Performance of existing criteria for HLH and MAS diagnosis.
| Cohort 1, n = 34 | Cohort 2, n = 41 | All, n = 76 | ||||
|---|---|---|---|---|---|---|
| Criteria | Sensitivity | Specificity | Sensitivity | Specificity | Sensitivity | Specificity |
| Cohort 1 decision rule | – | – | 90 | 85 | – | – |
| Cohort 2 decision rule | 90 | 63 | – | – | – | – |
| PReS Lupus Working Group-proposed criteria for MAS in cSLE | 100 | 17 | 100 | 32 | 100 | 25 |
| Familial HLH criteriaa | 50 | 86 | 44 | 100 | 47 | 93 |
– Estimation of sensitivity and specificity in these cohorts would be overfit, since these cohorts gave rise to the decision rule.
↵a Restricted to patients with bone marrow aspirates/biopsies (cohort 1: n = 20; cohort 2: n = 23). Soluble interleukin receptor and natural killer cell activity were not included in sensitivity and specificity calculations. cSLE: childhood-onset systemic lupus erythematosus; HLH: hemophagocytic lymphohistiocytosis; MAS: macrophage activation syndrome; PReS: Paediatric Rheumatology European Society.