High-dose etoposide with granulocyte colony-stimulating factor for mobilization of peripheral blood progenitor cells: efficacy and toxicity at three dose levels

High-dose etoposide (2.0-2.4 g m(-2)) with granulocyte colony-stimulating factor (G-CSF) is an effective strategy to mobilize peripheral blood progenitor cells (PBPCs), although in some patients this is associated with significant toxicity. Sixty-three patients with malignancy were enrolled into this non-randomized sequential study. The majority (55/63, 87%) had received at least two prior regimens of chemotherapy, and seven patients had previously failed to mobilize following high-dose cyclophosphamide with G-CSF. Consecutive patient groups received etoposide at three dose levels [2.0 g m(-2) (n = 22), 1.8 g m(-2) (n = 20) and 1.6 g m(-2) (n = 21)] followed by daily G-CSF. Subsequent leukaphereses were assayed for CD34+ cell content, with a target total collection of 2.0 x 10(6) CD34+ cells kg(-1). Toxicity was assessed by the development of significant mucositis, the requirement for parenteral antibiotics or blood component support and rehospitalization incidence. Ten patients (16%) had less than the minimum target yield collected. Median collections in the three groups were 4.7 (2 g m(-2)), 5.7 (1.8 g m(-2)) and 6.5 (1.6 g m(-2)) x 10(6) CD34+ cells kg(-1). Five of the seven patients who had previously failed cyclophosphamide mobilization achieved more than the target yield. Rehospitalization incidence was significantly lower in patients receiving 1.6 g m(-2) etoposide than in those receiving 2.0 g m(-2) (P = 0.03). These data suggest that high-dose etoposide with G-CSF is an efficient mobilization regimen in the majority of heavily pretreated patients, including those who have previously failed on high-dose cyclophosphamide with G-CSF. An etoposide dose of 1.6 g m(-2) appears to be as effective as higher doses but less toxic.

Molecular characterization of the 7q deletion in myeloid disorders

Deletion of the long arm of chromosome 7 is a common karyotypic finding in myeloid disorders and in particular is found in association with secondary leukaemias. We have used restriction fragment length polymorphisms and gene dosage experiments to assess the loss or retention of sequences localized to chromosome 7q in five patients with clonal myeloid disorders and a 7q deletion. The deletion was interstitial in all cases with retention of the anonymous marker pS194 located at 7q36-qter. Three out of five cases also retained the more proximal gene T-cell receptor beta (TCR beta) located at 7q35. The proximal breakpoints of all five cases were localized to 7q22 by cytogenetic analysis. In two cases the proximal breakpoint lay between the genes for elastin (ELN) and collagen type 1 alpha (COL1A2) and in three cases distal to this region between the genes for erythropoietin (EPO) and acetylcholinesterase (ACHE). The genes of ACHE, plasminogen activator inhibitor 1 (PLANH1), CCAAT displacement protein (CUTL1) and Met proto-oncogene (MET) were deleted in all cases. Molecular analysis of the 7q deletion in myeloid leukaemias demonstrates heterogeneity of the breakpoints, supporting a recessive mechanism of tumourigenesis.

When to harvest peripheral-blood stem cells after mobilization therapy: prediction of CD34-positive cell yield by preceding day CD34-positive concentration in peripheral blood

PURPOSE

To evaluate whether the CD34+ yield from a single peripheral-blood stem-cell (PBSC) harvest could be predicted by measurement of the patient's circulating WBC and CD34+ cell concentrations on the day before harvest.

PATIENTS AND METHODS

Thirty-nine patients with hematologic or nonhematologic malignancy underwent 41 stem-cell mobilization episodes with cytotoxic chemotherapy and/or granulocyte colony-stimulating factor (G-CSF), and a total of 63 leukapheresis procedures were performed. Peripheral-blood samples were analyzed for WBC and CD34+ cell concentration both on the day before and the day of leukapheresis.

RESULTS

The median WBC and CD34+ concentrations on the day preceding leukapheresis were 10.0 x 10(9)/L (range, 0.4 to 44.4) and 24.9 x 10(6)/L (range, 0.1 to 349.4), respectively. On the day of harvest, the corresponding figures were 15.1 x 10(9)/L (range, 1.5 to 52.6) and 29.3 x 10(6)/L (range, 0.1 to 543.1), respectively. The median CD34+ cell number collected in a single leukapheresis was 2.6 x 10(6)/kg body weight (range, 0.1 to 26.1). Both the preceding day (r = .84, P < .001) and harvest day (r = .95, P < .001) CD34+ circulating concentrations correlated significantly with the number of CD34+ cells per kilogram collected at leukapheresis. The correlation between CD34+ cells per kilogram collected and harvest day WBC count was also significant (r = .43, P <.001), but with the preceding day WBC count was nonsignificant.

CONCLUSION

The number of CD34+ cells harvested in a single leukapheresis can be predicted by measurement of the preceding day peripheral-blood circulating CD34+ concentration, and on the basis of these data a table of probable CD34+ cell yield has been constructed. This correlation may facilitate the efficient organization of leukapheresis procedures.

Hematological features of patients with myelodysplastic syndromes associated with a chromosome 5q deletion

The hematological and clinical features of 26 patients with myelodysplasia and a chromosome 5q deletion in the bone marrow are presented. We have examined the relationship of French-American-British Co-operative Group (FAB) 1982 classification and bone marrow karyotype at diagnosis with patient outcome and the presence or absence of the classical features of the 5q-syndrome. Those patients classified as refractory anemia (RA) with no additional karyotypic abnormalities have the typical features of the 5q-syndrome and a good prognosis. None of the patients in this group transformed to acute leukemia during the period of follow-up. Patients with either refractory anemia and excess blasts (RAEB) or additional karyotypic abnormalities show many of the hematologic features of the 5q-syndrome but do not share the good prognosis. We conclude that the 5q-syndrome may be best defined as primary MDS of the FAB type RA with a 5q deletion as the sole karyotypic abnormality. This simple definition will distinguish patients with a good prognosis and all the classical features of the 5q-syndrome.

Severe rotavirus-associated diarrhoea following bone marrow transplantation: treatment with oral immunoglobulin

Two patients developed acute severe rotavirus-associated diarrhoea following BMT. Both received treatment with oral immunoglobulin and in each case the diarrhoea substantially resolved within 3 days, and rotavirus became undetectable in their stool. Oral immunoglobulin may be a useful therapy for rotavirus gastroenteritis post-BMT.

Clonality of cell populations in refractory anaemia using combined approach of gene loss and X-linked restriction fragment length polymorphism-methylation analyses

We have used X-linked restriction fragment length polymorphism (RFLP)-methylation and gene deletion analyses to investigate the nature of the progenitor cell of origin in the myelodysplastic syndromes (MDS). Gene deletion studies were performed on the granulocyte and T-lymphocyte fractions of six women with refractory anaemia (RA) and either a partial deletion of the long arm of chromosome 5 (5q-) or monosomy 7. All six showed gene loss in the granulocyte but not the T-lymphocyte fractions, indicating monoclonality of the granulocytes but not the T-lymphocytes. In order to further investigate this finding, we subsequently performed X-RFLP-methylation studies using the probe M27 beta, and also a probe for the phosphoglycerate kinase (PGK) gene. These studies have confirmed the monoclonality of the granulocytes and the polyclonality of the T-lymphocytes in these cases. Our findings suggest that in this group of patients with MDS the T-lymphocytes were not involved in the disorder, and furthermore, in the one case where B-lymphocytes were also available, that the progenitor cell of origin was restricted to the myeloid lineage.

Structure of the granulocyte macrophage colony-stimulating factor gene in patients with the myelodysplastic syndromes

DNA samples from 76 patients with the myelodysplastic syndromes, including 10 cases with a partial deletion of the long arm of chromosome 5 (5q-), were examined for structural rearrangements of the granulocyte/macrophage colony-stimulating factor (GM-CSF) gene. No abnormalities were detected, indicating that structural aberrations of this gene are not a feature of the myelodysplastic syndromes.

A new HincII polymorphism at the epidermal growth factor receptor locus on chromosome 7

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