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F van Rhee

Publications and source records attributed to F van Rhee.

47 records · Page 3Linked to original sources
PubMed1995

Molecular cytogenetics of chronic myeloid leukemia with atypical t(6;9) (p23;q34) translocation.

We report the molecular cytogenetic analysis of a case of Philadelphia (Ph)-negative, BCR-positive chronic myeloid leukemia (CML) which appeared by conventional cytogenetics to have a t(6;9)(p23;q34) as the sole cytogenetic abnormality. Neither conventional nor pulse-field Southern blots detected any rearrangement of the DEK or CAN genes which are often fused in acute myeloid leukemia (AML) with t(6;9)(p23;q34). However, rearrangements of both BCR and ABL genes were detected. The breakpoint in BCR was located in the major translocation cluster region between exons b1 and b3. ABL rearrangements were detected with an ABL exon 1B probe and with a probe located 5' of the entire ABL gene. Comigration between the rearranged fragments obtained with M-bcr-5' and ABL exon 1B probes was observed, implying that the entire ABL gene was fused to the 5' part of the BCR gene. Fluorescence in situ hybridization (FISH) analyses using BCR and ABL probes showed that in 20% of metaphases BCR and ABL signals were present on one chromosome 6 at 6p23, whilst in 80% of metaphases BCR and ABL signals were identified on both copies of chromosome 6. Furthermore, FISH analysis with a whole-chromosome 22 paint demonstrated that chromosome 22 material was present on both copies of chromosome 6. These data indicate a complex Philadelphia translocation involving chromosome band 6p23 and duplication of the whole aberrant chromosome. The nature of the gene locus on 6p23, involved in this rearrangement, remains unknown. A similar translocation has been previously reported in a case of CML, which also lacked DEK and CAN gene rearrangements implying that abnormalities of 6p23 involving genes other than DEK may be a recurrent abnormality in CML.

Blotting, Southern↗
PubMed1995

Quantification of residual disease in Philadelphia-positive acute lymphoblastic leukemia: comparison of blood and bone marrow.

We designed a new semi-quantitative competitor-based PCR assay to assess the amount of p190 BCR-ABL mRNA in patients with Ph-positive ALL. Transcript numbers were compared in 29 paired specimens of blood and marrow collected contemporaneously from 18 patients at differing stages of disease. In general, the numbers of BCR-ABL transcripts detected in marrow in blood were not significantly different (p = 0.1). However, in four samples BCR-ABL transcripts (< 10-1000/micrograms RNA) were detected in the marrow while the blood was negative; the reverse, positive blood and negative marrow, was not seen. In a further three samples the number of BCR-ABL transcripts was more than 10-fold higher in the marrow. We measured the number of ABL transcripts/micrograms RNA in all samples as an internal standard in order to control for variations in sample quality and other parameters. For two out of the four discordant samples in which blood was PCR negative, the number of ABL transcripts/micrograms RNA detected in the marrow was substantially higher than in the blood, suggesting poor quality blood specimens. However, the ratio of BCR-ABL to ABL in marrow and blood was similar for the three discordant samples in which both tissues were PCR positive. We conclude that in general, blood and marrow contain similar BCR-ABL transcript numbers in Ph-positive ALL but some samples are discordant. Marrow is therefore the preferred tissue for residual disease studies. Quantification of ABL mRNA as an internal control is useful in the interpretation of competitive PCR data and may serve as a robust way to standardize results between laboratories.

Base Sequence↗
PubMed1994

Relapse of chronic myeloid leukemia after allogeneic bone marrow transplant: the case for giving donor leukocyte transfusions before the onset of hematologic relapse.

Fourteen patients with chronic myeloid leukemia (CML) relapsing after allogeneic bone marrow transplant (BMT) were treated with leukocyte transfusions from the original marrow donor (sibling, n = 9; volunteer unrelated, n = 5). The relapse was defined at the molecular level in two cases, cytogenetically in five cases and hematologically in seven cases. Ten patients responded, seven of seven patients with cytogenetic/molecular relapse compared with three of seven with hematologic relapse (P < .03). All five recipients of cells from unrelated donors responded. Eight of the 10 responders have achieved polymerase chain reaction-negative status and this persisted in three patients for more than 2 years; no responder has shown sign of relapse. Reversible marrow aplasia occurred in two patients, both treated in hematologic relapse. Severe graft-versus-host disease occurred in four patients and was fatal in one. We confirm previous reports that donor leukocyte transfusions are effective in the management of CML in relapse after BMT. In this series, therapeutic intervention before the onset of hematologic relapse was associated with an increased likelihood of response and no marrow aplasia.

Adult↗
PubMed1994

Aplasia after donor lymphocyte infusion (DLI) for CML in relapse after sex-mismatched BMT: recovery of donor-type haemopoiesis predicted by non-isotopic in situ hybridization (ISH).

We report a patient with CML in relapse after a sex-mismatch bone marrow transplant who was treated with donor lymphocyte infusions and developed severe marrow aplasia 3 months later. As cytogenetic analysis at this point was not possible because of the very low number of marrow cells available, we used in situ hybridization (ISH) for sex chromosomes and the BCR/ABL gene together with quantitative PCR to monitor the patient's response. The results suggest that recovering haemopoiesis was derived from donor cells and contributed to the decision not to transfuse donor marrow cells on a second occasion.

Adult↗
PubMed1994

Distinct T cell populations distinguish chronic myeloid leukaemia cells from lymphocytes in the same individual: a model for separating GVHD from GVL reactions.

Donor lymphocyte responses to minor histocompatibility antigen (mHA) differences are involved in allo-responses between HLA matched pairs causing GVHD and graft-versus-leukaemia (GVL). Since some mHA are tissue-restricted, GVHD and GVL responses may be separable. We studied donor lymphocyte responses to patients with CML in a series of 10 HLA-matched sibling and 10 unrelated donor-recipient pairs comparing proliferation to recipient PHA blasts and CML cells and attempting to selectively deplete responses to PHA blasts in vitro. Responses in counts per min (c.p.m) to CML cells and PHA blasts were, respectively, 2809 +/- 2205 (SD) and 7376 +/- 1877 in related and 12,107 +/- 7191 and 26,136 +/- 22,479 in unrelated pairs. Autologous responses to PHA blasts were significantly lower (mean 779 +/- 735) (p < 0.001). Results correlated with clinical outcome: higher responses to recipient cells correlated with transplant-related death (p = 0.02 for CML and p = 0.06 for PHA blasts). Higher responses to CML correlated with GVHD grade > or = II (p = 0.025). Donor lymphocytes exposed to recipient PHA blasts for 5 days and treated with a ricin-conjugated anti-CD25 antibody retained over 75% of their response to CML but < 10% to PHA blasts. Similarly, depletion of response to CML but not to PHA blasts occurred when CML was the primary challenge. These results indicate that distinct populations of donor T cells respond to recipient leukaemic and non-leukaemic cells, and provide the basis for a clinically applicable technique to selectively deplete donor GVHD reacting cells while conserving GVL.

Graft vs Host Disease↗
PubMed1994

Detection of residual leukaemia more than 10 years after allogeneic bone marrow transplantation for chronic myelogenous leukaemia.

The clinical status of a homogeneous cohort of long-term survivors of allogeneic marrow transplantation was assessed and residual leukaemia was studied by reverse transcription polymerase chain reaction for leukaemia specific BCR-ABL mRNA. The group comprised 34 consecutive patients with CML in chronic phase treated by chemoradiotherapy and transplantation of bone marrow from HLA-identical sibling donors between February 1981 and December 1983 in the joint Hammersmith-Northwick Park programme. The probability of survival at 10 years was 59 +/- 17%. Eighteen of the 19 surviving (95%) patients have Karnofsky scores of 90 or 100% indicative of a good performance status. One of the survivors had evidence of relapse 6.5 years after transplant but has since been restored to complete remission by treatment with interferon-alpha followed by donor leucocyte transfusions. Surprisingly, 2 of the 19 patients who have been in remission for over 10 years have molecular evidence of persisting leukaemic cells. Quantification by competitive PCR indicated that the malignant clone persisted at low levels. The data suggest that the majority of long-term survivors after BMT for CML are in good health and may be regarded as cured. Some long-term survivors, however, may still harbour residual leukaemic cells and continued monitoring for late relapse is warranted. Late relapse is amenable to further therapy with leukocyte transfusions from the original marrow donor.

Adult↗
PubMed1992

Abnormal haemoglobin electrophoresis caused by BW 12C.

BW 12C, a substituted benzaldehyde, stabilises haemoglobin in the oxy-conformation and has attracted interest as an anti-sickling agent. The drug causes a left shift in the oxygen saturation curve and may induce tumour anoxia and enhance the effect of cytotoxic drugs. During clinical trials in patients with cancer abnormal bands on haemoglobin electrophoretic strips were observed. This made correct diagnosis of abnormal haemoglobins impossible. Solubility tests for sickling disorders (Itano) also proved unreliable.

Adenocarcinoma↗
PubMed1991

Bilateral retinal artery occlusion due to mitral valve prolapse.

We report a case of bilateral retinal artery occlusion due to mitral valve prolapse. Most patients with retinal ischaemia in whom it is found have not been previously known to have it. Since it is a common condition it would seem essential that it be included in the differential diagnosis of amaurosis fugax and retinal artery occlusion if future ischaemic events are to be prevented. All patients with retinal ischaemia should have a full cardiovascular examination supplemented by echocardiography.

Aged↗
PubMedDate not supplied

In vitro generation of Epstein-Barr virus-specific cytotoxic T cells in patients receiving haplo-identical allogeneic stem cell transplantation.

Use of a partially mismatched related donor (PMRD) is an option for patients who require allogeneic transplantation but do not have a matched sibling or unrelated donor. Epstein-Barr virus (EBV)-induced lymphoma is a major cause of mortality after PMRD transplantation. In this study, we present a clinical grade culture system for donor-derived EBV-specific cytotoxic T cells (CTLs) that do not recognize haplo-identical recipient cells. The EBV-specific CTLs were tested for cytolytic specificity and other functional properties, including ability to transgress into tissues, propensity for apoptosis, degree of clonality, stability of dominant T-cell clones, and Tc and Th phenotypes. The EBV-specific CTLs were routinely expanded to greater than 80 x 10(6) over a period of 5 weeks, which is sufficient for clinical application. A CD8+ phenotype predominated, and the CTLs were highly specific for donor lymphoblastoid cell lines (LCLs) without killing of recipient targets or K562. Vbeta spectratyping showed an oligoclonal population that was stable on prolonged culture. The EBV-specific CTLs were activated (D-related human leukocyte antigen [HLA-DR+], L-selectin+/-) and of memory phenotype (CD45RO+). Expression of the integrin VLA-4 suggested that these CTLs could adhere to endothelium and migrate into tissues. The Bcl-2 message was upregulated, which may protect the CTLs from the apoptosis. The first demonstration of overexpression of bcl-2 in human memory CTLs. In addition, we show that lymphoblastoid cell lines used to generate CTLs are readily genetically modified with recombinant lentivirus, indicating that genetically engineered antigen presentation is feasible.

Adolescent↗