Baseline characteristics of the study population
| Patient subgroup . | Total (n = 52) . | Treatment naïve (n = 34) . | Previous corticosteroid treatment (n = 18) . | P value . |
|---|---|---|---|---|
| General | ||||
| Gender (male/female), n | 30/22 | 22/12 | 8/10 | .239 |
| Median age (range), y | 3.7 (0.1-14.4) | 4.45 (0.7-14.2) | 1.7 (0.1-14.4) | .008 |
| Duration before diagnosis, d | 19 (4-150) | 17.5 (4-100) | 23.5 (5-150) | .471 |
| Clinical parameters, % | ||||
| Fever (>38.5°C) | 100 | 100 | 100 | |
| Splenomegaly | 76.9 | 79.4 | 72.2 | .731 |
| Hepatomegaly | 73.1 | 76.5 | 66.7 | .519 |
| Lymphadenopathy | 80.8 | 82.4 | 77.8 | .723 |
| Jaundice | 19.2 | 20.6 | 16.7 | .521 |
| Rash | 40.4 | 35.5 | 50.0 | .378 |
| CNS involvement | 19.2 | 17.6 | 22.2 | .732 |
| Laboratory findings | ||||
| White blood cells, ×109/L | 2.84 (0.58-46.29) | 2.13 (0.58-14.14) | 7.64 (0.58-46.29) | .077 |
| Neutrophils, ×109/L | 0.87 (0.03-10.85) | 0.79 (0.03-8.83) | 1.08 (0.17-10.85) | .063 |
| Platelets, ×109/L | 74.5 (10-506) | 81.5 (10-506) | 56.5 (11-383) | .532 |
| Hemoglobin, g/L | 87.5 (55-129) | 89.5 (58-128) | 84 (55-129) | .222 |
| Fibrinogen, g/L | 1.6 (0.46-3.15) | 1.39 (0.47-3.08) | 1.72 (0.46-3.15) | .510 |
| Triglycerides, mmol/L | 2.86 (0.54-10.48) | 2.94 (0.76-10.48) | 2.67 (0.54-5.97) | .801 |
| AST, U/L | 208 (16-6790) | 223 (22-2037) | 187 (16-6790) | .373 |
| ALT, U/L | 156 (9.6-1918) | 171 (9.6-1044) | 143 (11-1918) | .309 |
| IFN-γ, increase (fold) | 38.5 (1.6-877.6) | 33.6 (1.6-877.6) | 42.6 (12.6-387.8) | .443 |
| Soluble CD25, increase (fold) | 6.2 (2.1-42.7) | 6.2 (2.1-41.8) | 5.6 (2.6-42.7) | .957 |
| Ferritin, increase (fold) | 8.0 (0.6-68.3) | 6.7 (0.6-58.3) | 8.3 (1.7-68.3) | .498 |
| Low NK cell activity, % | 75.0 | 76.5 | 72.2 | .747 |
| Hemophagocytosis, % | 76.9 | 82.4 | 66.7 | .300 |
| Patient subgroup . | Total (n = 52) . | Treatment naïve (n = 34) . | Previous corticosteroid treatment (n = 18) . | P value . |
|---|---|---|---|---|
| General | ||||
| Gender (male/female), n | 30/22 | 22/12 | 8/10 | .239 |
| Median age (range), y | 3.7 (0.1-14.4) | 4.45 (0.7-14.2) | 1.7 (0.1-14.4) | .008 |
| Duration before diagnosis, d | 19 (4-150) | 17.5 (4-100) | 23.5 (5-150) | .471 |
| Clinical parameters, % | ||||
| Fever (>38.5°C) | 100 | 100 | 100 | |
| Splenomegaly | 76.9 | 79.4 | 72.2 | .731 |
| Hepatomegaly | 73.1 | 76.5 | 66.7 | .519 |
| Lymphadenopathy | 80.8 | 82.4 | 77.8 | .723 |
| Jaundice | 19.2 | 20.6 | 16.7 | .521 |
| Rash | 40.4 | 35.5 | 50.0 | .378 |
| CNS involvement | 19.2 | 17.6 | 22.2 | .732 |
| Laboratory findings | ||||
| White blood cells, ×109/L | 2.84 (0.58-46.29) | 2.13 (0.58-14.14) | 7.64 (0.58-46.29) | .077 |
| Neutrophils, ×109/L | 0.87 (0.03-10.85) | 0.79 (0.03-8.83) | 1.08 (0.17-10.85) | .063 |
| Platelets, ×109/L | 74.5 (10-506) | 81.5 (10-506) | 56.5 (11-383) | .532 |
| Hemoglobin, g/L | 87.5 (55-129) | 89.5 (58-128) | 84 (55-129) | .222 |
| Fibrinogen, g/L | 1.6 (0.46-3.15) | 1.39 (0.47-3.08) | 1.72 (0.46-3.15) | .510 |
| Triglycerides, mmol/L | 2.86 (0.54-10.48) | 2.94 (0.76-10.48) | 2.67 (0.54-5.97) | .801 |
| AST, U/L | 208 (16-6790) | 223 (22-2037) | 187 (16-6790) | .373 |
| ALT, U/L | 156 (9.6-1918) | 171 (9.6-1044) | 143 (11-1918) | .309 |
| IFN-γ, increase (fold) | 38.5 (1.6-877.6) | 33.6 (1.6-877.6) | 42.6 (12.6-387.8) | .443 |
| Soluble CD25, increase (fold) | 6.2 (2.1-42.7) | 6.2 (2.1-41.8) | 5.6 (2.6-42.7) | .957 |
| Ferritin, increase (fold) | 8.0 (0.6-68.3) | 6.7 (0.6-58.3) | 8.3 (1.7-68.3) | .498 |
| Low NK cell activity, % | 75.0 | 76.5 | 72.2 | .747 |
| Hemophagocytosis, % | 76.9 | 82.4 | 66.7 | .300 |
ALT, alanine aminotransferase; AST, aspartate aminotransferase; IFN-γ, interferon-γ; NK, natural killer.
Normal reference range by the clinical laboratory: AST ≤ 40 U/L; ALT ≤ 40 U/L; IFN-γ ≤ 8 pg/mL; ferritin ≤ 500 μg/L; soluble CD25 ≤ 6400 pg/mL; natural killer cell activity ≥15.11%. The baseline values of soluble CD25 and ferritin were described as “increase (fold),” which was calculated based on the upper limits of normal (6400 pg/mL and 500 μg/L, respectively).