H Demuynck

Feasibility of peripheral blood progenitor cell harvest and transplantation in patients with poor-risk myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a group of clonal haematological disorders with a highly unfavourable prognosis. Allogeneic bone marrow transplantation offers the sole possibility for cure and prolonged survival, but is only available for a minority of patients. Therefore, we investigated the feasibility of PBPC collection and transplantation in 11 patients with high‐risk myelodysplasia who were not eligible for allogeneic bone marrow transplantation. In six patients, PBPC were harvested after mobilization with G‐CSF alone. Five patients were harvested during the recovery phase of intensive chemotherapy combined with G‐CSF. This resulted in seven patients in an adequate CD34 progenitor yield >1 × 106/kg. Six patients obtained a CFU‐GM content of the PBPC harvest >10 ×104/kg. Five patients were subsequently transplanted following a standard BuCy4 regimen. The median to ANC (absolute neutrophil count) ≥0.5 and 1.0 × 109/l was respectively 14 d (range 10–18) and 16 d (range 11–25). Platelets were self‐supporting ≥20 × 109/l after a median of 41 d (range 8–144). One patient had a persistent lack of platelet engraftment unresponsive to infusion of back‐up bone marrow.

Risks of rhG-CSF treatment in drug-induced agranulocytosis

Nine patients with drug-induced agranulocytosis received recombinant human granulocyte colonystimulating factor (rhG-CSF) to accelerate myeloid recovery because of life-threatening infections related to neutropenia. All patients showed a quick recovery of their granulocyte counts. Side effects were substantial, however. Three patients, two with a severe infection and one with preexisting pulmonary infiltrates, developed worsening of their respiratory status during neutrophil recovery, resulting in clinical manifestations of the adult respiratory distress syndrome (ARDS). In view of these major complications, the exact place of hematopoietic growth factors in the treatment of drug-induced agranulocytosis remains to be determined.

Recombinant human erythropoietin for the treatment of anemia in the myelodysplastic syndromes: A clinical and erythrokinetic assessment

SummaryThe clinical and ferrokinetic effects of escalating doses of subcutaneously administered recombinant human erythropoietin (rh-EPO) were studied in ten patients with myelodysplastic syndromes and severe transfusion-dependent anemia. Red blood cell transfusion requirements diminished in four patients, and one of the patients eventually became transfusion independent with an EPO-induced rise of Hb from 7.7 g/dl to 12.3 g/dl. Endogenous serum levels of EPO were significantly increased in all patients (100–5700 mU/ml), but three of four responders had a relatively low baseline level. The effective red cell iron turnover (RCIT) improved in two responding patients and even normalized in one patient. This increase in RCIT was accompanied with a decline in the ineffective red cell iron turnover (IIT). The other responding patients had a relatively preserved RCIT before EPO treatment. EPO therapy further increased the fraction of IIT in the latter patients. Red cell survival time did not increase during EPO therapy, even in the responding patients. One transient and one maintained increase in platelet count were observed. Disease progression with a sustained increase in blast cells in one patient and a transient elevation of blasts in another patient was seen. No other side effects of EPO therapy were observed. These results suggest that anemic MDS patients with low serum EPO levels and relatively spared effective erythropoiesis as measured by ferrokinetic studies may be the best candidates for treatment with recombinant human EPO.

Patients with high-risk myelodysplastic syndrome can have polyclonal or clonal haemopoiesis in complete haematological remission.

The clonality of mature peripheral blood‐derived myeloid and lymphoid cells and bone marrow haemopoietic progenitors from 18 females with myelodysplasia (MDS) (five refractory anaemia, RA; one RA with ringed sideroblasts, RARS; three chronic myelomonocytic leukaemia, CMML; four RA with excess of blasts, RAEB; five RAEB in transformation, RAEB‐t) was studied by X‐chromosome inactivation analysis. Using the human androgen‐receptor (HUMARA) assay, we analysed the clonal patterns of highly purified immature CD34+38− and committed CD34+38+ marrow‐derived progenitors, and CD16+14− granulocytes, CD14+ monocytes, CD3+ T and CD19+ B lymphocytes from peripheral blood. In high‐risk patients (RAEB, RAEB‐t), clonality analysis was performed before and after intensive remission‐induction treatment. All patients, except one with RA, had predominance of a single clone in their granulocytes and monocytes. The same clonal pattern was found in CD34+ progenitor cells. In contrast, CD3+ T lymphocytes were polyclonal or oligoclonal in 14/18 patients. X‐chromosome inactivation patterns of CD19+B cells were highly concordant with CD3+ T cells except for two patients (one RA, one CMML) with monoclonal B and polyclonal T lymphocytes, therefore suggesting a clonal mutation in a progenitor common to the myeloid and B‐lymphoid lineages or the coexistence of MDS and a B‐cell disorder in these particular patients. After high‐dose non‐myeloablative chemotherapy, polyclonal haemopoiesis was reinstalled in the mature myeloid cells and immature and committed marrow progenitors in three of four patients achieving complete haematological remission. Therefore we conclude that most haematological remissions in MDS are associated with restoration of polyclonal haemopoiesis.

Comparative study of peripheral blood progenitor cell collection in patients with multiple myeloma after single-dose cyclophosphamide combined with rhGM-CSF or rhG-CSF

Summary. Patients suffering from high‐risk multiple myeloma (MM) were randomized to receive single high‐dose cyclophosphamide followed by either rhGM‐CSF or rhG‐CSF in order to harvest circulating peripheral blood progenitor cells. The safety of the procedure, the mobilization kinetics, the relative efficacy of rhGM‐CSF and rhG‐CSF to mobilize progenitor cells and their relative toxicity were studied. Special attention was paid to the antigenic profile of CD34+ progenitor cells.

Caries-related salivary microorganisms and salivary flow rate in bone marrow recipients

Cancer treatments often induce oral complications. In this study we investigate longitudinally the salivary gland function, the salivary caries-related microorganisms, and buffer capacity in bone marrow recipients. Stimulated saliva samples were taken midmorning. The salivary factors were studied in 42 patients from before transplant until 4 months after transplant. A dramatic reduction (66%) of salivary flow rate is noticed in all patients at 1 month after transplant, and only a partial recovery (42% reduction) is seen after 4 months. A clear shift toward a lower buffer capacity and a higher amount of cariogenic microorganisms is seen posttransplant. This shift is more pronounced when total body irradiation was included in the pretransplant conditioning therapy. These findings indicate that the studied parameters in transplant recipients can contribute to a higher caries risk and oral complications during the early posttransplant period.

Translocation t(1;6)(p35.3;p25.2): a new recurrent aberration in ‘unmutated’ B-CLL

Although reciprocal chromosomal translocations are not typical for B-cell chronic lymphocytic leukemia (B-CLL), we identified the novel t(1;6)(p35.3;p25.2) in eight patients with this disorder. Interestingly, all cases showed lack of somatically mutated IgVH. Clinical, morphological, immunologic, and genetic features of these patients are described. Briefly, the age ranged from 33 to 81 years (median: 62.5 years) and the sex ratio was 6M:2F. Most of the patients (6/8) presented with advanced clinical stage. Therapy was required in seven cases. After a median follow-up of 28 months, five patients are alive and three died from disease evolution. Three cases developed transformation into diffuse large B-cell lymphoma. Translocation t(1;6) was found as the primary karyotypic abnormality in three patients. Additional chromosomal aberrations included changes frequently found in unmutated B-CLL, that is, del(11)(q), trisomy 12 and 17p aberrations. Fluorescence in situ hybridization analysis performed in seven cases allowed us to map the t(1;6) breakpoints to the 1p35.3 and 6p25.2 chromosomal bands, respectively. The latter breakpoint was located in the genomic region coding for MUM1/IRF4, one of the key regulators of lymphocyte development and proliferation, suggesting involvement of this gene in the t(1;6). Molecular characterization of the t(1;6)(p35.3;p25.2), exclusively found in unmutated subtype of B-CLL, is in progress.

Hypercalcemia, monoclonal protein and osteolytic bone lesions in chronic lymphocytic leukemia

SummaryWe describe a patient with a long history of typical chronic lymphocytic leukemia (CLL) who developed hypercalcemia, osteolytic bone lesions, and a monoclonal protein, all features of a secretory plasma cell disorder. These features in CLL have been reported in only four previous cases. The hypercalcemia in our patient is felt to result from an increase in the osteoclastic process.

Minor myeloid component in Ph chromosome-positive acute lymphoblastic leukaemia: correlation with cytogenetic pattern and implication for poor response to therapy

Morphological, immunological and cytogenetic features were studied in 27 adults presenting with Ph chromosome‐positive acute lymphoblastic leukaemia (ALL), in correlation with clinical outcome.

Philadelphia chromosome-positive chronic myelogenous leukemia in treated Hodgkin's disease

A patient who developed Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) 8 years after successful treatment for Hodgkins disease (HD) is reported. The Ph chromosome with a typical 9(22) translocation was identified by banding techniques in 80% of bone marrow (BM) cells. Southern blot analysis showed breakpoint cluster region (BCR) rearrangement as observed in classical CML. Until now, only three cases of Ph + CML have been reported after treatment for HD. At present, it is not clear whether development of CML after HD represents a therapy-induced complication, an increased susceptibility to secondary malignancies owing to the malignant process itself, a consequence of the immunological deficiencies in HD, or possibly a genetic susceptibility to malignancy.