Table.
Study population
| Healthy controls (n=462) | Non-inflammatory controls* (n=33) | MIS-C (n=21) | Kawasaki disease (n=24) | Inactive systemic juvenile idiopathic arthritis (n=10) | Asymptomatic or mild COVID-19 (n=146) | ||
|---|---|---|---|---|---|---|---|
| Demographic characteristics | |||||||
| Age, years | 8 (0–16) | 10·6 (3·0–15·3) | 7·0 (1·5–17·0) | 3·0 (0·1–7·5) | 15·5 (9·0–18·0) | 8 (0–16) | |
| Sex | |||||||
| Female | 230 (50%) | 13 (39%) | 11 (52%) | 9 (38%) | 5 (50%) | 72 (49%) | |
| Male | 232 (50%) | 20 (61%) | 10 (48%) | 15 (63%) | 5 (50%) | 74 (51%) | |
| Clinical manifestations | |||||||
| Fever >3 days | 163 (35%)† | 0 | 21 (100%) | 24 (100%) | 0 | 57 (39%)† | |
| Rash | 23 (5%) | 0 | 14 (67%) | 17 (71%) | 0 | 3 (2%) | |
| Bilateral conjunctivitis | 20 (4%)‡ | 0 | 15 (71%) | 21 (88%) | 0 | 5 (3%)‡ | |
| Gastrointestinal symptoms | 108 (23%)§ | 0 | 18 (86%) | 4 (17%) | 0 | 29 (20%)§ | |
| Cardiac involvement | NA | 0 | 13 (62%) | 24 (100%) | 0 | NA | |
| Coronary artery aneurysms | NA | 0 | ND | 4 (17%) | 0 | NA | |
| Arthritis | NA | 0 | 0 | 2 (8%) | 1 (10%) | NA | |
| Laboratory parameters | |||||||
| C-reactive protein, mg/L | ND | ND | 214 (74–440) | 95 (3–382) | <0·5 (not detectable–13) | ND | |
| Ferritin, ng/mL | ND | ND | 565 (67–40 006) | ND | 35 (24–226) | ND | |
| Natrium, mmol/L | ND | ND | 133 (124–141) | 135 (126–138) | 140 (138–142) | ND | |
| Leukocyte count, ×109 cells/L | ND | ND | 17·8 (10·3–30·6) | 15·9 (7·9–37·3) | 6·4 (4·4–32·5) | ND | |
| Neutrophils, % | ND | ND | NA | 82 (53–86) | 55 (36–85) | ND | |
| Platelet count, ×103 cells/mL | ND | ND | 151 (78–1248) | 547 (135–974) | 296 (214–339) | ND | |
| SARS-CoV-2, serology positive | 0 | ND¶ | 19/20 (95%) | ND¶ | ND‖ | 146 (100%) | |
| SARS-CoV-2, PCR positive** | ND | ND‖ | 4/20 (20%) | ND‖ | ND‖ | ND | |
| Treatment | |||||||
| IVIG†† | 0 | 0 | 19 (90%) | 24 (100%) | 0 | 0 | |
| Steroids | 0 | 0 | 20 (95%) | 1 (4%) | 3 (30%) | 0 | |
| Anakinra | 0 | 0 | 15 (71%) | 21 (88%) | 5 (50%) | 0 | |
| Ventilation | 0 | 0 | 9 (43%) | 0 | 0 | 0 | |
Data are median (range), n (%), or n/N (%) where N is patients with available data. Body weight is reported for the MIS-C group in the appendix (pp 1-2); weight data were not collected or unavailable for all other groups. MIS-C=multisystem inflammatory syndrome in children. NA=not available. ND=not determined. IVIG=intravenous immunoglobulin.
Children with suspected growth retardation.
Parent report of fever >38·5°C.
Parent report of conjunctivitis.
Parent report of diarrhoea or nausea.
Collected before 2019.
Collected before 2020.
PCR at admission to hospital.
The analysed serum or plasma study samples were all collected from IVIG-naive patients (except two MIS-C cases); patients were subsequently treated during the disease course as medically indicated.