Diagnostic studies
| . | Dried blood spot . | Erythrocytes . | |||
|---|---|---|---|---|---|
| ADA activity nmol/h/mg . | Percent dAXP . | ADA activity nmol/h/mg . | dAXP nmol/mL . | Percent dAXP . | |
| Sib A | 0.15 | 7.1 | 2.2 | 140 | 9.6 |
| Sib B | 0.30 | 2.1 | 1.5 | 56 | 5.8 |
| Brother | 51.6 | < 0.1 | 58.4 | ||
| Brother | 15.5 | < 0.1 | |||
| Mother | 19.5 | < 0.1 | 26.9 | < 1 | < 0.1 |
| Father | 19.1 | < 0.1 | 27.8 | < 1 | < 0.1 |
| Patient Y | 0.1 | 6.0 | |||
| Patient R | 0.0 | 8.5 | |||
| SCID | 0.38 ± 0.5 | 41.9 ± 17 | < 0.5 | 766 ± 344 | 50.3 ± 18 |
| Delayed onset | 186 ± 55 | 15.5 ± 4 | |||
| Control | 32.5 ± 14 | < 0.1 | 63.0 ± 41 | < 2 | < 0.2 |
| . | Dried blood spot . | Erythrocytes . | |||
|---|---|---|---|---|---|
| ADA activity nmol/h/mg . | Percent dAXP . | ADA activity nmol/h/mg . | dAXP nmol/mL . | Percent dAXP . | |
| Sib A | 0.15 | 7.1 | 2.2 | 140 | 9.6 |
| Sib B | 0.30 | 2.1 | 1.5 | 56 | 5.8 |
| Brother | 51.6 | < 0.1 | 58.4 | ||
| Brother | 15.5 | < 0.1 | |||
| Mother | 19.5 | < 0.1 | 26.9 | < 1 | < 0.1 |
| Father | 19.1 | < 0.1 | 27.8 | < 1 | < 0.1 |
| Patient Y | 0.1 | 6.0 | |||
| Patient R | 0.0 | 8.5 | |||
| SCID | 0.38 ± 0.5 | 41.9 ± 17 | < 0.5 | 766 ± 344 | 50.3 ± 18 |
| Delayed onset | 186 ± 55 | 15.5 ± 4 | |||
| Control | 32.5 ± 14 | < 0.1 | 63.0 ± 41 | < 2 | < 0.2 |
Control values are mean ± SD. Control blood spots were obtained from 42 healthy individuals used as “simultaneous controls” for immunodeficient patients. Control values for erythrocytes are from > 200 non–ADA-deficient immunodeficient and healthy individuals tested in this laboratory at Duke University. Values for ADA activity and dAXP concentration in erythrocytes of ADA-deficient patients with SCID and delayed-onset phenotypes are as reported in Arredondo-Vega et al.6 It should be noted that ADA activity eluted from blood spots and present in hemolysates is normalized to total protein derived from different sources (red cells versus whole blood). Therefore, these values cannot be directly compared.