Short and long-term safety of lenograstim administration in healthy peripheral haematopoietic progenitor cell donors: a single centre experience.

Healthy donors (HDs) who were mobilized using lenograstim (LENO) and who were undergoing peripheral haematopoietic progenitor cell collection with apheresis (HPC-A) were enrolled in a surveillance protocol. In all, 184 HDs have been assessed with a median follow-up of 62 months (range 2-155). HDs received LENO at a median dose of 10 microg/kg (range 5-15). Bone pain was reported as the most frequent short-term adverse event (71.2%). Other commonly observed short-term symptoms included fatigue (19.0%), fever (5.4%), headache (27.7%), nausea (12.0%) and insomnia (22.3%). Spleen size increased in 4.3% of the donors. No vascular disorders or cardiac disease occurred. Long-term follow-up included monitoring of adverse events, neoplastic disease or other pathologies. Transit ischaemic attack occurred in one donor (39 months post-donation). One autoimmune event was reported at 28 months post-recombinant human granulocyte (rhG)-CSF (ankylosing spondylitis); one donor with a history of chronic obstructive pulmonary disease developed secondary polyglobulia (50 months post-rhG-CSF). One donor was diagnosed with lung cancer at 19 months post-donation. No haematological disease was observed. In conclusion, the short-term safety appears to be verified, whereas, although the study identified no increased risks of malignancy among HDs who received rhG-CSF, long-term safety requires more complete data sets, especially a longer follow-up and a larger number of HDs.

Harvesting peripheral blood progenitor cells from healthy donors with a short course of recombinant human granulocyte-colony-stimulating factor.

A short-course administration of non-glycosylated granulocyte-colony-stimulating factor (G-CSF) was investigated in 68 healthy donors (HDs) in order to collect > or = 4 x 10(6) CD34+ cells per kilogram of recipient's body weight. G-CSF was given at 10 microg/kg per day administered in two divided doses for 3 days. Leukapheresis was scheduled on day 4, 12 h after the last dose of G-CSF. A median of 35.6 circulating CD34+ cells microL(-1) (range, 3.1-185) was found on the day of leukapheresis. This allowed a median collection of CD34+ cells of 4.2 x 10(6) per kilogram of recipient's weight (range, 1.0-17.4). One single procedure was sufficient to reach the target level of CD34+ cells in 36 (53%) of 68 donors; significant correlations were found between the number of CD34+ cells collected on day 4 and the patient's sex, body-weight and volume of blood processed. A retrospective analysis was made with a historical group of HDs collected on day 5. The day 5 schedule allowed a more consistent achievement of the target cell dose with one leukapheresis (P = 0.005) and resulted in the initial collection of a significantly larger number of CD34+ cells (P = 0.006).

Chlorambucil synergizes with purine analogs in inducing in vitro cytotoxicity in B-cell chronic lymphocytic leukemia.

Combinations of different drug concentrations of CLB + FAMP and CLB + 2-CDA were synergistic in, respectively, 42.9% and 34.8%. At leukemic cell survival < or = 50%, 16.4% and 23.4% of all combinations were synergistic in the 2-CDA and FAMP groups, respectively. A significantly higher mean value of antagonistic interactions was observed in the 2-CDA group (p = 0.037).

In vitro drug-induced cytotoxicity predicts clinical response to fludarabine in B-cell chronic lymphocytic leukaemia.

We investigated the possible value of an in vitro drug-induced cytotoxicity assay in predicting clinical response to fludarabine (FAMP) in chronic lymphocytic leukaemia (CLL). The median FAMP-LD50 values for cases designated as complete response (CR), partial response (PR), no response (NR) and progressive disease (PD) were 1.43, 2.05, 24.8 and 77.9 microg/ml, respectively (P=0.013). A significant lower mean FAMP-LD50 value was observed in the in vivo responding cases as compared to non-responding ones (3.0 +/- 0.82 SEM v 42.3 +/- 12.6 SEM, P=0.001). Only FAMP-LD50 < or = 2.5 microg/ml and more than four FAMP courses significantly influenced the response rate in univariate and multivariate analyses. The MTT assay may be of value in predicting clinical response to FAMP in CLL patients.

In vitro improvement of chlorambucil-induced cytotoxicity by deflazacort and 6-methylprednisolone in B-cell chronic lymphocytic leukaemia.

We examined whether CLL cell chemosensitivity to in vitro exposure to chlorambucil (CLB) might be improved by the presence of deflazacort (DFZ) in comparison to 6-methylprednisolone (PDN). The PDN lethal dose (LD)50 values were low in 5 samples, intermediate in 4 and high in 7. Low, intermediate and high DFZ-LD50 values were detected in 3, 2 and 11 samples, respectively. The CBL-LD50 mean values were significantly reduced at all PDN and at the 4 highest DFZ concentrations. However, a dose-response effect was seen only in the DFZ group. Both CLB-DFZ and CLB-PDN interactions were analysed in 16 samples at 25 different dose-combinations, resulting in 400 comparisons between expected and observed leukaemic cell survival (LCS) values for each group. In particular, 45.75% and 40% dose combinations were synergistic in CLB-DFZ and CLB-PDN groups, respectively. A relatively higher number of antagonistic interactions were observed among CLB-PDN dose combinations, while analogous number of additive interactions were detected. At concentrations of CLB x1 microgram/ml the phenomenon of synergism, regardless of the steroid concentration, did occur more frequently. On the other hand, a more elevated number of antagonistic interactions were counted at CLB 100 micrograms/ ml. In conclusion, both DFZ and PDN synergize in vitro with CLB, especially at low concentrations of the alkylating agent.

Bcl-2 protein expression and p53 gene mutation in chronic lymphocytic leukemia: correlation with in vitro sensitivity to chlorambucil and purine analogs.

BACKGROUND AND OBJECTIVE: Bcl-2 oncogenic protein expression plays a major role in blocking the apoptotic mechanism. p53 gene mutations have also been suggested to account for the chlorambucil resistance in CLL. Thus we studied the relationship between bcl-2 protein expression, p53 gene mutations and in vitro drug sensitivity in CLL. METHODS: Fifty-three samples from untreated CLL patients in early disease stages were tested in vitro for chemosensitivity to chlorambucil (CLB), fludarabine (FAMP) and 2-chlorodeoxyadenosine (2-CDA) using the MTT assay. Intracellular bcl-2 protein expression was evaluated by flow cytometry analysis. p53 gene mutations were detected by using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. RESULTS: The median LD50 values were 1.55 microM, 4.41 microM and 58.2 microM for 2-CDA, FAMP and CLB, respectively. About 23%, 41% and 11% of samples were defined as being sensitive to FAMP, 2-CDA and CLB, respectively, when samples were clustered for LD50 threshold values corresponding to the plasmatic levels of the drug. No statistically significant difference in bcl-2 protein expression was noted between sensitive and resistant samples for each drug. A p53 gene mutation was detected in 4 of the 30 cases studies and all of them were among samples resistant to CLB. INTERPRETATION AND CONCLUSIONS: Bcl-2 expression is not an indicator of in vitro response to drugs in CLL; similarly, although the four cases showing a p53 gene mutation were associated with CLB resistance, drug resistant samples were also observed in the group of patients showing wild type p53, suggesting multiple mechanisms of drug resistance in CLL.

The in vitro cytotoxic effect of mitoxantrone in combination with fludarabine or pentostatin in B-cell chronic lymphocytic leukemia.

BACKGROUND AND OBJECTIVE: Clinical studies indicate that combination chemotherapy with mitoxantrone (Mitox) and a purine analog can improve the response rate in indolent lymphoproliferative disorders. We explored the in vitro Mitox- fludarabine (FAMP)- and pentostatin (Pento)-induced cytotoxicity and their interactions in CLL. METHODS: The peripheral lymphocytes of 24 CLL patients were tested at different drug concentrations, with Mitox, FAMP or their combinations in 22 cases, and with Mitox, Pento or their combinations in 20 cases, 18 of which were the same from the FAMP group. The MTT assay was chosen for the drug-induced cell cytotoxicity and flow cytometry analysis of the DNA hypodiploid peak for the study of the apoptotic process. Drug interactions were calculated in the MTT assay according to both multiplicative and maximum models. RESULTS: According to the lethal dose (LD) 50 values, when the three drugs were tested alone, 11 out of 22 and 8 out of 20 samples were sensitive to Mitox in the FAMP and Pento groups, respectively; on the other hand, 2 out of 22 and 0 out of 20 samples appeared sensitive to FAMP or Pento alone, respectively. Analyzing the MTT assay data with the multiplicative and maximum model, the combinations of Mitox+FAMP and Mitox+Pento at different drug concentrations were synergistic in 28.2% and 39.3%, respectively. At leukemic cell survival < or = 50%, 11.7% and 11.1% of all combinations were synergistic in the Pento and FAMP group, respectively. The number of synergistic interactions at a therapeutically achievable plasma-drug concentration was an inverse function of the Mitox concentration. In the FAMP group, a direct correlation was found between the LD50 values of both FAMP and Mitox and the number of synergistic interactions, while the Pearson correlation coefficient was not significant in the Pento group. Finally, as measured by the DNA hypodiploid peak, Mitox (0.25 microgram/mL) plus Pento (0.16 microgram/mL) showed a significantly enhanced apoptosis in comparison to each single drug, while Mitox failed to demonstrate an additive effect with FAMP (1 microgram/ml). INTERPRETATION AND CONCLUSIONS: This experience demonstrates the extent of the in vitro synergism of Mitox with FAMP and Pento in inducing cell cytotoxicity; it also shows an adjunctive apoptotic effect for the Mitox-Pento association only.

In vitro sensitivity of chronic lymphocytic leukemia B-cells to fludarabine, 2-chlorodeoxyadenosine and chlorambucil: correlation with clinico-hematological and immunophenotypic features.

BACKGROUND: Chlorambucil (CLB), 2-chlorodeoxyadenosine (2-CDA) and fludarabine (FAMP) are among the most widely used drugs in chronic lymphocytic leukemia (CLL). Therefore we evaluated in vitro sensitivity to these drugs and cross-resistance of purine analogs. In addition, we correlated the in vitro data with the main clinico-hematological variables and surface markers. PATIENTS AND METHODS: Eighty CLL samples obtained from 63 untreated and 17 treated CLL patients were tested in vitro with the MTT assay. Lethal dose (LD)50 values were calculated to determine sensitivity to CLB, 2-CDA and FAMP. RESULTS: Samples were clustered either for a one-log increase of LD50 values or for LD50 threshold values of 3 microM for FAMP, 0.3 microM for 2-CDA and 7 microM for CLB, which correspond to the therapeutically achievable plasmatic levels of these drugs. A higher number of samples sensitive to 2-CDA were identified by the first approach; with the second method the relative order of sensitivity was FAMP > 2-CDA > CLB. Concerning 2-CDA and FAMP cross-resistance, out of 61 samples resistant to 2-CDA, 29.5% were sensitive to FAMP. Conversely, 13.9% out of 43 samples resistant to FAMP were sensitive to 2-CDA. No correlation was found between the main clinico-hematological features and the LD50 values of each drug either considering the whole series or only the untreated cases. In vitro drug sensitivity was also evaluated during the steady-state of the disease and at disease progression in six untreated cases. We observed a mean increase in the LD50 values of about 13, 38 and 22 times for CLB, FAMP and 2-CDA, respectively. Among the treated cases, the LD50 values of both purine analogs and CLB correlated with bone marrow histology. CLL cells expressing CD14, CD11c, CD11b, and FMC7 were more resistant in vitro to purine analogs but not to CLB. CONCLUSIONS: This study suggests that i) the purine analogs exert a greater cytotoxic effect on CLL cells; ii) 2-CDA and FAMP are not cross-resistant in vitro in a percentage of CLL samples, iii) a possible change in LD50 values may be related to modification of the disease status, and iv) the expression of certain surface markers, which are CLL-unrestricted, identifies samples with higher in vitro resistance to purine analogs.

Modulation of purine analogs- and chlorambucil-induced cytotoxicity by alpha-interferon and interleukin-2 in chronic lymphocytic leukemia.

The decrease in cell viability observed in vitro from the effect of chlorambucil (CLB), fludarabine (FAMP) and 2-chlorodeoxy-adenosine (CDA) on peripheral lymphocytes from 49 untreated CLL patients was investigated by the MTT colorimetric assay. The effects of recombinant-interleukin (r-IL)-2 and alpha-interferon (alpha-IFN) on drug-induced cell death were evaluated. r-IL-2 significantly increased in vitro resistance to CLB, while purine analog cytotoxicity was slightly reduced by the cytokine. The potential in vivo significance of r-IL-2, acting as a survival signal on CLB-induced cell death, is supported by the correlation between the lowest IL-2 serum levels, the highest in vitro sensitivity to CLB and a major clinical response after CLB treatment in six out of eight CLL patients. Using 25 samples, alpha-IFN enabled CLL cells to increase resistance to CLB, CDA and FAMP in 14, eight and seven samples, respectively; conversely, alpha-IFN showed a synergism with both CLB and FAMP in six samples and with CDA in four. These results correlate with immunoenzymatic assay data showing that alpha-IFN either up- or down-regulates tumor necrosis factor and IL-1 levels in supernatants of some CLL samples. Apparently, alpha-IFN plays a dual role in regulating drug-induced cell death, while IL-2 seems to solely favor cell survival in CLL.