Neutrophil Apoptosis Before and During G-CSF Therapy
| Ex Vivo Addition of G-CSF . | Time to 50% Apoptosis (h) . | |||
|---|---|---|---|---|
| C Day 0 . | P Day 0 . | C Day 4 . | P Day 4 . | |
| (−) G-CSF | 17.3 ± 1.0 | 18.3 ± 0.8 | 17.1 ± 0.8 | 30.8 ± 2.95-150 |
| (+) G-CSF | 37.6 ± 1.6 | 41.4 ± 2.2 | 42.0 ± 4.7 | 55.1 ± 4.45-151 |
| Ex Vivo Addition of G-CSF . | Time to 50% Apoptosis (h) . | |||
|---|---|---|---|---|
| C Day 0 . | P Day 0 . | C Day 4 . | P Day 4 . | |
| (−) G-CSF | 17.3 ± 1.0 | 18.3 ± 0.8 | 17.1 ± 0.8 | 30.8 ± 2.95-150 |
| (+) G-CSF | 37.6 ± 1.6 | 41.4 ± 2.2 | 42.0 ± 4.7 | 55.1 ± 4.45-151 |
Neutrophils were isolated from controls and treated volunteers. Apoptosis was assayed as described in Materials and Methods. The predicted time to 50% apoptosis was calculated using a logistic regression model and the results represent the time (hours) to 50% apoptosis. There was a significantly prolonged time to 50% apoptosis (P = .007) after 5 days of G-CSF therapy in vivo without G-CSF added to the culture system. This effect was enhanced further when G-CSF (25 ng/mL) was added to the culture suspension in vitro at time 0 (P = .02). Results are expressed, in hours, as mean ± SEM, n = 8 (matched pairs).
P = .007.
P = .02.