Experimental hematology
-
Experimental hematology · Dec 1995
Case ReportsAllogeneic cell therapy for relapsed leukemia after bone marrow transplantation with donor peripheral blood lymphocytes.
Allogeneic bone marrow transplantation (BMT) is the treatment of choice for hematologic malignancies resistant to conventional chemotherapy and for patients who are at high risk for relapse. Until recently, no cure could be offered to patients relapsing following allogeneic BMT. We present our long-term observations of the first patient with remission reinduced by allogeneic cell therapy (allo-CT) using donor peripheral blood lymphocytes (PBL). ⋯ Although GVHD was frequent among responders, accompanied occasionally by transient or irreversible marrow aplasia, remissions were also obtained in patients with no GVHD. Allo-CT should therefore be considered as treatment of choice for overt relapse or de novo minimal residual disease post-BMT. Administration of donor peripheral blood lymphocytes in graded increments at an early stage of relapse may be the best approach for combining optimal timing at the stage of minimal disease while controlling and minimizing the risk of GVHD on an individual basis.
-
Experimental hematology · Dec 1995
Comparative StudyDifferential effect of type I interferons on hematopoietic progenitor cells: failure of interferons to inhibit IL-3-stimulated normal and CML myeloid progenitors.
We observed a differential effect of type I interferons (IFNs) in inhibiting the proliferation of various hematopoietic progenitor cell types. Upon stimulation with interleukin-3 (IL-3), IFN-alpha and IFN-beta failed to inhibit colony formation of myeloid progenitors (day-14 colony-forming units-granulocyte/macrophage [CFU-GM]) obtained from peripheral blood (PB) and bone marrow (BM) of untreated chronic myelogenous leukemia (CML) patients in chronic phase even at IFN doses as high as 10,000 U/mL. In contrast, day-7 CFU-GM stimulated with granulocyte colony-stimulating factor (G-CSF) and burst-forming units-erythroid (BFU-E) were readily inhibited by moderate doses of IFNs. ⋯ The failure of IFN to inhibit immature myeloid progenitors was confirmed in normal and CML cells highly enriched in CD34-expressing cells. Combinations of growth factors were required for sufficient colony formation in these cells, whereas IL-3 alone provided only an inadequate stimulation, which was further inhibited by IFN. In purified CD34+ cells, day-14 CFU-GM were protected from IFN-mediated inhibition only upon stimulation with stem cell factor (SCF) in combination with IL-3 or G-CSF.
-
Experimental hematology · Dec 1995
Comparative StudyEilatin: a novel marine alkaloid inhibits in vitro proliferation of progenitor cells in chronic myeloid leukemia patients.
We examined the effect of Eilatin, a novel marine product, on the survival of human myeloid progenitor cells (CFU-C) isolated from normal individuals and from 12 patients with Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) in chronic phase and blastic crisis. We compared its effect to the effect of interferon-alpha (IFN-alpha) and cytosine arabinoside (Ara-C). Eilatin, IFN-alpha, and Ara-C inhibited the proliferation of CFU-C from normal individuals and CML patients in a dose-dependent manner. ⋯ BCR/ABL translocations were detected in 94.6 +/- 0.6% of CD34+ cells after growth in liquid culture for 7 days. The level of BCR/ABL fusion signals detected after exposure of CD34+ cells for 16 hours to Eilatin 10(-7) M, IFN-alpha 500 U/mL, or Ara-C 10(-9) M were 54.5 +/- 5%, 63.6 +/- 5%, and 70 +/- 4%, respectively (mean +/- SE, n = 5). Our data indicate that Eilatin, a substance isolated from the Red Sea purple tunicate Eudistoma sp., has an antileukemic effect against in vitro Ph+ cells and may be used in conjunction with currently available agents for ex vivo purging of BM and/or PB of CML patients in conjunction with autologous bone marrow transplantation.
-
Experimental hematology · Dec 1995
Comparative StudyDetection of bcr-abl mRNA in single progenitor colonies from patients with chronic myeloid leukemia by PCR: comparison with cytogenetics and PCR from uncultured cells.
Bone marrow and/or peripheral blood of patients with chronic myeloid leukemia (CML) was investigated by the following three parameters: Ph' chromosome, bcr-abl expression in fresh blood and/or bone marrow, and bcr-abl expression in single hematopoietic progenitor colonies generated from blood and/or bone marrow. Expression of bcr-abl was proven by a reverse "nested primer" polymerase chain reaction (PCR) that is able to detect 1 pg of hybrid mRNA. We performed 108 investigations on 68 patients containing all three parameters: 12 on untreated patients, seven after interferon-alpha (IFN-alpha), seven after low-dose cytosine arabinoside (Ara-C), 22 after cyclic high-dose hydroxyurea (HU), 49 after allogeneic BMT, five before and three after stem cell mobilization, and three after autologous stem cell transplantation (ASCT). ⋯ The value of these observations is not clear. A follow-up of the patients will show if such sleeping progenitors can be activated in vivo. Concluding our observations, we can say that in special cases (therapy follow-up, detection of minimal residual disease) it could be useful to perform a PCR analysis of single progenitors in parallel with the routine investigations.
-
Experimental hematology · Dec 1995
5-Fluorouracil-resistant CD34+ cell population from peripheral blood of CML patients contains BCR-ABL-negative progenitor cells.
Despite the marked expansion of leukemic cells observed in the hematopoietic system of chronic myeloid leukemia (CML) patients, there is clinical and experimental evidence that normal nonclonal cells persist in the bone marrow (BM) and peripheral blood (PB) of patients in the early chronic phase. In this study, we attempt to select the benign progenitor-enriched population from the PB of CML patients. The CD34+ cells isolated from the PB of 12 CML patients in the chronic phase were treated with low doses (5 or 10 micrograms/mL) of 5-fluorouracil (5-FU). ⋯ For the presence of BCR-ABL, mRNA from each of the 12 patients was studied by reverse-transcriptase-polymerase chain reaction (RT-PCR) on 10-15 pooled CFU-GM colonies plucked from methylcellulose cultures of starting and expanded populations. Although all PCR results were positive for colonies harvested before liquid culture, we were able to identify BCR-ABL-negative colonies from an expanded CD34+ population cultured in the presence of recombinant cytokines in 11 of 12 patients studied. 5-FU pretreatment of CML CD34+ cells markedly reduced their clonogenic potential and growth factor-mediated cell proliferation but favored higher frequency of BCR-ABL-free colonies. In conclusion, these data show that 5-FU-resistant CD34+ cells from the PB of CML patients contain normal progenitor cells, which can be selected and expanded in short-term cytokine-mediated cultures.