Table 3.
Profile of patients’ clinical, laboratory, and pathologic criteria for meeting the diagnosis of HLH
| Criterion (bolded are “major” criteria) | Number of cases with criterion out of total observed/tested (prevalence rate) | Median (interquartile range) |
|---|---|---|
| Fever | 26 of 30 (87%) | |
| Splenomegaly | 26 of 30 (87%) | |
| Cytopenias (affecting ≥2 of 3 lineages in the peripheral blood) | 26 of 30 (87%) | |
| Hemoglobin <90 g/l (in infants <4 weeks: hemoglobin <100 g/l) | 22 of 30 (73%) | 83 g/l (74–94 g/l) |
| Platelets <100 × 109/l | 25 of 30 (83%) | 69.5 × 109/l (26–92 × 109/l) |
| Neutrophils <1.0 × 109/l | 15 of 27 (60%) | 0.8 × 109/l (0.2–9.8 × 109/l) |
| Hypertriglyceridemia and/or hypofibrinogenemia | 24 of 29 (83%) | |
| Fasting triglycerides ≥3.0 mmol/l (i.e., ≥265 mg/dl) | 20 of 27 (74%) | 317 mg/dl (190–484 mg/dl) |
| Fibrinogen ≤1.5 g/l | 7 of 27 (26%) | 2.41 g/l (1.64–4.1 g/l) |
| Hemophagocytosis in bone marrow or spleen or lymph nodes | 26 of 29 (90%) | |
| Hemophagocytosis in bone marrow | 22 of 28 (79%) | |
| Hemophagocytosis in spleen | 5 of 18 (28%) | |
| Hemophagocytosis in lymph node | 4 of 21 (19%) | |
| Low or absent NK-cell activity | 1 of 2 (50%) | |
| Increased ferritin ≥500 μg/l | 27 of 28 (96%) | 3081 μg/l (1222–9000 μg/l) |
| Increased soluble CD25(i.e., soluble IL-2R) ≥2400 U/ml | 9 of 10 (90%) | 3406 U/ml (1719–10903 U/ml) |
HLH, hemophagocytic lymphohistiocytosis; IL-2R, interlukin-2 receptor; NK-cell, natural killer cell.