Demographic and clinical characteristics of patients with pHLH
| Parameter . | Overall (N = 46) . | Children (aged <12 y) (n = 39)∗ . | Adolescents and adults (aged ≥12 y) (n = 7)∗ . |
|---|---|---|---|
| Age at pHLH diagnosis, median (range), y | 1.0 (0.3-21.0) | 1.0 (0.3-10) | 14.0 (12.0-21.0) |
| Male, n (%) | 28 (60.9) | 23 (59.0) | 5 (71.4) |
| Female, n (%) | 18 (39.1) | 16 (41.0) | 2 (28.6) |
| Race, n (%) | |||
| White | 18 (39.1) | 15 (38.5) | 3 (42.9) |
| Black | 7 (15.2) | 7 (18.0) | 0 |
| Hispanic | 9 (19.6) | 8 (20.5) | 1 (14.3) |
| Asian | 5 (10.9) | 2 (5.1) | 3 (42.9) |
| ≥2 | 2 (4.4) | 2 (5.1) | 0 |
| Other | 2 (4.4) | 2 (5.1) | 0 |
| Unknown | 3 (6.5) | 3 (7.7) | 0 |
| Genetic testing, n (%) | 44/46 (95.7) | 37/39 (94.9) | 7/7 (100.0) |
| PRF1 | 15/40 (37.5)† | 13/33 (39.4) | 2/7 (28.6) |
| UNC13D | 10/40 (25.0)† | 8/33 (24.2) | 2/7 (28.6) |
| STX11 | 2/40 (5.0)† | 1/33 (3.0) | 1/7 (14.3) |
| STXBP2 | 3/40 (7.5)† | 3/33 (9.1) | 0 |
| RAB27A | 4/40 (10.0)† | 3/33 (9.1) | 1/7 (14.3) |
| LYST | 5/40 (12.5)† | 5/33 15.2 | 0 |
| AP3B1 | 3/40 (7.5)† | 2/33 (6.1) | 1/7 (14.3) |
| SH2D1A | 3/40 (7.5)† | 2/33 (6.1) | 1/7 (14.3) |
| XIAP/BIRC4 | 3/40 (7.5)† | 3/33 (9.1) | 0 |
| Patients with ≥5 of 8 HLH-2004 criteria,‡ n (%) | 27/30 (90.0) | 23/25 (92.0) | 4/5 (80.0) |
| Patients with infection at diagnosis,§ n (%) | 25/46 (54.3) | 20/39 (51.3) | 5/7 (71.4) |
| Patients with CNS involvement at diagnosis, n (%) | 10/46 (21.7) | 9/39 (23.1) | 1/7 (14.3) |
| Age, y, at emapalumab initiation, median (range) | 1.0 (0.5-22.0) | 1 (0.5-11) | 15.0 (12.0-22.0) |
| Patients initiated emapalumab in an ICU, n (%) | 15/46 (32.6) | 13/39 (33.3) | 2/7 (28.6) |
| Patients receiving supportive care,|| n (%) | 11/46 (23.9) | 9/39 (23.1) | 2/7 (28.6) |
| Ventilator only | 6/11 (54.5) | 5/9 (55.6) | 1/2 (50.0) |
| Dialysis only | 2/11 (18.2) | 1/9 (11.1) | 1/2 (50.0) |
| Multiple (≥1 of the following: mechanical ventilation, dialysis, vasopressors, ECMO, MARS) | 3/11 (27.3) | 3/9 (33.3) | 0 |
| Patients with abnormal laboratory markers or cytokine levels at emapalumab initiation, n (%) | |||
| Platelet count (<100 × 109/L) | 25/46 (54.4) | 22/39 (56.4) | 3/7 (42.9) |
| Absolute neutrophil count (<1.0 × 109/L) | 21/44 (47.7) | 19/37 (51.4) | 2/7 (28.6) |
| Fibrinogen (≤1.5 g/L) | 13/40 (32.5) | 11/34 (32.4) | 2/6 (33.3) |
| Ferritin (>500 μg/L) | 33/41 (80.9) | 27/34 (79.4) | 6/7 (85.7) |
| sCD25 (≥2400 U/mL) | 21/31 (67.7) | 19/26 (73.1) | 2/5 (40.0) |
| Absolute lymphocyte count¶ | 28/42 (66.7) | 23/36 (63.9) | 5/6 (83.3) |
| Alanine transaminase¶ | 35/45 (77.8) | 29/38 (76.3) | 6/7 (85.7) |
| CXCL9¶ | 19/20 (95.0) | 15/16 (93.8) | 4/4 (100.0) |
| Parameter . | Overall (N = 46) . | Children (aged <12 y) (n = 39)∗ . | Adolescents and adults (aged ≥12 y) (n = 7)∗ . |
|---|---|---|---|
| Age at pHLH diagnosis, median (range), y | 1.0 (0.3-21.0) | 1.0 (0.3-10) | 14.0 (12.0-21.0) |
| Male, n (%) | 28 (60.9) | 23 (59.0) | 5 (71.4) |
| Female, n (%) | 18 (39.1) | 16 (41.0) | 2 (28.6) |
| Race, n (%) | |||
| White | 18 (39.1) | 15 (38.5) | 3 (42.9) |
| Black | 7 (15.2) | 7 (18.0) | 0 |
| Hispanic | 9 (19.6) | 8 (20.5) | 1 (14.3) |
| Asian | 5 (10.9) | 2 (5.1) | 3 (42.9) |
| ≥2 | 2 (4.4) | 2 (5.1) | 0 |
| Other | 2 (4.4) | 2 (5.1) | 0 |
| Unknown | 3 (6.5) | 3 (7.7) | 0 |
| Genetic testing, n (%) | 44/46 (95.7) | 37/39 (94.9) | 7/7 (100.0) |
| PRF1 | 15/40 (37.5)† | 13/33 (39.4) | 2/7 (28.6) |
| UNC13D | 10/40 (25.0)† | 8/33 (24.2) | 2/7 (28.6) |
| STX11 | 2/40 (5.0)† | 1/33 (3.0) | 1/7 (14.3) |
| STXBP2 | 3/40 (7.5)† | 3/33 (9.1) | 0 |
| RAB27A | 4/40 (10.0)† | 3/33 (9.1) | 1/7 (14.3) |
| LYST | 5/40 (12.5)† | 5/33 15.2 | 0 |
| AP3B1 | 3/40 (7.5)† | 2/33 (6.1) | 1/7 (14.3) |
| SH2D1A | 3/40 (7.5)† | 2/33 (6.1) | 1/7 (14.3) |
| XIAP/BIRC4 | 3/40 (7.5)† | 3/33 (9.1) | 0 |
| Patients with ≥5 of 8 HLH-2004 criteria,‡ n (%) | 27/30 (90.0) | 23/25 (92.0) | 4/5 (80.0) |
| Patients with infection at diagnosis,§ n (%) | 25/46 (54.3) | 20/39 (51.3) | 5/7 (71.4) |
| Patients with CNS involvement at diagnosis, n (%) | 10/46 (21.7) | 9/39 (23.1) | 1/7 (14.3) |
| Age, y, at emapalumab initiation, median (range) | 1.0 (0.5-22.0) | 1 (0.5-11) | 15.0 (12.0-22.0) |
| Patients initiated emapalumab in an ICU, n (%) | 15/46 (32.6) | 13/39 (33.3) | 2/7 (28.6) |
| Patients receiving supportive care,|| n (%) | 11/46 (23.9) | 9/39 (23.1) | 2/7 (28.6) |
| Ventilator only | 6/11 (54.5) | 5/9 (55.6) | 1/2 (50.0) |
| Dialysis only | 2/11 (18.2) | 1/9 (11.1) | 1/2 (50.0) |
| Multiple (≥1 of the following: mechanical ventilation, dialysis, vasopressors, ECMO, MARS) | 3/11 (27.3) | 3/9 (33.3) | 0 |
| Patients with abnormal laboratory markers or cytokine levels at emapalumab initiation, n (%) | |||
| Platelet count (<100 × 109/L) | 25/46 (54.4) | 22/39 (56.4) | 3/7 (42.9) |
| Absolute neutrophil count (<1.0 × 109/L) | 21/44 (47.7) | 19/37 (51.4) | 2/7 (28.6) |
| Fibrinogen (≤1.5 g/L) | 13/40 (32.5) | 11/34 (32.4) | 2/6 (33.3) |
| Ferritin (>500 μg/L) | 33/41 (80.9) | 27/34 (79.4) | 6/7 (85.7) |
| sCD25 (≥2400 U/mL) | 21/31 (67.7) | 19/26 (73.1) | 2/5 (40.0) |
| Absolute lymphocyte count¶ | 28/42 (66.7) | 23/36 (63.9) | 5/6 (83.3) |
| Alanine transaminase¶ | 35/45 (77.8) | 29/38 (76.3) | 6/7 (85.7) |
| CXCL9¶ | 19/20 (95.0) | 15/16 (93.8) | 4/4 (100.0) |
ECMO, extracorporeal membrane oxygenation; MARS, molecular adsorbent recirculating system; sCD25, soluble interleukin-2 receptor.
Patients were classified as children (aged <12 years) and adolescents and adults (aged ≥12 years) based on age at time of emapalumab initiation.
The denominator (n = 40) is based on number of patients with genetic mutations known to cause pHLH.
As reported by treating physician. Data on at least 5 of 8 parameters were available for 30 patients. Data on <5 parameters were available for the remaining 16 patients and therefore not included in the evaluation.
Viral infections were the most common (18/25, 72%).
At emapalumab initiation.
As reported by treating physician. Because these parameters are not part of the HLH-2004 criteria, we have no criteria or cut off point for them.