Features of Intestinal Disease Associated With COVID-Related Multisystem Inflammatory Syndrome in Children

Pathologic Analysis of Twenty-one Appendices From Children With Multisystem Inflammatory Syndrome Compared to Specimens of Acute Appendicitis: A Cross-sectional Study

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a rare, severe complication of coronavirus disease 2019, commonly involving the gastrointestinal tract. Some children with MIS-C undergo appendectomy before the final diagnosis. There are several hypotheses explaining the pathomechanism of MIS-C, including the central role of the viral antigen persistence in the gut, associated with lymphocyte exhaustion. We aimed to examine appendectomy specimens from MIS-C patients and assess their pathologic features, as well as the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens.

METHODS

In this cross-sectional study we included 21 children with MIS-C who underwent appendectomy. The control group included 21 sex- and age-matched children with acute appendicitis (AA) unrelated to SARS-CoV-2 infection. Histologic evaluation of appendiceal specimens included hematoxylin and eosin staining and immunohistochemical identification of lymphocyte subpopulations, programmed cell death protein-1 (PD-1) and SARS-CoV-2 nucleocapsid antigen.

RESULTS

Appendices of MIS-C patients lacked neutrophilic infiltrate of muscularis propria typical for AA (14% vs. 95%, P < 0.001). The proportion of CD20+ to CD5+ cells was higher in patients with MIS-C (P = 0.04), as was the proportion of CD4+ to CD8+ (P < 0.001). We found no proof of SARS-CoV-2 antigen presence, nor lymphocyte exhaustion, in the appendices of MIS-C patients.

CONCLUSIONS

The appendiceal muscularis of patients with MIS-C lack edema and neutrophilic infiltration typical for AA. SARS-CoV-2 antigens and PD-1 are absent in the appendices of children with MIS-C. These findings argue against the central role of SARS-CoV-2 persistence in the gut and lymphocyte exhaustion as the major triggers of MIS-C.

Long COVID-19 gastrointestinal related disorders and traditional Chinese medicine: A network target-based approach

The significant number of individuals impacted by the pandemic makes prolonged symptoms after COVID-19 a matter of considerable concern. These are numerous and affect multiple organ systems. According to the World Health Organization (WHO), prolonged gastrointestinal issues are a crucial part of post-COVID-19 syndrome. The resulting disruption of homeostasis underscores the need for a therapeutic approach based on compounds that can simultaneously affect more than one target/node. The present review aimed to check for nutraceuticals possessing multiple molecular mechanisms helpful in relieving Long COVID-19-specific gastrointestinal symptoms. Specific plants used in Keywords Chinese Medicine (TCM) expected to be included in the WHO Global Medical Compendium were selected based on the following criteria: (1) they are widely used in the Western world as natural remedies and complementary medicine adjuvants; (2) their import and trade are regulated by specific laws that ensure quality and safety (3) have the potential to be beneficial in alleviating intestinal issues associated with Long COVID-19. Searches were performed in PubMed, Elsevier, Google Scholar, Scopus, Science Direct, and ResearchGate up to 2023. Cinnamomum cassia, Glycyrrhiza uralensis, Magnolia officinalis, Poria cocos, Salvia miltiorrhiza, Scutellaria baicalensis, and Zingiber officinalis were identified as the most promising for their potential impact on inflammation and oxidative stress. Based on the molecular mechanisms of the phytocomplexes and isolated compounds of the considered plants, their clinical use may lead to benefits in gastrointestinal diseases associated with Long COVID-19, thanks to a multiorgan and multitarget approach.

Evaluation of acute terminal ileitis in children before and during the COVID-19 pandemic

OBJECTIVES

The aim of this study was to examine the clinical features of acute terminal ileitis in children and evaluate its rate before and during the COVID-19 pandemic.

METHODS

This retrospective study was performed in our pediatric emergency department between 2018 and 2022. The records of 5363 patients who required abdominal imaging due to acute abdomen were analyzed, and 143 patients with terminal ileitis were included. The rate and etiological causes were compared during and before the COVID-19 pandemic.

RESULTS

The rate of acute terminal ileitis has increased over the years. The fastest increase was in 2021, when the COVID-19 pandemic was experienced. While 59 (41.2%) patients showed acute nonspecific ileitis, the most common etiologic cause that could be identified was acute gastroenteritis. It was determined that multisystem inflammatory syndrome in children was among the causes of ileitis after the COVID-19 pandemic and was one of the top three causes.

CONCLUSIONS

Acute terminal ileitis, which has many etiologies, is one of the rare radiological findings in acute abdominal pain. Examination and laboratory findings are not specific. Guidelines are needed for the investigation of the underlying etiology of acute terminal ileitis in children. The incidence of acute terminal ileitis is increasing, and the increase has been found to be faster after the COVID-19 pandemic.

Cell-free DNA reveals distinct pathology of multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) is a rare but life-threatening hyperinflammatory condition induced by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes pediatric COVID-19 (pCOVID-19). The relationship of the systemic tissue injury to the pathophysiology of MIS-C is poorly defined. We leveraged the high sensitivity of epigenomics analyses of plasma cell-free DNA (cfDNA) and plasma cytokine measurements to identify the spectrum of tissue injury and glean mechanistic insights. Compared with pediatric healthy controls (pHCs) and patients with pCOVID-19, patients with MIS-C had higher levels of cfDNA primarily derived from innate immune cells, megakaryocyte-erythroid precursor cells, and nonhematopoietic tissues such as hepatocytes, cardiac myocytes, and kidney cells. Nonhematopoietic tissue cfDNA levels demonstrated significant interindividual variability, consistent with the heterogenous clinical presentation of MIS-C. In contrast, adaptive immune cell-derived cfDNA levels were comparable in MIS-C and pCOVID-19 patients. Indeed, the cfDNA of innate immune cells in patients with MIS-C correlated with the levels of innate immune inflammatory cytokines and nonhematopoietic tissue-derived cfDNA, suggesting a primarily innate immunity-mediated response to account for the multisystem pathology. These data provide insight into the pathogenesis of MIS-C and support the value of cfDNA as a sensitive biomarker to map tissue injury in MIS-C and likely other multiorgan inflammatory conditions.

Multisystem inflammatory syndrome in children: another COVID-19 sequel

With the rapid expansion of the COVID-19 pandemic, the disease burden and its consequences on the paediatric population has been progressively recognised. Although COVID-19 infection in children presents as asymptomatic to mild illness, instances of hyperinflammation and multi-organ involvement following the viral infection have been described. This condition, known as the multisystem inflammatory syndrome in children (MIS-C), has gained a wide global attention. Despite the global efforts to uncover the disease characteristics and management, a clear pathogenesis and a unified treatment regimen have not been reached yet. This paper tackles the epidemiology of the MIS-C, discusses its suggested pathogenesis, drives through its varying clinical presentations, and evaluates the different treatment regimens employed in managing MIS-C.

Coronavirus disease 2019 and gastrointestinal disorders in children

During the past 3 years, the coronavirus disease 2019 (COVID-19) pandemic has had a great impact on people all over the world. However, it has become evident that disease manifestations and severity differ across age groups. Most children have a milder disease course than adults but possibly more pronounced gastrointestinal (GI) symptoms. Given the child's developing immune system, the impact of COVID-19 on disease development may differ compared to adults. This study reviews the potential bi-directional relationship between COVID-19 and GI diseases in children, focusing on common pediatric conditions such as functional GI disorders (FGID), celiac disease (CeD), and inflammatory bowel disease (IBD). Children with GI diseases, in general, and CeD and IBD, in particular, do not seem to have an increased risk of severe COVID-19, including risks of hospitalization, critical care need, and death. While infections are considered candidate environmental factors in both CeD and IBD pathogenesis, and specific infectious agents are known triggers for FGID, there is still not sufficient evidence to implicate COVID-19 in the development of either of these diseases. However, given the scarcity of data and the possible latency period between environmental triggers and disease development, future investigations in this field are warranted.

Antibody response in children with multisystem inflammatory syndrome related to COVID-19 (MIS-C) compared to children with uncomplicated COVID-19

Objectives

To comprehensively analyze the quality of the antibody response between children with Multisystem inflammatory syndrome (MIS-C) and age-matched controls at one month after SARS-CoV-2 exposure, and infected in the same time-period.

Methods

Serum from 20 MIS-C children at admission, and 14 control children were analyzed. Antigen specific antibody isotypes and subclasses directed against various antigens of SARS-CoV-2 as well as against human common coronavirus (HCoVs) and commensal or pathogenic microorganisms were assessed by a bead-based multiplexed serological assay and by ELISA. The functionality of these antibodies was also assessed using a plaque reduction neutralization test, a RBD-specific avidity assay, a complement deposition assay and an antibody-dependent neutrophil phagocytosis (ADNP) assay.

Results

Children with MIS-C developed a stronger IgA antibody response in comparison to children with uncomplicated COVID-19, while IgG and IgM responses are largely similar in both groups. We found a typical class-switched antibody profile with high level of IgG and IgA titers and a measurable low IgM due to relatively recent SARS-CoV-2 infection (one month). SARS-CoV-2-specific IgG antibodies of MIS-C children had higher functional properties (higher neutralization activity, avidity and complement binding) as compared to children with uncomplicated COVID-19. There was no difference in the response to common endemic coronaviruses between both groups. However, MIS-C children had a moderate increase against mucosal commensal and pathogenic strains, reflecting a potential association between a disruption of the mucosal barrier with the disease.

Conclusion

Even if it is still unclear why some children develop a MIS-C, we show here that MIS-C children produce higher titers of IgA antibodies, and IgG antibodies with higher functionality, which could reflect the local gastro-intestinal mucosal inflammation potentially induced by a sustained SARS-CoV-2 gut infection leading to continuous release of SARS-CoV-2 antigens.

The Impact of COVID-19 Infection on Miscellaneous Inflammatory Disorders of the Gastrointestinal Tract

The novel coronavirus pandemic of COVID-19 has emerged as a highly significant recent threat to global health with about 600,000,000 known infections and more than 6,450,000 deaths worldwide since its emergence in late 2019. COVID-19 symptoms are predominantly respiratory, with mortality largely related to pulmonary manifestations, but the virus also potentially infects all parts of the gastrointestinal tract with related symptoms and manifestations that affect patient treatment and outcome. COVID-19 can directly infect the gastrointestinal tract because of the presence of widespread angiotensin-converting enzyme 2 receptors in the stomach and small intestine that can cause local COVID-19 infection and associated inflammation. This work reviews the pathopysiology, clinical manifestations, workup, and treatment of miscellaneous inflammatory disorders of the gastrointestinal tract other than inflammatory bowel disease.

Terminal ileitis and cytotoxic lesion of corpus callosum as the presenting features of Multisystem inflammatory syndrome in children (MIS-C): a case report

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a post-viral inflammatory vasculopathy characterized by persistent fever, multiorgan dysfunction, significant laboratory markers of inflammation, lack of an alternative diagnosis, and prior SARS-CoV-2 infection or exposure in children and adolescents. The most common early symptoms include a prolonged fever, as well as dermatologic, mucocutaneous, and gastrointestinal symptoms such abdominal pain, vomiting, and diarrhea.

CASE PRESENTATION

We present a pediatric patient with multisystem inflammatory syndrome with the development of abdominal pain and seizure who was found to have a circumferential wall thickening of the terminal ileum and ileocecal junction in abdominal CT scan. The brain MRI of the patient showed cytotoxic lesions of the corpus callosum (CLOCC) which had hypersignal intensity with a few diffusion restrictions in the splenium of the corpus callosum.

CONCLUSION

This case is being reported to raise awareness of MIS-C presenting characteristics. Given the rising number of MIS-C patients and a lack of understanding regarding early diagnostic clinical characteristics and therapy, further research into clinical presentations, treatment, and outcomes is urgently needed.

Update on the treatment of multisystem inflammatory syndrome in children associated with COVID-19

In late 2019, SARS-CoV-2 was detected in China and spread worldwide. In rare cases, children who were infected with COVID-19 may develop multisystem inflammatory syndrome (MIS-C), which could have higher mortality than COVID-19 itself. Therefore, diagnosis and management are critical for treatment. Specifically, most of the initial treatment options of MIS-C choose intravenous immunoglobulin (IVIG) and steroids as the first-line treatment for patients. Moreover, antagonists of some cytokines are used as potential future therapeutics. Of note, therapeutic plasmapheresis can be used as a treatment for refractory severe MIS-C. We believe that each patient, especially those with comorbid conditions, should have individualized treatment based on both multidisciplinary consensus approach and expert opinion.

Imaging of Right Lower Quadrant Pain in Children and Adolescents: AJR Expert Panel Narrative Review

Right lower quadrant (RLQ) pain is a common clinical presentation in children, and accurate clinical diagnosis remains challenging given that this nonspecific presentation is associated with numerous surgical and nonsurgical conditions. The broad differential diagnosis varies by patient age and sex. Important considerations in the selection of a diagnostic imaging strategy include the sequencing, performance, and cost of tests. This article provides a comprehensive narrative review of the diagnostic imaging of RLQ pain in children and adolescents, including a discussion of the complementary roles of ultrasound, CT, and MRI; description of key imaging findings based on available evidence; and presentation of salient differential diagnoses. Subspecialized pediatric emergency medicine and surgical perspectives are also provided as further clinical insight into this common, but often challenging, scenario. Finally, the current status of imaging of RLQ pain in children and adolescents is summarized on the basis of expert consensus.

The pathogenesis of coronavirus-19 disease

Severe acute respiratory syndrome-associated coronavirus-2 (SARS-CoV-2) is the causal agent of coronavirus disease-2019 (COVID-19), a systemic illness characterized by variably severe pulmonary symptoms, cardiac conduction abnormalities, diarrhea, and gastrointestinal bleeding, as well as neurologic deficits, renal insufficiency, myalgias, endocrine abnormalities, and other perturbations that reflect widespread microvascular injury and a pro-inflammatory state. The mechanisms underlying the various manifestations of viral infection are incompletely understood but most data suggest that severe COVID-19 results from virus-driven perturbations in the immune system and resultant tissue injury. Aberrant interferon-related responses lead to alterations in cytokine elaboration that deplete resident immune cells while simultaneously recruiting hyperactive macrophages and functionally altered neutrophils, thereby tipping the balance from adaptive immunity to innate immunity. Disproportionate activation of these macrophages and neutrophils further depletes normal activity of B-cells, T-cells, and natural killer (NK) cells. In addition, this pro-inflammatory state stimulates uncontrolled complement activation and development of neutrophil extracellular traps (NETS), both of which promote the coagulation cascade and induce a state of “thrombo-inflammation”. These perturbations have similar manifestations in multiple organ systems, which frequently show pathologic findings related to microvascular injury and thrombosis of large and small vessels. However, the pulmonary findings in patients with severe COVID-19 are generally more pronounced than those of other organs. Not only do they feature inflammatory thromboses and endothelial injury, but much of the parenchymal damage stems from failed maturation of alveolar pneumocytes, interactions between type 2 pneumocytes and non-resident macrophages, and a greater degree of NET formation. The purpose of this review is to discuss the pathogenesis underlying organ damage that can occur in patients with SARS-CoV-2 infection. Understanding these mechanisms of injury is important to development of future therapies for patients with COVID-19, many of which will likely target specific components of the immune system, particularly NET induction, pro-inflammatory cytokines, and subpopulations of immune cells.

A complicated case of terminal ileitis post-COVID-19 infection requiring bowel resection

Since the beginning of the COVID-19 pandemic, there have been reports of children developing systemic hyperinflammatory response to COVID-19 infection, known as Paediatric Inflammatory Multisystem Syndrome Temporally associated with SARS-COV-2 (PIMS-TS). Here we would like to discuss a case of a 15-year-old male with PIMS-TS presenting as complicated terminal ileitis, requiring ileocaecal resection. Histopathologic findings of the ileocaecal specimen revealed thickened bowel mucosa, with features of granulomatous inflammation similar to Crohn’s disease, without features of intestinal vasculitis or viral particles. His post-operative course was complicated by fresh rectal bleeding, requiring urgent blood transfusion and endoscopy. Source of bleeding was not identified and his bleeding self-resolved. Gut biopsies of the remaining bowel taken during endoscopy were normal. Although this case suggests that the inflammatory process is focal to the terminal ileum with a good short-term prognosis, further follow-up is required to assess for long-term effects and risks of bowel disease.

Gastrointestinal Manifestations in Hospitalized Children With Acute SARS-CoV-2 Infection and Multisystem Inflammatory Condition: An Analysis of the VIRUS COVID-19 Registry

BACKGROUND

Describe the incidence and associated outcomes of gastrointestinal (GI) manifestations of acute coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in hospitalized children (MIS-C).

METHODS

Retrospective review of the Viral Infection and Respiratory Illness Universal Study registry, a prospective observational, multicenter international cohort study of hospitalized children with acute COVID-19 or MIS-C from March 2020 to November 2020. The primary outcome measure was critical COVID-19 illness. Multivariable models were performed to assess for associations of GI involvement with the primary composite outcome in the entire cohort and a subpopulation of patients with MIS-C. Secondary outcomes included prolonged hospital length of stay defined as being >75th percentile and mortality.

RESULTS

Of the 789 patients, GI involvement was present in 500 (63.3%). Critical illness occurred in 392 (49.6%), and 18 (2.3%) died. Those with GI involvement were older (median age of 8 yr), and 18.2% had an underlying GI comorbidity. GI symptoms and liver derangements were more common among patients with MIS-C. In the adjusted multivariable models, acute COVID-19 was no associated with the primary or secondary outcomes. Similarly, despite the preponderance of GI involvement in patients with MIS-C, it was also not associated with the primary or secondary outcomes.

CONCLUSIONS

GI involvement is common in hospitalized children with acute COVID-19 and MIS-C. GI involvement is not associated with critical illness, hospital length of stay or mortality in acute COVID-19 or MIS-C.

Paediatric inflammatory multisystem syndrome: temporally associated with SARS-CoV-2 (PIMS-TS) — A mimic of intra-abdominal malignancy

We report the case of a school-aged boy who presented with clinical features suggesting acute appendicitis. However, further imaging which included CT, demonstrated an inflammatory mass involving the transverse colon raising the suspicion of lymphoma. He then developed intestinal obstruction, and in view of the rapid progression of the disease, he was thought to have non-Hodgkin’s lymphoma. He underwent an open excisional biopsy, which revealed a necroinflammatory process and no suggestion of lymphoma or an alternative malignancy or specific diagnosis. His steroid treatment was stopped, and he made a good recovery postoperatively. Positive COVID-19 antibodies, positive response to steroids, results and clinical features were consistent with paediatric inflammatory multisystem syndrome (PIMS-TS), with extensive investigation not offering an alternative diagnosis.

While PIMS-TS is a relatively new entity, we believe that this case highlights the importance of it being considered a differential diagnosis of a child presenting with an inflammatory mass.

Is It Inflammatory Bowel Disease Flare or Pediatric Inflammatory Multisystem Syndrome Temporally Associated with COVID-19?

Background: Pediatric inflammatory multisystem syndrome temporally associated with COVID-19/multi-system inflammatory syndrome in children (PIMS-TS/MIS-C) is a potentially life-threatening complication of SARS-CoV-2 infection in children. Gastrointestinal manifestations are prominent in children with PIMS-TS/MIS-C. Thus, it is challenging to differentiate this condition from an exacerbation of inflammatory bowel disease (IBD). We aimed to present the clinical characteristics, and diagnostic and therapeutic difficulties in patients with overlapping IBD and PIMS-TS/MIS-C; Methods: We reviewed medical records of children hospitalized due to overlapping IBD and PIMS-TS/MIS-C in a single pediatric hospital from December 2020 to December 2021; Results: There were four children with overlapping IBD flare and PIMS-TS/MIS-C. In three cases, IBD recognition preceded PIMS-TS/MIS-C onset and PIMS-TS/MIS-C occurred during anti-inflammatory therapy of IBD. All children presented with gastrointestinal symptoms at PIMS-TS/MIS-C onset. All patients received IVIG and ASA treatment. In three children there was a need to use steroids to resolve PIMS-TS/MIS-C symptoms. One child was vaccinated against COVID-19; Conclusions: SARS-CoV-2 infection may affect patients with underlying inflammatory conditions such as IBD, inducing systemic symptoms of PIMS-TS/MIS-C, and probably triggering IBD after PIMS-TS/MIS-C. The resemblance of clinical presentations is the main source of diagnostic and therapeutic challenges in PIMS-TS/MIS-C in patients with underlying IBD.

Comparison of Multisystem Inflammatory Syndrome (MIS-C) and Dengue in Hospitalized Children

OBJECTIVE

Multisystem inflammatory syndrome (MIS-C) in children is a febrile illness that has overlapping presentation with other locally prevalent illnesses. Clinicolaboratory profile of children admitted with MIS-C and dengue were compared to understand their presentation at the outset.

METHODS

This was a retrospective study of children ≤ 12 y admitted with MIS-C (WHO definition) or laboratory-confirmed dengue between August 2020 and January 2021 at a tertiary center in North India.

RESULTS

A total of 84 children (MIS-C - 40; dengue - 44) were included. The mean (SD) age [83.5 (39) vs. 91.6 (35) mo] was comparable. Rash (72.5% vs. 22.7%), conjunctival injection (60% vs. 2.3%), oral mucocutaneous changes (27.5% vs. 0) and gallop rhythm (15% vs. 0) were seen more frequently with MIS-C, while petechiae [29.5% vs. 7.5%], myalgia (38.6% vs. 10%), headache (22.7% vs. 2.5%), and hepatomegaly (68.2% vs. 27.5%) were more common with dengue. Children with MIS-C had significantly higher C-reactive protein (124 vs. 3.2 mg/L) and interleukin 6 (95.3 vs. 20.7 ng/mL), while those with dengue had higher hemoglobin (12 vs. 10.2 g/dL) lower mean platelet count (26 vs. 140 × 10⁹/L), and greater elevation in aspartate (607 vs. 44 IU/L) and alanine (235.5 vs. 56 IU/L) aminotransferases. The hospital stay was longer with MIS-C; however, PICU stay and mortality were comparable.

CONCLUSION

In hospitalized children with acute febrile illness, the presence of mucocutaneous features and highly elevated CRP could distinguish MIS-C from dengue. The presence of petechiae, hepatomegaly, and hemoconcentration may favor a diagnosis of dengue.

Management of acute abdomen during the active disease course of COVID-19 and multisystem inflammatory syndrome in children

Purpose

To evaluate the management of children with severe gastrointestinal symptoms during the disease course of COVID-19 and multisystem inflammatory syndrome (MIS-C).

Methods

After ethical approval, we reviewed the medical records, retrospectively, of children with COVID-19 or MIS-C requiring surgical consultation for severe gastrointestinal symptoms.

Results

The subjects comprised 15 children, 13 with MIS-C and 2 with COVID-19. Twelve children (80%) had been in known close contact with a person with SARS-CoV-19 and 13 were positive for Anti-SARS-CoV-2 IgG. All the children had experienced fever for at least 1 day and had signs of involvement of two or more systems. Three patients required surgical intervention: one underwent surgical exploration with a presumptive diagnosis of acute appendicitis in the referring center and was transported to our center following clinical deterioration, where a diagnosis of MIS-C was confirmed; and the remaining two developed appendicitis during hospitalization for COVID-19. All three patients had a longer duration of abdominal pain, a higher number of lymphocytes, and a lower level of inflammatory markers than the non-surgically managed patients. None of the patients presenting with MIS-C underwent surgical exploration.

Conclusion

Gastrointestinal involvement may mimic acute abdomen in children with COVID-19. Thus, children presenting with acute abdomen in the pandemic era require careful evaluation and prompt diagnosis to avoid unnecessary surgical intervention.

Gastrointestinal, hepatic and pancreatic manifestations of COVID-19 in children

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a well-established respiratory tract pathogen. Recent studies in adults and children have shown an increasing number of patients reporting gastrointestinal manifestations of SARS-CoV-2 infection such as diarrhoea, nausea, vomiting and abdominal pain. SARS-CoV-2 RNA can be detected in faeces for an extended period, even after respiratory samples have tested negative and patients are asymptomatic. However, faecal-oral transmission has not yet been proven. In this article, the latest evidence on gastrointestinal, hepato-biliary, and pancreatic manifestations in children with coronavirus disease-19 and multisystem inflammatory syndrome will be analysed.

Abdominal US in Pediatric Inflammatory Multisystem Syndrome Associated with SARS-CoV-2 (PIMS-TS)

Background Children with pediatric inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS), also known as multisystem inflammatory syndrome in children, present with abdominal pain among other nonspecific symptoms. Although initial imaging features of PIMS-TS have been reported, the duration of sonographic features remains unknown. Purpose To describe the abdominal US features of PIMS-TS at initial presentation and follow-up. Materials and Methods A retrospective review of children and young adults presenting with clinical features suspicious for PIMS-TS between April 2020 and June 2021 was carried out. US features were documented and reviewed at initial presentation and follow-up. Descriptive statistics were used and interobserver variability was calculated. Results Of 140 children and young adults presenting with suspected PIMS-TS, 120 had confirmed PIMS-TS (median age, 9 years; interquartile range, 7-12 years; 65 male patients) and 102 underwent abdominal US at presentation. PIMS-TS was present as a single abnormality in 109 of the 120 patients (91%) and abdominal symptoms were present in 104 of the 109 (95%). US examinations were abnormal in 86 of 102 patients (84%), with ascites being the most common abnormality in 65 (64%; 95% CI: 54, 73). Bowel wall thickening was present at US in 14 of the 102 patients (14%; 95% CI: 7, 20) and mesenteric inflammation was present in 16 (16%; 95% CI: 9, 23); all of these patients presented with abdominal symptoms. Among the patients with bowel wall thickening, the distal and terminal ileum were most involved (eight of 14 patients, 57%). Abdominal symptoms decreased to seven of 56 patients (13%) in those followed up at 6 months. Thirty-eight patients underwent follow-up US, and the presence of bowel inflammation had decreased to three of 27 patients (11%; 95% CI: -1, 23) in those followed up for less than 2 months and 0 of 17 (0%) in those followed up for more than 2 months. Conclusion Of 102 patients with pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 who underwent US at presentation, 14 (14%) had abdominal US findings of bowel inflammation and 16 (16%) had mesenteric edema. All US abnormalities resolved after 2 months. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by van Rijn and Pajkrt in this issue.

Acute abdomen in multisystem inflammatory syndrome in children: A systematic review

AIM

Multisystem inflammatory syndrome in children (MIS-C), a rare severe complication of SARS-CoV-2 infection, has been recently reported to mimic acute abdomen and lead to surgical interventions, posing challenges for clinicians. In this systematic review, we evaluated the rate of acute abdomen and abdominal surgical emergencies in children with MIS-C.

METHODS

Systematic review of all MIS-C cases presented with acute abdomen.

RESULTS

A total of 385 patients with MIS-C, from 38 studies, were included. Gastrointestinal manifestations were prominent in 233/385 (60.5%) children. Acute abdomen was noted in 72/385 (18.7%) of MIS-C cases and in 72/233 (30.9%) of MIS-C cases with gastrointestinal symptoms. Final diagnoses were mostly non-surgical (55/72, 76.4%), such as mesenteric lymphadenitis (23/72, 31.9%), terminal ileitis/ileocolitis (19/72, 26.4%), free abdominal fluid/ascites (8/72, 11.1%) and paralytic ileus (3/72, 4.2%). Laparotomy was performed in 35/72 (48.6%) of children with MIS-C, and acute abdomen and was proven unnecessary in 18/35 (51.4%) cases. True abdominal surgical emergencies, such as appendicitis and obstructive ileus, were confirmed in 17/72 (23.6%) cases.

CONCLUSION

MIS-C often presents with acute abdomen, mostly due to non-surgical intestinal inflammatory pathology. However, surgical complications occur in patients with MIS-C; therefore, a high index of suspicion should remain.

Imaging findings in acute pediatric coronavirus disease 2019 (COVID-19) pneumonia and multisystem inflammatory syndrome in children (MIS-C)

The two primary manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children are acute coronavirus disease 2019 (COVID-19) pneumonia and multisystem inflammatory syndrome (MIS-C). While most pediatric cases of acute COVID-19 disease are mild or asymptomatic, some children are at risk for developing severe pneumonia. In MIS-C, children present a few weeks after SARS-CoV-2 exposure with a febrile illness that can rapidly progress to shock and multiorgan dysfunction. In both diseases, the clinical and laboratory findings can be nonspecific and present a diagnostic challenge. Thoracic imaging is commonly obtained to assist with initial workup, assessment of disease progression, and guidance of therapy. This paper reviews the radiologic findings of acute COVID-19 pneumonia and MIS-C, highlights the key distinctions between the entities, and summarizes our understanding of the role of imaging in managing SARS-CoV-2-related illness in children.

COVID-19-Related Intestinal Ischemia in A 7-Year Old Boy

Severe abdominal pain and vomiting are common symptoms in children with pediatric multisystem inflammatory syndrome (PIMS). Mesenteric lymphadenitis and aseptic peritonitis are predominantly reported in cases where acute surgical abdomen was suspected and laparotomy was performed at the early stage of the pandemic. These reports generally discouraged surgeons to perform exploration in COVID-19-related cases and medical management was prioritized. Only a few COVID-19-specific surgical cases with intestinal ischemia were published. Here, we report another case of COVID-19-related intestinal ischemia complicated with Meckel's diverticulitis in a non-immunocompromised child who clearly required surgical intervention. In our case, the combination of COVID-19-related vasculitis and low blood pressure episodes may have contributed to this severe outcome.

Case Report: Simil-Appendicitis Presentation May Precede Cardiac Involvement in MIS-C Patient

INTRODUCTION

Multisystem inflammatory syndrome in children (MIS-C) is a new clinical entity characterized by a systemic hyperinflammation triggered by SARS-CoV-2 infection in children and adolescents. This condition could potentially involve all organs with main complications concerning cardiovascular system. Despite up to 90% of patients complain gastrointestinal symptoms (nausea, vomit, and diarrhea), a presentation mimicking acute appendicitis has rarely been reported, and can be the presenting feature of the disease, potentially leading to misdiagnosis and delayed treatment.

CASE DESCRIPTION

A 15-year-old boy presented to the Emergency Department for a 2-day history of fever, vomiting, and mild abdominal pain. One month before, the patient complained ageusia and anosmia while his mother tested positive for Sars-CoV2 nasopharyngeal swab. At admission, laboratory tests showed leukocytosis with lymphopenia and elevation of inflammatory markers, while cardiac enzymes, electrocardiogram and echocardiography were unremarkable. An abdominal ultrasound displayed a thickening of terminal ileus and cecum with ascites. Because of the worsening abdominal pain and a physical examination suggestive of acute appendicitis, a laparoscopy was performed but no surgical condition was found. After surgery, fever and generalized malaise persisted, so a cardiac evaluation was repeated, showing a relevant increase in inflammatory markers and cardiac enzymes. Electrocardiogram demonstrated a QTc prolongation with mild decrease in left ventricular ejection fraction at echocardiogram. A MIS-C was diagnosed and intravenous immunoglobulin along with a steroid treatment started. After 36 h, the patient presented a complete clinical recovery with fever cessation. Cardiac anomalies normalized in 3 weeks.

CONCLUSION

MIS-C has been defined as a systemic inflammation, involving at least two organs, after a previous SARS-CoV2 infection in children and adolescents. Physicians should be aware that while gastrointestinal manifestations are common, a pseudo appendicitis presentation may also occur, leading to misdiagnosis and delayed treatment. This report suggests that in patients with symptoms suggestive of an acute appendicitis, the presence of lymphopenia, hypoalbuminemia and ultrasound images of terminal ileus inflammation, should raise the suspect for MIS-C even without initial overt signs of cardiac involvement.

Case report: Histological findings of peri-appendicitis in three children with SARS-CoV-2 - related multisystem inflammatory syndrome: A mark for systemic inflammation?

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious condition that can potentially develop after SARS-CoV-2 infection in children. Gastrointestinal manifestation in MIS-C can mimic acute abdomen, potentially leading to unnecessary surgical treatment. Immune-mediated mechanisms seem to be a determining factor in its pathogenesis, and histological studies can help to shed light on this aspect. We describe three cases of children diagnosed with MIS-C that underwent appendectomy.

METHODS

We retrospectively collected the clinical features and histological findings of three previously healthy children who underwent appendectomy for clinical suspicion of acute appendicitis but were later diagnosed with MIS-C.

FINDINGS

The three children presented with prominent abdominal manifestations and fever leading to the suspicion of acute abdomen. Histological findings showed transmural and perivascular inflammation. Notably, CD68⁺ macrophages were predominant in the child with milder abdominal symptoms without cardiac injury, while CD3⁺ lymphocytes in the patient presented with more severe abdominal pain and cardiovascular involvement at admission.

INTERPRETATION

Gastrointestinal symptoms of children with MIS-C improve after proper immunomodulatory therapy, conversely showing inadequate response to surgical appendectomy. Histological findings revealed different inflammatory cell infiltration that primarily involved perivisceral fat and vessels, and subsequently mucosal tissue, in contrast to other forms of acute appendicitis. Our findings suggest that this kind of peri-appendicitis in MIS-C could represent a focal sign of systemic inflammation, with different histological patterns compared to other forms of acute appendicitis.

Necrotizing Enterocolitis in a 34-Week Premature Infant with COVID-19

Coronavirus disease 2019 (COVID-19) is a viral respiratory infection caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). While SARS-CoV-2 is a leading cause of morbidity and mortality in older adults, COVID-19 also affects newborn infants in nurseries and the Neonatal Intensive Care Units (NICUs). The majority of infected neonates are believed to acquire SARS-CoV-2 by horizontal transmission, and most of them have asymptomatic or mild symptomatic infections. In rare cases, infants with COVID-19 may have severe complications resulting in death. We report a case of COVID-19 in a premature neonate born at 34 weeks gestational age who presented with hypothermia and respiratory distress and subsequently developed clinical and radiological signs of necrotizing enterocolitis (NEC). The neonate received medical management, including antibiotics, suspension of gastric feeds, and intensive NICU support. The neonate's clinical condition improved without surgical intervention, and after 10 days of antibiotics and gradual reestablishment of gastric feeds, patient health condition returned to normal, and weeks later, he was discharged home. COVID-19 in infants is frequently asymptomatic or associated with mild disease, and in rare cases, it may be associated with severe gastrointestinal complications including NEC.

Acute Abdomen—A Clinical Presentation of MIS-C in Children

Objective Multisystemic inflammatory syndrome in children (MIS-C) is characterized by persistent fever, systemic hyperinflammation, and multiple-organ dysfunction. There are a few reports about MIS-C presenting with acute abdomen. The aim of this study was to demonstrate the clinical characteristics and treatment options for MIS-C-related acute abdomen and appendicitis.

Methods This was a retrospective study conducted between April 2020 and October 2020 in our pediatric intensive care unit in Turkey. Patients between the ages of 1 month and 18 years who presented with acute abdomen and were ultimately diagnosed with MIS-C were included.

Results Seven patients with a median age of 12.5 (interquartile range 10.5–13) years were enrolled. Four were females. The most frequent symptoms were fever, abdominal pain, and vomiting. Three patients had involvement of the appendix that required surgical intervention. All pathology reports were compatible with appendicitis. The other patients also had an acute abdomen. One patient had malignant hyperthermia during induction of anesthesia, so surgery was postponed and medical management was commenced. The clinical picture regressed with immunomodulation. All patients were treated with intravenous immunoglobulin and steroids. Four patients with acute abdomens improved with immunomodulation, and surgery was not needed.

Conclusion MIS-C may present with an acute abdomen. Immunomodulation should be considered instead of surgery if the clinical course is not complicated.

COVID-19 and Pediatric Gastroenterology

Pediatric gastroenterologists took on a variety of challenges during the coronavirus disease 2019 pandemic, including learning about a new disease and how to recognize and manage it, prevent its spread among their patients and health professions colleagues, and make decisions about managing patients with chronic gastrointestinal and liver problems in light of the threat. They adapted their practice to accommodate drastically decreased numbers of in-person visits, adopting telehealth technologies, and instituting new protocols to perform endoscopies safely. The workforce pipeline was also affected by the impact of the pandemic on trainee education, clinical experience, research, and job searches.

Review of COVID-19, part 1: Abdominal manifestations in adults and multisystem inflammatory syndrome in children

The coronavirus disease 2019 (COVID -19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world, resulting in severe morbidity, mortality and economic hardship, and altering the landscape of healthcare forever. Although primarily a pulmonary illness, it can affect multiple organ systems throughout the body, sometimes with devastating complications and long-term sequelae. As we move into the second year of this pandemic, a better understanding of the pathophysiology of the virus and the varied imaging findings of COVID-19 in the involved organs is crucial to better manage this complex multi-organ disease and to help improve overall survival. This manuscript provides a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19 with the exception of unique cardiothoracic features associated with multisystem inflammatory syndrome in children (MIS-C). In Part I, extra-thoracic manifestations of COVID-19 in the abdomen in adults and features of MIS-C will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

Abdominal manifestation of multisystemic inflammatory syndrome in children

Summary

Multisystemic inflammatory syndrome (MIS-C) can develop as a complication of SARS CoV-2 infection, involving the gastrointestinal system mainly by vasoconstriction, edema, glandular hyperplasia, and a procoagulant state leading to direct tissue injury.

Method

ology: a series of cases including 8 patients with MIS-C treated in two highly complex institutions is presented. These patients, had abdominal symptoms of surgical management.

Results

The average age was 9.5 years and the most frequent symptoms were fever, abdominal pain, diarrhea (100%); in addition, 87.5% presented shock. The diagnosis of SARS CoV-2 was confirmed by RT-PCR test in 37.5%, antigen 12.5% and the rest of the patients showed IgM and IgG antibodies. In laboratories, the increase in acute phase reactants, Erythrocyte Sedimentation Rate (ESR), C-reactive protein, procalcitonin, as well as troponin, D dimer and proBNP, is highlighted. The surgical outcome documented 2 patients with a normal appendix, 3 patients with edematous appendicitis, and 3 patients with complicated appendicitis.

Conclusions

patients with MIS-C display abdominal symptoms similar to those present in surgical emergencies and a non-negligible number of cases require surgical exploration. This condition poses a new differential diagnosis to the surgical abdomen in pediatric patients.

Gastrointestinal Perspective of Coronavirus Disease 2019 in Children-An Updated Review

Gastrointestinal symptoms are common findings in children with severe acute respiratory syndrome coronavirus 2 infection, including vomiting, diarrhoea, abdominal pain, and difficulty in feeding, although these symptoms tend to be mild. The hepato-biliary system and the pancreas may also be involved, usually with a mild elevation of transaminases and, rarely, pancreatitis. In contrast, a late hyper-inflammatory phenomenon, termed multisystem inflammatory syndrome (MIS-C), is characterized by more frequent gastrointestinal manifestations with greater severity, sometimes presenting as peritonitis. Gastrointestinal and hepato-biliary manifestations are probably related to a loss in enterocyte absorption capability and microscopic mucosal damage caused by a viral infection of intestinal epithelial cells, hepatocytes and other cells through the angiotensin conversion enzyme 2 receptor resulting in immune cells activation with subsequent release of inflammatory cytokines. Specific conditions such as inflammatory bowel disease (IBD) and liver transplantation may pose a risk for the more severe presentation of coronavirus disease 2019 (COVID-19) but as adult data accumulate, paediatric data is still limited. The aim of this review is to summarize the current evidence about the effect of COVID-19 on the gastrointestinal system in children, with emphasis on the emerging MIS-C and specific considerations such as patients with IBD and liver transplant recipients.

Clinical features of multisystem inflammatory syndrome in children

PURPOSE OF REVIEW

To review diagnosis, clinical characteristics and treatment of multisystem inflammatory syndrome in children (MIS-C) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

RECENT FINDINGS

MIS-C emerged in spring 2020 as a hyperinflammatory syndrome following SARS-CoV-2 exposure in children. Despite growing awareness of MIS-C, diagnosis remains challenging due to the range of phenotypes and severity. Fever accompanied by shock, cardiac dysfunction, gastrointestinal symptoms, or mucocutaneous signs suggestive of Kawasaki disease, especially in the presence of known or suspected coronavirus disease 2019 exposure, should trigger consideration of MIS-C. However, clinical presentations are highly varied and may overlap with other infectious diseases. Clinicians must maintain a high index of suspicion for MIS-C and be aware that patients may develop coronary artery aneurysms and myocarditis even with few or no Kawasaki disease symptoms. More precise diagnostic criteria and specific biomarkers are needed to aid diagnosis. Intravenous immunoglobulin (IVIG) is first-line therapy, and steroids should be considered as initial adjunctive treatment for patients with severe manifestations or other risk factors. Prompt treatment is essential, as patients may worsen acutely, though overall prognosis is reassuring.

SUMMARY

MIS-C associated with SARS-CoV-2 has varied clinical manifestations. Clinicians must be aware of the common presentation and potential for decompensation and cardiac sequalae to guide appropriate evaluation and treatment.

A Systematic Review of Abdominal Imaging Findings in COVID-19 Patients

OBJECTIVE

The objective of this systematic review was to evaluate key imaging manifestations of COVID-19 on abdominal imaging by utilizing a comprehensive review of the published literature.

METHOD

A systematic literature search from PubMed, Google Scholar, and Scopus was performed for studies mentioning abdominal imaging findings in COVID-19 patients. Studies published from inception to 15 March 2021 were included.

RESULTS

A total of 116 studies comprising 1,198 patients were included. Abdominal pain was the most common indication for abdominal imaging in 50.2% of the patients. No abnormality was seen in 48.1% of abdominopelvic computed tomography scans. Segmental bowel wall thickening (14.7%) was the most common imaging abnormality, followed by bowel ischemia (7.1%), solid organ infarction (6.7%), vessel thrombosis (6.7%), and fluid-filled colon (6.2%). Other relevant findings were dilated air-filled bowel, pancreatitis, pneumatosis/portal venous gas, bowel perforation, and appendicitis. Other than abdominal findings, COVID-19-related basal lung changes were incidentally detected in many studies. Moreover, the presence of bowel imaging findings was positively correlated with the clinical severity of COVID-19 infection.

CONCLUSION

This review describes the abdominal imaging findings in COVID-19 patients. This is pertinent for the early diagnosis of COVID-19 in patients presenting solely with abdominal symptoms as well as in identifying abdominal complications in a known case of COVID-19.

COVID-19 associated Multisystem Inflammatory Syndrome in Children (MIS-C) guidelines; revisiting the Western New York approach as the pandemic evolves

Multisystem inflammatory syndrome of children (MIS-C) continues to be a highly concerning diagnosis in those recently infected with SARS-CoV-2. The diagnosis of MIS-C cases will likely become even more challenging as vaccine uptake and natural immunity in previously infected persons leads to lower circulating rates of SARS-CoV-2 infection and will make cases sporadic. Febrile children presenting with cardiac dysfunction, symptoms overlapping Kawasaki disease or significant gastrointestinal complaints warrant a thorough screen in emergency departments, urgent care centers, and outpatient pediatric or family medicine practices. An increased index of suspicion and discussion regarding higher level of care (transferring to pediatric tertiary care centers or to intensive care) continues to be recommended. Herein we outline a broad approach with a multidisciplinary team for those meeting the case definition and believe such an approach is crucial for successful outcomes.

Intestinal Abnormalities in Patients With SARS-CoV-2 Infection: Histopathologic Changes Reflect Mechanisms of Disease

Approximately 20% of patients with symptomatic syndrome-associated coronavirus-2 (SARS-CoV-2) infection have gastrointestinal bleeding and/or diarrhea. Most are managed without endoscopic evaluation because the risk of practitioner infection outweighs the value of biopsy analysis unless symptoms are life-threatening. As a result, much of what is known about the gastrointestinal manifestations of coronavirus disease-2019 (COVID-19) has been gleaned from surgical and autopsy cases that suffer from extensive ischemic injury and/or poor preservation. There are no detailed reports describing any other gastrointestinal effects of SARS-CoV-2 even though >3,000,000 people have died from COVID-19 worldwide. The purpose of this study is to report the intestinal findings related to SARS-CoV-2 infection by way of a small case series including one with evidence of direct viral cytopathic effect and 2 with secondary injury attributed to viral infection. Infection can be confirmed by immunohistochemical stains directed against SARS-CoV-2 spike protein, in situ hybridization for spike protein-encoding RNA, and ultrastructural visualization of viruses within the epithelium. It induces cytoplasmic blebs and tufted epithelial cells without inflammation and may not cause symptoms. In contrast, SARS-CoV-2 infection can cause gastrointestinal symptoms after the virus is no longer detected, reflecting systemic activation of cytokine and complement cascades rather than direct viral injury. Reversible mucosal ischemia features microvascular injury with hemorrhage, small vessel thrombosis, and platelet-rich thrombi. Systemic cytokine elaboration and dysbiosis likely explain epithelial cell injury that accompanies diarrheal symptoms. These observations are consistent with clinical and in vitro data and contribute to our understanding of the protean manifestations of COVID-19.

COVID-19 induced mesenteric venous infarction

We present a rare case of mesenteric venous infarction in a 36-year-old man due to coronavirus disease-19 (COVID-19). Although COVID-19 usually presents with respiratory disease, multi-system manifestations are increasingly reported. Coagulopathy manifestations are also reported on imaging, including in vascular thrombosis, embolus, and organ infarction. Because the clinical variables poorly predict or suspect coagulopathy and its complications, it is important to be aware of imaging manifestations of coagulopathy complications of COVID-19.

An autopsy study of the spectrum of severe COVID-19 in children: From SARS to different phenotypes of MIS-C

BACKGROUND

COVID-19 in children is usually mild or asymptomatic, but severe and fatal paediatric cases have been described. The pathology of COVID-19 in children is not known; the proposed pathogenesis for severe cases includes immune-mediated mechanisms or the direct effect of SARS-CoV-2 on tissues. We describe the autopsy findings in five cases of paediatric COVID-19 and provide mechanistic insight into the mechanisms involved in the pathogenesis of the disease.

METHODS

Children and adolescents who died with COVID-19 between March 18 and August 15, 2020 were autopsied with a minimally invasive method. Tissue samples from all vital organs were analysed by histology, electron microscopy (EM), reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC).

FINDINGS

Five patients were included, one male and four female, aged 7 months to 15 years. Two patients had severe diseases before SARS-CoV-2 infection: adrenal carcinoma and Edwards syndrome. Three patients were previously healthy and had multisystem inflammatory syndrome in children (MIS-C) with distinct clinical presentations: myocarditis, colitis, and acute encephalopathy with status epilepticus. Autopsy findings varied amongst patients and included mild to severe COVID-19 pneumonia, pulmonary microthrombosis, cerebral oedema with reactive gliosis, myocarditis, intestinal inflammation, and haemophagocytosis. SARS-CoV-2 was detected in all patients in lungs, heart and kidneys by at least one method (RT-PCR, IHC or EM), and in endothelial cells from heart and brain in two patients with MIS-C (IHC). In addition, we show for the first time the presence of SARS-CoV-2 in the brain tissue of a child with MIS-C with acute encephalopathy, and in the intestinal tissue of a child with acute colitis. Interpretation: SARS-CoV-2 can infect several cell and tissue types in paediatric patients, and the target organ for the clinical manifestation varies amongst individuals. Two major patterns of severe COVID-19 were observed: a primarily pulmonary disease, with severe acute respiratory disease and diffuse alveolar damage, or a multisystem inflammatory syndrome with the involvement of several organs. The presence of SARS-CoV-2 in several organs, associated with cellular ultrastructural changes, reinforces the hypothesis that a direct effect of SARS-CoV-2 on tissues is involved in the pathogenesis of MIS-C.

FUNDING

Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Bill and Melinda Gates Foundation.

Inflammatory Bowel Disease Presenting With Concurrent COVID-19 Multisystem Inflammatory Syndrome

Coronavirus disease 2019 is associated with a postinfectious multisystem inflammatory syndrome in children (MIS-C). This syndrome is marked by cytokine storm and multiorgan dysfunction, often affecting the gastrointestinal tract, the heart, and the hematopoietic system. We describe the case of a 16-year-old boy with an initial presentation of severe inflammatory bowel disease and concurrent MIS-C. He presented with abdominal pain, diarrhea, and hematochezia and met criteria for the systemic inflammatory response syndrome. Laboratory inflammatory profiling revealed markedly elevated ferritin, D-dimer, C-reactive protein, soluble interleukin 2, and interleukin 6 levels. Endoscopy and colonoscopy revealed severe active gastroduodenitis, patchy colitis, and a normal-appearing terminal ileum. The patient was treated with a combination of steroids, intravenous immunoglobulin, and infliximab, and his symptoms slowly resolved over a 3-week period. In this case, we describe coincident MIS-C with a remarkably severe and difficult-to-treat initial presentation of inflammatory bowel disease and highlight the need to investigate the effect of coronavirus disease 2019 and MIS-C on inflammatory disorders.

Recognizing a MIS-Chievous Cause of Acute Viral Gastroenteritis

Historically, children evaluated for vomiting and diarrhea secondary to viral enteritis have symptoms lasting 2-4 days and respond to supportive care, including oral rehydration and anti-emetics if required. Recently, within a 14-day timespan, we encountered three children with severe diarrhea who rapidly became dehydrated and went into hypotensive shock. Although SARS-CoV-2 molecular tests were negative by nasopharyngeal swab, all were later found to have MIS-C. This small case series underscores features reported in previous larger studies and emphasizes the rapid clinical evolution of this condition. We highlight the importance of early recognition of cardinal laboratory findings characteristic of MIS-C (i.e., lymphopenia, markedly elevated acute phase reactants, and hypoalbuminemia). We also show serologic evidence that the pathophysiological mechanism of SARS-CoV-2 related diarrhea may differ from other causes of dehydrating vomiting and diarrhea, with no serologic evidence of villus cell injury.

SARS-CoV-2-associated multisystem inflammatory syndrome in children: clinical manifestations and the role of infliximab treatment

This study was conducted to assess the clinical spectrum, management, and outcome of SARS-CoV-2-related multisystem inflammatory syndrome in children (MIS-C). We reviewed medical records of children with MIS-C diagnosis seen at the Children's Hospital of Michigan in Detroit between April and June 2020. Thirty-three children were identified including 22 who required critical care (group 1) and 11 with less intense inflammation (group 2). Children in group 1 were older (median 7.0 years) than those in group 2 (median 2.0 years). Abdominal pain was present in 68% of patients in group 1. Hypotension or shock was present in 17/22 patients in group 1. Thirteen (39.4%) had Kawasaki disease (KD)-like manifestations. Five developed coronary artery dilatation; All resolved on follow-up. Intravenous immunoglobulin (IVIG) was given to all patients in group 1 and 7/11 in group 2. Second-line therapy was needed in 13/22 (group 1) for persisting inflammation or myocardial dysfunction; 12 received infliximab. All patients recovered.Conclusion: MIS-C clinical manifestations may overlap with KD; however, MIS-C is likely a distinct inflammatory process characterized by reversible myocardial dysfunction and rarely coronary artery dilatation. Supportive care, IVIG, and second-line therapy with infliximab were associated with a favorable outcome. What is Known: • Multisystem inflammatory syndrome in children (MIS-C) manifestations include fever, gastrointestinal symptoms, shock, and occasional features of Kawasaki disease (KD). • Treatment includes immunomodulatory agents, most commonly IVIG and corticosteroids. What is New: • Spectrum of MIS-C varies from mild to severe inflammation and coronary artery dilatation occurred in 5/22 (23%) critically ill patients. • IVIG and infliximab therapy were associated with a favorable outcome including resolution of coronary dilatation; only 2/33 received corticosteroids.

The JANUS of chronic inflammatory and autoimmune diseases onset during COVID-19 - A systematic review of the literature

The diverse clinical manifestations of COVID-19 is emerging as a hallmark of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. While the initial target of SARS-CoV-2 is the respiratory tract, it is becoming increasingly clear that there is a complex interaction between the virus and the immune system ranging from mild to controlling responses to exuberant and dysfunctional multi-tissue directed autoimmune responses. The immune system plays a dual role in COVID-19, being implicated in both the anti-viral response and in the acute progression of the disease, with a dysregulated response represented by the marked cytokine release syndrome, macrophage activation, and systemic hyperinflammation. It has been speculated that these immunological changes may induce the loss of tolerance and/or trigger chronic inflammation. In particular, molecular mimicry, bystander activation and epitope spreading are well-established proposed mechanisms to explain this correlation with the likely contribution of HLA alleles. We performed a systematic literature review to evaluate the COVID-19-related autoimmune/rheumatic disorders reported between January and September 2020. In particular, we investigated the cases of incident hematological autoimmune manifestations, connective tissue diseases, antiphospholipid syndrome/antibodies, vasculitis, Kawasaki-like syndromes, acute arthritis, autoimmune-like skin lesions, and neurologic autoimmune conditions such as Guillain–Barré syndrome. We screened 6263 articles and report herein the findings of 382 select reports which allow us to conclude that there are 2 faces of the immune response against SARS-CoV-2, that include a benign virus controlling immune response and a many faceted range of dysregulated multi-tissue and organ directed autoimmune responses that provides a major challenge in the management of this viral disease. The number of cases for each disease varied significantly while there were no reported cases of adult onset Still disease, systemic sclerosis, or inflammatory myositis.

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The immune system plays a major role in the acute progression of COVID-19.

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SARS-CoV-2 infection shares features with autoimmune diseases.

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SARS-CoV-2 can induce Guillain-Barré syndrome, arthritis, chilblain-like lesions.