Complete remission of accelerated phase chronic myeloid leukemia by treatment with leukemia-reactive cytotoxic T lymphocytes.

Relapse of chronic myeloid leukemia (CML) in chronic phase after allogeneic stem cell transplantation (SCT) can be successfully treated by donor lymphocyte infusion (DLI). However, relapse of accelerated phase CML, blast crisis, or acute leukemia after allogeneic SCT are resistant to DLI in the majority of cases. In vitro-selected and expanded leukemia-reactive T-cell lines may be more effective in inducing an antileukemic response in vivo. To treat a patient with accelerated phase CML after allogeneic SCT, leukemia-reactive cytotoxic T-lymphocyte (CTL) lines were generated from her HLA-identical donor. Using a modification of a limiting dilution assay, T cells were isolated from the donor, selected based on their ability to inhibit the in vitro growth of CML progenitor cells, and subsequently expanded in vitro to generate CTL lines. Three CTL lines were generated that lysed the leukemic cells from the patient and inhibited the growth of leukemic progenitor cells. The CTL did not react with lymphocytes from donor or recipient and did not affect donor hematopoietic progenitor cells. The 3 leukemia-reactive CTL lines were infused at 5-week intervals at a cumulative dose of 3.2 x 10(9) CTL. Shortly after the third infusion, complete eradication of the leukemic cells was observed, as shown by cytogenetic analysis, fluorescence in situ hybridization, molecular analysis of BCR/ABL-mRNA, and chimerism studies. These results show that in vitro cultured leukemia-reactive CTL lines selected on their ability to inhibit the proliferation of leukemic progenitor cells in vitro can be successfully applied to treat accelerated phase CML after allogeneic SCT.

HLA-B44-directed cytotoxic T cells associated with acute graft-versus-host disease following unrelated bone marrow transplantation.

We describe the recipient of a marrow graft from an HLA-serologically identical unrelated donor from whom highly potent host-reactive CTL of donor origin were isolated in association with acute GVHD. Extensive sequence and biochemical analysis of the HLA complex of this donor and recipient revealed several disparities in class I and class II HLA with the potential to be recognized by T cells from the donor or the host. The donor-derived CTL exclusively recognized a class I HLA difference associated with HLA-B44. Nucleotide sequencing of donor and recipient cells revealed that the patient possessed the HLA-B*4402 allele recognized by IEF as B44.2 while the donor possessed HLA-B*4403 (IEF variant B44.1). These alleles differ at one amino acid residue located at position 156 in the alpha 2 domain. The donor-derived CTL were shown to be specific for B44.2 by blocking studies and by the lysis of five different B44.2+ unrelated cell lines, two of which were confirmed by sequencing to be homozygous for B*4402. A host-specific difference involving a HLA-DRB1 allele was not recognized by the CTL, neither did HLA differences unique to the donor HLA-B*4403 and HLA-DQ8 elicit a host response. These data show that certain HLA disparities may be tolerated at the same time that other disparities elicit a potent immunologic response. The chemical nature of the difference, its structural impact, as well as the conditions of transplant appear to influence the type of response which occurs.

Sequential study of myeloid differentiation antigens of neutrophil granulocytes in different phases of chronic myeloid leukaemia: natural history and prognostic significance.

In an attempt to contribute to the knowledge of the natural history of Philadelphia-chromosome-positive chronic myeloid leukaemia (CML) and its prognosis, we analyzed sequentially the myeloid differentiation antigens of peripheral blood neutrophil granulocytes (NG) in different evolutive stages of the disease. Four monoclonal antibodies (CD15, CD24, 31D8, and 13F6) were used, and a total number of 116 sequential studies were performed in 43 patients. At diagnosis, there is a significant decrease of NG expressing myeloid differentiation antigens, which recover to nearly normal levels after initial control of the disease. The onset reduction is probably due to the circulation of incompletely mature NG. In accelerated/blastic phase NG expressing myeloid differentiation antigens decrease again, probably due to a true antigen loss. This reduction could herald by a few months the development of accelerated/blastic phase. In such a case, its predictive strength is higher than that of the well recognized initial prognostic parameters in CML. These results indicate that the sequential study of NG myeloid differentiation antigens may contribute to both a better understanding of the natural history of CML and the evolutive prognosis of this disease.

Molecular remission occurring after donor leukocyte infusions for the treatment of relapsed chronic myelogenous leukemia after allogeneic bone marrow transplantation.

Donor leukocyte infusions were administered to a patient who had relapsed with chronic myelogenous leukemia after having failed two successive HLA-matched allogeneic bone marrow transplants. Serial cytogenetic, restriction fragment length polymorphism, and polymerase chain reaction studies of the patient's marrow and blood after receiving donor leukocyte infusions revealed disappearance of the leukemic clone and the establishment of complete donor chimerism. An antileukemic response in this patient occurred initially in the absence of clinically evident graft-versus-host disease (GVHD), but complete eradication of the leukemic clone did not occur until after the onset of GVHD. The patient is now 48 weeks post infusion and remains in complete remission. This case demonstrates that leukocyte infusions are an effective form of adoptive immunotherapy which can result in a sustained molecular remission.

Expression of hematopoietic progenitor cell associated antigen CD34 in chronic myeloid leukemia.

The expression of progenitor cell associated antigen CD34 was investigated in cells from 28 patients with chronic myeloid leukemia (CML). The CD34 positivity varied from 0-26% in patients with chronic phases CML (n = 17); from 6-64% in patients with accelerated phase CML (n = 4); and from 27-97% in the patients with blastic crisis of CML (n = 8). The difference in CD34 positivity between chronic (mean 10.1 +/- 2.3%), accelerated (37.7 +/- 13.3%) and blastic (58.0 +/- 7.3%) phases of CML is statistically significant (p less than 0.05), however, the number of patients studied, especially in accelerated and blastic phases is very small. There was no difference in the CD34 positivity of the cells in the peripheral blood and in the bone marrow. CD34 positivity was higher in patients with chronic phase CML at diagnosis (untreated patients) than in those who were studied during treatment. The possible importance of serially studying CD34 positivity in patients with CML is discussed in the paper.

Analysis of CD1 molecules on haematological malignancies of myeloid and lymphoid origin. I. Cell surface antigen expression.

One hundred and ninety well-characterized acute and chronic leukaemias were studied for the expression of CD1a antigen by indirect immunofluorescence (IIF). CD1a was detected on 28 per cent of mature B cell lymphoproliferative disorders, 26 per cent of acute non-lymphoblastic leukaemias (ANLL), 21 per cent of chronic granulocytic leukaemias in blast crisis (CML-BC), 53 percent of T acute lymphocytic leukaemias (T-ALL) and in only one out of 35 common acute lymphoblastic leukaemias (c-ALL). In some cases the expression of the CD1a antigen on the surface of leukaemic cells showed a spontaneous fluctuation after a short period of incubation in vitro. CD1b and CD1c molecules were also detected on B cells and acute non-lymphoblastic leukaemias. The presence of CD1 antigens was confirmed using a dot blot assay (DBA) on the lysate of leukaemic cells.

The use of unrelated bone marrow donors in the treatment of patients with chronic myelogenous leukemia: experience of four marrow transplant centers.

Thirty-seven patients with chronic myelogenous leukemia who lacked an HLA-identical sibling were transplanted with bone marrow from an HLA-A,B,DR-matched, one locus-mismatched, or two locus-mismatched unrelated volunteer donor. Twenty-two were in chronic phase and 15 had advanced to either accelerated phase or blast crisis. The projected 1000-day survival is 55% for chronic phase patients and 22% for accelerated or blast phase patients. For patients transplanted during chronic phase, results appeared to be comparable whether the donor was fully HLA-matched or HLA one locus-mismatched. These results indicate that marrow grafting from either HLA-identical or HLA one locus-mismatched volunteer donors may be effective therapy for patients with chronic myelogenous leukemia who lack an acceptable related donor.