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PubMed2001

Effect of slow lymphocyte recovery and type of graft-versus-host disease prophylaxis on relapse after allogeneic bone marrow transplantation for acute myelogenous leukemia.

Allogeneic BMT is potentially curative for patients with acute myelogenous leukemia (AML) in first remission. However, many patients relapse after transplantation. Various immunotherapeutic options have been attempted with variable success in preventing relapse. Early identification of patients at high risk for relapse could allow prompt intervention. We examined the effect of slow lymphocyte recovery after sibling-matched allogeneic BMT on the risk of relapse in patients with AML. We also examined the effect of prednisone-containing GVHD prophylaxis on the rate of lymphocyte recovery. Patients with absolute lymphocyte count (ALC) <150 x 10(6)/l by day +30 had a 3.5-fold higher risk of relapse (P = 0.0088) and a lower overall survival (P = 0.0079) than patients with a higher ALC. We did not find correlation between lymphocyte count determined earlier in the post-transplantation course (day +21) and the risk of relapse. Patients receiving prednisone had a significantly lower ALC at day +30 than those who did not receive prednisone (289 vs 549 x 10(6)/l, P = 0.002). We conclude that a slow lymphocyte recovery after allogeneic BMT for AML is strongly predictive of subsequent relapse and that the type of GVHD prophylaxis should be considered when analyzing lymphocyte recovery.

Adolescent↗

PubMed2005

Management of chronic myeloid leukaemia in relapse following donor lymphocyte infusion induced remission: a retrospective study of the Clinical Trials Committee of the British Society of Blood & Marrow Transplantation (BSBMT).

Donor lymphocyte infusion (DLI) can restore remission in a high percentage of patients with chronic myeloid leukaemia (CML) who relapse after allogeneic stem cell transplant (SCT). Subsequent relapses after a DLI-induced remission do occur and the optimal management of these patients is not defined. A retrospective study of the practice of UK transplant centres was conducted. In all, 13 patients from seven centres were identified: all were treated for relapse post allogeneic SCT with DLI and achieved either a complete cytogenetic (n=5) or molecular (n=8) remission. All patients subsequently had a second relapse, at molecular (n=7), cytogenetic (n=4) and haematological (n=2) levels. Further DLI was used in the treatment of 11 patients, imatinib mesylate in three and chemotherapy in two. The two patients with haematological relapse died of blastic disease. The remaining 11 patients achieved either a complete cytogenetic (n=2) or molecular (n=9) remission. Nine patients remain in molecular remission at a median follow-up of 29 months, seven of whom had received DLI alone as treatment for second relapse, one DLI plus imatinib and one imatinib alone. Toxicity following DLI for second relapse was low. Longer follow-up will be required to see if these second DLI-induced remissions will be durable.

Adult↗

PubMed1999

Prevention of relapse in pediatric patients with acute leukemias and MDS after allogeneic SCT by early immunotherapy initiated on the basis of increasing mixed chimerism: a single center experience of 12 children.

The success of allogeneic stem cell transplantation (allo-SCT) in children is mainly affected by relapse or graft rejection. We have recently shown in a study of 55 patients with acute leukemias (ALL 21, AML 20 and MDS 14), that patients who demonstrate increase amounts of autologous marrow repopulation (increasing mixed chimerism) have a significantly enhanced risk of relapse (P < 0. 0001). Based on these findings, we asked whether post-transplant relapse can be prevented by withdrawal of immunosuppression and/or by donor lymphocyte infusion (DLI). We describe the results of a pilot study where adoptive immunotherapy was used to treat 12 patients (five ALL, three AML, four MDS) who showed increasing mixed chimerism (MC) post-transplant. A response to immunotherapy, defined as the re-establishment of complete chimerism (CC) and continuous complete remission (CCR), was achieved in four patients (two ALL, two AML) following withdrawal of CsA and in a further six patients (three ALL, three MDS) after additional DLI. One ALL patient, who initially responded to DLI, developed severe GVHD that required further immunosuppression. GVHD was controlled but this patient subsequently relapsed. Another patient with ALL became a CC but developed an isolated relapse in the bone marrow 260 days later. One patient with MDS developed severe GVHD after DLI and died. Two children (one AML and one MDS) did not show any response to interventional treatment and died due to relapse. Of the 12 patients treated, seven remain in CCR at a median follow-up of 747 days (range 351-1109 days). In summary, these results provide evidence that increasing MC can be used to guide adoptive immunotherapy strategies and that these treatment modalities can be used to prevent relapse in children with acute leukemias or MDS after allo-SCT.

Adolescent↗

PubMed2000

Relapse in childhood acute lymphoblastic leukemia is associated with a decrease of the Bax/Bcl-2 ratio and loss of spontaneous caspase-3 processing in vivo.

Dysfunction of the p53/Bax/caspase-3 apoptosis signaling pathway has been shown to play a role in tumorigenesis and tumor progression, ie the development of acquired drug resistance. Low expression of the apoptosis inducer Bax correlates with poor response to therapy and shorter overall survival in solid tumors. In the present study, we analyzed the p53/Bax/caspase-3 pathway in a paired and an unpaired sample series of children with acute lymphoblastic leukemia (ALL) at initial diagnosis and relapse. The data demonstrate that both Bax expression levels and the Bax/Bcl-2 ratio are significantly lower in samples at relapse as compared with samples at initial diagnosis (P=0.013, Wilcoxon signed rank test (paired samples); P=0.0039, Mann-Whitney U test (unpaired samples)). The loss of Bax protein expression was not a consequence of Bax frameshift mutations of the G8 tract and could not be attributed to mutations of the p53 coding sequence (exons 5 to 8) which were detected to a similar extent in de novo ALL samples and at relapse. Analysis of the downstream effector caspase-3 showed loss of spontaneous caspase-3 processing at relapse. Whereas nine out of 14 (64%, paired samples) or 37 out of 77 (48%, unpaired samples) ALL patients at initial diagnosis displayed spontaneous in vivo processing of caspase-3, this was completely absent in patients at relapse (paired samples) or detected in only one out of 34 patients at relapse (2.9%, unpaired samples). We therefore conclude that in ALL relapse a severe disturbance of apoptotic pathways occurs, both at the level of Bax expression and caspase-3 activation.

Adolescent↗

PubMed2000

Molecular detection of minimal residual disease is a strong predictive factor of relapse in childhood B-lineage acute lymphoblastic leukemia with medium risk features. A case control study of the International BFM study group.

The medium-risk B cell precursor acute lymphoblastic leukemia (ALL) accounts for 50-60% of total childhood ALL and comprises the largest number of relapses still unpredictable with diagnostic criteria. To evaluate the prognostic impact of minimal residual disease (MRD) in this specific group, a case control study was performed in patients classified and treated as medium (or intermediate)-risk according to the criteria of national studies (ALL-BFM 90, DCLSG protocol ALL-8, AIEOP-ALL 91), which includes a good day 7 treatment response. Standardized polymerase chain reaction (PCR) analysis of patient-specific immunoglobulin and T cell receptor gene (TCR) rearrangements were used as targets for semi-quantitative estimation of MRD levels: > or =10(-2), 10(-3), < or =10(-4). Twenty-nine relapsing ALL patients were matched with the same number of controls by using white blood cell count (WBC), age, sex, and time in first complete remission, as matching factors. MRD was evaluated at time-point 1 (end of protocol Ia of induction treatment, ie 6 weeks from diagnosis) and time-point 2 (before consolidation treatment, ie 3 months from diagnosis). MRD-based high risk patients (> or =10(-3) at both time-points) were more frequently present in the relapsed cases than in controls (14 vs 2), while MRD-based low risk patients (MRD negative at both time-points) (1 vs 18) showed the opposite distribution. MRD-based high risk cases experienced a significantly higher relapse rate than all other patients, according to the estimated seven-fold increase in the odds of failure, and a much higher rate than MRD-based low risk patients (OR = 35.7; P= 0.003). Using the Cox model, the prediction of the relapse-free interval at 4 years was 44.7%, 76.4% and 97.7% according to the different MRD categories. MRD-based risk group classification demonstrate their clinical relevance within the medium-risk B cell precursor ALL which account for the largest number of unpredictable relapses, despite the current knowledge about clinical and biological characteristics at diagnosis. Therefore, MRD detection during the first 3 months of follow-up can provide the tools to target more intensive therapy to those patients at true risk of relapse.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2003

DNA microarrays for comparison of gene expression profiles between diagnosis and relapse in precursor-B acute lymphoblastic leukemia: choice of technique and purification influence the identification of potential diagnostic markers.

Microarrays for gene expression profiling are rapidly becoming important research tools for the identification of novel markers, for example, for novel classification of leukemias and lymphomas. Here, we review the considerations and infrastructure for microarray experiments. These considerations are illustrated via a microarray-based comparison of gene expression profiles of paired diagnosis-relapse samples from patients with precursor-B acute lymphoblastic leukemia (ALL), who relapsed during therapy or after completion of treatment. Initial experiments showed that several seemingly differentially expressed genes were actually derived from contaminating non-leukemic cells, particularly myeloid cells and T-lymphocytes. Therefore, we purified the ALL cells of the diagnosis and relapse samples if their frequency was lower than 95%. Furthermore, we observed in earlier studies that extra RNA amplification leads to skewing of particular gene transcripts. Sufficient (non-amplified) RNA of purified and paired diagnosis-relapse samples was obtained from only seven cases. The gene expression profiles were evaluated with Affymetrix U95A chips containing 12 600 human genes. These diagnosis-relapse comparisons revealed only a small number of genes (n=6) that differed significantly in expression: mostly signaling molecules and transcription factors involved in cell proliferation and cell survival were highly upregulated at relapse, but we did not observe any increase in drug-resistance markers. This finding fits with the observation that tumors with a high proliferation index have a poor prognosis. The genes that changed between diagnosis and relapse are currently not in use as diagnostic or disease progression markers, but represent potential new markers for such applications. Leukemia (2003) 17, 1324-1332. doi:10.1038/sj.leu.2402974

Biomarkers↗

PubMed2003

Lymphocyte recovery after allogeneic bone marrow transplantation predicts risk of relapse in acute lymphoblastic leukemia.

Allogeneic blood and marrow transplantation (BMT) is curative for many patients with high-risk and relapsed acute lymphoblastic leukemia (ALL). However, relapse is an important cause of post-transplantation failure, and there are no reliable markers to predict relapse. A retrospective review of patients with ALL who underwent matched related allogeneic BMT was carried out to examine whether the rate of lymphocyte recovery after transplantation had any prognostic value in ALL. The absolute lymphocyte count (ALC) at days 21 and 30 after transplantation was obtained for 43 patients who received transplants during an 18-year period. Patients with an ALC of 175 x 10(6)/l or less on day 21 were more likely to relapse than those with ALC greater than 175 x 10(6)/l (relative risk, 4; 95% confidence interval, 1.5-11.2). Patients with slower lymphocyte recovery had significantly lower relapse-free survival than those with faster recovery (P=0.0028). There was also a trend toward poorer overall survival among those with a slow lymphocyte recovery (log-rank test; P=0.028). The rate of lymphocyte recovery is prognostic in patients with ALL undergoing allogeneic BMT, and this should be integrated with other predictors to identify patients at high risk of relapse. Such patients could be considered for interventions aimed at prevention of relapse, including rapid withdrawal of immunosuppressive medication or donor lymphocyte infusion.

Adolescent↗

PubMed2006

Stability and prognostic influence of FLT3 mutations in paired initial and relapsed AML samples.

In acute myeloid leukemia (AML), activating mutations in the fms-like tyrosine kinase 3 (FLT3) gene predict poor prognosis. We determined FLT3 internal tandem duplications (FLT3/ITD) and D835 point mutations in paired initial and relapse samples from 80 pediatric and adult AML patients. One D835 point mutation was found in an initial pediatric AML sample. Fms-like tyrosine kinase 3/ITDs were present in 21 initial and 22 relapse samples (26.3 and 27.5%, respectively). Interestingly, FLT3/ITD positivity was related to a significantly shorter time to relapse, most pronounced when the ITD-positive status was found at relapse (P<0.001). However, FLT3/ITD status changed between diagnosis and relapse in 14 cases. In four patients, the FLT3/ITD became undetectable at relapse in five patients FLT3/ITDs were only detected at relapse, and in five patients the length or number of FLT3/ITDs changed. Gain of FLT3/ITDs may suggest oligoclonality with selective outgrowth of the FLT3/ITD-positive clone, whereas losses may reflect ITDs in the more mature leukemic cells rather than in the leukemic stem cell, or, alternatively, that other genetic aberrations provided a greater selective advantage. Studying FLT3/ITD kinetics in minimal residual disease setting may provide some answers for the changes we observed. Fms-like tyrosine kinase 3/ITD is a relevant marker for prognosis, and remains an important target for therapeutic inhibition.

Adolescent↗

PubMed2004

Placebo-controlled continuation treatment with mirtazapine: acute pattern of response predicts relapse.

Pattern of response to antidepressants has been proposed as a method to identify patients whose improvement is more likely due to drug vs those whose improvement on drug is more likely to be a placebo effect. It is hypothesized that those with 'true-drug initial response pattern' are most likely to benefit from continuation treatment. The relationship between acute patterns of response and subsequent placebo-controlled continuation treatment with the antidepressant mirtazapine is examined. A total of 410 outpatients were treated openly with mirtazapine for 8-12 weeks. Patients who remitted in the acute phase were randomized to continue the same dose of mirtazapine or switched to placebo. Acute phase responders were classified as 'placebo initial response pattern' (early responders and nonpersistent responders) and 'true-drug initial response pattern' (delayed and persistent responders). Of those with a 'true-drug initial response pattern,' 10/40 (25.0%) relapsed with continuation mirtazapine, and 23/41 (56.1%) relapsed when switched to placebo. The difference (31.1%) is significant. Of those with a 'placebo initial response pattern,' 5/36 (13.9%) relapsed with continuation mirtazapine, and 12/39 (30.8%) relapsed with placebo substitution. This difference (16.9%) is not statistically significant. Moreover, the relapse rate for 'true-drug initial response pattern' patients switched to placebo (56.1%) was also significantly greater than for 'placebo initial response pattern' patients switched to placebo (30.8%). It has been suggested that patients with late onset and persistence are more likely to have improved because of drug. This hypothesis gains support from this study because of the different relapse rates of 'true-drug' responders on drug and placebo. The low relapse rate for patients with an acute placebo pattern switched to placebo suggests specific drug effect played a smaller role in their initial improvement.

Adult↗

PubMed2006

Cue-induced brain activity changes and relapse in cocaine-dependent patients.

This study used functional magnetic resonance imaging (fMRI) to examine the association between brain activation during exposure to cocaine-related cues and relapse to drug use in cocaine-dependent (CD) patients. We imaged 17 CD subjects during a 2-week in-patient stay. The subjects then entered a 10-week outpatient placebo-controlled, double-blind randomized clinical trial where urine toxicologies were assessed three times weekly to calculate the treatment effectiveness score (TES). Worse TES correlated with BOLD activation in the left precentral, superior temporal, and posterior cingulate cortices (PCC), and right middle temporal and lingual cortices (R>0.65; P<0.005). The left PCC activation also distinguished eight nonrelapsers (TES above mean and completed treatment) from nine relapsers. Cocaine-free urines were significantly greater in the nonrelapsers (92%) than in the relapsers (66%), who also remained in treatment for an average of only 3.2 weeks. Self-reports of craving during fMRI did not differ between nonrelapsers and relapsers and did not correlate with TES. Relapse to cocaine abuse was associated with increased activation in the sensory association cortex, the motor cortex, and PCC while viewing images of cocaine-related cues. These results suggest that relapse to cocaine abuse is associated with increased brain activation to cocaine cues in sensory, motor, and cognitive-emotional processing areas. This physiological activation was a better predictor of relapse than subjective reports of craving, and may be a useful target for treatment development.

Adult↗

PubMed1999

A comparison of the beliefs of Indian alcohol-dependent patients and their close family members on their reasons for relapse.

AIMS: To study and compare the perspectives of relapsed alcohol-dependent patients and their family members regarding relapse precipitants. DESIGN: Observational, cross-sectional survey. SETTING: An addiction centre in northern India. PARTICIPANTS: Thirty consecutive male patients attending the centre with relapse of alcohol dependence following previous inpatient treatment, and their respective family members. MEASUREMENTS: Relapse precipitants, as generated by a 25-item, three-factor, self-report inventory eliciting the subjects' beliefs about events or circumstances leading to relapse. FINDINGS: Both the patients and their families listed items related to 'reduced cognitive vigilance' as the most common relapse precipitants. Reasons pertaining to external situations and euphoric states as well as unpleasant mood states were also frequently reported by them. The rank order correlation between the items by patients and their families was positive and statistically significant (r = 0.80, p < 0.001). Individual item-wise comparison by chi-squared test yielded statistically significant difference in only one of 25 items. CONCLUSIONS: There was a high degree of concordance between the patients and their family members regarding beliefs about precipitants of alcoholic relapse.

Alcoholism↗

PubMed2002

Factors associated with abstinence, lapse or relapse to heroin use after residential treatment: protective effect of coping responses.

AIMS: This study investigates factors associated with abstinence, lapse or relapse to heroin use after residential treatment and, specifically, the extent to which changes in cognitive, avoidance and distraction coping responses were related to heroin use and other drug use outcomes. DESIGN, SETTING, PARTICIPANTS: The sample comprised 242 clients from 23 residential programmes in the NTORS project, who used heroin before treatment and who were followed-up after treatment during the first 12 months of the study. MEASUREMENTS: Data on client characteristics and problems, coping responses, drug use and other outcomes, were collected by structured face-to-face interviews. FINDINGS: Many clients (60%) used heroin after treatment, with the first occasion of heroin use usually occurring very soon after leaving treatment: 40% remained abstinent from heroin. Analyses were conducted for three groups based upon heroin outcome status (abstinent, lapsed, relapsed). Clients who avoided a full relapse to heroin use (abstinent and lapse groups) consistently made more use of cognitive, avoidance and distraction coping strategies at follow-up than at intake. Treatment completion was related to better outcome. The lapse and relapse groups reported higher rates of use of illicit drugs other than heroin after treatment than the abstinent group. CONCLUSIONS: Despite generally satisfactory drug use outcomes, the lapses and relapses to heroin use give rise to concern. Treatment services should develop further and strengthen relapse prevention and relapse coping skills among drug misusers.

Adaptation, Psychological↗

PubMed2000

VML 295 (LY-293111), a novel LTB4 antagonist, is not effective in the prevention of relapse in psoriasis.

Leukotriene B4 (LTB4) receptor antagonists have been the subject of several studies in the treatment of inflammatory diseases, including psoriasis. A novel oral LTB4 antagonist, VML 295 (LY-293111) has recently been developed and has a pronounced effect on epidermal inflammatory parameters. However, oral treatment of psoriasis for 4 weeks did not result in a decrease in disease severity. The present study was performed in order to investigate whether prolonged treatment with VML 295 up to 8 weeks has a beneficial effect on the overall severity of psoriasis. Moreover, we studied to what extent VML 295 is able to prevent relapse in psoriasis. In the present study, 35 patients with stable chronic plaque psoriasis were included. A representative plaque of at least 16 cm2 was initially treated with clobetasol-17-propionate lotion under hydrocolloid occlusion in all patients. Clearance was achieved within 6 weeks in 31 patients. After clearance, the patients were randomized to treatment and received oral VML 295 capsules 200 mg twice daily or placebo for 8 weeks. Twenty-five patients completed the study. The psoriasis area and severity index (PASI) was assessed before treatment, at clearance, and on days 15, 29, 43 and 5 7 of the treatment period. Biopsies were taken from the treated lesion before treatment, after clearance and at relapse, and cells were analysed by flow cytometry with markers for differentiation (keratin 10), inflammation (vimentin), and proliferation (DNA content). After 8 weeks of treatment, 14 of 15 VML 295-treated patients had relapsed and 11 of 16 placebo-treated patients had relapsed. A total of six patients were withdrawn. The time to relapse and the number of relapsed patients was not significantly different comparing the treatment groups. There was no significant difference in PASI scores between VML 295-treated patients and placebo-treated patients after 8 weeks of treatment. Flow cytometric parameters for differentiation, inflammation and proliferation did not show significant differences between VML 295- and placebo-treated patients. We conclude that oral VML 295 (LY-293111) is not effective in preventing relapse in psoriasis, either clinically or at the cellular level, and that in our group of patients VML 295 had no beneficial effect on overall psoriasis severity. Moreover, we conclude that further development of LTB4 modulating drugs for the treatment of psoriasis is not indicated.

Administration, Topical↗

PubMed1997

Detection of BCR/ABL RNA transcripts using the polymerase chain reaction is highly predictive for relapse in patients transplanted with unrelated marrow grafts for chronic myelogenous leukaemia.

Relapse after allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukaemia (CML) is thought to result from residual leukaemia cells which survive the intensive conditioning regimen and are not eradicated by donor-derived immune effector cells capable of mediating a graft-versus-leukaemia (GVL) effect. Early relapse can be detected using highly sensitive assays such as the polymerase chain reaction (PCR) which have been shown to have predictive value for subsequent relapse in selected patient populations. The validity of PCR for predicting CML relapse in unrelated marrow transplant recipients where the GVL effect appears to be augmented due to increased HLA disparity between donor and recipient, however, has not been well defined. In this study we assessed the prognostic value of PCR in a cohort of 52 patients transplanted with T-cell-depleted unrelated marrow grafts for CML. The actual probability of relapse at 3 years was 71% in patients with at least one positive assay versus 6% in patients with no positive assays post-transplant. Patients with one or more positive assays at any time post-transplant had a 56-fold increased risk of relapse which was significantly higher (P=0.0002) than that observed in patients who remained persistently PCR negative. Moreover, PCR detected relapse a median of 5 months earlier than cytogenetic analysis in a subgroup of patients in whom concurrent sampling had been performed. These data validate the use of PCR as a prognostic test in this patient population and may help to identify a cohort of patients to be considered as candidates for pre-emptive adoptive immunotherapy.

Adult↗

PubMed1998

Comparison of bone marrow transplant and chemotherapy for relapsed childhood acute lymphoblastic leukaemia: the MRC UKALL X experience. Medical Research Council Working Party on Childhood Leukaemia.

We examined the outcome of the 489 children with acute lymphoblastic leukaemia (ALL) who relapsed in the UKALL X trial, and produced graphical displays of adjusted comparisons of event-free survival (EFS) for chemotherapy versus bone marrow transplantation (BMT) from a sibling or volunteer unrelated donor, and autologous BMT (ABMT). EFS at 5 years was only 3% (95% CI 0-6%) for children who relapsed in the bone marrow (BM) within 2 years of diagnosis, irrespective of type of post-relapse treatment, whereas for those with late extramedullary relapse it was 66% (95% CI 48-85%). Comparison of the types of treatment did not show benefit for ABMT. For allogeneic BMT the overall reduction in the odds of an event was 26% (95% CI 1-51%) (2P= 0.05), resulting in an absolute increase in 5-year event-free survival of 14% (from 26.4% to 40.7%). New approaches are needed for children with early BM relapses whose prognosis is virtually hopeless with current therapy; however, a conventional chemotherapy approach may be justifiable for late extramedullary relapses. For the remaining patients (71%), with later BM or early extramedullary relapses, the optimal treatment is still not clear. This uncertainty warrants a formal randomized comparison of BMT and chemotherapy, to avoid the biases due to unmeasurable selection factors.

Adolescent↗

PubMed2000

Relapse after bone marrow transplantation: evidence for distinct immunological mechanisms between adult and paediatric populations.

Donor lymphocyte infusions are particularly effective for remission induction in malignant cells in patients who relapse after allogeneic progenitor cell transplantation (PCT) and who remain sensitive to the administration of unprimed donor T and/or natural killer (NK) cells present in donor lymphocyte infusions. To determine whether relapse after unmanipulated PCT could be ascribed to donor T and/or NK cell loss or tolerization, we evaluated the chimeric status of 81 patients with haematological malignancies who were receiving allogeneic unmanipulated PCT. The incidence of mixed chimaerism (MC) in unfractionated mononuclear leucocyte samples decreased rapidly after transplant, and was not detectable 4 months after PCT, even in patients who subsequently relapsed. The chimeric status of immune effector cell subsets was then evaluated in 15 patients at the time of relapse. All adults demonstrated complete donor haematopoiesis (CDH) for all cell lineages, whereas T- and NK-cell MC was only found in patients younger than age 13 years (P = 0.004). MC was not found in T nor NK cells of a control group consisting of age-matched paediatric patients in remission after allogeneic PCT. Thus, in adults, T and NK cell MC disappears early after unmanipulated allogeneic PCT and is absent at the time of relapse. However, the identification of donor T and NK cell loss in the paediatric relapsed but not remission patients suggests a distinct mechanism of relapse.

Adolescent↗

PubMed2001

INK4A/ARF deletions are acquired at relapse in childhood acute lymphoblastic leukaemia: a paired study on 25 patients using real-time polymerase chain reaction.

Current risk-adjusted intensive therapies for childhood acute lymphoblastic leukaemia (ALL) are expected to result in an event-free survival of greater than 75%. In sharp contrast, relapsed paediatric ALL is a difficult disease to treat. In this study, 25 paediatric patients with ALL were analysed at diagnosis and relapse for their p16 (exon 2) status using the most accurate method of detection, real-time polymerase chain reaction (PCR). The median time to relapse for the group was 27 months. At diagnosis, the incidence of p16 homozygous and hemizygous deletion in this group was 32% and 20% respectively. The incidence of homozygous p16 deletion at relapse was 64%. A large number of patients, eight of 16 (50%), developed p16 homozygous deletion at relapse. Of those eight patients, four were hemizygous and four were germline at diagnosis. At diagnosis, those patients with a homozygous or hemizygous p16 deletion relapsed sooner than those germline for p16. We have shown that p16 alterations are frequently present in relapsed lymphoblastic leukaemia in children.

Adolescent↗

PubMed2003

Residual leukaemia after bone marrow transplant in children with acute lymphoblastic leukaemia after first haematological relapse or with poor initial presenting features.

Relapse is the major obstacle to cure for children with acute lymphoblastic leukaemia (ALL) after allogeneic bone marrow transplant (BMT). Development of salvage therapy for post-transplant relapse could be expedited by understanding the post-transplant behaviour of microscopically undetectable leukaemia and the ability to predict impending relapse. We have used a quantitative polymerase chain reaction method (sensitivity of 5.0 x 10-6) to measure residual leukaemia before the conditioning regimen, and at five time-points after transplantation. In total, 18 patients with ALL transplanted in first or second remission were studied for 1 year: For the first year post BMT, 12 remained in remission, four had haematological relapses, one had a cutaneous relapse, and one died of severe graft-versus-host disease. The post-engraftment levels of the leukaemia-specific immunoglobulin heavy (IgH) chain gene rearrangement for patients with haematological relapses were significantly different from those who remained in remission. The levels for the patients who remained in remission decreased with time, although there were occasional increases consistent with the known standard deviation of the measurement assay. In contrast, all clinical relapses were preceded by a rapid increase in levels. Both the rate of this increase and its timing were variable. These results suggest that residual leukaemia measurements can be used to direct post-transplant interventions and measure their effects.

Adolescent↗