IVIG Compared With IVIG Plus Infliximab in Multisystem Inflammatory Syndrome in Children

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.

Treatment of multisystem inflammatory syndrome in children

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C), a relatively uncommon but severe pediatric complication, is associated with coronavirus disease 2019 (COVID-19). A variety of treatment approaches, including intravenous immunoglobulins (IVIGs), glucocorticoids (GCs) and biologic agents, such as anakinra and infliximab, have been described for the management of COVID-19-related MIS-C. Anticoagulant therapy is also important. However, a well-developed treatment system has not been established, and many issues remain controversial. Several recently published articles related to the treatment of MIS-C have been released. Hence, in this review, we identified relevant articles published recently and summarized the treatment of MIS-C more comprehensively and systematically.

DATA SOURCES

We reviewed the literature on the treatment of MIS-C through 20 September 2023. The PubMed/Medline, Web of Science, EMBASE, and Cochrane Library databases were searched with the combination of the terms "multisystem inflammatory syndrome", "MIS-C", "PIMS-TS", "therapy", "treatment", "drug", "IVIG", "GCs", "intravenous immunoglobulin", "corticosteroids", "biological agent", and "aspirin".

RESULTS

The severity of MIS-C varies, and different treatment schemes should be used according to the specific condition. Ongoing research and data collection are vital to better understand the pathophysiology and optimal management of MIS-C.

CONCLUSIONS

MIS-C is a disease involving multiple systems and has great heterogeneity. With the accumulation of additional experience, we have garnered fresh insights into its treatment strategies. However, there remains a critical need for greater standardization in treatment protocols, alongside the pressing necessity for more robust and meticulously conducted studies to deepen our understanding of these protocols. Supplementary file1 (MP4 208044 kb).

COVID-19-Related Multi-systemic Inflammatory Syndrome in Children (MIS-C)

Multisystem inflammatory syndrome in children (MIS-C) is a severe complication of SARS-CoV-2 infections in children. This syndrome manifests about a month after the initial viral infection and is characterized by fever, multiorgan dysfunction, and systemic inflammation. This chapter will review the emergence, epidemiology, clinical characteristics, diagnosis, pathophysiology, immunomodulatory treatment, prognosis, outcomes, and prevention of MIS-C. While the pathophysiology of MIS-C remains to be defined, it is a post-infection, hyperinflammatory syndrome of childhood with elevated inflammatory cytokines.

Kawasaki Disease-Associated Cytokine Storm Syndrome

Kawasaki disease (KD) is a hyperinflammatory syndrome manifesting as an acute systemic vasculitis characterized by fever, nonsuppurative conjunctival injection, rash, oral mucositis, extremity changes, and cervical lymphadenopathy. KD predominantly affects young children and shares clinical features and immunobiology with other hyperinflammation syndromes including systemic juvenile idiopathic arthritis (sJIA) and multisystem inflammatory syndrome in children (MIS-C). Cytokine storm syndrome (CSS) is an acute complication in ~2% of KD patients; however, the incidence is likely underestimated as many clinical and laboratory features of both diseases overlap. CSS should be entertained when a child with KD is unresponsive to IVIG therapy with recalcitrant fever. Early recognition and prompt institution of immunomodulatory treatment can substantially reduce the mortality and morbidity of CSS in KD. Given the known pathogenetic role of IL-1β in both syndromes, the early use of IL-1 blockers in refractory KD with CSS deserves consideration.

Impact of anakinra use on clinical outcomes in children with moderate or severe multisystem inflammatory syndrome in children: a propensity score matched retrospective cohort study

BACKGROUND

The treatment of children with multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 infection involves immunomodulatory therapies such as IVIG and steroids. Anakinra, an interleukin-1 receptor inhibitor, has also been used, but its effectiveness is not established yet. As optimal regimens for MIS-C remain unknown, we aimed to assess the effect of anakinra in reducing hospital stay in patients with MIS-C.

METHODS

We included children admitted from May 2020 to May 2021 diagnosed with MIS-C based on CDC criteria. The exposure of interest was anakinra use at any point during admission. The anakinra exposed group and the anakinra unexposed group were propensity score matched based on demographic and clinical severity indicators at initial presentation. Our primary outcome was length of hospital stay. Secondary outcomes were duration of vasoactive support, vasoactive inotropic score (VIS), level of respiratory support, time to fever resolution, reduction of CRP levels, and length of ICU stay. We used Wilcoxon rank sum, t-test, Chi square and Fisher's exact tests.

RESULTS

Of 138 children diagnosed with MIS-C, 79% had moderate or severe illness and 41% received anakinra. Of those, 31 patients who received anakinra were propensity score matched to 31 who did not. The length of stay in the hospital but not in the ICU was longer in the anakinra group. There were no differences in median duration of vasoactive support, fever resolution, CRP reduction, or VIS.

CONCLUSIONS

In patients with moderate to severe MIS-C, use of anakinra was associated with longer duration of hospital stay.

Variation in Early Anakinra Use and Short-Term Outcomes in Multisystem Inflammatory Syndrome in Children

OBJECTIVE

Evidence regarding effectiveness of interleukin-1 receptor antagonism in multisystem inflammatory syndrome in children (MIS-C) is lacking. We characterized variation in initial treatment with anakinra and evaluated cardiovascular outcomes associated with adding anakinra to standard initial therapy.

METHODS

We conducted a retrospective cohort study of MIS-C cases in a US surveillance registry from November 2020 to December 2021. Day 0 was the first calendar day of immunomodulatory treatment. Factors associated with initial anakinra use (days 0-1) were identified. We compared cases in patients ages 2-20 years receiving intravenous immunoglobulin (IVIG) and glucocorticoids versus anakinra plus IVIG and/or glucocorticoids on days 0-1, using inverse probability weighting to balance disease severity. Primary outcomes were vasopressor requirement on day 3 and impaired left ventricular ejection fraction on days 3-4. The secondary outcome was 50% reduction in C-reactive protein on day 3.

RESULTS

Among 1,516 MIS-C cases at 44 sites, 193 (13%) patients received anakinra alone or with other immunomodulators as initial treatment (range 0-74% by site). Site accounted for 59% of residual variance in anakinra use. After balancing disease severity, initial treatment with anakinra plus IVIG and/or glucocorticoids (n = 121) versus IVIG plus glucocorticoids (n = 389) was not associated with significant differences in vasopressor requirement (25.6% versus 20.1%, respectively; risk ratio [RR] 1.27 [95% confidence interval (95% CI) 0.88-1.84]), ventricular dysfunction (33.7% versus 25.7%, respectively; RR 1.31 [95% CI 0.98-1.75]), or C-reactive protein reduction.

CONCLUSION

We identified substantial variation in initial anakinra use in a real-world population of children with MIS-C, but no average short-term improvement in cardiovascular outcomes associated with early addition of anakinra to IVIG and/or glucocorticoids compared to IVIG and glucocorticoids alone.

Management of Multisystem Inflammatory Syndrome in Children: Decision-Making Regarding a New Condition in the Absence of Clinical Trial Data

Multisystem inflammatory syndrome in children (MIS-C) is a new illness that evolved during the COVID-19 pandemic with initial reports of severe disease including use of extracorporeal membrane oxygenation and death. Institutions rapidly assembled task forces to develop treatment algorithms. At the national/international levels, collaboratives and associations assembled consensus writing groups to draft guidelines. These guidelines and algorithms were initially on the basis of expert opinion and small case series. Some groups used the Delphi approach, and the resultant guidelines often mimicked those for other conditions that resembled MIS-C, like Kawasaki disease (KD). For instance, intravenous immunoglobulin (IVIG), a known effective treatment for KD, was recommended for MIS-C. Early in the pandemic many favoured IVIG over steroids as first-line therapy. As evidence evolved so did some guidelines, which now endorse the dual use of IVIG with steroids as first-line therapy. In contrast, withholding immunotherapy became an option for some MIS-C patients with mild symptoms. Herein, we review guidelines and discuss the evidence informing early recommendations, how this has evolved, the role and limitations of expert opinion and observational data, and the importance of leveraging existing research infrastructures, such as the intensive care unit collaborative (Overcoming COVID-19 surveillance registry), and the International Kawasaki Disease Registry. Finally, we discuss strategies to rapidly develop, deploy, and adapt clinical trials evaluating the treatment of such rare conditions in children, which might include alternatives to conventional clinical trial design. The emergence of MIS-C during the COVID-19 pandemic has highlighted unmet needs regarding research of a new condition.

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

Impact of Severe Acute Respiratory Syndrome Coronavirus 2 Variants on Short- and Mid-term Cardiac Outcomes in Multisystem Inflammatory Syndrome in Children

Cardiac outcomes of 131 children with multisystem inflammatory syndrome (MIS-C) were examined. The majority of the cohort was male (66.4%) and half were Black (49.6%). Cardiac involvement was evident in 25% of the cohort at diagnosis. Favorable short- and mid-term outcomes were documented on follow-up, irrespective of the severe acute respiratory syndrome coronavirus 2 variants causing the infection.

Nutraceuticals for Complementary Treatment of Multisystem Inflammatory Syndrome in Children: A Perspective from Their Use in COVID-19

Multisystem inflammatory syndrome in children (MIS-C) has been widely reported in some children diagnosed with SARS-CoV-2. Clinical signs of MIS-C are manifested at 2 to 4 weeks after SARS-CoV-2 infection, where elevated biomarkers of inflammation and cardiac dysfunction are the hallmark of this syndrome when infection or exposure to SARS-CoV-2 has been confirmed. However, after two years of acknowledgment, MIS-C treatment is still under research to reach safety and effectiveness in the acute phase in children. Therefore, in this review, we discuss the potential use of natural compounds with antioxidant and anti-inflammatory effects to reduce collateral damage caused by hyperinflammation in MIS-C pathology for new research in treatment and interventions.

Drugs for the prevention and treatment of COVID-19 and its complications: An update on what we learned in the past 2 years

The COVID-19 Committee of the Lincei Academy has reviewed the scientific evidence supporting the efficacy and safety of existing and new drugs/biologics for the preventing and treating of COVID-19 and its complications. This position paper reports what we have learned in the field in the past 2 years. The focus was on, but not limited to, drugs and neutralizing monoclonal antibodies, anti-SARS-CoV-2 agents, anti-inflammatory and immunomodulatory drugs, complement inhibitors and anticoagulant agents. We also discuss the risks/benefit of using cell therapies on COVID-19 patients. The report summarizes the available evidence, which supports recommendations from health authorities and panels of experts regarding some drugs and biologics, and highlights drugs that are not recommended, or drugs for which there is insufficient evidence to recommend for or against their use. We also address the issue of the safety of drugs used to treat underlying concomitant conditions in COVID-19 patients. The investigators did an enormous amount of work very quickly to understand better the nature and pathophysiology of COVID-19. This expedited the development and repurposing of safe and effective therapeutic interventions, saving an impressive number of lives in the community as well as in hospitals.

Das Pädiatrische Inflammatorische Multisystem Syndrom (PIMS) in der COVID-19 Pandemie

Nach einer meist mild verlaufenden SARS-CoV-2-Infektion kommt es bei einem kleinen Teil der Kinder nach einem Zeitraum von ca. 6–8 Wochen zu einer ausgeprägten multisystemischen Hyperinflammation (Pediatriac multisystemic inflammatory syndrome (PIMS)). Klinisch präsentieren sich diese Patienten mit Zeichen eines Kawasaki-Syndroms bzw. eines toxischen Schocksyndroms. Gerade die kardiale Manifestation mit einer deutlichen Einschränkung der Herzfunktion erfordert in vielen Fällen eine intensivmedizinische Behandlung.

Die Pathophysiologie ist trotz des beeindruckenden Erkenntnisgewinns der letzten 1 ½ Jahre noch unklar. Möglicherweise spielen Superantigene eine wesentliche Rolle, die T-Zellen an einer bestimmten β-Kette des T-Zellrezeptors polyklonal stimulieren.

Neben den z.T. intensivmedizinischen supportiven Maßnahmen werden zur Kontrolle der Inflammation intravenöse Immunglobuline, Steroide und Biologika eingesetzt.

Multisystem Inflammatory Syndrome in Adult after First Dose of mRNA Vaccine

A 32-year-old man in Japan experienced respiratory failure after receiving the first dose of coronavirus disease (COVID-19) vaccine. He was treated with noninvasive ventilation and corticosteroids. Serologic test results suggested previous COVID-19; therefore, he received a diagnosis of multisystem inflammatory syndrome. COVID-19 vaccination could be a trigger for this condition.

American College of Rheumatology Clinical Guidance for Multisystem Inflammatory Syndrome in Children Associated With SARS-CoV-2 and Hyperinflammation in Pediatric COVID-19: Version 3

OBJECTIVE

To provide guidance on the management of Multisystem Inflammatory Syndrome in Children (MIS-C), a condition characterized by fever, inflammation, and multiorgan dysfunction that manifests late in the course of SARS-CoV-2 infection. Recommendations are also provided for children with hyperinflammation during COVID-19, the acute, infectious phase of SARS-CoV-2 infection.

METHODS

The Task Force is composed of 9 pediatric rheumatologists and 2 adult rheumatologists, 2 pediatric cardiologists, 2 pediatric infectious disease specialists, and 1 pediatric critical care physician. Preliminary statements addressing clinical questions related to MIS-C and hyperinflammation in COVID-19 were developed based on evidence reports. Consensus was built through a modified Delphi process that involved anonymous voting and webinar discussion. A 9-point scale was used to determine the appropriateness of each statement (median scores of 1-3 for inappropriate, 4-6 for uncertain, and 7-9 for appropriate). Consensus was rated as low, moderate, or high based on dispersion of the votes. Approved guidance statements were those that were classified as appropriate with moderate or high levels of consensus, which were prespecified before voting.

RESULTS

The guidance was approved in June 2020 and updated in November 2020 and October 2021, and consists of 41 final guidance statements accompanied by flow diagrams depicting the diagnostic pathway for MIS-C and recommendations for initial immunomodulatory treatment of MIS-C.

CONCLUSION

Our understanding of SARS-CoV-2-related syndromes in the pediatric population continues to evolve. This guidance document reflects currently available evidence coupled with expert opinion, and will be revised as further evidence becomes available.

The Role of Glucocorticoids in the Treatment of Multisystem Inflammatory Syndrome (MIS-C)—Data from POLISH MIS-C Registry

Background: Multisystem inflammatory syndrome (MIS-C) is a condition related to COVID-19. It’s most significant feature is cardiac involvement. Methods: We have analyzed data from 42 hospitals in the Polish MIS-C Registry. To compare the effect of GCS on fever, we formed two groups: the first treated with IVIG and the second treated with IVIG+GCS. Results: There were 111 boys and 56 girls; the mean age was 8.57 years. All the patients were treated with IVIG: 76 patients with IVIG only, and 91 patients with IVIG+GCS. There were no statistically significant differences between the groups regarding age, gender, BMI, or inflammatory markers. Methylprednisolone was the most common drug (80%). Echocardiographic abnormalities on admission were more prevalent in the IVIG+GCS group. Mean time from IVIG infusion to subsidence of fever was 1.1 days, and 1.5 for those in the IVIG+GCS group. Conclusions: GCS are commonly used in the treatment of MIS-C patients in Poland. Various GCS regimens are used, from a single dose to a month-long therapy. Children with lower lymphocyte levels and cardiac abnormalities on an echocardiographic examination performed on admission were more likely to receive GCS+IVIG. The effect of GCS is difficult to access as patients were not randomly assigned to receive the treatment.

Infliximab treatment for refractory COVID-19-associated multisystem inflammatory syndrome in a Japanese child

Patients with multisystem inflammatory syndrome in children (MIS-C) can develop clinical features resembling Kawasaki disease (KD). A full picture of MIS-C in East Asia which has higher incidence of KD than other regions remains unclear. We report on a 15-year-old Japanese boy with refractory MIS-C who was successfully treated with infliximab. A Japanese boy who was diagnosed with coronavirus disease 2019 (COVID-19) before a month developed MIS-C with fulfilling six principal symptoms of KD. Laboratory data showed extreme hyperferritinemia (11,404 ng/mL), besides lymphopenia and thrombocytopenia. The patient was refractory to initial therapy with intravenous immunoglobulin (IVIG; 2 g/kg), aspirin, and prednisolone. He was therefore administered a second IVIG (2 g/kg) and infliximab (5 mg/kg) on days 7 and 8 from the onset of fever, respectively, which resulted in an improvement of clinical symptoms. Only four Japanese cases with MIS-C were reported and all of them were responsive to IVIG. The hyperferritinemia in this case was distinctive from previously reported MIS-C cases in Japan and other cohorts and may be associated with refractoriness to IVIG therapy. Marked elevation of circulating ferritin levels is known to be induced by tumor necrosis factor-α, which plays a key role in the pathogenesis of both KD and MIS-C. Thus, for MIS-C patients with hyperferritinemia, early intervention with adjunctive infliximab may induce a more rapid resolution of inflammation and improve outcome. Because MIS-C may be heterogeneous with respect to immunopathology, genetic background, clinical phenotypes and response to therapies, optimized treatment strategies according to immunopathogenesis are required.

Timely Recognition and Early Multi-Step Antinflammatory Therapy May Prevent ICU Admission of Patients With MIS-C: Proposal for a Severity Score

In this observational study, we report the clinical, therapeutics and outcome features of 23 patients with multisystem inflammatory syndrome (MIS-C) who have been treated in Gaslini Children Hospital (Genoa, Italy) with a multistep antinflammatory treatment protocol, based on disease severity at admission. Patients were initially assigned to four severity classes on admission and treated accordingly. The therapeutic options ranged from IV immunoglobulin alone to a combination of IVIG plus pulses of methylprednisolone plus anakinra for patients with marked cardiac function impairment or signs of macrophage activation syndrome, with rapid treatment escalation in case of inadequate therapeutic response. With the application of this therapeutic strategy, no patient required admission to Intensive Care Unit (ICU) or invasive mechanical ventilation, and no inotropic drugs administration was required. Early aggressive treatment of MIS-C, with therapeutic interventions modulated based on the severity of clinical manifestations may help to prevent the progression of the inflammatory process and to avoid the need of admission to the ICU. A timely intervention with anti-IL-1 blockers can play a pivotal role in very severe patients that are at risk to have an incomplete response to immunoglobulins and steroids.