[The chronic Philadelphia chromosome-negative myeloproliferative syndrome II. Clinical findings, diagnostics and treatment]. / Det kroniske Philadelphia-kromosom-negative myeloproliferative syndrom II. Klinik, diagnostik og behandling.

Polycythaemia vera (PV) and essential thrombocytosis (ET) are clinically characterised by non-specific neurologic symptoms, peripheral circulatory disturbances (acrocyanosis, wounds, erythromelalgia) or abdominal symptoms. The treatment of PV includes phlebotomy, antiaggregation and cytoreduction. In ET, the primary treatment is also low-dose aspirin except for patients presenting with a haemorrhagic diathesis. Hydroxyurea may be associated with an increased risk of acute leukaemia or myelodysplasia. Therefore alpha-interferon and anagrelide should be considered in younger patients. Early cytoreductive therapy is advocated in patients with idiopathic myelofibrosis (IMF) to inhibit further progression of bone marrow fibrosis and further expansion of myeloid metaplasia in the spleen and liver. Treatment with androgens (danazol) and glucocorticoids may improve severe anaemia and thrombocytopenia. In younger patients, allogeneic bone marrow transplantation should be considered.

Serial cytogenetic studies in allografted patients with chronic myeloid leukemia.

Serial marrow karyotyping was performed in 31 chronic myeloid leukemia (CML) patients treated with allogeneic bone marrow transplantation (BMT). Of 11 hematological relapses, seven were heralded for up to 20 months by a cytogenetic relapse (characterized by increasing percentages of Philadelphia (Ph)-positive metaphases, seen on serial karyotypes). Chromosomal abnormalities additional to the Ph, seen before BMT, were not found again at relapse. Relapses were characterized by clonal evolutions of the Ph-positive cells, likely corresponding to cytogenetic patterns of treatment-induced leukemia [del(5q), del(7q), complex karyotypes] and were different from those generally found in CML evolution. Involvement of chromosome 1 was also frequent. Sporadic Ph-positive metaphases (not seen in repeated karyotypes) were seen only during the first 8 months after BMT.

Appearance of Ph negative recipient clones in chronic myeloid leukemia patients following bone marrow transplantation.

Seven patients were studied following bone marrow transplantation for chronic myeloid leukemia. Cytogenetic heteromorphisms were used to determine the origin of cells present post-BMT. Differences were found between results from blood and bone marrow samples, and between karyotype and interphase Y-body studies on the same samples. Philadelphia negative (Ph-) hematopoietic chimerism was found in 6 of 7 patients, all of whom had been Ph+ before BMT. One patient also demonstrated hematopoietic chimerism with Ph+ recipient cells following clinical evidence of relapse. In two patients who had received T-cell depleted grafts, cytogenetically rearranged Ph- clones of recipient cells were prominent in PHA-stimulated blood. In one case two clones had appeared only 1 month post BMT. The appearance of these clones so soon after transplant suggests very rapid clonal expansion, or that they were already present pre-BMT but at levels too low to have been detected. In the second patient, clones were not observed until more than 12 months post-BMT, after which four were found. These collectively expanded to occupy an increasing proportion of the total cells. These two patients with clones both remain in good health 44 and 51 months post-BMT. Further studies are needed to determine the true frequency and the significance of such findings.

Prolonged remission of accelerated phase Philadelphia chromosome negative chronic myeloid leukemia following autologous recovery of normal hematopoietic elements after busulfan/cyclophosphamide and allogeneic marrow transplantation.

We describe here a patient with accelerated phase Philadelphia chromosome (Ph1) negative chronic myelogenous leukemia without BCR gene rearrangement, who received an allogeneic bone marrow transplant following a conditioning regimen consisting of busulfan (BU) and cyclophosphamide (CY). Hematopoiesis was restored following splenectomy performed 1 month post-transplant. There were no distinguishing cytogenetic differences between donor and host. Five years post-transplant the patient relapsed with the original disease. Restriction fragment length polymorphism (RFLP) studies performed at that time exhibited host specific DNA markers suggesting recurrent leukemia of host origin. RFLP analysis of the cells cryopreserved immediately post-transplant also revealed all cells to be of host origin. This patient experienced 5 years of remission with autologous hematopoietic recovery from an aggressive myeloproliferative disorder after high dose BU and CY without engraftment of donor hematopoietic cells.

In vitro marrow purging in chronic myelogenous leukemia: effect of mafosfamide and recombinant granulocyte--macrophage colony-stimulating factor.

Clinical and experimental evidence revealing Ph1-negative hematopoietic stem cells in the majority of chronic myelogenous leukemia (CML) patients, suggests that autologous bone marrow transplantation (ABMT) may represent a therapeutic approach for these patients. It was the aim of the present study to evaluate the efficacy of the cyclophosphamide derivative mafosfamide as a marrow purging agent in a group (n = 15) of CML patients. Chemical purging was followed by a short-term liquid culture phase supplemented with recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF). Mafosfamide (100 micrograms/ml) incubation induced a marked inhibition of progenitor cell growth, the percentages of surviving CFU-GEMM, BFU-E, and CFU-GM being 3.4, 5.4, and 4.9, respectively. At the cytogenetic level, the purging procedure failed to show any modulating effect on Ph1-negative clones in 9/15 cases. In contrast, 6/15 cases showed a significant increase in the mean (+/- SD) percentage of Ph1-negative metaphases in response to rGM-CSF (46 +/- 26, p less than or equal to 0.05), mafosfamide incubation (53 +/- 12, p less than or equal to 0.01), and the combination of mafosfamide incubation plus rGM-CSF (63 +/- 29, p less than or equal to 0.025). Immunological analysis revealed that mafosfamide incubation induced a significant enrichment of MY10 (28 +/- 9, 0.05) B73.1-positve cells (25 +/- 9, p less than or equal to 0.05). Four mafosfamide-responsive patients with CML in second chronic phase have been autografted with mafosfamide purged marrow. In all patients a Ph1-negative phase lasting 5-14 months was observed. In conclusion, it appears that (a) in a subgroup of CML patients mafosfamide purging is effective in reducing the size of the malignant clone and might induce through its cytotoxic and immune actions a modification of the balance between leukemic and normal clones, and (b) this experimental approach may be used as a screening test to select patients to undergo marrow harvest and ABMT with mafosfamide purged marrow.