Evidence mapping and review of long-COVID and its underlying pathophysiological mechanism

Traditional Chinese medicine for post-COVID: A retrospective cohort study

Post-COVID syndrome affects at least 10% of individuals recovering from COVID-19. Currently, there is no causal treatment. This retrospective cohort study aimed to evaluate the potential of traditional Chinese medicine (TCM) in treating post-COVID symptoms. TCM physicians in Germany and Austria completed online questionnaires to retrospectively record symptoms, treatment approaches, and outcomes for patients diagnosed with post-COVID. Nine physicians collected data from 79 patients (65% female, 47 ± 16 SD). The most common TCM treatments for post-COVID were acupuncture (n = 66; 85%), Chinese pharmacological therapy (n = 61; 77%), and Chinese dietary counseling (n = 32; 41%). After an average of 7 ± 4 TCM consultations, physicians rated global symptom improvement as 62% ± 29%. Significant alleviation from the start of TCM treatment was observed in major symptoms, such as fatigue (P < .001), impaired physical performance (P < .001), and exertional dyspnea (P < .001). TCM treatment was associated with significant improvements in post-COVID symptoms, warranting further evaluation through randomized controlled studies.

A multidisciplinary review of long COVID to address the challenges in diagnosis and updated management guidelines

Long COVID has emerged as a significant challenge since the COVID-19 pandemic, which was declared as an outbreak in March 2020, marked by diverse symptoms and prolonged duration of disease. Defined by the WHO as symptoms persisting or emerging for at least two months post-SARS-CoV-2 infection without an alternative cause, its prevalence varies globally, with estimates of 10-20% in Europe, 7.3% in the USA, and 3.0% in the UK. The condition's etiology remains unclear, involving factors, such as renin-angiotensin system overactivation, persistent viral reservoirs, immune dysregulation, and autoantibodies. Reactivated viruses, like EBV and HSV-6, alongside epigenetic alterations, exacerbate mitochondrial dysfunction and energy imbalance. Emerging evidence links SARS-CoV-2 to chromatin and gut microbiome changes, further influencing long-term health impacts. Diagnosis of long COVID requires detailed systemic evaluation through medical history and physical examination. Management is highly individualized, focusing mainly on the patient's symptoms and affected systems. A multidisciplinary approach is essential, integrating diverse perspectives to address systemic manifestations, underlying mechanisms, and therapeutic strategies. Enhanced understanding of long COVID's pathophysiology and clinical features is critical to improving patient outcomes and quality of life. With a growing number of cases expected globally, advancing research and disseminating knowledge on long COVID remain vital for developing effective diagnostic and management frameworks, ultimately supporting better care for affected individuals.

Neuropsychiatric Manifestations of Long COVID-19: A Narrative Review of Clinical Aspects and Therapeutic Approaches

The COVID-19 (C-19) pandemic has highlighted the significance of understanding the long-term effects of this disease on the quality of life of those infected. Long COVID-19 (L-C19) presents as persistent symptoms that continue beyond the main illness period, usually lasting weeks to years. One of the lesser-known but significant aspects of L-C19 is its impact on neuropsychiatric manifestations, which can have a profound effect on an individual's quality of life. Research shows that L-C19 creates neuropsychiatric issues such as mental fog, emotional problems, and brain disease symptoms, along with sleep changes, extreme fatigue, severe head pain, tremors with seizures, and pain in nerves. People with cognitive problems plus fatigue and mood disorders experience great difficulty handling everyday activities, personal hygiene, and social interactions. Neuropsychiatric symptoms make people withdraw from social activity and hurt relationships, thus causing feelings of loneliness. The unpredictable state of L-C19 generates heavy psychological pressure through emotional suffering, including depression and anxiety. Neuropsychiatric changes such as cognitive impairment, fatigue, and mood swings make it hard for people to work or study effectively, which decreases their output at school or work and lowers their job contentment. The purpose of this narrative review is to summarize the clinical data present in the literature regarding the neuropsychiatric manifestations of L-C19, to identify current methods of diagnosis and treatment that lead to correct management of the condition, and to highlight the impact of these manifestations on patients' quality of life.

The negative effects of long COVID-19 on cardiovascular health and implications for the presurgical examination

CONTEXT

In 2019, emergence of the novel and communicable severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection took scientific communities by surprise and imposed significant burden on healthcare systems globally. Although the advent of this disease piqued the interest of academic centers, healthcare systems, and the general public, there is still much yet to be elucidated regarding epidemiology, pathophysiology, and long-term impacts of coronavirus disease 2019 (COVID-19). It has been established that long COVID-19 can impact multiple organ systems, including the cardiovascular system, unfavorably. Although the pathophysiology of this damage is not well understood, adverse sequelae may range from chest pain and arrhythmias to heart failure (HF), myocardial infarction, or sudden cardiac death. For any postacute COVID-19 patient requiring a surgical procedure, the potential for cardiac injury secondary to long COVID-19 must be considered in the preoperative cardiac examination.

OBJECTIVES

This literature review serves to add to the growing body of literature exploring postacute cardiovascular outcomes of COVID-19, with a focus on presurgical cardiac clearance in the adult patient. Specifically, this review studies the prevalence of cardiovascular symptomatology including chest pain, arrhythmias, blood pressure changes, myo-/pericarditis, HF, cardiomyopathy, orthostatic intolerance, and thromboembolism. Although current evidence is scarce in both quality and quantity, it is the goal that this review will highlight the negative impacts of long COVID-19 on cardiovascular health and encourage providers to be cognizant of potential sequelae in the context of the presurgical examination.

METHODS

For this study, peer-reviewed and journal-published articles were selected based on established inclusion and exclusion criteria to address the question "How does long COVID-19 impact the presurgical cardiac examination of an adult scheduled to undergo a noncardiac procedure?" Inclusion criteria included human studies conducted in adult patients and published in peer-reviewed journals up until May 2024 examining the effects of long-COVID-19 infection on the cardiovascular system. Exclusion criteria eliminated unpublished reports, preprints, duplicate articles, literature regarding coronavirus strains other than COVID-19, studies regarding post-COVID-19 vaccination complications, animal studies, and studies conducted in people younger than 18 years of age. A total of 6,675 studies were retrieved from PubMed and Google Scholar. Following screening, 60 studies were included in final consideration.

RESULTS

Cardiovascular symptoms of postacute COVID-19 infection were encountered with the following percentages prevalence (total numbers of articles mentioning symptom/total number of articles [60]): chest pain (83.3), arrhythmias (88.3), hypertension (40.0), hypotension (16.7), myocarditis (80.0), pericarditis (51.7), HF (70.0), cardiomyopathy (55.0), orthostatic intolerance (56.7), and thromboembolic events (85.0).

CONCLUSIONS

The presence of persisting COVID symptoms may negatively impact the patient's physical examination, blood tests, electrocardiogram (ECG), imaging, and/or echocardiogram. Cardiac conditions associated with long COVID require special attention in the context of the presurgical candidate due to an increased risk of sudden cardiac death, myocarditis, stroke, and myocardial infarction - even in those who were healthy prior to acute COVID-19 infection. Until more specific scientific evidence comes to light, care of these patients should be viewed through the prism of the best practices already in use and clinicians should maintain a low threshold to pursue more extensive cardiac workup prior to surgery.

Chronic inflammation in post-acute sequelae of COVID-19 modulates gut microbiome: a review of literature on COVID-19 sequelae and gut dysbiosis

BACKGROUND

Long COVID or Post-acute sequelae of COVID-19 is an emerging syndrome, recognized in COVID-19 patients who suffer from mild to severe illness and do not recover completely. Most studies define Long COVID, through symptoms like fatigue, brain fog, joint pain, and headache prevailing four or more weeks post-initial infection. Global variations in Long COVID presentation and symptoms make it challenging to standardize features of Long COVID. Long COVID appears to be accompanied by an auto-immune multi-faceted syndrome where the virus or viral antigen persistence causes continuous stimulation of the immune response, resulting in multi-organ immune dysregulation.

MAIN TEXT

This review is focused on understanding the risk factors of Long COVID with a special emphasis on the dysregulation of the gut-brain axis. Two proposed mechanisms are discussed here. The first mechanism is related to the dysfunction of angiotensin-converting enzyme 2 receptor due to Severe Acute Respiratory Syndrome Corona Virus 2 infection, leading to impaired mTOR pathway activation, reduced AMP secretion, and causing dysbiotic changes in the gut. Secondly, gut-brain axis dysregulation accompanied by decreased production of short-chain fatty acids, impaired enteroendocrine cell function, and increased leakiness of the gut, which favors translocation of pathogens or lipopolysaccharide in circulation causing the release of pro-inflammatory cytokines. The altered Hypothalamic-Pituitary-Adrenal axis is accompanied by the reduced level of neurotransmitter, and decreased stimulation of the vagus nerve, which may cause neuroinflammation and dysregulation of serum cortisol levels. The dysbiotic microbiome in Long COVID patients is characterized by a decrease in beneficial short chain fatty acid-producing bacteria (Faecalibacterium, Ruminococcus, Dorea, and Bifidobacterium) and an increase in opportunistic bacteria (Corynebacterium, Streptococcus, Enterococcus). This dysbiosis is transient and may be impacted by interventions including probiotics, and dietary supplements.

CONCLUSIONS

Further studies are required to understand the geographic variation, racial and ethnic differences in phenotypes of Long COVID, the influence of viral strains on existing and emerging phenotypes, to explore long-term effects of gut dysbiosis, and gut-brain axis dysregulation, as well as the potential role of diet and probiotics in alleviating those symptoms.

Mapping the Potential Genes and Associated Pathways Involved in Long COVID-Associated Brain Fog Using Integrative Bioinformatics and Systems Biology Strategy

One of the recent emerging global health issues is long COVID. Among long COVID patients, long COVID-associated brain fog is an important area. We noted an immense gap in understanding the genes and associated pathways involved in long COVID-associated brain fog. Therefore, the study has been selected to understand the genes and pathways involved in patients with long COVID-associated brain fog. A GEO dataset, which was developed through the RNA-seq, was used for the analysis. The dataset encompasses 22 human samples of PBMC. The dataset (human samples of PBMC) was grouped into four cohorts for this study: healthy cohort, COVID convalescent, long COVID, and long COVID brain fog. Therefore, the selection criteria for the 22 PBMC samples were based on the individual infection type (COVID convalescent, long COVID, and long COVID brain fog) and the healthy cohort. Using DEG profile evaluation, we revealed 250 top-ranked DEGs with P values, Padj, baseMean, etc. From the top-ranked DEGs, we listed 24 significant DEGs and some significant DEGs are SMAD3 (P value = 6.34e-07), PF4 (P value = 1.88e-05), TNFAIP3 (P value = 3.70e-06), CXCL5 (P value = 1.22e-08), etc. Among the top-ranked DEGs, we found some genes linked with different biological functions, such as inflammatory cytokine secretion, inflammation, microclot formation, and BBB disruption. From our investigation, we found some genes that are associated with this condition, namely PF4, SMAD3, CXCL5, TNFAIP3, etc. From the literature survey and functional pathway enrichment analysis, we noted the function of the genes such as PF4, SMAD3, and CXCL5. We found that PF4 assists in clot formation, and SMAD3 is associated with neuroinflammation. Similarly, CXCL5 is an inflammatory marker associated with neuroinflammation and BBB damage. At the same time, the study with functional pathway enrichment analysis reflects that DEGs of long COVID-related brain fog might be associated with several biological pathways and processes, cell signatures, and gene-disease associations. It reflects that the disease is a highly complex one. Our study will provide an understanding of the genes and associated pathways in long COVID-related brain fog, which will assist in the next-generation biomarker discovery and therapeutics for these patients.

No signs of mast cell involvement in long-COVID: A case-control study

Long-COVID caused by SARS-CoV-2 infection has significant and increasing effects on human health worldwide. Although a unifying molecular or biological explanation is lacking, several pathophysiological mechanisms have been proposed. Involvement of mast cells-evolutionary old "multipurpose" innate immune cells-was reported recently in studies of acute infection and post-acute-COVID-19 syndrome. Mast cell activity has been suggested in long-COVID. In this case-control study, we compared data from 24 individuals with long-COVID (according to the NICE criteria) and 24 age- and sex-matched healthy individuals with a history of SARS-CoV-2 infection without developing sequelae. Serum levels of the proteases beta-tryptase (TPSB2) and carboxypeptidase (CPA3), which are mast cell specific, were measured using immunoassays. The values were compared between the two groups and correlated to measures of physical exertional intolerance. TPSB2 and CPA3 levels were median (range) 26.9 (2.0-1000) and 5.8 (1.5-14.0) ng/mL, respectively, in the long-COVID group. The corresponding values in the control group were 10.9 (2.0-1000) (p = 0.93) and 5.3 (3.5-12.9) ng/mL (p = 0.82). No significant correlations between TPSB2 or CPA3 levels and scores on the ten physical subscales of SF-36, 3.1-3.10 were revealed. We found no significant differences in the levels of mast cell activation markers TPSB2 and CPA3 between the long-COVID and control groups and no correlations with proxy markers of exercise intolerance. Mast cell activation does not appear to be part of long-term pathogenesis of long-COVID, at least in the majority of patients.

COVID-19-Related Cholangiopathy: Histological Findings

Cholangiopathy has been described in survivors of severe COVID-19, presenting significant clinical parallels to the pre-pandemic condition of secondary sclerosing cholangitis in critically ill patients (SSC-CIP). We aimed to examine the liver histopathology of individuals with persistent cholestasis after severe COVID-19.

METHODS

We subjected post-COVID-19 cholestasis liver samples to routine staining techniques and cytokeratin 7 immunostaining and semi-quantitatively analyzed the portal and parenchymal changes.

RESULTS

All ten patients, five men, had a median age of 56, an interquartile range (IQR) of 51-60, and required intensive care unit and mechanical ventilation. The median and IQR liver enzyme concentrations proximal to biopsy were in IU/L: ALP 645 (390-1256); GGT 925 (664-2169); ALT 100 (86-113); AST 87 (68-106); and bilirubin 4 (1-9) mg/dL. Imaging revealed intrahepatic bile duct anomalies and biliary casts. We performed biopsies at a median of 203 (150-249) days after molecular confirmation of infection. We found portal and periportal fibrosis, moderate-to-severe ductular proliferation, and bile duct dystrophy in all patients, while we observed hepatocyte biliary metaplasia in all tested cases. We observed mild-to-severe parenchymal cholestasis and bile plugs in nine and six cases. We also observed mild swelling of the arteriolar endothelial cells in five patients. We observed a thrombus in a small portal vein branch and mild periductal fibrosis in one case each. One patient developed multiple small biliary infarctions. We did not observe ductopenia in any patient.

CONCLUSIONS

The alterations were like those observed in SSC-CIP; however, pronounced swelling of endothelial cells, necrosis of the vessel walls, and thrombosis in small vessels were notable.

Occupational therapy-based self-management education in persons with post-COVID-19 condition related fatigue: a feasibility study with a pre-post design

PURPOSE

Persons with post-COVID condition are a growing population requiring support returning to everyday life. Energy management education (EME) is a group self-management intervention based on energy conservation and management strategies delivered by occupational therapists. Data on the effectiveness of EME in persons with long COVID-related fatigue still need to be provided. This study aims to investigate procedural and methodological parameters to plan a future study analyzing the effectiveness of EME in individuals with post-COVID-19 conditions.

MATERIALS AND METHODS

A pre-post design was used. The procedural data was collected regarding eligibility, reasons for participation decline, dropout, and follow-up rates. Changes in self-efficacy in using energy management strategies, fatigue impact, competency in daily activities, and quality of life were collected three times. Implemented behavior strategies at five months from EME were documented.

RESULTS

During five months, 17 of 30 eligible participants were included in the study. No dropouts were registered during the intervention period. The follow-up response rate was 70%. The effect size was large in three out of four outcomes post-intervention, with a tendency to increase at follow-up.

CONCLUSIONS

This study demonstrated the feasibility of study procedures and reported promising effect sizes for EME that should be further researched.

Inflammaging, immunosenescence, and cardiovascular aging: insights into long COVID implications

Aging leads to physiological changes, including inflammaging-a chronic low-grade inflammatory state with significant implications for various physiological systems, particularly for cardiovascular health. Concurrently, immunosenescence-the age-related decline in immune function, exacerbates vulnerabilities to cardiovascular pathologies in older individuals. Examining the dynamic connections between immunosenescence, inflammation, and cardiovascular aging, this mini-review aims to disentangle some of these interactions for a better understanding of their complex interplay. In the context of cardiovascular aging, the chronic inflammatory state associated with inflammaging compromises vascular integrity and function, contributing to atherosclerosis, endothelial dysfunction, arterial stiffening, and hypertension. The aging immune system's decline amplifies oxidative stress, fostering an environment conducive to atherosclerotic plaque formation. Noteworthy inflammatory markers, such as the high-sensitivity C-reactive protein, interleukin-6, interleukin-1β, interleukin-18, and tumor necrosis factor-alpha emerge as key players in cardiovascular aging, triggering inflammatory signaling pathways and intensifying inflammaging and immunosenescence. In this review we aim to explore the molecular and cellular mechanisms underlying inflammaging and immunosenescence, shedding light on their nuanced contributions to cardiovascular diseases. Furthermore, we explore the reciprocal relationship between immunosenescence and inflammaging, revealing a self-reinforcing cycle that intensifies cardiovascular risks. This understanding opens avenues for potential therapeutic targets to break this cycle and mitigate cardiovascular dysfunction in aging individuals. Furthermore, we address the implications of Long COVID, introducing an additional layer of complexity to the relationship between aging, immunosenescence, inflammaging, and cardiovascular health. Our review aims to stimulate continued exploration and advance our understanding within the realm of aging and cardiovascular health.

Mast cell activation syndrome: An up-to-date review of literature

Mast cells are a subtype of white blood cells and are involved in the immune system. These cells contain many chemical substances called mediators, which are involved in the allergic response. The fact that mast cells play a role in many events that require urgent intervention, especially anaphylaxis, has led to a more detailed study of these cells. The diseases also caused by dysfunctions of mast cells have been examined in many circumstances. For instance, mast cell activation syndrome is known as an augmented number of cells due to decreased cell death, resulting in clinical symptoms affecting many systems. The main common symptoms include flushing, hypotension, urticaria, angioedema, headache, vomiting and diarrhea. Although the underlying mechanism is not yet clearly known, we aim to review the literature in a broad perspective and bring together the existing knowledge in the light of the literature due to the diversity of its involvement in the body and the fact that it is a little known syndrome.

Characteristics of long COVID and the impact of COVID-19 vaccination on long COVID 2 years following COVID-19 infection: prospective cohort study

This prospective cohort study aimed to identify characteristics of long COVID and any potential mitigating effects of COVID-19 vaccinations in patients 24 months following COVID-19 infection. Adult patients diagnosed with COVID-19 between February 17, 2020, and March 24, 2020, were scheduled to visit the study hospital four times (6, 12, 18, and 24 months after infection) to assess their symptoms, quality of life, and mental health. Among the 235 patients, 121 (51.5%) completed the study visits. Of these, 59.5% were female, with a median age of 52 years. Mild to moderate disease severity were identified in 101 (83.4%) patients. A total of 75 participants (62.0%) were still experiencing long COVID symptoms 24 months after acute infection. Fatigue, amnesia, difficulty concentrating, and insomnia were the most common symptoms. The frequency of neuropsychiatric symptoms did not differ based on vaccination status or the number of doses received. Quality of life improved over time for the participants, but 32.2% of respondents still reported anxiety/depression at the end of the study. Overall, our cohort demonstrates that long COVID can persist up to 24 months after COVID-19 infection, affecting mental health and quality of life.

Post-COVID-19 syndrome: Descriptive analysis based on a survivors' cohort in Colombia

Background

The prevalence of post-COVID-19 Syndrome (PCS) is estimated to be between 10% and 20%. The main reported symptoms are fatigue, memory alterations, dyspnea, sleep disorders, arthralgia, anxiety, taste alterations, coughing and depression. This study aims to determine the prevalence of post-COVID-19 symptoms in a group of Colombian patients who were recruited during their outpatient appointments.

Methodology

This cross-sectional study was conducted between December 2021 to May 2022. It included patients from outpatient facilities located in five main cities in Colombia who were positive for SARS-CoV-2 infection detected by reverse transcription-polymerase chain reaction (RT-PCR) testing and reported PCS in the following 12 weeks after their COVID-19 diagnosis.

Results

A total of 1047 individuals >18 years old met the inclusion criteria and were included in the study. The median age was 46 years old. 68.2% of the participants were female, 41.5% of the patients reported having a pre-existent condition (hypertension, anxiety disorder, diabetes, hyperthyroidism, obesity and asthma). Only 22% had received at least one dose of COVID-19 vaccine prior to the COVID-19 episode registered. The more prevalent symptoms within our group are described as follows: fatigue (53.3%), dyspnea (40.3%), arthralgia and/or myalgia (43%), cephalea (40.5%), sleep disorders (35.7%) and coughing (31.3%). 72% of the patients presented four or more post-COVID 19 symptoms, 9% two symptoms, and 10% only one symptom.

Conclusion

The findings of this study are consistent with international literature publicly available. The distribution and prevalence of post-COVID symptoms highlight the importance of further research to improve understanding and its potential consequences and implications in terms of quality of life and health care planning services.

Clinical and pulmonary function analysis in long-COVID revealed that long-term pulmonary dysfunction is associated with vascular inflammation pathways and metabolic syndrome

Introduction

Long-term pulmonary dysfunction (L-TPD) is one of the most critical manifestations of long-COVID. This lung affection has been associated with disease severity during the acute phase and the presence of previous comorbidities, however, the clinical manifestations, the concomitant consequences and the molecular pathways supporting this clinical condition remain unknown. The aim of this study was to identify and characterize L-TPD in patients with long-COVID and elucidate the main pathways and long-term consequences attributed to this condition by analyzing clinical parameters and functional tests supported by machine learning and serum proteome profiling.

Methods

Patients with L-TPD were classified according to the results of their computer-tomography (CT) scan and diffusing capacity of the lungs for carbon monoxide adjusted for hemoglobin (DLCOc) tests at 4 and 12-months post-infection.

Results

Regarding the acute phase, our data showed that L-TPD was favored in elderly patients with hypertension or insulin resistance, supported by pathways associated with vascular inflammation and chemotaxis of phagocytes, according to computer proteomics. Then, at 4-months post-infection, clinical and functional tests revealed that L-TPD patients exhibited a restrictive lung condition, impaired aerobic capacity and reduced muscular strength. At this time point, high circulating levels of platelets and CXCL9, and an inhibited FCgamma-receptor-mediated-phagocytosis due to reduced FcγRIII (CD16) expression in CD14+ monocytes was observed in patients with L-TPD. Finally, 1-year post infection, patients with L-TPD worsened metabolic syndrome and augmented body mass index in comparison with other patient groups.

Discussion

Overall, our data demonstrated that CT scan and DLCOc identified patients with L-TPD after COVID-19. This condition was associated with vascular inflammation and impair phagocytosis of virus-antibody immune complexes by reduced FcγRIII expression. In addition, we conclude that COVID-19 survivors required a personalized follow-up and adequate intervention to reduce long-term sequelae and the appearance of further metabolic diseases.

Longitudinal Evaluation of an Integrated Post-COVID-19/Long COVID Management Program Consisting of Digital Interventions and Personal Support: Randomized Controlled Trial

BACKGROUND

The postacute COVID-19 syndrome (PACS) can be addressed with multidisciplinary approaches, including professional support and digital interventions.

OBJECTIVE

This research aimed to test whether patients who received a health care facilitation program including medical internet support from human personal pilots and digital interventions (intervention group [IG] and active control group [ACG]) would experience fewer symptoms and have higher work ability and social participation than an untreated comparison group (CompG). The second objective was to compare the impact of a diagnostic assessment and digital interventions tailored to patients' personal capacity (IG) with that of only personal support and digital interventions targeting the main symptoms (ACG).

METHODS

In total, 1020 patients with PACS were recruited. Using a randomized controlled trial design between the IG and the ACG, as well as propensity score matching to include the CompG, analyses were run with logistic regression and hierarchical-linear models.

RESULTS

Symptoms decreased significantly in all groups over time (βT1-T2=0.13, t549=5.67, P<.001; βT2-T4=0.06, t549=2.83, P=.01), with a main effect of the group (β=-.15, t549=-2.65, P=.01) and a more pronounced effect in the IG and ACG compared to the CompG (between groups: βT1-T2=0.14, t549=4.31, P<.001; βT2-T4=0.14, t549=4.57, P<.001). Work ability and social participation were lower in the CompG, but there was no significant interaction effect. There were no group differences between the IG and the ACG.

CONCLUSIONS

Empowerment through personal pilots and digital interventions reduces symptoms but does not increase work ability and social participation. More longitudinal research is needed to evaluate the effects of a diagnostic assessment. Social support and digital interventions should be incorporated to facilitate health care interventions for PACS.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05238415; https://classic.clinicaltrials.gov/ct2/show/NCT05238415.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1186/s12879-022-07584-z.

Type 2 diabetes and Covid-19: Lessons learnt, unanswered questions and hints for the future

Type 2 diabetes (T2DM) and COVID-19 represent a considerable burden of disease for patients and healthcare systems. New evidence is transpiring detailing the existence of a bidirectional relationship between T2DM and COVID-19. Alongside the acute influence of pre-existing T2DM on the course of COVID-19 and the exacerbation of dysglycemia following acute infection, long-term sequalae resulting from the synergistic interplay between the two is emerging, namely the development of COVID-induced diabetes and long-COVID in patients with pre-existing diabetes. This review presents our current understanding of the bidirectionality between these two conditions with a view to highlighting questions which remain unanswered and suggesting avenues for future research. In doing so, it emphasises critical gaps where concentrated research efforts are likely to yield the most beneficial improvements in understanding of the relationship between the two conditions, translating to tangible optimisations in care for the affected population.

Aged brain and neuroimmune responses to COVID-19: post-acute sequelae and modulatory effects of behavioral and nutritional interventions

Advanced age is one of the significant risk determinants for coronavirus disease 2019 (COVID-19)-related mortality and for long COVID complications. The contributing factors may include the age-related dynamical remodeling of the immune system, known as immunosenescence and chronic low-grade systemic inflammation. Both of these factors may induce an inflammatory milieu in the aged brain and drive the changes in the microenvironment of neurons and microglia, which are characterized by a general condition of chronic inflammation, so-called neuroinflammation. Emerging evidence reveals that the immune privilege in the aging brain may be compromised. Resident brain cells, such as astrocytes, neurons, oligodendrocytes and microglia, but also infiltrating immune cells, such as monocytes, T cells and macrophages participate in the complex intercellular networks and multiple reciprocal interactions. Especially changes in microglia playing a regulatory role in inflammation, contribute to disturbing of the brain homeostasis and to impairments of the neuroimmune responses. Neuroinflammation may trigger structural damage, diminish regeneration, induce neuronal cell death, modulate synaptic remodeling and in this manner negatively interfere with the brain functions.In this review article, we give insights into neuroimmune interactions in the aged brain and highlight the impact of COVID-19 on the functional systems already modulated by immunosenescence and neuroinflammation. We discuss the potential ways of these interactions with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and review proposed neuroimmune mechanisms and biological factors that may contribute to the development of persisting long COVID conditions. We summarize the potential mechanisms responsible for long COVID, including inflammation, autoimmunity, direct virus-mediated cytotoxicity, hypercoagulation, mitochondrial failure, dysbiosis, and the reactivation of other persisting viruses, such as the Cytomegalovirus (CMV). Finally, we discuss the effects of various interventional options that can decrease the propagation of biological, physiological, and psychosocial stressors that are responsible for neuroimmune activation and which may inhibit the triggering of unbalanced inflammatory responses. We highlight the modulatory effects of bioactive nutritional compounds along with the multimodal benefits of behavioral interventions and moderate exercise, which can be applied as postinfectious interventions in order to improve brain health.

[Long COVID-A New Challenge in Medicine: Focus on Pregnancy and Breastfeeding]

Long COVID (coronavirus disease) has been described as a new multi-organ disease, which appears to be more prevalent in women than in men. Pregnant and breastfeeding women are a special subgroup of patients to consider with long COVID, as only scarce data have been collected to date. Menstrual changes are commonly observed during or after COVID-19; some studies also attribute slight changes of cycle length to previous inoculation against the virus. Pregnant women who have a symptomatic infection with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) are at a higher risk for adverse outcomes and pregnancy-associated complications. Moreover, more and robust data are required to evaluate vertical transmission. COVID vaccines are the most effective tool against the pandemic, as they prevent infection, but also appear to be able to ease long COVID symptoms. Vaccines have been proven safe and effective in both pregnant and breastfeeding women. This article aims to present current data on long COVID in pregnant and breastfeeding women and elucidate risk factors and possible treatment options.