Flt3 ligand and thrombopoietin serum levels during peripheral blood stem cell mobilization with chemotherapy and recombinant human glycosylated granulocyte colony-stimulating factor (rhu-G-CSF, lenograstim) and after high-dose chemotherapy.

The purpose of this investigation was to study thrombopoietin (TPO) and Flt3 ligand (FL) serum levels in the course of peripheral blood stem cell (PBSC) mobilization and high-dose chemotherapy (HDC) and to correlate the values with stem cell yield and engraftment. Thirty-nine patients were included. PBSC were mobilized by chemotherapy followed by two body surface area-dependent doses of glycosylated recombinant human granulocyte colony-stimulating factor (rhu-G-CSF, lenograstim). PBSC could be harvested in 35 patients and 30 received a total of 62 courses of HDC (1-3 per patient). Fifty-six were analyzed and TPO and FL serum levels were measured at the start of PBSC mobilization, at the first PBSC collection, on the day of PBSC infusion, and until engraftment. Mean baseline TPO and FL serum levels were 173 pg/ml and 192 pg/ml and increased to 493 and 323 pg/ml at the start of PBSC collection. Maximum values were 2279 pg/ml TPO after HDC 1 and 2375 pg/ml after HDC 2, while the mean maximum serum levels for FL were 1181 and 1236 pg/ml after HDC 1 and 2 and PBSC transfusion, respectively. FL serum levels at the start of PBSC mobilization correlated with the total yield of CD34+ cells (17.61+/-18.8x10(6)/kg body weight, r=0.81), while TPO serum levels on days 11-13 after PBSC infusion were inversely correlated with the amount of transfused CD34+61+62+ cells (r=-0.88 and -0.79 for HDC 1 and 2). There was no strong correlation between TPO or FL serum levels and WBC and platelet engraftment. In conclusion, chemotherapy followed by glycosylated rhu-G-CSF induced elevated serum levels of TPO and to a lower degree of FL at the start of PBSC collection. The maximum increase was 13.7-fold for TPO and 6.4-fold for FL after PBSC infusion indicating endogenous release which should be considered if the clinical use of these cytokines is intended in this setting.

Kinetic study of CD34+ cells during peripheral blood stem cell collections.

The impact of the separated volume on the yield of CD34+ cells during peripheral blood stem cell collections (PBSCC) remains controversial. We therefore studied the CD34+ cell concentration in the peripheral blood of patients (pts) during PBSCC as well as the total amount of CD34+ cells collected after each blood volume (BV) processed and engraftment data for each cycle of high dose chemotherapy (HD Ctx). A total of 21 PBSCC from 20 patients with different malignancies were analyzed. Stem cells were mobilized by chemotherapy and G-CSF (14 pts) or GM-CSF (6 pts). Samples from the pts peripheral blood and the collection bag were taken after each BV processed and analyzed for CD34+ cells, WBC, platelets (plt), and hemoglobin (Hb). The total volume processed was two to five times the pts calculated BV (mean value 17.4 L, range 9.0-24.0 L). Sixteen pts could be evaluated for engraftment. The mean peripheral blood CD34+ cell count was 116+/-103.5/microl at the start of PBSCC and decreased to 57+/-61.6/microl after processing of four times the pts BV. The mean number of CD34+ cells collected after each BV was 2.3+/-2.4, 5.8+/-5.2, 8.5+/-7.2, and 11.8+/-10.3x10(6) per kg body weight, respectively. The mean plt count decreased by 53+/-40.2/nl, Hb by 1.+/-0.5 g/dl and WBC by 0.+/-6.1/nl after separation of 4 BV. All but two pts reached the target value of 1.5x10(6) CD34+ cells/kg body weight and planned cycle of HD Ctx with 1 PBSCC. All pts engrafted and reached neutrophils>500/microl and plt>20,000/microl at a median of 11 and 13 days, respectively. We could demonstrate, that the yield of CD34+ cells during PBSCC increased continuously with the volume of the separated BV and that up to 5x the patients' BV could be processed safely without serious side effects. Most pts had to undergo only 1 PBSCC to collect sufficient numbers of CD34+ cells to support sequential courses of HD Ctx without delayed engraftment.

Chronic myelogenous leukemia: effect of interferon-alpha treatment on phagocytic activity and capacity of circulating neutrophils.

This study focuses on the effect of interferon (IFN)-alpha on phagocytosis of FITC-labeled Escherichia coli by polymorphonuclear neutrophils (PMNs) in chronic myelogenous leukemia (CML). The phagocytic activity and capacity of PMNs from IFN-alpha treated patients (n = 17), untreated CML patients (n = 9) and from healthy donors (n = 20) were compared using flow cytometry. Both parameters of PMN phagocytosis were reduced in untreated CML and in IFN-alpha treated CML with Ph1 chromosome persistence but normal in IFN-alpha treated CML with Ph1 conversion. Thus, the phagocytic performance of PMNs in patients with chronic phase CML is significantly improved after successful treatment with IFN-alpha.

Kinetics of cytokine secretion by mononuclear cells of the blood from rheumatoid arthritis patients are different from those of healthy controls.

Mononuclear cells from peripheral blood (PBMC) of rheumatoid arthritis (RA) patients and healthy controls were incubated with alpha-CD3. Cytokine secretion from 2 h to 72 h of incubation was measured by ELISA. There were no significant differences in secretion of T cell derived IL-2 and IL-4 in cultures from RA patients and controls. The macrophage-derived cytokines, IL-1 beta and tumour-necrosis factor-alpha (TNF-alpha) were secreted with a steep increase of concentration during the first 16 h of incubation by PBMC from RA patients. PBMC from healthy controls secreted both cytokines at a constantly rising rate with a maximum for TNF-alpha at 48 h and for IL-1 beta at 72 h. Interferon-gamma (IFN-gamma) is secreted in significantly reduced concentrations by PBMC from untreated RA patients compared with controls. Gold-salt treatment led to a slightly delayed and enhanced secretion of TNF-alpha and IL-1 beta, an enhanced secretion of IL-2 and a restored secretion of IFN-gamma.