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6-month multidisciplinary follow-up and outcomes of patients with paediatric inflammatory multisystem syndrome (PIMS-TS) at a UK tertiary paediatric hospital: a retrospective cohort study

Our take —

This study followed up 46 children in the UK who had a multisystem inflammatory syndrome associated with SARS-CoV-2 infection (called PIMS-TS or MIS-C), and assessed clinical, laboratory, and functional outcomes after six months. No children died, and there was significant normalization of organ-specific sequelae (i.e., the prevalence of gastrointestinal, neurologic, and echocardiogram abnormalities dropped considerably) for most children. Though all children had systemic inflammation on admission, all but one had normalized inflammatory biomarker values at six months. However, nearly half of children showed poor exercise tolerance at six months, and about one-fifth of children reported severe emotional difficulties. This study was from a single hospital with a small study population, which may not be representative of all children with this syndrome; additionally, it has not yet been possible to assess longer-term outcomes. The study nonetheless provides valuable data that may help guide provider and patient expectations regarding the course of this syndrome.

Study design

Case Series; Retrospective Cohort

Study population and setting

This study included 46 children (median age 10.2 years, 65% male, 80% from minority ethnic groups) who met the criteria for pediatric inflammatory multisystem syndrome (PIMS-TS; also called multisystem inflammatory syndrome in children, or MIS-C) admitted to a single hospital in the UK from April 4 to September 1, 2020. Outcomes were assessed 6 months after admission.  Included patients had evidence of SARS-CoV-2 infection from a positive PCR test, a positive antibody test, or an epidemiologic link to a confirmed case. All patients were seen by a multidisciplinary team of specialists at 6 weeks and 6 months after admission. Patients were assessed for a wide range of laboratory, clinical, and radiologic features at both follow-up times. Additionally, self-reported outcomes related to physical, emotional, social, and school function were assessed with the PedsQL 4.0 Generic Core Scales. Parents or guardians of patients also completed a structured interview. The authors compared patients older versus younger than 12 years and patients with versus without neurologic symptoms.

Summary of Main Findings

Eight (17%) children had baseline comorbidities; none died by six months after admission. Six weeks from admission, all participants were PCR-negative for SARS-CoV-2 infection. Of the 42 children who tested positive for anti-SARS-CoV-2 antibodies within six weeks of admission, 38 (90%) remained seropositive at six months. At admission, everyone had significantly elevated markers of inflammation, but only one child had systemic inflammation six months later. At baseline, 15 (33%) children had significant abnormalities on echocardiograms; at six months, 2 children (4%) had abnormal echocardiograms. The prevalence of gastrointestinal symptoms dropped from 98% at baseline to 13% at six months. Four of 43 (9%) participants with urinalysis had proteinuria at six weeks, and one of 44 (2%) had proteinuria at six months. Four of 42 (10%) had blood pressure above the 95th percentile at six months. There were abnormal neurological symptoms in 24 (52%) children at six weeks and 18 (39%) at six months; however, these abnormalities were largely minor, and the median Expanded Disability Status score to assess functionality at six months was 0 (interquartile range (IQR): 0 to 1). The median manual muscle-8 test score was 53/80 (IQR: 43 to 64) at admission, and this improved to 80/80 (IQR: 68 to 80) at six months. At six months, 18 of 40 (45%) children had six-minute walk test results below the 3rd percentile for their age and sex. Eight of 38 (22%) participants self-reported severe emotional difficulties at six months.

Study Strengths

The six-month follow-up time provided useful data on longer-term outcomes for children afflicted with PIMS-TS/MIS-C. Participants were evaluated for a broad range of laboratory, clinical, and functional parameters by specialists at standardized follow-up times after initial presentation.

Limitations

The number of study participants was small, though this is understandable given the rarity of PIMS-TS/MIS-C in the general population. There was no comparison group of either healthy controls or children presenting with another inflammatory syndrome (e.g., Kawasaki disease). Participants were recruited from a single center and may not be representative of the broader population of children with the inflammatory syndrome. No data were available on laboratory, clinical, or functional parameters before hospital admission, preventing a comparison of 6-month outcomes with patients’ condition before SARS-CoV-2 infection. It is unclear from the data presented why functional outcomes were poor compared to other outcomes.

Value added

This study provides one of the highest-quality and longest-term assessments of outcomes associated with PIMS-TS/MIS-C to date.

This review was posted on: 8 June 2021