COVID-19-related Multisystem Inflammatory Syndrome in a Young Adult

Post COVID-19 Condition in Children and Adolescents: An Emerging Problem

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection became a pandemic in 2020 and by March 2022 had caused more than 479 million infections and 6 million deaths worldwide. Several acute and long-term symptoms have been reported in infected adults, but it remains unclear whether children/adolescents also experience persistent sequelae. Hence, we conducted a review of symptoms and pathophysiology associated with post-coronavirus disease 2019 (post-COVID-19) condition in children and adolescents. We reviewed the scientific literature for reports on persistent COVID-19 symptoms after SARS-CoV-2 infection in both children/adolescents and adults from 1 January 2020 to 31 March 2022 (based on their originality and relevance to the broad scope of this review, 26 reports were included, 8 focused on adults and 18 on children/adolescents). Persistent sequelae of COVID-19 are less common in children/adolescents than in adults, possibly owing to a lower frequency of SARS-CoV-2 infection and to the lower impact of the infection itself in this age group. However, cumulative evidence has shown prolonged COVID-19 to be a clinical entity, with few pathophysiological associations at present. The most common post-COVID-19 symptoms in children/adolescents are fatigue, lack of concentration, and muscle pain. In addition, we found evidence of pathophysiology associated with fatigue and/or headache, persistent loss of smell and cough, and neurological and/or cardiovascular symptoms. This review highlights the importance of unraveling why SARS-CoV-2 infection may cause post-COVID-19 condition and how persistent symptoms might affect the physical, social, and psychological well-being of young people in the future.

Immunopathology and Immunopathogenesis of COVID-19, what we know and what we should learn

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) directly interacts with host's epithelial and immune cells, leading to inflammatory response induction, which is considered the hallmark of infection. The host immune system is programmed to facilitate the clearance of viral infection by establishing a modulated response. However, SARS-CoV-2 takes the initiative and its various structural and non-structural proteins directly or indirectly stimulate the uncontrolled activation of injurious inflammatory pathways through interaction with innate immune system mediators. Upregulation of cell-signaling pathways such as mitogen-activate protein kinase (MAPK) in response to recognition of SARS-CoV-2 antigens by innate immune system receptors mediates unbridled production of proinflammatory cytokines and cells causing cytokine storm, tissue damage, increased pulmonary edema, acute respiratory distress syndrome (ARDS), and mortality. Moreover, this acute inflammatory state hinders the immunomodulatory effect of T helper cells and timely response of CD4+ and CD8+ T cells against infection. Furthermore, inflammation-induced overproduction of Th17 cells can downregulate the antiviral response of Th1 and Th2 cells. In fact, the improperly severe response of the innate immune system is the key to conversion from a non-severe to severe disease state and needs to be investigated more deeply. The virus can also modulate the protective immune responses by developing immune evasion mechanisms, and thereby provide a more stable niche. Overall, combination of detrimental immunostimulatory and immunomodulatory properties of both the SARS-CoV-2 and immune cells does complicate the immune interplay. Thorough understanding of immunopathogenic basis of immune responses against SARS-CoV-2 has led to developing several advanced vaccines and immune-based therapeutics and should be expanded more rapidly. In this review, we tried to delineate the immunopathogenesis of SARS-CoV-2 in humans and to provide insight into more effective therapeutic and prophylactic strategies.

Multisystem Inflammatory Syndrome Associated with SARS-CoV-2 Infection in an Adult: A Case Report from the Maldives

The multisystem inflammatory syndrome in adults (MIS-A) is a novel syndrome observed during COVID-19 outbreaks. This hyper-inflammatory syndrome is seen predominantly in children and adolescents. The case of an adult from the Maldives who had asymptomatic SARS-CoV-2 infection three weeks before presenting to the hospital with fever, rash, and shock is presented. De-identified clinical data were retrospectively collected to summarize the clinical progression and treatment during hospitalization and the six-month follow-up. SARS-CoV-2 infection was confirmed by RT-PCR. Other laboratory findings included anemia (hemoglobin: 9.8 g/dL), leukocytosis (leukocytes: 20,900/µL), neutrophilia (neutrophils: 18,580/µL) and lymphopenia (lymphocytes: 5067/µL), and elevated inflammatory markers, including C-reactive protein (34.8 mg/dL) and ferritin (2716.0 ng/dL). The electrocardiogram had low-voltage complexes, and the echocardiogram showed hypokinesia, ventricular dysfunction, and a pericardial effusion suggestive of myocardial dysfunction compromising hemodynamics and causing circulatory shock. These findings fulfilled the diagnostic criteria of MIS-A. The case was managed in the intensive care unit and required non-invasive positive pressure ventilation, inotropes, and steroids. With the new surges of COVID-19 cases, more cases of MIS-A that require the management of organ failure and long-term follow-up to recovery are anticipated. Clinicians should therefore be vigilant in identifying cases of MIS-A during the pandemic.

Clinical Characteristics of Multisystem Inflammatory Syndrome in Adults: A Systematic Review

IMPORTANCE

Multisystem inflammatory syndrome in adults (MIS-A) has not been well described. Improved diagnosis and treatment of MIS-A might mitigate COVID-19 morbidity and mortality.

OBJECTIVE

To summarize the descriptive epidemiology and clinical characteristics of MIS-A.

EVIDENCE REVIEW

This systematic review identified patients with MIS-A using 3 strategies: (1) literature review from May 1, 2020, to May 25, 2021, by searching MEDLINE, Embase, Global Health, CAB Abstracts, PsycINFO, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Academic Search Complete, Scopus, World Health Organization Global COVID-19 Literature Database, and Google Scholar; (2) voluntary reports of MIS-A to the Centers for Disease Control and Prevention (CDC); and (3) reports among persons aged 18 to 20 years in the CDC surveillance system for MIS in children.

FINDINGS

Of 221 patients with MIS-A, the median age was 21 (interquartile range [IQR], 19-34) years, and 154 of 219 (70%) with data available were men. Sixty of 169 patients (36%) were non-Hispanic Black individuals, and 122 of 209 (58%) had no underlying comorbidity. One hundred two of 149 patients (68%) noted a previous symptomatic COVID-19-like illness (median, 28 [IQR, 20-36] days previously). Most patients with MIS-A presented with fever (197 of 205 [96%]), hypotension (133 of 220 [60%]), cardiac dysfunction (114 of 210 [54%]), shortness of breath (102 of 198 [52%]), and/or diarrhea (102 of 197 [52%]). The median number of organ systems involved was 5 (IQR, 4-6). Median hospital stay was 8 (IQR, 5-12) days; 115 of 201 patients (57%) were admitted to the intensive care unit; 101 of 213 (47%) required respiratory support, and 15 of 220 (7%) died. Most patients (176 of 195 [90%]) had elevated markers of coagulopathy and/or inflammation and a positive SARS-CoV-2 serologic finding (139 of 194 [72%]). Ten patients with MIS-A presented with Kawasaki disease.

CONCLUSIONS AND RELEVANCE

These findings suggest that MIS-A is a serious hyperinflammatory condition that presents approximately 4 weeks after onset of acute COVID-19 with extrapulmonary multiorgan dysfunction.