The emerging threat of multisystem inflammatory syndrome in adults (MIS-A) in COVID-19: A systematic review

Coronary Implications of COVID-19

Patients with SARS-CoV-2 infection carry an increased risk of cardiovascular disease encompassing various implications, including acute myocardial injury or infarction, myocarditis, heart failure, and arrhythmias. A growing volume of evidence correlates SARS-CoV-2 infection with myocardial injury, exposing patients to higher mortality risk. SARS-CoV-2 attacks the coronary arterial bed with various mechanisms including thrombosis/rupture of preexisting atherosclerotic plaque, de novo coronary thrombosis, endotheliitis, microvascular dysfunction, vasculitis, vasospasm, and ectasia/aneurysm formation. The angiotensin-converting enzyme 2 receptor plays pivotal role on the cardiovascular homeostasis and the unfolding of COVID-19. The activation of immune system, mediated by proinflammatory cytokines along with the dysregulation of the coagulation system, can pose an insult on the coronary artery, which usually manifests as an acute coronary syndrome (ACS). Electrocardiogram, echocardiography, cardiac biomarkers, and coronary angiography are essential tools to set the diagnosis. Revascularization is the first-line treatment in all patients with ACS and obstructed coronary arteries, whereas in type 2 myocardial infarction treatment of hypoxia, anemia and systemic inflammation are indicated. In patients presenting with coronary vasospasm, nitrates and calcium channel blockers are preferred, while treatment of coronary ectasia/aneurysm mandates the use of antiplatelets/anticoagulants, corticosteroids, immunoglobulin, and biologic agents. It is crucial to untangle the exact mechanisms of coronary involvement in COVID-19 in order to ensure timely diagnosis and appropriate treatment. We have reviewed the current literature and provide a detailed overview of the pathophysiology and clinical spectrum associated with coronary implications of SARS-COV-2 infection.

Multisystem inflammatory syndrome in children: A review

AIM

To comprehensively review the literature on multisystem inflammatory syndrome in children (MIS-C).

METHODS

Narrative review of relevant studies published between April 2020 and January 2024.

RESULTS

MIS-C is a SARS-CoV-2-related hyperinflammatory syndrome developing 2-6 weeks after COVID-19 in genetically susceptible individuals. Persisting fever, mucocutaneous manifestations, GI and cardiac involvement, together with lymphopenia and elevated inflammatory and cardiac markers are the main clinical features. It is believed to recognise some pathogenetic and clinical overlap with Kawasaki disease. New case definitions have been proposed after an assessment of the diagnostic performance of existing criteria; epidemiological criterion is however progressively losing its usefulness as the pandemic turns into an endemic and in the areas with the highest rates of COVID-19 vaccination. Current guidelines recommend both intravenous immunoglobulin and glucocorticoids in the first-line immunomodulatory treatment, mainly based on comparative retrospective cohorts; the actual role of biologics remains to be adequately established. Strict follow-up is mandatory, especially for those with severe cardiac involvement, as longitudinal studies evaluate the long-term evolution of cardiac damage.

CONCLUSION

In this paper, we review the epidemiological, pathogenetic, clinical and prognostic features of MIS-C, and outline the main questions which still remain unanswered after more than 3 years of research.

Multisystem Inflammatory Syndrome of the Adults (MIS-A) - The undercover threat for young adults. A systematic review and meta-analysis of medical cases

Background

COVID-19 related syndromes are not yet well described and understood. Multisystem inflammatory syndrome of the adults (MIS-A) is a recently characterized syndrome affecting multiple organs of young adults, causing serious complications, even shock and death.

Objectives

To determine the clinical characteristics, course, and complications of MIS-A in a systematic way and summarize currently used treatments.

Methods

Literature search in March 2023 in PubMed and Scopus databases. Case reports and case-series that fulfilled the CDC criteria for MIS-A were eligible for inclusion.

Results

A total of 71 patients from 60 reports were included. 66% of the patients were male and the mean age of the synthetic cohort was 32.9 years old. The majority (70.4%) of the enrolled cases had no significant medical history. MIS-A was diagnosed after a median of 4 weeks period. All but two patients presented with cardiac symptoms, while the most common secondary diagnostic criterion was abdominal pain, vomiting or diarrhea followed by shock or hypotension. Heart failure therapy and immunomodulation were used as therapeutic options. Although more than half of the cohort was admitted to the Intensive Care Unit (ICU) (n=39) only 4 deaths were reported.

Conclusion

MIS-A can affect patients independently of age, sex, and co-morbidity status, resulting in serious complications, often including severe cardiac disease, shock, acute kidney injury and sometimes death. It can occur immediately after SARS-CoV-2 acute infection until two months later, usually manifesting four weeks after acute disease.

Esophageal ulcer and multisystem inflammatory syndrome after COVID-19: A case report

BACKGROUND

Multisystem inflammatory syndrome in adults (MIS-A) is a rare but severe disease occurring several weeks after severe acute respiratory syndrome coronavirus 2 infection. It develops in adults with inflammation of different organs including the gastrointestinal tract, heart, kidneys, skin and hematopoietic system.

CASE SUMMARY

We present a 58-year-old Chinese man diagnosed with MIS-A. His chief complaints were fever, generalized fatigue and anorexia, accompanied with rashes on his back. Further examination showed cardiac, renal and liver injury. He had melena and gastroscopy indicated esophageal ulcer and severe esophagitis. Repeated blood and sputum culture did not show growth of bacteria or fungi. Antibiotic treatment was stopped due to unsatisfactory performance. His condition improved after prednisone and other supportive treatment.

CONCLUSION

Gastrointestinal involvement in MIS-A is not uncommon. Intestinal involvement predominates, and esophageal involvement is rarely reported. Esophageal ulcer with bleeding could also be a manifestation of MIS-A.

Severity predictors for multisystemic inflammatory syndrome in children after SARS-CoV-2 infection in Vietnam

Multisystemic inflammatory syndrome in children (MIS-C) might manifest in a broad spectrum of clinical scenarios, ranging from mild features to multi-organ dysfunction and mortality. However, this novel entity has a heterogenicity of data regarding prognostic factors associated with severe outcomes. The present study aimed to identify independent predictors for severity by using multivariate regression models. A total of 391 patients (255 boys and 136 girls) were admitted to Vietnam National Children's Hospital from January 2022 to June 2023. The median age was 85 (range: 2-188) months, and only 12 (3.1%) patients had comorbidities. 161 (41.2%) patients required PICU admission, and the median PICU LOS was 4 (2-7) days. We observed independent factors related to PICU admission, including CRP ≥ 50 (mg/L) (OR 2.52, 95% CI 1.39-4.56, p = 0.002), albumin ≤ 30 (g/L) (OR 3.18, 95% CI 1.63-6.02, p = 0.001), absolute lymphocyte count ≤ 2 (× 109/L) (OR 2.18, 95% CI 1.29-3.71, p = 0.004), ferritin ≥ 300 (ng/mL) (OR 2.35, 95% CI 1.38-4.01), p = 0.002), and LVEF < 60 (%) (OR 2.48, 95% CI 1.28-4.78, p = 0.007). Shock developed in 140 (35.8%) patients, especially for those decreased absolute lymphocyte ≤ 2 (× 109/L) (OR 2.48, 95% CI 1.10-5.61, p = 0.029), albumin ≤ 30 (g/L) (OR 2.53, 95% CI 1.22-5.24, p = 0.013), or LVEF < 60 (%) (OR 2.24, 95% CI 1.12-4.51, p = 0.022). In conclusion, our study emphasized that absolute lymphocyte count, serum albumin, CRP, and LVEF were independent predictors for MIS-C severity. Further well-designed investigations are required to validate their efficacy in predicting MIS-C severe cases, especially compared to other parameters. As MIS-C is a new entity and severe courses may progress aggressively, identifying high-risk patients optimizes clinicians' follow-up and management to improve disease outcomes.

Concomitant Cytomegalovirus Viraemia in Multisystem Inflammatory Syndrome in Adults (MIS-A) following COVID-19

Multisystem inflammatory syndrome in adults (MIS-A) is recognised as an infrequent complication of coronavirus disease 2019 (COVID-19). This syndrome occurs following COVID-19 infection in some individuals and is characterised by inflammation of multiple organ systems, such as the heart, liver, bowel, and lymph nodes. Cytomegalovirus (CMV) viraemia is associated primarily with immunosuppression. In COVID-19 patients, it has been reported in severe and critical cases. We present a case of an adult patient diagnosed with MIS-A and concomitant CMV viraemia.

A case of meningoencephalitis caused by multisystem inflammatory syndrome in adult SARS-CoV-2 infection

A 37-year-old woman was hospitalized with fever and consciousness disturbance. She showed systemic inflammation with stress cardiomyopathy. Brain computed tomography showed diffuse brain edema. Cerebrospinal fluid (CSF) findings revealed markedly elevated cerebrospinal fluid pressure with pleocytosis, elevated protein, and elevated interleukin 6. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nicking enzyme amplification reaction test using a nasopharyngeal swab was positive, and the patient was diagnosed with SARS-CoV-2 infection. From the negative result of the CSF SARS-CoV-2 polymerase chain reaction test and no findings of bacterial or viral infection, we diagnosed meningoencephalitis by multisystem inflammation syndrome in adults (MIS-A). Intravenous methylprednisolone pulse therapy improved her symptoms and brain edema. There have been no cases of MIS-A with meningoencephalitis, and no initial treatment strategy has been established, especially in emergency cases of suspected MIS-A. The present case suggested Early intravenous methylprednisolone pulse with anti-coronaviral therapies after the exclusion of bacterial infection would be useful in suspected MIS-A with emergent meningoencephalitis cases.

New insight into the intravenous immunoglobulin treatment in Multisystem Inflammatory Syndrome in children and adults

Within 6 months of the coronavirus pandemic, a new disease entity associated with a multisystem hyperinflammation syndrome as a result of a previous infection with the SARS-CoV-2 virus is increasingly being identified in children termed Multisystem Inflammatory Syndrome in Children (MIS-C) and more recently in adults(MIS-A). Due to its clinical similarity with Kawasaki Disease, some institutions have used intravenous immunoglobulins and steroids as first line agents in the management of the disease. We seek to find how effective intravenous immunoglobulin therapy is across these two disease entities. A comprehensive English literature search was conducted across PubMed, MEDLINE, and EMBASE databases using the keywords multisystem inflammatory syndrome in children/adults and treatment. All major online libraries concerning the diagnosis and treatment of MIS-C and MIS-A were searched. Relevant papers were read, reviewed, and analyzed. The use of intravenous immunoglobulins (IVIG) and steroids for the treatment of multisystemic inflammatory syndrome in children(MIS-C) is well established and recommended by multiple pediatric governing institutions. However, there is still no optimal treatment guideline or consensus on the use of IVIG in adults. The use of IVIG in both the child and adult populations may lower the risk of treatment failure and the need for adjunctive immunomodulatory therapy. Despite the promising results of IVIG use for the management of MIS-C and MIS-A, considering the pathophysiological differences between MIS-C and MIS-A, healthcare professionals need to further assess the differences in disease risk and treatment. The optimal dose, frequency, and duration of treatment are still unknown, more research is needed to establish treatment guidelines.

The exploration of glucocorticoid pathway based on disease severity in COVID-19 patients

Systemic inflammation is a hallmark of Coronavirus Disease 2019 (COVID-19) and is the key to the pathophysiology of its severe cases with host cytokine involvement. Glucocorticoids can moderate this inflammatory effect due to receptor binding (NRC31-the gene encoded), influencing the expression of effector genes and pro-inflammatory cytokines. Another important pathway in the processes of the immune and inflammatory responses is nuclear factor-κB (NF-κB) signaling (NFKBIA-the gene encoded). We aimed to explore the expression of genes in the glucocorticoid pathway in mild and severe COVID-19. We performed a cross-sectional, observational study on COVID-19 cases, assessing the expression of RNA in white blood cells. The Illumina® platform was used for RNA sequencing, and FASTQ data were quality-checked with Multiqc. The raw data were analyzed using CLC Genomics Workbench®. Our study included 23 patients with severe COVID-19 and 21 patients with mild COVID-19 with an average age of 49.9 ± 18.2 years old. The NR3C1 and NFKBIA expressions did not show a significantly significant difference between groups (log2 fold change 0.5, p = 0.1; 0.82, p = 0.09). However, the expressions of TSC22D3, DUSP-1, JAK-1 and MAPK-1 were significantly higher in mild cases (log2 fold change 1.3, p < 0.001; 2.6, p < 0.001; 0.9, p < 0.001; 1.48, p-value<0.001; respectively). Furthermore, the TNF, IL-1β, and IL-6 expressions were significantly lower in mild cases (log2 fold change 4.05, p < 0.001; 3.33, p < 0.001; 6.86, p < 0.001; respectively). In conclusion, our results showed that although the NRC31 and NFKBIA expressions did not show a statistically significant difference between groups, the expression of TSC22D3 was higher in mild cases. These results highlight the importance of effector genes, specifically TSC22D3, in combatting systemic inflammation. Our recent findings have the potential to lead to the identification of novel pharmacological targets that could prove to be vital in the fight against diseases associated with inflammation.

Multisystem inflammatory syndrome in adults with cardiac engagement: a case report and literature review

Background

Following infection with severe acute respiratory syndrome coronavirus, a post-infectious multisystem inflammatory syndrome in adults (MIS-A) has been identified. It affects multiple organ systems and can lead to multi-organic failure.

Case summary

This case report describes a patient with MIS-A with significant cardiac involvement including peri-myocarditis, pulmonary hypertension, right-sided heart failure, tricuspid regurgitation, and cardiogenic shock. After being diagnosed and treated correctly for MIS-A, the patient recovered completely, without any cardiac sequelae.

Discussion

The hyperinflammation in MIS-A can have cardiac engagement. Although more research is required to further clarify the underlying mechanisms, prompt diagnosis and anti-inflammatory treatment are crucial for better outcomes and cardiac recovery.

Associated organs and system with COVID-19 death with information of organ support: a multicenter observational study

BACKGROUND

The organ dysfunction that is associated with death in COVID-19 patients has not been determined in multicenter epidemiologic studies. In this study, we evaluated the major association with death, concomitant organ dysfunction, and proportion of multiple organ failure in deaths in patients with COVID-19, along with information on organ support.

METHODS

We performed an observational cohort study using the Japanese multicenter research of COVID-19 by assembling a real-world data (J-RECOVER) study database. This database consists of data on patients discharged between January 1 and September 31, 2020, with positive SARS-CoV-2 test results, regardless of intensive care unit admission status. These data were collected from the Diagnosis Procedure Combination and electronic medical records of 66 hospitals in Japan. The clinician identified and recorded the organ responsible for the death of COVID-19.

RESULTS

During the research period, 4,700 patients with COVID-19 were discharged from 66 hospitals participating in the J-RECOVER study; of which, 272 patients (5.8%) from 47 institutions who died were included in this study. Respiratory system dysfunction (87.1%) was the leading association with death, followed by cardiovascular (4.8%), central nervous (2.9%), gastrointestinal (2.6%), and renal (1.1%) dysfunction. Most patients (96.7%) who died of COVID-19 had respiratory system damage, and about half (48.9%) had multi-organ damage. Of the patients whose main association with death was respiratory dysfunction, 120 (50.6%) received mechanical ventilation.

CONCLUSION

This study showed that although respiratory dysfunction was the most common association with death in many cases, multi-organ dysfunction was associated with death due to COVID-19.

COVID-19-related multisystem inflammatory syndrome in adult: the first death in Brazil

The precise pathogenesis of COVID-19-related multisystem inflammatory syndrome remains largely elusive, despite its rarity. The syndrome symptoms often overlap with those of other infections, posing challenges for prompt diagnosis. A male patient, 34 years old, was admitted with suspicion of severe dengue, rapidly progressing to multiple organ dysfunction. Dengue tests resulted negative, and he passed away after four days. This case occurred approximately four weeks after the initial onset of COVID-19 and met all diagnostic criteria as defined by the Centers for Disease Control and Prevention. This report presents the first documented case of fatal multisystem inflammatory syndrome in adult (MIS-A) in Brazil. Recognizing the significance of suspecting this syndrome and promptly initiating treatment at an early stage are essential for minimizing damage and mortality.

Severe systemic inflammation mimicking TAFRO syndrome following COVID-19

TAFRO syndrome is a rare systemic inflammatory disease. Its pathogenesis mainly involves excessive cytokine secretion and autoimmune dysfunction. Although its etiology is unclear, some viral infections have been reported to cause it. Here, we report a case of severe systemic inflammation mimicking TAFRO syndrome that arose after COVID-19. A 61-years-old woman suffered from a continuous fever, ascites, and edema after contracting COVID-19. She developed progressive thrombocytopenia, renal failure, and elevated C-reactive protein levels. She was tentatively diagnosed with multisystem inflammatory syndrome in adults (MIS-A) and received steroid pulse therapy. However, she exhibited worsening fluid retention and progressive renal failure, which are not typical of MIS-A. A bone marrow examination showed reticulin myelofibrosis and an increased number of megakaryocytes. Although a definitive diagnosis of TAFRO syndrome was not made according to current diagnostic criteria, we determined that her symptoms were clinically consistent with those of TAFRO syndrome. Combination therapy, including steroid pulse therapy, plasma exchange, rituximab, and cyclosporine, improved her symptoms. There are pathological similarities between hyperinflammation that arises after COVID-19 and TAFRO syndrome in terms of the associated cytokine storms. COVID-19 may have triggered the development of systemic inflammation mimicking TAFRO syndrome in this case.

Multisystem Inflammatory Syndrome in an Adult on Hemodialysis with Markedly Elevated Procalcitonin and Ferritin Levels

A 21-year-old man on hemodialysis was hospitalized for coronavirus disease 2019 (COVID-19) pneumonia. After admission, he had a persistent high fever and developed erythema induratum on his extremities. Laboratory tests conducted 25 days after onset showed markedly increased procalcitonin (PCT) levels (>100 ng/mL). The patient developed impaired consciousness and hypotensive shock and required endotracheal intubation. Based on the presence of erythema induratum and multiorgan dysfunction, he was diagnosed with multisystem inflammatory syndrome (MIS). The MIS resolved after treatment with intravenous immunoglobulin and methylprednisolone. This report illustrates that MIS can occur in adults and may be accompanied by high PCT levels.

A global systematic review and meta-analysis on the emerging evidence on risk factors, clinical characteristics, and prognosis of multisystem inflammatory syndrome in adults (MIS-A)

Background

The multisystem inflammatory syndrome in adults (MIS-A) has emerged, similar to those in children associated with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) [multisystem inflammatory syndrome in children (MIS-C)]. This review aimed to analyze the risk factors, clinical course, and prognosis of MIS-A.

Methods

A comprehensive literature search was conducted using several databases for cases reporting MIS-A from 1 December 2019 till 9 September 2021. The case definitions used to identify potential cases were those recommended by the World Health Organization, Center for Disease Control, and individual country/physician classification. The meta-analysis was performed using Comprehensive Meta-Analysis (CMA) 2.2.027 and Review Manager (RevMan) 5.4.1, employing 95% confidence intervals (CI).

Results

Seventy studies were assessed for full-text eligibility, out of which 37 were included. The mean age of the study population was 32.52±10.29 years. The most common symptoms were fever (89.8%, 95% CI: 77.7-95.7%) and diarrhea (49%, 95% CI: 35.4-62.7%). Ventricular tachycardia (57.1%, 95% CI: 43.1-70.1%) was the most common electro-cardiac abnormality. The most common inflammatory marker was elevated C-reactive protein (89.8%, 95% CI: 77.7-95.7%). Abnormal echocardiogram was the most common imaging test result (commonly, ventricular dysfunction and arrhythmias), while steroids were the most administered treatment. Severe cases had a higher need for vasopressor and inotropic support and antibiotic therapy compared to the non-severe cases. One death was reported due to cardiovascular failure.

Conclusion

Our collated findings will help clinicians identify the typical presenting symptoms and optimal management of MIS-A. Further research is required to understand the long-term prognosis and the correlation between coronavirus disease 2019 (COVID-19) and MIS-A to understand its pathogenesis and clinical spectrum.

Successful Use of Granulocyte and Monocyte Adsorptive Apheresis in a Patient with Post-COVID-19 Multisystem Inflammatory Syndrome in Adults

Multisystem inflammatory syndrome in adults (MIS-A) is a life-threatening disease that can develop weeks after coronavirus disease 2019 (COVID-19). MIS-A symptoms include multiorgan involvement, especially gastrointestinal tract and heart involvement, and Kawasaki disease-like symptoms. We herein report a 44-year-old Japanese man with MIS-A who had contracted COVID-19 five weeks ago and went into shock after acute gastroenteritis, acute kidney injury, and Kawasaki disease-like symptoms. Methylprednisone pulse and high-dose intravenous immunoglobulin resulted in recovery of shock and his renal function, but diffuse ST-segment elevation on electrocardiography and pericardial effusion with a fever emerged after therapy. Additional granulocyte-monocyte adsorptive apheresis successfully ameliorated the cardiac involvement.

Clinical and biological heterogeneity of multisystem inflammatory syndrome in adults following SARS-CoV-2 infection: a case series

Importance

Multisystem inflammatory syndrome in adults (MIS-A) is a poorly understood complication of SARS-CoV-2 infection with significant morbidity and mortality.

Objective

Identify clinical, immunological, and histopathologic features of MIS-A to improve understanding of the pathophysiology and approach to treatment.

Design

Three cases of MIS-A following SARS-CoV-2 infection were clinically identified between October 2021 - March 2022 using the U.S. Centers for Disease Control and Prevention diagnostic criteria. Clinical, laboratory, imaging, and tissue data were assessed.

Findings

All three patients developed acute onset cardiogenic shock and demonstrated elevated inflammatory biomarkers at the time of hospital admission that resolved over time. One case co-occurred with new onset Type 1 diabetes and sepsis. Retrospective analysis of myocardial tissue from one case identified SARS-CoV-2 RNA. All three patients fully recovered with standard of care interventions plus immunomodulatory therapy that included intravenous immunoglobulin, corticosteroids, and in two cases, anakinra.

Conclusion

MIS-A is a severe post-acute sequela of COVID-19 characterized by systemic elevation of inflammatory biomarkers. In this series of three cases, we find that although clinical courses and co-existent diseases vary, even severe presentations have potential for full recovery with prompt recognition and treatment. In addition to cardiogenic shock, glucose intolerance, unmasking of autoimmune disease, and sepsis can be features of MIS-A, and SARS-CoV-2 myocarditis can lead to a similar clinical syndrome.

Biventricular Takotsubo Cardiomyopathy as an Unusual Presentation of SARS-CoV-2 mRNA Vaccine-Associated Multisystemic Inflammatory Syndrome

Biventricular takotsubo cardiomyopathy (BiTCM) is a rare entity, seldom reported. We describe a case of a female presenting with multisystemic inflammatory syndrome associated with the administration of a vaccine against coronavirus disease 2019 (COVID-19). In this particular case, the patient experienced the onset of symptoms shortly after receiving a COVID-19 vaccine. Early recognition of biventricular takotsubo cardiomyopathy and timely initiation of appropriate treatment are crucial. Prompt management includes stabilizing the patient's hemodynamic status, alleviating symptoms, and addressing any underlying causes, such as inflammation or immune-related responses. Close clinical surveillance is necessary to monitor the patient's cardiac function, assess response to treatment, and prevent potential complications.

A Young Adult With Multisystem Inflammatory Syndrome Following Weeks of Initial COVID-19 Respiratory Infection, With No Prior COVID-19 Vaccination: A Case Report

Multisystem inflammatory syndrome (MIS) following COVID-19, a condition primarily diagnosed in children, has also been observed less frequently in adults. It usually presents with a multitude of symptoms, mimicking a shock-like state characterized by multiple organ failure. Diagnosis often involves ruling out other conditions and timely management to mitigate morbidity and mortality. In this case, a 39-year-old unvaccinated Caucasian male patient reported symptoms of fever, chills, night sweats, diarrhea, headache, nasal congestion, and facial pain. Despite treatment with antipyretics, the fever persisted. The patient had tested positive for COVID-19 via polymerase chain reaction (PCR) six weeks prior. Clinical findings included low oxygen saturation, sinus tachycardia, abnormal liver function, elevated inflammatory markers, a negative respiratory viral panel, a negative immunologic workup, and a positive Clostridium difficile (C. difficile) PCR. Following complaints of chest pain which quickly escalated to cardiac arrest, he was diagnosed with myopericarditis. These manifestations met the multisystem inflammatory syndrome in adults (MIS-A) diagnostic criteria as stipulated by the Centers for Disease Control and Prevention. The diagnosis of MIS-A was reached through exclusion. Notably, the patient responded well to symptomatic management. Given the infrequent occurrence of MIS-A cases, even in 2023, it remains a challenging diagnosis. Despite existing guidelines for management, the recovery of this patient solely through symptomatic treatment prior to the consideration of conventional treatment is striking. The patient had concurrent infections, including a C. difficile infection, but these did not account for the overall clinical presentation, particularly the myopericarditis and positive laboratory findings.

SARS-CoV-2 Infection in Venezuelan Pediatric Patients-A Single Center Prospective Observational Study

Several studies suggest that children infected with SARS-CoV-2 have fewer clinical manifestations than adults; when they develop symptoms, they rarely progress to severe disease. Different immunological theories have been proposed to explain this phenomenon. In September 2020, 16% of the active COVID-19 cases in Venezuela were children under 19 years. We conducted a cross-sectional study of pediatric patients' immune response and clinical conditions with SARS-CoV-2 infection. The patients were admitted to the COVID-19 area of the emergency department of Dr José Manuel de los Ríos Children's Hospital (2021-2022). The lymphocyte subpopulations were analyzed by flow cytometry, and IFNγ, IL-6, and IL-10 serum concentrations were quantified using commercial ELISA assays. The analysis was conducted on 72 patients aged one month to 18 years. The majority, 52.8%, had mild disease, and 30.6% of the patients were diagnosed with MIS-C. The main symptoms reported were fever, cough, and diarrhea. A correlation was found between IL-10 and IL-6 concentrations and age group, lymphocyte subpopulations and nutritional status and steroid use, and IL-6 concentrations and clinical severity. The results suggest a different immune response depending on age and nutritional status that should be considered for treating pediatric COVID-19 patients.

Multisystem inflammatory syndrome in children: A dysregulated autoimmune disorder following COVID-19

Multisystem inflammatory syndrome in children (MIS-C) is a dysregulated autoimmune-mediated illness in genetically susceptible patients following COVID-19 with an interval of 2-6 weeks. The median age of patients with MIS-C is 6-11 years. Most common manifestations are involvement of gastrointestinal tract, cardiovascular system, hematological system, and mucocutaneous system. Respiratory tract, neurological system, musculoskeletal system, and kidney are less frequently affected. Mucocutaneous manifestations and coronary artery abnormalities characteristic for Kawasaki disease (KD) may be observed in a significant proportion of MIS-C patients that may make the differential diagnosis be difficult for some patients, especially in the post-pandemic era. The mortality rate is 1-3%. Management and prognosis of MIS-C are similar to that of KD. MIS-C and KD may share a common pathogenic process. Based on the observation of MIS-C-like illness in uninfected neonates, i.e. multisystem inflammatory syndrome in neonates, both MIS-C and KD may be a consequence of dysregulated, over-exaggerated humoral immune responses triggered by a specific infectious agent.

Is COVID-19 All That Glitters?

Over the last three years, the Coronavirus-19 disease has been a global health emergency, playing a primary role in the international scientific community. Clinical activity and scientific research have concentrated their efforts on facing the pandemic, allowing the description of novel pathologies correlated to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), such as the Multisystemic Inflammatory Syndrome in Children and Adults (MIS-C, MIS-A). Conversely, this shift of attention to COVID-19 disease and its complications could, in some cases, have delayed and underestimated the diagnosis of diseases not associated with SARS-CoV-2, including rare diseases. Here we describe the diagnostic process that led to the definition of a rare vasculitis in a young woman with a recent clinical history of SARS-CoV-2.

Multisystem inflammatory syndrome in neonates (MIS-N): a systematic review

Recently, a new pattern of multisystem inflammatory syndrome following an infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged globally. The initial cases were described in the adult population followed by sporadic cases in the pediatric population also. By the end of 2020, similar reports were recognised in the neonatal age group. The purpose of this study was to systematically review clinical characteristics, laboratory parameters, treatment, and outcomes of neonates with multisystem inflammatory syndrome in neonates (MIS-N). A systematic review was conducted after registering with PROSPERO and electronic databases including MEDLINE, EMBASE, PubMed, SCOPUS, Google Scholar, and Web of Science were searched from January 1st 2020 till September 30th 2022. A total of 27 studies describing 104 neonates were analysed. The mean gestation age and birth weight was 35.9 ± 3.3 weeks and 2255.7 ± 783.7 g respectively. A large proportion (91.3%) of the reported cases belonged to the South-East Asian region. The median age of presentation was 2 days (range: 1-28 days) with cardiovascular system being the predominant system involved in 83.65% followed by respiratory (64.42%). Fever was noted in only 20.2%. Commonly elevated inflammatory markers were IL-6 in 86.7% and D-dimer in 81.1%. Echocardiographic evaluation suggested ventricular dysfunction in 35.8% and dilated coronary arteries in 28.3%. Evidence of SARS-CoV-2 antibodies (IgG or IgM) was seen in 95.9% neonates and evidence of maternal SARS-CoV-2 infection, either as history of COVID infection or positive antigen or antibody test, was noted in 100% of the cases. Early MIS-N was reported in 58 (55.8%) cases, late MIS-N in 28 (26.9%), and 18 cases (17.3%) did not report the timing of presentation. There was a statistically increased proportion of preterm infants (67.2%, p < 0.001), and a trend towards increased low birth weight infants, in the early MIS-N group when compared to the infants with late MIS-N. Fever (39.3%), central nervous system (50%), and gastrointestinal manifestations (57.1%) were significantly higher in the late MIS-N group (p = 0.03, 0.02, 0.01 respectively). The anti-inflammatory agents used for the treatment of MIS-N included steroids 80.8% which were given for a median of 10 (range 3-35) days and IVIg in 79.2% with a median of 2 (range 1-5) doses. The outcomes were available for 98 cases, of whom 8 (8.2%) died during treatment in hospital and 90 (91.8%) were successfully discharged home.   Conclusion: MIS-N has a predilection for late preterm males with predominant cardiovascular involvement. The diagnosis is challenging in neonatal period due to overlap with neonatal morbidities and a high risk of suspicion is warranted, especially in presence of supportive maternal and neonatal clinical history. The major limitation of the review was inclusion of case reports and case series, and highlights need of global registries for MIS-N. What is Known: • A new pattern of multisystem inflammatory syndrome following SARS-CoV-2 infection has emerged in adult population with sporadic cases now being reported in neonates. What is New: • MIS-N is an emerging condition with a heterogeneous spectrum and has a predilection for late preterm male infants. Cardiovascular system is the predominant system involved  followed by respiratory, however fever remains an uncommon presentation unlike other age-groups. There are two subtypes based on timing of presentation, with early MIS-N being reported more in preterm and low-birth weight infants.

Multisystem Inflammatory Syndrome in Adults Associated with Recent Infection with COVID-19

Multisystem inflammatory syndrome in adults (MIS-A) is an uncommon but severe and still understudied post-infectious complication of COVID-19. Clinically, the disease manifests itself most often 2-6 weeks after overcoming the infection. Young and middle-aged patients are especially affected. The clinical picture of the disease is very diverse. The dominant symptoms are mainly fever and myalgia, usually accompanied by various, especially extrapulmonary, manifestations. Cardiac damage (often in the form of cardiogenic shock) and significantly increased inflammatory parameters are often associated with MIS-A, while respiratory symptoms, including hypoxia, are less frequent. Due to the seriousness of the disease and the possibility of rapid progression, the basis of a successful treatment of the patient is early diagnosis, based mainly on anamnesis (overcoming the disease of COVID-19 in the recent past) and clinical symptoms, which often imitate other severe conditions such as, e.g., sepsis, septic shock, or toxic shock syndrome. Because of the danger of missing the treatment, it is necessary to initiate it immediately after the suspicion of MIS-A is expressed, without waiting for the results of microbiological and serological examinations. The cornerstone of pharmacological therapy is the administration of corticosteroids and intravenous immunoglobulins, to which the majority of patients clinically react. In this article, the authors describe the case report of a 21-year-old patient admitted to the Clinic of Infectology and Travel Medicine for febrility up to 40.5 °C, myalgia, arthralgia, headache, vomiting, and diarrhea three weeks after overcoming COVID-19. However, as part of the routine differential diagnosis of fevers (imaging and laboratory examinations), their cause was not clarified. Due to the overall worsening of the condition, the patient was transferred to the ICU with suspicion of developing MIS-A (he met all clinical and laboratory criteria). Given the above, reserve antibiotics, intravenous corticosteroids, and immunoglobulins were added to the treatment due to the risk of missing them, with a good clinical and laboratory effect. After stabilizing the condition and adjusting the laboratory parameters, the patient was transferred to a standard bed and sent home.

COVID-19 in the Asia Pacific: Impact on climate change, allergic diseases and One Health

Climate change and environmental factors such as air pollution and loss of biodiversity are known to have a major impact not only on allergic diseases but also on many noncommunicable diseases. Coronavirus disease 2019 (COVID-19) resulted in many environmental changes during the different phases of the pandemic. The use of face masks, enhanced hand hygiene with hand rubs and sanitizers, use of personal protective equipment (gowns and gloves), and safe-distancing measures, reduced the overall incidence of respiratory infections and other communicable diseases. Lockdowns and border closures resulted in a significant reduction in vehicular traffic and hence environmental air pollution. Paradoxically, the use of personal protective equipment and disposables contributed to an increase in environmental waste disposal and new problems such as occupational dermatoses, especially among healthcare workers. Environmental changes and climate change over time may impact the exposome, genome, and microbiome, with the potential for short- and long-term effects on the incidence and prevalence of the allergic disease. The constant use and access to mobile digital devices and technology disrupt work-life harmony and mental well-being. The complex interactions between the environment, genetics, immune, and neuroendocrine systems may have short- and long-term impact on the risk and development of allergic and immunologic diseases in the future.

Immune and coagulation profiles in 3 adults with multisystem inflammatory syndrome

Introduction: There is a paucity of information on the cytokine, complement, endothelial activation, and coagulation profiles of multisystem inflammatory syndrome in adults (MIS-A), a rare but serious complication following recovery from SARS-CoV-2 infection. We aim to examine the immune biomarker and coagulation profiles in association with the clinical presentation and course of MIS-A. Method: The clinical features of MIS-A patients admitted to our tertiary hospital were documented. Their levels of interleukin (IL)-1β, IL-6, IL-10, IL-17, IL-18, interferon-α (IFN-α), IFN-γ, interferon gamma-induced protein 10 (IP-10), tumour necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, complement activation product (complement 5a [C5a]), and endothelial biomarker intercellular adhesion molecule-1 (ICAM-1) levels were assayed. The haemostatic profile was assessed with standard coagulation testing and thromboelastography. Results: Three male patients were diagnosed with MIS-A at our centre from January to June 2022 with a median age of 55 years. All had tested positive for SARS-CoV-2 12–62 days prior to MIS-A presentation, with gastrointestinal and cardiovascular systems as the most commonly involved. Levels of IL-6, IL-10, IL-18, IP-10 and MCP-1 were raised whereas IL-1β, IFN-α, IFN-γ, IL-17 and TNF-α remained normal. Markedly elevated levels of C-reactive protein (CRP), ferritin and ICAM-1 were present in all. C5a was elevated in 2 patients. A hypercoagulable state was demonstrated by raised levels of D-dimer, factor VIII, von Willebrand factor antigen, and ristocetin cofactor with corresponding raised parameters in thromboelastography in the 2 patients who had their coagulation profile assessed. Conclusion: MIS-A patients demonstrate activation of pro-inflammatory cytokines, endotheliopathy, complement hyperactivation and hypercoagulability. Keywords: COVID-19, cytokines, hypercoagulability, hyperinflammatory syndrome

Multisystem inflammatory syndrome in adults: Characteristics, treatment, and outcomes

Following the rapidly increasing number of multisystem inflammatory syndromes in children (MIS-C), a similar clinical scenario has been observed in adult patients. Although its prevalence is low and probably related to underdiagnosis, its development can be associated with high mortality. Multisystem inflammatory syndrome in adults (MIS-A) can develop following both asymptomatic and symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and in previously healthy people. Like MIS-C, MIS-A is a multisystem disease that can involve the cardiovascular, respiratory, gastrointestinal, dermatologic, hematologic, and neurologic systems. In addition to the clinical manifestations, the diagnosis of MIS-A requires laboratory evidence of inflammation and SARS-CoV-2 infection. The appropriate treatment for MIS-A remains unclear; anti-inflammatory agents, including intravenous immunoglobulin and corticosteroids, are commonly used. However, there are still many unknowns regarding MIS-A. Further studies are needed to determine the true prevalence, pathogenesis, and effective treatment for MIS-A.

Autoimmunity and Immunodeficiency in Severe SARS-CoV-2 Infection and Prolonged COVID-19

SARS-CoV-2 causes the complex and heterogeneous illness known as COVID-19. The disease primarily affects the respiratory system but can quickly become systemic, harming multiple organs and leading to long-lasting sequelae in some patients. Most infected individuals are asymptomatic or present mild symptoms. Antibodies, complement, and immune cells can efficiently eliminate the virus. However, 20% of individuals develop severe respiratory illness and multiple organ failure. Virus replication has been described in several organs in patients who died from COVID-19, suggesting a compromised immune response. Immunodeficiency and autoimmunity are responsible for this impairment and facilitate viral escape. Mutations in IFN signal transduction and T cell activation are responsible for the inadequate response in young individuals. Autoantibodies are accountable for secondary immunodeficiency in patients with severe infection or prolonged COVID-19. Antibodies against cytokines (interferons α, γ and ω, IL1β, IL6, IL10, IL-17, IL21), chemokines, complement, nuclear proteins and DNA, anticardiolipin, and several extracellular proteins have been reported. The type and titer of autoantibodies depend on age and gender. Organ-specific autoantibodies have been described in prolonged COVID-19. Their role in the disease is under study. Autoimmunity and immunodeficiency should be screened as risk factors for severe or prolonged COVID-19.

Pathogenesis and Preventive Tactics of Immune-Mediated Non-Pulmonary COVID-19 in Children and Beyond

The COVID-19 pandemic has evolved to immune escape and threatened small children and the elderly with a higher severity and fatality of non-pulmonary diseases. These life-threatening non-pulmonary COVID-19 diseases such as acute necrotizing encephalopathies (ANE) and multisystem inflammatory syndrome in children (MIS-C) are more prevalent in children. However, the mortality of multisystem inflammatory syndrome in adults (MIS-A) is much higher than that of MIS-C although the incidence of MIS-A is lower. Clarification of immunopathogenesis and genetic susceptibility of inflammatory non-pulmonary COVID-19 diseases would provide an appropriate guide for the crisis management and prevention of morbidity and fatality in the ongoing pandemic. This review article described three inflammatory non-pulmonary COVID-19 diseases including (1) meningoencephalitis (ME), (2) acute necrotizing encephalopathies (ANE), and (3) post-infectious multisystem inflammatory syndrome in children (MIS-C) and in adults (MIS-A). To prevent these life-threatening non-pulmonary COVID-19 diseases, hosts carrying susceptible genetic variants should receive prophylactic vaccines, avoid febrile respiratory tract infection, and institute immunomodulators and mitochondrial cocktails as early as possible.

SARS-CoV-2-related Multisystem Inflammatory Syndrome in Adult complicated by myocarditis and cardiogenic shock

Multisystem Inflammatory Syndrome in Adult (MIS-A) is a rare COVID-19 complication, presenting as fever with laboratory evidence of inflammation, severe illness requiring hospitalization and multisystem organ involvement. We report on a 25-year-old man presenting with fever, rash, abdominal pain, diarrhoea and vomiting following prior asymptomatic COVID-19 infection. He developed refractory shock and type 1 respiratory insufficiency requiring mechanical ventilation. Diagnostic testing revealed significant inflammation, anemia, thrombocytopenia, acute kidney injury, hepatosplenomegaly, colitis, lymphadenopathy and myocarditis necessitating inotropy. Ventilatory, vasopressor and inotropic support was weaned following pulse corticosteroids and intravenous immunoglobulins. Heart failure therapy was started. Short-term follow-up shows resolution of inflammation and cardiac dysfunction.

Pathogenic Connections in Post-COVID Conditions: What Do We Know in the Large Unknown? A Narrative Review

The coronavirus 2019 (COVID-19) disease has long-term effects, known as post-COVID conditions (PCC) or long-COVID. Post-COVID-19 syndrome is defined by signs and symptoms that occur during or after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection which persist for more than 12 weeks and cannot be supported by an alternative diagnosis. The cardiovascular damage caused by COVID-19 in the severe forms of the disease is induced by severe systemic inflammation, considered to be one of the causes of myocardial lesions, with increased levels of circulating cytokines and toxic response mediators. We have focused on conditions that can induce long-COVID-19, or multisystem inflammatory syndrome in adults or children (MIS-C/MIS-A), with an emphasis on endocrinological and metabolic disorders. Although described less frequently in children than in adults, long-COVID syndrome should not be confused with MIS-C, which is an acute condition characterized by multisystem involvement and paraclinical evidence of inflammation in a pediatric patient who tested positive for SARS-CoV-2. At the same time, we mention that the MIS-A symptoms remit within a few weeks, while the duration of long-COVID is measured in months. Long-COVID syndrome, along with its complications, MIS-A and MIS-C, represents an important challenge in the medical community. Underlying comorbidities can expose both COVID-19 adult and pediatric patients to a higher risk of negative outcomes not only during, but in the aftermath of the SARS-CoV-2 infection as well.