Corticosteroids may be an effective treatment for children who develop a rare but serious condition after COVID-19 infection.
This is the finding of an international study of 614 children, published in the New England Journal of Medicine, led by Imperial College London.
All children in the study developed a serious disorder following COVID-19 infection. This condition, called multi-system inflammatory syndrome in children (MIS-C), is thought to affect 1 in 50,000 children with SARS-CoV-2 infection.
The new disorder, which is also called paediatric inflammatory multi-system syndrome temporally associated with SARS-CoV-2 infection (PIMS-TS), affects children of all ages but is more common in older children and teenagers. The disorder generally occurs 2-6 weeks after infection with the SARS-CoV-2 virus.
The illness is characterised by persistent high fever, often accompanied by abdominal pain, vomiting, red eyes and red rash. Severely affected children have developed heart inflammation, with shock and failure of multiple organs.
Fortunately, with optimal treatment the majority of affected children have recovered well. However, worldwide most reports suggest a fatality rate of 2-4%.
An important concern has been that some affected children have developed inflammation of their arteries that supply the heart with blood (called coronary arteries), resulting in widening of these arteries. This is also known to happen in another condition called Kawasaki disease.
The new study, supported by the EU's Horizon 2020 programme, investigated two initial treatments for this condition: a type of steroid called corticosteroids (such as methyl prednisolone) and antibody treatment (called immunoglobulin). The antibodies come from human blood, and have been shown to reduce inflammation in the body. The study also compared initial treatment with steroids together with immunoglobulin.
The study involved hundreds of doctors worldwide uploading information about patient outcomes onto an online database, and was not a randomised controlled trial (see Notes to Editors).
All three treatments (immunoglobulin, immunoglobulin combined with corticosteroids and cortico-steroids alone) resulted in more rapid resolution of inflammation, as measured by the level of a protein that indicates inflammation levels in the body, called C-reactive protein (CRP).
The CRP fell by half approximately one day quicker in those receiving treatment. There were no clear differences between the three treatments in rate of recovery from organ failure, or progression to organ failure.
The number of fatal cases (2%) was too low to enable comparison between treatments, but death was included in a combined assessment with organ failure, which found no significant differences between the three treatments.
However, when analysis was restricted to the 80% of children who met the World Health Organization's criteria for MIS-C, there was evidence of a lower rate of organ support or death at 2 days in those receiving steroids alone as initial treatment, compared to immunoglobulin alone.
Dr Elizabeth Whittaker, one of the authors of the study from Imperial's Department of Infectious Disease, and one of the first doctors in the world to originally identify this condition, together with colleagues at Imperial College and Imperial College Healthcare NHS Trust, said: "The finding that outcome is similar for patients treated with steroids alone as with those treated with steroids and immunoglobulin or immunoglobulin alone, suggests that steroids may be a cheaper and more available alternative to immunoglobulin. Corticosteroids are cheap and available worldwide whereas immunoglobulin is expensive, and there is a worldwide shortage of it. This is a particular problem in many low and middle income countries. "
However the authors stress there is insufficient data to establish that all three treatments are equivalent in preventing coronary artery aneurysms. Around 6 per cent of children in the study suffered a coronary artery aneurysm.
Professor Michael Levin, from the Department of Infectious Disease at Imperial, who led the study, said: "The study has been a real example of international collaboration and the willingness of paediatricians in many countries to share their data and experience to enable important questions as to optimal treatment to be answered. Our finding, that treatments with immunoglobulin, steroids or a combination of both agents all result in more rapid resolution of inflammation (and have similar rates of progression to organ failure or recovery from critical illness), will be of great value to paediatricians worldwide in their treatment of children with this new disorder. As immunoglobulin is unavailable or in short supply in many countries, and is expensive, the findings of this study may provide some reassurance for those who only have access to corticosteroids, particularly in those countries with more limited resources.
However it is important to note that our study does not yet provide a definitive answer as to whether any of the treatments lowers the risk of coronary artery aneurysms, as the numbers with this complication were too low. The study is continuing to enrol patients and our planned further analysis with larger numbers of patients should provide answers to this question."
About the BATS study
Soon after MIS-C was first recognised in April and May 2020, the research team at Imperial College London, headed by Professor Michael Levin, initiated an international study to identify the optimal treatment for this new disease. The study called "Best Available Treatment Study" (BATS) invited paediatricians worldwide to upload data from patients with MIS-C. The hypothesis underlying the study was that if a large enough number of patients were included and treated using whatever drugs individual paediatricians felt were beneficial, the outcome of children treated with different treatment regimes could be compared. Although randomised placebo-controlled trials provide the best evidence for benefit of any drugs, randomised trials take considerable time to develop and often require extensive funding. The speed with which the new disease was evolving made it unlikely that there would be information from such trials rapidly. As an alternative the BATS study utilised new statistical approaches to correct for any differences in severity or other confounding effects in order to compare the different treatments given to children with MIS-C.
The study compared the outcome of children with MIS-C treated with the three most common regimes: intravenous immunoglobulin (the proven treatment of Kawasaki disease), immunoglobulin combined with corticosteroids and corticosteroids alone. The study showed evidence that all three treatment regimes resulted in more rapid resolution of inflammation than in children who did not receive immune modulating drugs. No statistically significant differences were seen between each of the three treatments in either the rate of progression to organ failure or recovery from organ failure. More patients who were treated with a single agent (immunoglobulin or steroids) required additional treatment than those who were commenced initially on both drugs. In children whose condition met the World Health Organisation definition of MIS-C, there was evidence for more rapid improvement in organ failure in children receiving corticosteroids than those receiving immunoglobulin alone. The number of patients who developed coronary artery aneurysms in each of the three treatment groups were too low for firm conclusions as to the role of these drugs in preventing coronary artery aneurysms.
New England Journal of Medicine