Table 1.
The characteristics of the study group and multisystem inflammatory syndrome course by age group.
| Overall Cohort | <5 Years | 5–11 Years | 12–18 Years | p-Value | ||
|---|---|---|---|---|---|---|
| Counts (%) or Median (25th–75th percentile) | 498 (100%) | 137 (28%) | 251 (50%) | 110 (22%) | ||
| Demographical features | ||||||
| Male sex | 314 (64%) | 76 (56%) | 159 (64%) | 79 (73%) | 0.02 | |
| Age | 8.3 (4.7–11.6) | 3.2 (1.9–4.2) | 8.60 (6.7–10.5) | 13.8 (13.0–15.2) | - | |
| Race | White | 496 (99.6%) | 135 (99%) | 251 (100%) | 110 (100%) | 0.12 |
| Asian | 2 (0.4%) | 2 (1%) | 0 (0%) | 0 (0%) | ||
| BMI | kg/m2 | 16.6 (14.9–19.6) | 15.2 (14.4–16.5) | 16.1 (14.7–19.0) | 20.6 (18.3–23.1) | 0.00 |
| BMI centiles | 51.9 (21.1–80.7) | 40.9 (17.4–77.0) | 50.7 (20.6–82.6) | 65.9 (30.8–83.9) | 0.01 | |
| Obesity | 33 (7%) | 7 (6%) | 18 (8.%) | 8 (8%) | 0.19 | |
| Comorbidities * | ||||||
| None | 447 (93%) | 126 (95%) | 223 (93%) | 98 (91%) | 0.47 | |
| Signs and symptoms | ||||||
| Days of fever | 7 (6–9) | 7 (6–8) | 7 (6–9) | 7 (6–9) | 0.12 | |
| Gastrointestinal symptoms | 436 (89%) | 110 (83%) | 224 (90%) | 102 (94%) | 0.03 | |
| Mucocutaneous involvement | 475 (96%) | 130 (96%) | 243 (97%) | 102 (94%) | 0.42 | |
| Upper respiratory symptoms | 173 (37%) | 48 (39%) | 80 (33%) | 45 (42%) | 0.23 | |
| Lower respiratory symptoms | 217 (46%) | 46 (36%) | 105 (44%) | 66 (63%) | 0.00 | |
| Neurological symptoms | 383 (91%) | 111 (93%) | 188 (89%) | 86 (92%) | 0.41 | |
| Osteoarticular and muscle involvement | 172 (37%) | 32 (27%) | 94 (39%) | 46 (44%) | 0.02 | |
| Systemic oedema | 2 (2%) | 0 (0%) | 1 (2%) | 1 (4%) | 0.70 | |
| Vital signs at peak of disease | ||||||
| AVPU other than A | 61 (14%) | 18 (15%) | 28 (12%) | 15 (15%) | 0.71 | |
| Heartrate (beats/min) |
Max | 135 (120–150) | 145 (130–160) | 130 (120–141) | 128 (110–140) | 0.00 |
| Min | 69 (57–81) | 80 (68–96) | 68 (56–80) | 62 (50–70) | 0.00 | |
| Prolonged CRT (>2 s) | 53 (14%) | 12 (12%) | 25 (14%) | 16 (20%) | 0.30 | |
| Systolic blood pressure (mmHg) | 85 (76–93) | 85 (75–93) | 84 (78–92) | 84 (75–95) | 0.59 | |
| Hypotension | 206 (49%) | 27 (25%) | 118 (56%) | 61 (62%) | 0.00 | |
| Max. respiratory rate (breaths/min) | 25 (20–30) | 28 (22–37) | 25 (20–30) | 25 (20–30) | 0.08 | |
| Min. SatO2 (%) | 96 (93–97) | 96 (94–98) | 96 (93–98) | 95 (92–97) | 0.02 | |
| Laboratory test results at the peak of disease | ||||||
| WBC max (103/μL) | 15.4 (11.1–20.6) | 16.8 (12.3–21.8) | 14.9 (10.9–20.3) | 14.7 (11.5–20.0) | 0.09 | |
| Neutrophils max (103/μL) | 10.1 (7.3–14.9) | 9.6 (6.4–14.6) | 9.9 (7.3–14.5) | 12.3 (8.8–16.2) | 0.05 | |
| Lymphocytes min (103/μL) | 1.0 (0.6–1.7) | 1.7 (1.0–3.0) | 0.9 (0.6–1.4) | 0.6 (0.5–1.0) | 0.00 | |
| Hb min (g/dL) | 10.4 (9.5–11.2) | 9.7 (9.0–10.4) | 10.5 (9.7–11.2) | 10.9 (10.1–11.9) | 0.00 | |
| PLT min (103/μL) | 163 (109–228) | 174 (111–265) | 164 (110–224) | 148 (107–203) | 0.09 | |
| CRP max (mg/L) | 169 (98–242) | 139 (88–208) | 169 (100–242) | 209 (121–289) | 0.00 | |
| ESR max (mm/h) | 57.0 (35.0–77.0) | 60.0 (36.0–72.0) | 58.0 (35.0–81.0) | 50.0 (33.0–77.0) | 0.73 | |
| Fibrinogen max (g/L) | 5.7 (4.6–7) | 5.5 (4.5–6.7) | 5.6 (4.5–6.9) | 6.3 (5.3–7.3) | 0.03 | |
| Procalcitonin max (ng/mL) | 4.1 (1.4–12.8) | 4.9 (2.2–10.4) | 3.7 (1.3–12.3) | 3.4 (1.1–13.4) | 0.61 | |
| Ferritin max (ug/L) | 387 (216–645) | 270 (156–421) | 413 (249–644) | 511 (238–929) | 0.00 | |
| Albumins min (g/dL) | 2.9 (2.6–3.4) | 2.9 (2.6–3.4) | 2.9 (2.5–3.4) | 3.0 (2.6–3.5) | 0.29 | |
| Sodium min (mmol/L) | 133 (130–135) | 134 (132–136) | 133 (130–135) | 133 (129–135) | 0.03 | |
| D-dimer max (mg/L) | 3.7 (2.0–5.6) | 3.8 (1.7–5.3) | 3.7 (2.1–6.1) | 3.5 (2.2–5.4) | 0.51 | |
| eGFR min (mL/min/1.73 m2) | 105 (85–126) | 112 (90–137) | 107 (88–125) | 88 (65–118) | 0.00 | |
| BNP max (pg/mL) | 1070 (264–5245) | 329 (87–1458) | 1577 (342–5580) | 2551 (448–11,480) | 0.00 | |
| NT-proBNP max (pg/mL) | 4744 (1462–11,479) | 4737 (1166–15,005) | 4136 (1592–9679) | 6340 (2718–16,000) | 0.14 | |
| Troponin elevated | 97 (50%) | 5 (16%) | 53 (51%) | 39 (64%) | 0.00 | |
| Echocardiography features | ||||||
| Any CAA | 36 (11%) | 17 (18%) | 12 (7%) | 7 (8%) | 0.04 | |
| Any contractility | 155 (41%) | 27 (28%) | 75 (40%) | 53 (59%) | 0.00 | |
| Any pericardial effusion | 47 (13%) | 13 (13%) | 23 (14%) | 11 (13%) | 1.00 | |
| Any valvular insufficiency | 190 (48%) | 45 (43%) | 104 (53%) | 41 (45%) | 0.15 | |
| Decreased LVEF (%) | 132 (36%) | 22 (23%) | 65 (39%) | 45 (51%) | 0.00 | |
| LVEF in initial echo (%) | 55.0 (46.0–64.0) | 55.0 (46.0–64.0) | 54.0 (46.0–63.2) | 55.0 (46.0–65.0) | 0.38 | |
| LVEF in follow-up echo (%) | 55.8 (49.0–66.0) | 55.0 (45.0–66.0) | 58.0 (49.0–67.0) | 51.0 (48.0–58.0) | 0.12 | |
| Management | ||||||
| PICU treatment | 32 (7%) | 3 (2%) | 17 (7%) | 12 (11%) | 0.02 | |
| IVIG administered | 447 (91%) | 128 (94%) | 223 (90%) | 96 (91%) | 0.31 | |
| GCS administered | 344 (72%) | 86 (64%) | 170 (72%) | 88 (81%) | 0.01 | |
| ASA administered | 438 (100%) | 125 (100%) | 224 (100%) | 89 (100%) | - | |
| Heparin administered | 128 (38%) | 28 (30%) | 61 (37%) | 39 (47%) | 0.07 | |
Abbreviations: AVPU, alert, verbal, pain, unresponsive; ASA, acetylsalicylic acid; BMI, body mass index; BNP, brain natriuretic peptide; CRP, C-reactive protein; CRT, capillary refill time; eGFR, estimated glomerular filtration rate; ESR, erythrocyte sedimentation rate; GCSs, glucocorticosteroids; Hb, haemoglobin; Hct, haematocrit; Il-6, interleukin 6; IQR, interquartile range; IVIGs, intravenous immunoglobulins; LDH, lactate dehydrogenase; LVEF, left ventricular ejection fraction; min, minutes; n, number; NT-proBNP, N-terminal prohormone for brain natriuretic peptide; PICU, paediatric intensive care unit; PLT, platelet count; s, seconds; SatO2, oxygen saturation; WBC, white blood count. * other than cardiovascular. Gastrointestinal symptoms encompassed nausea, vomiting, diarrhoea or abdominal pain; mucocutaneous involvement encompassed rash, erythema at BCG site, conjunctivitis, hands and feet erythema or oedema, digital peeling, inflammation of the oral cavity or cervical lymphadenopathy; upper respiratory symptoms encompassed coryza or sore throat; lower respiratory symptoms encompassed cough, breathing effort, chest pain and swallowing difficulty; neurological involvement encompassed meningeal signs, lethargy, seizures, headache, muscle hypotension, peripheral nerve paralysis, paresis, loss of smell or taste, photophobia, agitation or skin hyperesthesia; osteoarticular and muscle involvement encompassed arthritis, arthralgia or muscle pain. Max stands for the maximal value of the result obtained. Min stands for the minimal value of the result obtained. p values less than 0.05 are bolded.