Recombinant methionyl granulocyte colony-stimulating factor (filgrastim): a new dimension in immunotherapy

Delayed effects of long-term administration of granulocyte colony-stimulating factor to mice

We studied the effects of chronic administration of granulocyte colony-stimulating factor in nonmobilizing doses to mice. Over 18 months of the study, 55% animals of the treatment group died of unknown cause, blood diseases and tumors were found in 20% mice, and in 5% animals pathological changes were absent. Control mice had no diseases (normal values of total and differential leukocyte count). The diagnoses made over the first 7 months mainly included myeloproliferative diseases. Solid tumors were found at later terms. Suppurative inflammation at the site of injection was observed in all mice after 3-month treatment with granulocyte colony-stimulating factor. Our results indicate that chronic administration of granulocyte colony-stimulating factor in low doses leads to the development of etiologically different tumors and sharply reduced animal life span. The use of granulocyte colony-stimulating factor during allogeneic transplantation of hemopoietic stem cells can be hazardous for donors.

Granulocyte colony-stimulating factor (G-CSF) serum levels in surgical intensive care patients

The granulocyte colony-stimulating factor (G-CSF) regulates neutrophil differentiation and function. Serum levels of G-CSF increase during acute infectious processes. The levels of G-CSF were measured in 59 surgical intensive care unit (ICU) patients. In general, G-CSF was only elevated during the first 2 days after admission to the ICU. Higher G-CSF levels were more frequently observed in patients without infectious complications and in patients who survived. Later on, G-CSF levels were below 100 pg/ml in almost all patients studied. The highest G-CSF level (20,000 pg/ml) was observed in one patient with septic shock 36 h after leukopenia. The patient recovered from septic shock and multiple organ failure and was discharged. It is proposed that surgical ICU patients with low or undetectable G-CSF serum levels may benefit from exogenous G-CSF substitution protocols.

Acceleration of hemopoietic recovery in dogs after extended-field partial-body irradiation by treatment with colony-stimulating factors: rhG-CSF and rhGM-CSF

PURPOSE

The influence of treatment with the two colony-stimulating factors, rhG-CSF and rhGM-CSF, on the hemopoietic recovery in aplastic bone marrow sites after extended-field irradiation was studied in a canine model.

METHODS AND MATERIALS

The dogs received irradiation of the cranial part of their body with a single dose of 11.7 Gy, comprising approximately 72% of the total bone marrow mass. Anatomically this type of exposure corresponds to upper body irradiation (UBI) as employed under clinical conditions. Treatment with both the CSFs was employed for 7 days by daily injections of 30 microg/kg, starting 24 hr after irradiation.

RESULTS

Treatment with rhGM-CSF did not completely prevent the initial decrease of the granulocyte counts, but caused an accelerated, though incomplete, recovery in the period from day 5 to day 15. In contrast, treatment with rhG-CSF caused two phases of granulocytosis and an early recovery to normal levels at day 11 after irradiation. Treatment with rhG-CSF, but not with rhGM-CSF, was associated with a strong supra-normal increase of progenitor cells in the blood within the first 8 days and an accelerated hemopoietic recovery in the irradiated sites particularly within the first 7 days after the exposure.

CONCLUSIONS

These results indicate that under conditions of partial-body irradiation short term treatment with G-CSF is superior to GM-CSF in initiating the hemopoietic recovery on the basis of endogenous stem cell seeding.