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J Kaeda

Publications and source records attributed to J Kaeda.

At least 19 recordsLinked to original sources
PubMed2007

Increased frequencies of CD4(+)CD25(high) T(regs) correlate with disease relapse after allogeneic stem cell transplantation for chronic myeloid leukemia.

The therapeutic efficacy of allogeneic hemopoietic stem cell transplantation (SCT) for chronic myeloid leukemia (CML) largely relies on the graft-versus-leukemia (GvL) effect exerted by donor T cells. CD4(+)CD25(high) regulatory T cells (T(regs)) have been shown to downregulate antitumor responses but their role on GvL has not been evaluated. We performed a cross-sectional study in which we enumerated and characterized CD4(+)CD25(high) T(regs) in the peripheral blood of CML patients undergoing allogeneic SCT. We documented higher frequencies of T(regs) in patients after transplant as compared to normal controls and newly diagnosed patients. The increment was particularly evident in patients who had received their SCT 18 months before. In vitro functional studies demonstrated that the T(regs) purified from SCT patients exhibited a more potent suppressive activity than T(regs) isolated from healthy volunteers. Patients in whom T(regs) numbers were higher than controls more than 18 months after SCT showed evidence of disease relapse. Although the increment in T(regs) might have an advantageous effect on graft rejection in the early phase post-transplant, our data suggest that T(regs) exert an inhibitory effect on GvL.

Adolescent↗
PubMed2006

Rationale for the recommendations for harmonizing current methodology for detecting BCR-ABL transcripts in patients with chronic myeloid leukaemia.

Molecular monitoring for patients with chronic myeloid leukaemia (CML) has become an important practice in the era of imatinib therapy. For successful widespread introduction into the mainstream patient monitoring schedule, many procedural aspects of the complex real-time quantitative polymerase chain reaction (RQ-PCR) technique for measuring BCR-ABL transcripts require optimization. Recommendations for harmonizing the differing methodologies have recently been proposed. These recommendations were designed to maximize reliability of analysis for clinical decision making and proposed the adoption of an International Scale of measurement. The purpose of this review is to present the evidence and supporting data for specific recommendations. These recommendations include use of the same source of cells, either blood or marrow, for analysis; for validation of equal PCR amplification efficiencies of cDNA and standards when using a plasmid to construct standard curves and for ensuring ongoing high-level performance by undertaking a quality assurance programme. Clinicians must know the measurement reliability of an RQ-PCR assay to be able to determine the significance of a change in BCR-ABL level. An assay with poor precision limits the clinical usefulness of results. International harmonization should establish RQ-PCR measurement of BCR-ABL as the best method for monitoring treatment response for patients with CML.

Drug Monitoring↗
PubMed2006

The presence of a BCR-ABL mutant allele in CML does not always explain clinical resistance to imatinib.

The expansion of a leukemia clone bearing a Bcr-Abl kinase domain mutation is associated with acquired resistance to imatinib and may also predict disease progression in patients with Philadelphia-positive chronic myeloid leukemia (CML). Here we report results of pyrosequencing to quantitate the non-mutated and mutant alleles in 12 CML patients monitored over periods ranging from 11 to 58 months, and describe three contrasting kinetic patterns: Group 1 - in four patients total BCR-ABL transcript numbers remained high with the mutant allele predominating; Group 2 - in four patients the total number of BCR-ABL transcripts fell to low levels but the mutant allele predominated; and Group 3 - in four other patients the total level of transcripts remained high (n = 2) or fell (n = 2) but the mutant clone persisted at relatively low level. In Group 2 the mutant leukemia clone was presumably still relatively sensitive to imatinib but in Group 1 the leukemia could be classified as resistant. In Group 3 patients the imatinib sensitivity of the leukemia was variable. We conclude that a mutant clone does not necessarily have a proliferative advantage and its presence does not always account for resistance to imatinib. Other mechanisms underlie resistance in at least some patients.

Adult↗
PubMed2005

Monitoring patients in complete cytogenetic remission after treatment of CML in chronic phase with imatinib: patterns of residual leukaemia and prognostic factors for cytogenetic relapse.

We monitored BCR-ABL transcript levels by quantitative real-time PCR in 103 patients treated with imatinib for chronic myeloid leukaemia in chronic phase for a median of 30.3 months (range 5.5-49.9) after they achieved complete cytogenetic remission (CCyR). The patients could be divided into three groups: (1) in 32 patients transcript levels continued to decline during the period of observation (nadir BCR-ABL/ABL ratio 0.015%); in five of these patients BCR-ABL transcripts became undetectable on repeated testing, (2) in 42 patients the transcript levels reached a plateau and (3) in 26 patients transcript numbers increased and the initial CCyR was lost. Three patients were not evaluable. Patients who remained in CCyR for at least 24 months appeared to have a low risk of subsequent cytogenetic relapse. We conclude that the pattern of 'residual' disease after achieving CCyR on imatinib is variable: some patients in CCyR show a progressive reduction in the level of residual disease, some reach a plateau where transcript numbers are relatively stable and others relapse with Ph-positive metaphases.

Adolescent↗
PubMed2004

Lymphoid transformation in a CML patient in complete cytogenetic remission following treatment with imatinib.

We describe here a patient with Philadelphia (Ph) chromosome-positive chronic myeloid leukemia who achieved a complete cytogenetic response following treatment with imatinib and then progressed abruptly to lymphoid blastic transformation. The sequence of events suggests that at least in some cases patients who respond well to imatinib may still harbor residual leukemia progenitor or 'stem' cells that are susceptible to acquisition of molecular events that underlie progression to advanced phase disease. The case highlights the need for molecular monitoring of responders and the need to develop strategies for reducing to a minimum or totally eradicating leukemia cells.

Aged↗
PubMed2001

Early detection of BCR-ABL transcripts by quantitative reverse transcriptase-polymerase chain reaction predicts outcome after allogeneic stem cell transplantation for chronic myeloid leukemia.

The reverse transcriptase-polymerase chain reaction (RT-PCR) has become widely used for monitoring minimal residual disease after allogeneic stem cell transplantation (SCT) for chronic myeloid leukemia (CML). However, most of these studies were performed using qualitative RT-PCR, and the interpretation of the results obtained has been conflicting. The correlation of a quantitative RT-PCR test performed early after SCT (at 3 to 5 months) and long-term outcome of CML patients surviving for more than 6 months was studied. Between January 1991 and June 1999, data from 138 CML patients who received allografts were evaluated. Early RT-PCR results were classified as (1) negative if there were no BCR-ABL transcripts detected (n = 61), (2) positive at low level if the total number of BCR-ABL transcripts was less than 100 per microg RNA and/or the BCR-ABL/ABL ratio was less than 0.02% (n = 14), or (3) positive at high level if transcript levels exceeded the thresholds defined above (n = 63). Three years after SCT the cumulative incidence of relapse was 16.7%, 42.9%, and 86.4%, respectively (P =.0001). The relationship between BCR-ABL transcript level and probability of relapse was apparent whether patients had received sibling or unrelated donor SCT and also whether or not the transplantation was T cell depleted. The results suggest that quantitative RT-PCR performed early after SCT is useful for predicting outcome and may help to define the need for further treatment.

Actuarial Analysis↗
PubMed2001

Immune haemolytic anaemia following T cell-depleted allogeneic bone marrow transplantation for chronic myeloid leukaemia: association with leukaemic relapse and treatment with donor lymphocyte infusions.

Immune haemolytic anaemia (IHA) is a recognised complication after allogeneic stem cell transplantation (SCT) and occurs more frequently if marrow cells have been subjected to T cell depletion (TCD). Among 58 consecutive patients who underwent TCD-allogeneic SCT from volunteer unrelated donors for the treatment of CML at the Hammersmith Hospital during a 3-year period (1 March 1996 to 28 February 1999) we identified nine cases of IHA. All patients had a strongly positive direct and indirect antiglobulin test and in eight patients the serological findings were typical of warm-type haemolysis often with antibody specificities within the Rh system. All nine cases had clinically significant haemolysis and were treated initially with prednisolone and immunoglobulin. The onset of IHA coincided with the occurrence of leukaemic relapse in six cases, and the presence of host haemopoiesis confirmed by lineage-specific chimerism in all four cases studied. Five patients received donor lymphocyte infusions (DLI); in three molecular remission and the restoration of full donor chimerism coincided with resolution of haemolysis. We conclude that in the context of leukaemic relapse, DLI is an effective therapy for IHA following allografts involving TCD.

Adolescent↗
PubMed2001

Analysis of chimaerism in thalassaemic children undergoing stem cell transplantation.

We have prospectively assessed the relative contribution of host and donor to haemopoiesis following stem cell transplantation (SCT) in children with beta-thalassaemia major (n = 35), using karyotype analysis or Southern blot/polymerase chain reaction analysis of variable number tandem repeats on genomic DNA from peripheral blood. Early haemopoiesis was fully donor in origin in 24 out of 35 cases and remained so throughout the post-transplant course in all but one patient, who evolved to stable mixed chimaerism. The remaining 11 cases (31%) initially showed mixed chimaerism: four of these rejected, one eventually eradicated host haemopoiesis to become fully donor haemopoietic, and the remaining six had persistent mixed chimaerism, with 5--38% host haemopoiesis. The risk of graft rejection was high when > 15% host haemopoiesis was present at 3 months post transplant: four out of six such patients rejected their grafts; conversely, zero out of 29 patients with < 15% host haemopoiesis at 3 months rejected (P < 0.0001). There was a higher incidence of significant acute and chronic graft-versus-host disease in patients with full donor chimaerism. These studies confirm that the mixed chimaeric state is common following SCT for thalassaemia, often persists (with up to 4 years follow-up) and is compatible with long-term cure. Analysis of chimaerism in patients undergoing SCT for beta-thalassaemia enables monitoring of engraftment in the early post-transplant period, provides insight into the biology of engraftment and may be useful in identifying patients at high risk of rejection.

ABO Blood-Group System↗
PubMed2001

Molecular studies in patients with chronic myeloid leukaemia in remission 5 years after allogeneic stem cell transplant define the risk of subsequent relapse.

We identified 103 consecutive patients who, 5 years after allogeneic transplantation for chronic myeloid leukaemia (CML), were in molecular remission (MR). The 103 patients were divided into three groups on the basis of reverse transcription-polymerase chain reaction (RT-PCR) studies for BCR-ABL transcripts in the first 5 years post transplant: Group A comprised 63 patients who had been continuously PCR negative; Group B comprised 20 patients with one or more positive PCR result but only at a low level; and Group C comprised 20 patients who had fulfilled the criteria for molecular relapse, been treated with donor lymphocyte infusions (DLI) and had thereafter regained complete MR within the 5-year post-transplant period. The median follow-up for all 103 patients was 8.4 years from transplant (range 5-17.6 years). In group A only one patient relapsed at 9.2 years. In group B eight patients (40%) relapsed: six at molecular, one at cytogenetic and one haematological levels. The actuarial probabilities of survival at 10 years for patients in Groups A, B and C were 97.4%, 92.9% and 100% respectively; the probabilities of relapse were 3%, 54% and 0% respectively. We conclude that molecular studies during the first 5 years post transplant can help to predict long-term leukaemia-free survival and, possibly, cure of CML.

Adolescent↗
PubMed2000

Durability of responses following donor lymphocyte infusions for patients who relapse after allogeneic stem cell transplantation for chronic myeloid leukemia.

An analysis was performed of the response to treatment with donor lymphocyte infusions (DLI) and the survival in 66 consecutive patients who relapsed after primary treatment by allogeneic stem cell transplantation for BCR-ABL-positive chronic myeloid leukemia. The transplant donor was an HLA-identical sibling (n = 35) or a "matched" unrelated volunteer (n = 31). Fifty-seven patients were transplanted in chronic phase, eight in accelerated phase, and one in second chronic phase. The recognition of relapse was based on precise molecular, cytogenetic, or hematologic criteria. The median interval from transplant to relapse was 12 months (range 3-85). The median interval from relapse to initiation of DLI was 9.4 months (range 1-70). Patients received DLI from their original transplant donors on a bulk-dose (n = 34) or on an escalating-dose (n = 32) regimen. Patients were monitored serially by hematologic, cytogenetic, and molecular criteria. Molecular remission was defined by the finding of negative results by nested primer reverse transcriptase polymerase chain reaction (RT-PCR) for BCR-ABL transcripts on two consecutive occasions, subject to satisfactory controls. Forty-four patients (67%) achieved molecular remission. Patients who had relapsed to advanced phase disease and patients with short intervals between transplant and relapse had significantly lower probabilities of achieving molecular remission. Of the 44 patients who achieved molecular remission, 4 reverted to a PCR-positive status at 15, 18, 37, and 87 weeks after remission. The probability of survival for patients who achieved molecular remission was significantly better than for those who failed to do so (95% versus 53% at 3 years post-DLI, P = .0001). We conclude that the majority of molecular remissions after DLI are durable, and thus the majority of responding patients may prove to have been cured. (Blood. 2000;96:2712-2716)

Adult↗
PubMed2000

Fusion of H4/D10S170 to the platelet-derived growth factor receptor beta in BCR-ABL-negative myeloproliferative disorders with a t(5;10)(q33;q21).

We have studied a patient who presented with clinical features suggestive of chronic myeloid leukemia in accelerated phase. BCR-ABL transcripts were undetectable by reverse transcription-PCR, but a novel reciprocal translocation, t(5;10)(q33;q21.2), was seen by standard cytogenetic analysis. Chromosome band 5q33 contains the gene encoding the platelet-derived growth factor beta receptor (PDGFbetaR), the receptor tyrosine kinase that is disrupted by the t(5;7), t(5;12), and t(5;14) in myeloid disorders, resulting in the fusion of PDGFbetaR to HIP1, TEL/ETV6, and CEV14, respectively. Southern analysis with PDGFbetaR cDNA revealed novel bands in patient but not control DNA after digestion with several restriction enzymes, indicating that this gene is also targeted by the t(5;10). Fluorescence in situ hybridization analysis of chromosome 5 indicated that a small inversion at 5q33 had taken place in addition to the interchromosomal translocation. The site of the chromosome 10 breakpoint fell within YAC 940e4. Because all PDGFbetaR fusions described thus far result in splicing to a common exon of this gene, we performed 5'-rapid amplification of cDNA ends PCR on patient RNA. Several clones were isolated in which PDGFbetaR fused in frame to H4/D10S170, a previously described ubiquitously expressed gene that is fused to the ret protein tyrosine kinase to form the PTC-1 oncogene in approximately 20% of papillary thyroid carcinomas. The presence of H4-PDGFbetaR chimeric mRNA in the patient was confirmed by reverse transcription-PCR; reciprocal PDGFbeta1R-H4 transcripts were not detected. We conclude that t(5;10)(q33;q21.2) is a novel translocation in BCR-ABL-negative chronic myeloid leukemia and that this abnormality results in an H4-PDGFbetaR fusion gene. This finding further strengthens the association between myeloproliferative disorders and deregulated tyrosine kinases.

Amino Acid Sequence↗
PubMed2000

Molecular heterogeneity in complete cytogenetic responders after interferon-alpha therapy for chronic myelogenous leukemia: low levels of minimal residual disease are associated with continuing remission. German CML Study Group and the UK MRC CML Study Group.

A substantial minority of patients with chronic myelogenous leukemia (CML) achieve a complete response (CR) to treatment with interferon-alpha (IFN), defined as the disappearance of Philadelphia chromosome-positive metaphases. Currently it is unclear how long IFN treatment should be continued for such patients. We used a competitive reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify levels of BCR-ABL transcripts in 297 peripheral blood specimens collected from 54 patients who had achieved CR with IFN. The median duration of observation was 1.9 years (range, 0.3-11.0 years). Total ABL transcripts were quantified as internal control and results were expressed as the ratio BCR-ABL/ABL. All 54 patients had molecular evidence of residual disease, although 3 patients were intermittently PCR negative. The median BCR-ABL/ABL ratio at the time of maximal response for each patient was 0.045% (range, 0%-3. 6%). During the period of observation 14 patients relapsed, 11 cytogenetically to chronic phase disease and 3 directly to blastic phase. The median ratio of BCR-ABL/ABL at maximal response was significantly higher in patients who relapsed than in those who remained in CR (0.49% versus 0.021%, P < 0.0001). Our findings show that the level of residual disease falls with time in complete responders to IFN, but molecular evidence of disease is rarely if ever eliminated. The actual level of minimal residual disease correlates with the probability of relapse. We suggest that for patients who reach CR, IFN should be continued at least until relatively low levels of residual leukemia are achieved. (Blood. 2000;95:62-66)

Adolescent↗
PubMed2000

Comparison of single-dose and escalating-dose regimens of donor lymphocyte infusion for relapse after allografting for chronic myeloid leukemia.

Donor lymphocyte infusion (DLI) was originally administered as a single, relatively large dose of lymphocytes called a bulk dose regimen (BDR). It has since been suggested that the use of an escalating dose regimen (EDR) may be equally effective against leukemia while it induces less graft-versus-host disease (GVHD). We therefore compared the efficacy and incidence of complications in a nonrandomized sequential study of the 2 regimens in 48 consecutive patients who had relapses with cytogenetic or hematologic evidence of chronic myeloid leukemia after allogeneic stem cell transplantation. Twenty-eight patients were treated on a BDR (August 1990 to November 1995) and 20 were treated on an EDR (December 1995 to January 1998). Although the probability of achieving cytogenetic remission within 2 years of starting DLI did not differ significantly between the 2 groups (EDR, 91% [CI, 63%-98%] vs. BDR, 67% [CI,49%-83%], P =.70), the incidence of GVHD was much lower using EDR (10% vs. 44%, P =.011). When we considered only subsets of patients treated by BDR or EDR who had received comparable total lymphoid cell doses, the incidence and severity of acute and chronic GVHD were both significantly lower for recipients treated by EDR than for recipients treated by BDR (P =.005 and P =.031, respectively). These findings suggest that the incidence of GVHD associated with the EDR is low, not because the final cell dose is small, but because lymphocytes are administered over a considerable number of months. (Blood. 2000;95:67-71)

Disease-Free Survival↗
PubMed1997

Clonal instability preceding lymphoid blastic transformation of chronic myeloid leukemia.

We have sought the presence of rearrangements of the immunoglobulin heavy chain gene locus in 13 patients with chronic myeloid leukemia (CML) in lymphoid blastic transformation (L-BT) using the polymerase chain reaction (PCR). The lymphoid nature of the transformation was confirmed by immunophenotyping and/or Southern blot hybridization with a J(H) probe. Clonal rearrangements were detected in 85% of cases and two or more rearrangements were visible in 64% of informative cases. The pattern of V(H) gene family utilization revealed an apparent reduction in V(H)4 family gene usage but otherwise reflected the known proportion of each gene family in the germline repertoire. In six cases the third complementary determining regions (CDR3) of the predominant blast crisis clone/s were sequenced revealing minimal evidence of somatic mutation. No clonal changes were detected in the chronic phase leukemia cells collected more than 6 months before the onset of L-BT in three of these patients. Of the other three patients studied in chronic phase from 1 to 6 months before L-BT, two showed clonal rearrangements which differed in size from those present at L-BT. In one patient a V(H)3 to V(H)5-D(H)-J(H) substitution had occurred at least 3 months prior to L-BT. In the other patient, however, the sequence of the rearrangement present 5 months prior to L-BT was unrelated to the rearrangements at the time of L-BT indicating a pattern of clonal succession. We conclude that: (1) IgH gene rearrangements are detectable in the majority of patients with L-BT using PCR and the lymphoid lineage of blastic CML is most readily confirmed using consensus primers to the framework 3 region; (2) somatic mutation is uncommon; and (3) B lymphoid clones distinct from those identified later may be detected before overt lymphoid BT. The identification of such 'abortive' clones is evidence for clonal instability before the onset of transformation and might have prognostic value.

Adolescent↗
PubMed1996

DNA haplotypes in Africans and West Indians with sickle cell anaemia or SC disease.

Considering that genetic variation linked to the beta S mutation may influence the clinical manifestations of sickle cell disease, we have analyzed the beta globin cluster haplotypes in 47 patients with this condition (33 SS homozygotes, one S/beta thal (0), and 13 SC) living in London (30 West Indian, 17 West African). Of the 80 chromosomes tested, 82.5% had the Benin haplotype and of the 13 C chromosomes tested, 85% had the Bantu-A4 haplotype. A minority of patients had Bantu or Senegal haplotypes, and in 5 patients we found new haplotypes called E, H and O which may have arisen through mutation or recombination. Because of the predominance of a single haplotype (Benin) nearly all our homozygous S patients were either homozygous or heterozygous for this haplotype. We concluded that the beta globin haplotype is unlikely to be an important determinant of the clinical severity in this patient population.

Africa, Western↗
PubMed1993

Beta-thalassemia mutations in the Portuguese; high frequencies of two alleles in restricted populations.

We report the characterization of seven different beta-thalassemia mutations in 131 newly diagnosed Portuguese beta-thalassemia heterozygotes. Methodology included the detection of abnormal fragments by agar gel electrophoresis of PCR-amplified DNA fragments after digestion with specific restriction endonucleases, as well as hybridization with synthetic nucleotide probes and sequencing of amplified DNA. Four mutations, including the newly discovered TGG-->TGA change at codon 15, occurred in excess of 10% and accounted for some 90% of the beta-thalassemia alleles in this population. The geographical distribution is uneven; the TGG-->TGA mutation at codon 15 was primarily observed in the coastal region north of Lisbon, while the IVS-I-6 (T-->C) mutation was confined to the central part of the country.

Alleles↗