk factor for deep surgical site infection after posterior instrumented lumbar fusion

BACKGROUND CONTEXT

Surgical site infections (SSIs) after spinal fusion surgery increase healthcare costs, morbidity and mortality. Routine measures of obesity fail to consider site specific fat distribution.

PURPOSE

To assess the association between the spine adipose index and deep surgical site infection and determine a threshold value for spine adipose index that can assist in preoperative risk stratification in patients undergoing posterior instrumented lumbar fusion (PILF).

STUDY DESIGN/SETTING

Multicenter retrospective case-control study.

PATIENT SAMPLE

We reviewed patients who underwent PILF from January 1, 2010 to December 31, 2018.

OUTCOME MEASURES

All patients developing a deep primary incisional or organ-space SSI within 90 days of surgery as per US Center for Disease Control and Prevention criteria were identified. We gathered potential pre-operative and intra-operative deep infection risk factors for each patient. A 1:1 match was performed using the following criteria: gender, age (±3 y), ethnicity, date of surgery (± 1 y), and hospital location of surgery. Spine adipose index was measured on pre-operative mid-sagittal cuts of T2 weighted MRI scans. Each measurement was repeated twice by three authors in a blinded fashion, with each series of measurement separated by a period of at least six weeks.

METHODS

Stepwise binary logistic regression analysis was used to assess the association between SAI and the development of deep SSI. Separate logistic regression models were used for body mass index (BMI) and direct measures of subcutaneous fat thickness. Receiver Operating Characteristic analysis was used to determine the optimal value for SAI, and subsequent risk ratios were calculated using the identified threshold. Intra- and inter-observer reliabilities were assessed using intra-class coefficients.

RESULTS

Forty-two patients were included in final analysis, with twenty-one cases and twenty-one matched controls. The spine adipose index was significantly greater in patients developing deep SSI (p=.029), and this relationship was maintained after adjusting for confounders (p=.046). Risk of developing deep SSI following PILF surgery was increased 2.0-fold when the spine adipose index was ≥0.51. The spine adipose index had excellent (ICC >0.9; p<.001) inter- and intra-observer reliabilities.

CONCLUSION

The spine adipose index is a novel radiographic measure and an independent risk factor for developing deep SSI, with 0.51 being the ideal threshold value for pre-operative risk stratification in patients undergoing PILF surgery.

COVID-19 infection, progression, and vaccination: Focus on obesity and related metabolic disturbances

Coronaviruses are constantly circulating in humans, causing common colds and mild respiratory infections. In contrast, infection with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease-2019 (COVID-19), can cause additional severe complications, particularly in patients with obesity and associated metabolic disturbances. Obesity is a principal causative factor in the development of the metabolic syndrome; a series of physiological, biochemical, clinical, and metabolic factors that increase the risk of obesity-associated diseases. "Metabolically unhealthy" obesity is, in addition to metabolic disturbances, also associated with immunological disturbances. As such, patients with obesity are more prone to develop serious complications from infections, including those from SARS-CoV-2. In this review, we first describe how obesity and related metabolic disturbances increase the risk of SARS-CoV-2 infection. Then, mechanisms contributing to COVID-19 complications and poor prognosis in these patients are discussed. Finally, we discuss how obesity potentially reduces long-term COVID-19 vaccination efficacy. Despite encouraging COVID-19 vaccination results in patients with obesity and related metabolic disturbances in the short-term, it is becoming increasingly evident that long-term COVID-19 vaccination efficacy should be closely monitored in this vulnerable group.

The antiviral immune defense may be adversely influenced by weight loss through a calorie restriction program in obese women

BACKGROUND

Obesity and weight loss are reported to be associated with immune function. This study aimed to investigate the changes in counts of lymphocytes involved in microbial defense during weight loss in obese women.

METHODS

This clinical trial involved 29 women with a body mass index (BMI) ≥ 30 kg/m². The intervention group was prescribed a low-calorie diet (600 kcal lower than caloric requirement per day) plus Orlistat (120 mg three times daily). The control group received ad libitum diet. Anthropometric indices, obesity-related traits, and blood pressure were assessed every three weeks. Metabolic indices and plasma count of lymphocyte subpopulations (CD3, CD4, CD8, CD19, and CD16/56, as well as the ratio of CD4:CD8) were measured at baseline and after the intervention (after 10% weight loss).

RESULTS

After the weight loss, natural killer cells (CD16/56) decreased in the intervention group (P=0.014) even after adapting for all confounders. No significant changes were observed in other immune markers compared to the control group.

CONCLUSIONS

Caloric restriction-induced weight loss might independently weaken the antiviral immune defense. Further clinical trials are warranted to better clarify the association between weight loss, calorie restriction, and immunity.

T Cell Immunosenescence in Aging, Obesity, and Cardiovascular Disease

Although advances in preventive medicine have greatly improved prognosis, cardiovascular disease (CVD) remains the leading cause of death worldwide. This clearly indicates that there remain residual cardiovascular risks that have not been targeted by conventional therapies. The results of multiple animal studies and clinical trials clearly indicate that inflammation is the most important residual risk and a potential target for CVD prevention. The immune cell network is intricately regulated to maintain homeostasis. Ageing associated changes to the immune system occurs in both innate and adaptive immune cells, however T cells are most susceptible to this process. T-cell changes due to thymic degeneration and homeostatic proliferation, metabolic abnormalities, telomere length shortening, and epigenetic changes associated with aging and obesity may not only reduce normal immune function, but also induce inflammatory tendencies, a process referred to as immunosenescence. Since the disruption of biological homeostasis by T cell immunosenescence is closely related to the development and progression of CVD via inflammation, senescent T cells are attracting attention as a new therapeutic target. In this review, we discuss the relationship between CVD and T cell immunosenescence associated with aging and obesity.

Asymptomatic Incidental Pyogenic Hepatic Abscess in an Obese Adult

A 35-year-old obese female patient presented to the emergency department (ED) endorsing symptoms of generalized weakness, dyspnea, and myalgia. Vitals on admission revealed hypotension, tachycardia, and a low-grade fever. Physical examination was unremarkable and was negative for any upper right quadrant tenderness or jaundice. Laboratory results revealed an elevated leukocytosis with a predominantly elevated neutrophil count, an elevated lactate dehydrogenase, aminotransferases, and an elevated anion gap. Sepsis protocol was initiated. Blood cultures revealed Group F Streptococcus. A chest x-ray for localization of the primary infection source was significant for an incidental hypodense liver mass. A follow-up magnetic resonance imaging (MRI) without contrast revealed a left hepatic multiloculated enhancing lesion prompting the diagnosis of beta-hemolytic Group F Streptococcus pyogenic hepatic abscess (PHA). This unusual case seeks to inform that an obese patient (i.e., immunocompromised) with systemic signs (e.g., fever, hypotension, tachycardia) should warrant careful monitoring as well as the inclusion of pyogenic liver abscess in the differential workup as our patient’s PHA was found incidentally on a chest x-ray. Appropriate management via sonographic guided drainage was initiated and systemic antibiotics were administered in both inpatient and outpatient settings, resulting in complete resolution of the hepatic abscess over the course of a month.

Determinants of IgG antibodies kinetics after severe and critical COVID-19

The kinetics of IgG antibodies after coronavirus disease 2019 (COVID-19) remain poorly understood. We investigated factors influencing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibody levels and time to seronegativation during the follow-up of severe and critically ill patients. We retrospectively reviewed serological evaluations drawn during the follow-up of severe or critical laboratory-proven COVID-19 patients hospitalized at a large academic hospital. Specific IgG titers were measured using a chemiluminescent assay targeting anti-spike and anti-nucleocapsid protein IgG. The influence of time, demographic factors, clinical and paraclinical characteristics, and COVID-19 therapeutics on IgG levels were assessed through linear regression using a mixed-effect model, and delay until IgG negativation through a Weibull regression model. The cohort included 116 patients with a total of 154 IgG measurements drawn at a median of 79 days after diagnosis. IgG antibodies were increased with age (p = 0.005) and decreased significantly over time (p = 0.0002). Using elapsed time and age as covariates, we demonstrated higher IgG levels in patients with a higher body mass index (BMI) (p = 0.0026) and lower IgG levels in immunocompromised patients (p = 0.032). A high BMI was further found to delay and immunodeficiency to hasten significantly seronegativation, whereas no significant effect was observed with corticosteroids. These data highlight the waning over time of IgG antibodies after severe or critical COVID-19. Age, BMI, and immunosuppression also appear to influence the IgG kinetics, while short-term corticotherapy does not. Those data improve the understanding of SARS-CoV-2 serology while further research should determine the determinants of long-term seroprotection.

High conversion of tuberculin skin tests during the first year of antiretroviral treatment among South African adults in primary care

OBJECTIVES

Anergy reduces the sensitivity of the tuberculin skin test (TST) to detect Mycobacterium tuberculosis infection in people living with HIV. Antiretroviral treatment (ART) can reverse TST anergy, but data is scarce.

METHODS

To estimate TST conversion rates and factors associated with TST conversion, TST was placed at ART initiation, and 6 and 12 months thereafter (if TST negative at prior assessment).

RESULTS

Of 328 ART-eligible participants, 70% (231/328) had a valid TST result of whom 78% (180/231) were TST negative. At 6-month follow-up, 22% (24/109, 95% confidence interval [CI] 15%, 31%) of participants on ART, without incident tuberculosis (TB), and with a valid TST result converted to a positive TST. Of these 109 individuals, those with baseline CD4+ cell count >250 cells/μl were more likely to TST convert compared to those with baseline CD4+ cell count ≤250 cells/μl (odds ratio [OR] 3.54, 95% CI 1.29, 11.47). At 12 months post-ART initiation, an additional 12% (9/78, 95% CI 6, 20) of participants on ART, without incident TB and with a valid TST result experienced TST conversion. After 1 year on ART, TST conversion rate was 38 per 100 person-years (95% CI 26, 52), and lower in individuals with baseline CD4+ cell count ≤250 cells/μl (23/100 person-years, 95% CI 11, 41) compared to those with baseline CD4+ cell count >250 cells/μl (50/100 person-years, 95% CI 32, 73).

CONCLUSIONS

TST conversion rate in the first year of ART is high, especially among people with CD4+ cell count >250 cells/μl. A TST-based eligibility strategy at ART initiation may underestimate eligibility for preventive therapy for tuberculosis.

Potential Physiological and Cellular Mechanisms of Exercise That Decrease the Risk of Severe Complications and Mortality Following SARS-CoV-2 Infection

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has unmasked mankind's vulnerability to biological threats. Although higher age is a major risk factor for disease severity in COVID-19, several predisposing risk factors for mortality are related to low cardiorespiratory and metabolic fitness, including obesity, cardiovascular disease, diabetes, and hypertension. Reaching physical activity (PA) guideline goals contribute to protect against numerous immune and inflammatory disorders, in addition to multi-morbidities and mortality. Elevated levels of cardiorespiratory fitness, being non-obese, and regular PA improves immunological function, mitigating sustained low-grade systemic inflammation and age-related deterioration of the immune system, or immunosenescence. Regular PA and being non-obese also improve the antibody response to vaccination. In this review, we highlight potential physiological, cellular, and molecular mechanisms that are affected by regular PA, increase the host antiviral defense, and may determine the course and outcome of COVID-19. Not only are the immune system and regular PA in relation to COVID-19 discussed, but also the cardiovascular, respiratory, renal, and hormonal systems, as well as skeletal muscle, epigenetics, and mitochondrial function.

Sex Differences in Immunity to Viral Infections

The ongoing COVID-19 pandemic has increased awareness about sex-specific differences in immunity and outcomes following SARS-CoV-2 infection. Strong evidence of a male bias in COVID-19 disease severity is hypothesized to be mediated by sex differential immune responses against SARS-CoV-2. This hypothesis is based on data from other viral infections, including influenza viruses, HIV, hepatitis viruses, and others that have demonstrated sex-specific immunity to viral infections. Although males are more susceptible to most viral infections, females possess immunological features that render them more vulnerable to distinct immune-related disease outcomes. Both sex chromosome complement and related genes as well as sex steroids play important roles in mediating the development of sex differences in immunity to viral infections.

Circadian Rhythm Modulation of Microbes During Health and Infection

Circadian rhythms, referring to 24-h daily oscillations in biological and physiological processes, can significantly regulate host immunity to pathogens, as well as commensals, resulting in altered susceptibility to disease development. Furthermore, vaccination responses to microbes have also shown time-of-day-dependent changes in the magnitude of protective immune responses elicited in the host. Thus, understanding host circadian rhythm effects on both gut bacteria and viruses during infection is important to minimize adverse effects on health and identify optimal times for therapeutic administration to maximize therapeutic success. In this review, we summarize the circadian modulations of gut bacteria, viruses and their interactions, both in health and during infection. We also discuss the importance of chronotherapy (i.e., time-specific therapy) as a plausible therapeutic administration strategy to enhance beneficial therapeutic responses.

Prevalence of and factors associated with COVID-19 diagnosis in symptomatic patients followed in general practices in Germany between March 2020 and March 2021

Aims

This study aimed to investigate the prevalence of and the factors associated with the diagnosis of coronavirus disease 2019 (COVID-19) in symptomatic patients followed in general practices in Germany between March 2020 and March 2021.

Methods

Symptomatic patients tested for COVID-19 and followed in one of 962 general practices in Germany from March 2020 to March 2021 were included in this study. Covariates included sex, age, and comorbidities present in at least 3% of the population. The association between these factors and the diagnosis of COVID-19 was analyzed using an adjusted logistic regression model.

Results

A total of 301,290 patients tested for COVID-19 were included in this study (54.7% women; mean [SD] age 44.6 [18.5] years). The prevalence of COVID-19 was 13.8% in this sample. Male sex and older age were positively and significantly associated with COVID-19. In terms of comorbidities, the strongest positive associations with COVID-19 were observed for cardiac arrhythmias, depression, and obesity. There was also a negative relationship between the odds of being diagnosed with COVID-19 and several conditions such as chronic sinusitis, asthma, and anxiety disorders.

Conclusions

Approximately 14% of symptomatic patients tested for COVID-19 were diagnosed with COVID-19 in German general practices from March 2020 to March 2021.

Age, obesity and hyperglycaemia: Activation of innate immunity initiates a series of molecular interactions involving anionic surfaces leading to COVID-19 morbidity and mortality

Obesity and type 2 diabetes are major factors in COVID-19 causing a progression to excessive morbidity and mortality. An important characteristic of these conditions is poor glycaemic control leading to inappropriate chemical reactions and the production of glycated proteins in which positively charged lysine and arginine residues are neutralised. We propose that this protein glycation primes the inflammatory system as the presence of aspartate and glutamate residues in any glycated zwitterionic protein will thus increase its anionic characteristics. As a result, these macromolecules will be recognised by the innate immune system and identified as originating from infection or cell damage (sterile inflammation). Many proteins in the body exist to non-specifically target these anionic macromolecules and rely heavily on positively charged (cationic) binding-sites to produce a relatively non-specific interaction as the first step in the body’s response. Proteins involved in this innate immunity are collectively referred to as damage associated molecular pattern molecules or pathogen associated molecular pattern molecules. A crucial player in this process is RAGE (Receptor for Advanced Glycation End products). RAGE plays a central role in the inflammatory response and on ligand binding stimulates many aspects of inflammation including the production of the key inflammatory mediator NF-κB, and the subsequent production of inflammatory cytokines. This process has the potential to show a positive feedback loop resulting in a dramatic response within the tissue. We propose that protein glycation primes the inflammatory system by generating negatively charged surfaces so that when a SARS-Cov-2 infection occurs within the lung the further release of negatively-charged macromolecules due to cell damage results in a potentially catastrophic inflammatory response resulting in the cytokine storm associated with COVID-19 morbidity and mortality. That part of the population who do not suffer from inflammatory priming (Phase 1), such as the young and the non-obese, should not be subjected to the catastrophic inflammatory response seen in others (Phase 2). This hypothesis further highlights the need for improved dietary intake to minimise the inflammatory priming resulting from poor glycaemic control.

Defective interferon amplification and impaired host responses against influenza virus in obese mice

OBJECTIVE

Obesity is a major risk factor that increases morbidity and mortality upon infection. Although type I and type III interferon (IFN)-induced innate immune responses represent the first line of defense against viral infections, their functionality in the context of metabolic disorders remains largely obscure. This study aimed to investigate IFN responses upon respiratory viral infection in obese mice.

METHODS

The activation of IFNs as well as IFN regulatory factors (IRFs) upon H3N2 influenza infection in mice upon high-fat-diet feeding was investigated.

RESULTS

Influenza infection of obese mice was characterized by higher mortalities. In-depth analysis revealed impaired induction of both type I and type III IFNs as well as markedly reduced IFN responses. Notably, it was found that IRF7 gene expression in obese animals was reduced in homeostasis, and its induction by the virus was strongly attenuated.

CONCLUSIONS

The results suggest that the attenuated IRF7 expression and induction are responsible for the reduced expression levels of type I and III IFNs and, thus, for the higher susceptibility and severity of respiratory infections in obese mice.

Enhancing Effects of Environmental Enrichment on the Functions of Natural Killer Cells in Mice

The environment of an organism can convey a powerful influence over its biology. Environmental enrichment (EE), as a eustress model, has been used extensively in neuroscience to study neurogenesis and brain plasticity. EE has also been used as an intervention for the treatment and prevention of neurological and psychiatric disorders with limited clinical application. By contrast, the effects of EE on the immune system are relatively less investigated. Recently, accumulating evidence has demonstrated that EE can robustly impact immune function. In this review, we summarize the major components of EE, the impact of EE on natural killer (NK) cells, EE's immunoprotective roles in cancer, and the underlying mechanisms of EE-induced NK cell regulation. Moreover, we discuss opportunities for translational application based on insights from animal research of EE-induced NK cell regulation.

The Role of Obesity in the Immunopathogenesis of COVID-19 Respiratory Disease and Critical Illness

Coronavirus disease (COVID-19), the clinical syndrome caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently a global health pandemic with substantial morbidity and mortality. COVID-19 has cast a shadow on nearly every aspect of society, straining health systems and economies across the world. Although it is widely accepted that a close relationship exists between obesity, cardiovascular disease, and metabolic disorders on infection, we are only beginning to understand ways in which the immunological sequelae of obesity functions as a predisposing factor related to poor clinical outcomes in COVID-19. As both the innate and adaptive immune systems are each primed by obesity, the alteration of key pathways results in both an immunosuppressed and hyperinflammatory state. The present review will discuss the cellular and molecular immunology of obesity in the context of its role as a risk factor for severe COVID-19, discuss the role of cytokine storm, and draw parallels to prior viral epidemics such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and 2009 H1N1.

Animal Models Utilized for the Development of Influenza Virus Vaccines

Animal models have been an important tool for the development of influenza virus vaccines since the 1940s. Over the past 80 years, influenza virus vaccines have evolved into more complex formulations, including trivalent and quadrivalent inactivated vaccines, live-attenuated vaccines, and subunit vaccines. However, annual effectiveness data shows that current vaccines have varying levels of protection that range between 40–60% and must be reformulated every few years to combat antigenic drift. To address these issues, novel influenza virus vaccines are currently in development. These vaccines rely heavily on animal models to determine efficacy and immunogenicity. In this review, we describe seasonal and novel influenza virus vaccines and highlight important animal models used to develop them.

COVID-19 disease, obesity and micronutrients: an updated narrative review of the literature

Purpose

The purpose of this paper is to critically summarize the current data concerning the impact of obesity and micronutrient adequacy and supplementation on the risk and severity of COVID-19 disease, and their potential impact on treatment and rehabilitation.

Design/methodology/approach

PubMed, Scopus and Google Scholar databases were thoroughly searched to identify studies concerning obesity and nutritional status, vitamin and other micronutrients adequacy with COVID-19 severity.

Findings

Individuals with higher body mass index are in greater risk of severe disease and need for mechanical ventilation. Concerning micronutrient adequacy, no published studies at the present time have evaluated the effect of supplementation on the risk and the treatment of the novel disease.

Originality/value

Recently, COVID-19 has monopolized the interest of the medical community regarding diet and nutritional status and it possibly plays an important role in disease severity.

Nutrition and immunity: lessons for COVID-19

The role of the immune system is to protect the individual against pathogenic organisms. Nutrition is one of multiple factors that determines the immune response and good nutrition is important in supporting the immune response. Immunity can be impaired in older people, particularly those who are frail, in those living with obesity, in those who are malnourished and in those with low intakes of micronutrients. The immune impairments associated with nutritional inadequacy increase susceptibility to infection and permit infections to become more severe, even fatal. The adverse impact of poor nutrition on the immune system, including its inflammatory component, may be one of the explanations for the higher risk of more severe outcomes from infection with SARS-CoV-2 seen in older people and in those living with obesity. Studies of individual micronutrients including vitamin D and zinc suggest roles in reducing severity of infection with SARS-CoV-2. Good nutrition is also important in promoting a diverse gut microbiota, which in turn supports the immune system. The importance of nutrition in supporting the immune response also applies to assuring robust responses to vaccination. There are many lessons from the study of nutrition and immunity that are relevant for the battle with SARS-CoV-2.