Laboratory investigations of multisystem inflammatory syndrome in children cases across the age categories*†
| Total (n=41) | <5 years (n=18) | 5–12 years (n=19) | >12–20 years (n=4) | |
| Hemogram at the time of presentation | ||||
| Haemoglobin (Hb) g/L (mean±SD) | 107.7±16.2 | 103.0±17.3 | 110.9±12.3 | 106.0±27.4 |
| Total leucocyte count (TLC) 109 /L (mean±SD) | 11.2±4.8 | 12.9±5.4 | 10.5±3.5 | 7.1±4.6 |
| Platelets (PLT) 109 /L (mean±SD) | 248±167 | 303±159 | 220±176 | 131±26 |
| Anaemia (Hb <110 g/L)—no. (%) | 20 (49) | 10 (56) | 7 (37) | 3 (75) |
| Leucopenia (TLC <4.0 × 109 cells/L)—no. (%) | 2 (5) | 1 (6) | 0 (0) | 1 (25) |
| Thrombocytopenia (PLT<150 × 109 cells/L)—no. (%) | 13 (31) | 3 (17) | 7 (37) | 3 (75) |
| Pancytopenia—no. (%)‡ | 2 (5) | 1 (6) | 0 (0) | 1 (25) |
| Lymphopenia—no. (%)§ | 26 (63) | 7 (39) | 15 (19) | 4 (100) |
| Peak values | ||||
| CRP mg/L—mean±SD or median (IQR) | 119±79 | 86±63 | 145±84 | 146 (64–234) |
| Positive CRP (>1 mg/L) | 41 (100) | 18 (100) | 19 (100) | 4 (100) |
| CRP (1-50) mg/L—no. (%) | 10 (24) | 7 (39) | 2 (11) | 1 (25) |
| CRP (51-100) mg/L—no. (%) | 8 (20) | 5 (28) | 3 (16) | 0 (0) |
| CRP (>100) mg/L—no. (%) | 23 (56) | 6 (33) | 14 (73) | 3 (75) |
| Procalcitonin μg/L | ||||
| Median (IQR) | 8.9 (1.6–51.0) | 11.4 (1.5–54.2) | 3.7 (1.5–13.8) | 48 (7.2–53.0) |
| no./total no. (%) | 16/41 (39) | 8/18 (44) | 5/19 (26) | 3/4 (75) |
| High procalcitonin (>0.5 µg/L) no./total no. (%) | 16/16 (100) | 8/8 (100) | 5/5 (100) | 3/3 (100) |
| Ferritin μg/L Median (IQR) | 350 (170–733) | 189 (98–429) | 570 (266–961) | 777 (180–1332) |
| High ferritin (>300 µg/L) no./total no. (%) | 22 (54) | 7 (39) | 13 (68) | 2 (50) |
| D-dimer mg/L Median (IQR) | 2.5 (1.1–4.3) | 1.5 (0.9–3.3) | 3.8 (1.5–5.2) | 2.6 (1.6–4.2) |
| High D-dimer (>0.5 mg/L) - no.(%) | 40 (98) | 18 (100) | 18 (94) | 4 (100) |
| Sodium mmol/L Mean±SD | 135±5 | 135±6 | 135±5 | 137±4 |
| Hyponatraemia (sodium <135 mmol/L) no.(%) | 9 (22) | 3 (17) | 5 (26) | 1 (25) |
| Albumin g/L (mean±SD) | 28.6±7.1 | 29.5±6.9 | 28.3±7.9 | 26.5±4.7 |
| Hypoalbuminaemia (albumin <35 g/L) no.(%) | 31 (76) | 14 (78) | 13 (68) | 4 (100) |
| AST IU/L median (IQR) | 35.0 (27.0–76.5) | 28.0 (22.5–47.5) | 34.0 (23.0–60.0) | 110.0 (37.0–351.0) |
| ALT IU/L median (IQR) | 29.5 (22.3–51.0) | 40.0 (27.5–63.5) | 29.0 (20.0–45.0) | 89.0 (35.5–442) |
| Transaminitis¶ no.(%) | 19 (46) | 9 (50) | 7 (37) | 3 (75) |
| Acute kidney injury (AKI)** | 4 (10) | 1 (6) | 1 (5) | 2 (50) |
| Sterile pyuria— no./total no. (%) | 10/20 (50) | 4/10 (40) | 4/7 (57) | 2/3 (67) |
| Proteinuria— no./total no. (%) | 6/20 (30) | 1/10 (10) | 3/7 (43) | 2/3 (67) |
| Troponin ng/L Median (IQR) no./ total no. (%) | 16 (6.7–30.0) | 19 (6.0–41.2) | 10.2 (4.0–35.6) | 19.3 (14.5–27.4) |
| 30/41 (73) | 12/18 (67) | 14/19 (74) | 4/4 (100) | |
| Elevated troponin (>20 ng/L) no./ total no. (%) | 10/30 (33) | 6/12 (50) | 3/14 (21) | 1/4 (25) |
| NT-ProBNP (pg/mL) Median (IQR) no./ total no. (%) | 1845 (403–6840) | 4342 (815–7803) | 529 (248–4647) | 3530 (2679–4382) |
| 19/41 (46) | 8/18 (44) | 9/19 (47) | 2/4 (50) | |
| Elevated NT-proBNP (>125 pg/mL) no./ total no. (%) | 18/19 (95) | 8/8 (100) | 8/9 (89) | 2/2 (100) |
| Fibrinogen g/L Mean±SD | 3.9±1.8 | 3.5±0.8 | 4.2±2.2 | 3.37 |
| no./total no. (%) | 11/41 (27) | 3/18 (17) | 7/19 (37) | 1/4 (25) |
| Hypofibrinogenaemia (fibrinogen <2.0 g/L) no./ total no. (%) | 1/11 (9) | 0/3 (0) | 1/7 (14) | 0/1 (0) |
| ESR mm/hour Mean±SD | 33.4±20.7 | 35.3±15.9 | 41.2±24.4 | 7.5±0.7 |
| no./total no. (%) | 14/41 (34) | 7/18 (39) | 5/19 (26) | 2/4 (50) |
| High ESR (>20) no./total no. (%) | 10/14 (71) | 6/7 (86) | 4/5 (80) | 0/2 (0) |
*Percentages may not total 100 because of rounding.
†CRP denotes C-reactive protein, AST aspartate aminotransferase, ALT alanine aminotransferase, NT-ProBNP N-terminal pro–B-type natriuretic peptide, ESR Erythrocyte sedimentation rate, IQR denotes interquartile range showing 25th and 75th centiles, and SD is the standard deviation.
‡Pancytopenia defined as hemoglobin <110 g/L, total leukocyte count < 4.0 x 109 /L and platelets < 150 x 109 /L.
§Lymphopenia defined as <3000 lymphocytes/μL (<2 years age), <1500 lymphocytes/μL (2-12 years age), and <1000 lymphocytes/μL (>12 years age).
¶Transaminitis defined as AST or ALT >40 IU/L.
**Acute Kidney Injury (AKI) is defined as any of the following: increase in serum creatinine by ≥ 0.3mg/dl (≥ 26.5 µmol/l) within 48 hours; or increase in serum creatinine to ≥ 1.5 times baseline, whichis known or presumed to have occurred within the prior 7 days; or urine volume <0.5 ml/kg/h for 6 hours.36
ALT, alanine aminotransferase; AST, aspartate aminotransferase; CRP, C reactive protein; ESR, erythrocyte sedimentation rate; NT-ProBNP, N-terminal pro–B-type natriuretic peptide.