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Biomedical subjects

R F Stevens

Publications and source records attributed to R F Stevens.

At least 19 recordsLinked to original sources
PubMed1999

Failure of allogeneic bone marrow transplantation to correct Diamond-Blackfan anaemia despite haemopoietic stem cell engraftment.

We report the case of a 10-year-old boy with congenital pure red cell aplasia (Diamond-Blackfan anaemia) who received an allogeneic bone marrow transplant (BMT) from his HLA-identical sister. The transplant was complicated by moderate veno-occlusive disease (VOD). Despite cytogenetic evidence of complete donor haemopoietic stem cell engraftment there was selective failure of red cell engraftment and he remains red cell transfusion-dependent. This is the first case of a stem cell transplant failing to correct the defect in this condition despite engraftment.

Bone Marrow Transplantation↗
PubMed1999

Outcome for children with relapsed acute myeloid leukaemia following initial therapy in the Medical Research Council (MRC) AML 10 trial. MRC Childhood Leukaemia Working Party.

Between May 1988 and March 1995, 359 children with acute myeloid leukaemia (AML) were treated in the MRC AML 10 trial. Three risk groups were identified based on cytogenetics and response to treatment. One hundred and twenty-five children relapsed--103 in the bone marrow only, 12 in the bone marrow combined with other sites, and six had isolated extramedullary relapses (site was not known in four cases). Eighty-seven children received further combination chemotherapy, one all-trans retinoic acid for acute promyelocytic leukaemia, and one a matched unrelated donor allograft in relapse, and 61 achieved a second remission. One patient with no details on reinduction therapy also achieved second remission. Treatment in second remission varied--44 children received a BMT (22 autografts, 12 matched unrelated donor allografts, 10 family donor allografts), and 17 were treated with chemotherapy alone. The overall survival rate for all children (treated and untreated) was 24% at 3 years, with a disease-free survival of 44% for those achieving a second remission. Length of first remission was the most important factor affecting response rates--children with a first remission of less than 1 year fared poorly (second remission rate 36%, 3 year survival 11%), whereas those with longer first remissions had a higher response rate (second remission rate 75%, 3 year survival 49%, P < 0.0001).

Acute Disease↗
PubMed1999

Treatment-related deaths during induction and first remission of acute myeloid leukaemia in children treated on the Tenth Medical Research Council acute myeloid leukaemia trial (MRC AML10). The MCR Childhood Leukaemia Working Party.

Between 1988 and 1995, 341 children with acute myeloid leukaemia (AML) were treated on the Medical Research Council Acute Myeloid Leukaemia Trial (MRC AML10). The 5-year overall survival was 57%, much improved on previous trials. However, there were 47 deaths (13. 8%), 11 of which were associated with bone marrow transplantation (BMT). The treatment-related mortality was significant at 13.8%, but decreased in the latter half of the trial from 17.8% in 1998-91 to 9. 6% in 1992-95 (P = 0.03%). The main causes of death were infection (65.9%), haemorrhage (19.1%) and cardiac failure (19.1%). Fungal infection was a significant problem, causing 23% of all infective deaths. Haemorrhage occurred early in treatment, in children with initial white cell counts >100 x 109/l (P = 0.001), and was more common in those with M4 and M5 morphology. Cardiac failure only occurred from the third course of chemotherapy onwards, with 78% (7/9) in conjunction with sepsis as a terminal event. Some deaths could be prevented by identifying those most at risk, and with prompt recognition and aggressive management of complications of treatment. Future options include the prophylactic use of antifungal agents, and the use of cardioprotectants or alternatives to conventional anthracyclines to decrease cardiac toxicity.

Acute Disease↗
PubMed1999

A simple, robust, validated and highly predictive index for the determination of risk-directed therapy in acute myeloid leukaemia derived from the MRC AML 10 trial. United Kingdom Medical Research Council's Adult and Childhood Leukaemia Working Parties.

Data on 1711 patients, aged up to 55 years, in the MRC AML 10 trial were used to create a prognostic index for use in risk-directed therapy decision making for younger patients with acute myeloid leukaemia (AML). Two parameters, response after course 1 and cytogenetics, were strongly predictive of outcome. For patients with complete remission, partial remission and resistant disease, 5-year survival from the start of course 2 was 53%, 44% and 22% and relapse rates were 46%, 48% and 69% respectively, and for patients with favourable, intermediate and adverse karyotypic abnormalities, survival was 72%, 43% and 17% and relapse rates were 34%, 51% and 75% respectively (all P < 0.0001). Patients with FAB type M3 but no cytogenetic t(15;17) also had a low relapse rate (29%). These three factors were combined to give three risk groups: good (favourable karyotype or M3, irrespective of response status or presence of additional abnormalities), standard (neither good nor poor), poor (adverse karyotype or resistant disease, and no good-risk features). Survival for these three groups was 70%, 48% and 15% respectively and relapse rates were 33%. 50% and 78% (both P < 0.0001). The index is simple (based on just three parameters), robust (derived from 1711 patients), highly discriminatory (55% survival difference between good and poor risk) and validated, so can be applied in the clinical setting to assist with therapeutic decisions as in the current AML 12 trial.

Acute Disease↗
PubMed1999

Subgroups of frequent users of an inpatient mental health program at a community hospital in Canada.

OBJECTIVE: The study examined demographic and clinical characteristics of frequent users of mental health services at a large community hospital in an urban-suburban area in Canada to identify subgroups within this patient population. METHODS: Patients who had had three or more inpatient admissions over any 12-month period between January 1, 1993, and December 31, 1995, were included in the study. Medical records were reviewed to collect summary data on 23 variables encompassing demographic characteristics and admission and discharge information. Quick cluster analysis was performed to identify subgroups within the frequent-user population. Chi square tests and analysis of variance were used to analyze group differences between clusters. RESULTS: Three patient subgroups accounted for 67 of the 83 patients (80.7 percent) identified as frequent users. Admission patterns were the strongest predictors of subgroup differences. CONCLUSIONS: Identifying subgroups within the frequent-user population may help in developing appropriate treatment and discharge plans with the aim of reducing the need for frequent utilization of inpatient mental health services.

Adolescent↗
PubMed1998

Seasonal variations in the onset of childhood leukaemia and lymphoma.

Infection has long been suspected as a possible factor in the aetiology of leukaemia and lymphoma. If seasonal variation in the onset of disease could be shown in any of the diagnostic subgroups of leukaemia or lymphoma, this would provide supportive evidence of an aetiology linked to exposure to infection. All cases in the Manchester Children's Tumour Registry (aged 0-14 years at diagnosis) with acute lymphoblastic leukaemia (ALL), acute non-lymphocytic leukaemia (ANLL), Hodgkin's disease (HD) or non-Hodgkin lymphoma (NHL) between 1 January 1954 and 31 December 1996 were included in an analysis of seasonal variation in the month of first symptom and the month of diagnosis. Cases of common acute lymphoblastic leukaemia (c-ALL) diagnosed from 1979 onwards were also analysed separately. The groups considered for analysis were: all cases of ALL (n = 1070), ALL diagnosed between 18 and 95 months of age (n = 730), ALL diagnosed over 95 months of age (n = 266), c-ALL (n = 309), ANLL (n = 244), all infant acute leukaemias (ALL and ANLL under 18 months; n = 107), HD (n = 166) and NHL (n = 189). Using the Edwards method, both c-ALL and HD demonstrated significant seasonal variation (P = 0.037 and 0.001 respectively) in date of first symptom, with peaks occurring in November and December respectively. Using this method, no indication of seasonal variation was found in the other diagnostic groups for date of first symptom or in any of the diagnostic groups for date of diagnosis. For comparison with a previous study, a further analysis based on date of diagnosis for all ALL cases, using summer-winter ratios, showed a significant summer excess. These results provide supportive evidence for an infectious aetiology for c-ALL and HD, and possibly for all ALL, which warrants further investigation.

Adolescent↗
PubMed1998

Evidence that an HLA-DQA1-DQB1 haplotype influences susceptibility to childhood common acute lymphoblastic leukaemia in boys provides further support for an infection-related aetiology.

Comparison of DQA1 and DQB1 alleles in 60 children with common acute lymphoblastic leukaemia (c-ALL) and 78 newborn infant control subjects revealed that male but not female patients had a higher frequency of DQA1*0101/*0104 and DQB1*0501 than appropriate control subjects. The results suggest a male-associated susceptibility haplotype in c-ALL and supports an infectious aetiology.

Alleles↗
PubMed1998

Marked improvements in outcome with chemotherapy alone in paediatric acute myeloid leukemia: results of the United Kingdom Medical Research Council's 10th AML trial. MRC Childhood Leukaemia Working Party.

359 eligible children with acute myeloid leukaemia (AML) entered the MRC AML 10 trial between May 1988 and March 1995. Patients received four courses of intensive induction and consolidation chemotherapy, with or without subsequent autologous (A-BMT) or allogeneic (allo-BMT) bone marrow transplant. There were randomized comparisons of thioguanine versus etoposide in induction and of A-BMT versus not. Allo-BMT was recommended for patients with a HLA-matched sibling and was evaluated by donor versus no donor comparison. The complete remission rate was 92%. In first remission there were 20 deaths during consolidation chemotherapy and 11 after BMT (8/61 allo-BMTs. 1/60 A-BMTs and 2/4 matched unrelated donor transplants). The relapse rate was low, decreasing from 26% in the first year to 2% in the fourth. Long-term outcome was excellent with survival at 7 years from entry of 56% and event-free survival of 48%. There were no significant differences between thioguanine and etoposide, whereas both A-BMT and allo-BMT reduced relapse risk but did not produce a significant survival benefit. It appears that over half the children entered into AML 10 are cured, a result which compares favourably with other reported series. We conclude that four courses of intensive chemotherapy are an effective approach to the treatment of paediatric AML, which avoids the acute toxicity and long-term side-effects of BMT and also avoids the need for prolonged maintenance therapy or cranial irradiation.

Acute Disease↗
PubMed1998

Lack of association between childhood common acute lymphoblastic leukaemia and an HLA-C locus dimorphism influencing the specificity of natural killer cells.

Previous serological studies documenting an association between acute lymphoblastic leukaemia (ALL) and HLA-Cw antigens suggested that the HLA-C locus might influence susceptibility to ALL. However, associations with more than one Cw antigen suggest that polymorphic variants shared by more than Cw allele could be involved. Recent studies have shown that the HLA-C locus encodes two ligands (NK1 and NK2) recognized by receptors on natural killer (NK) cells. HLA-Cw alleles encoding these ligands are dimorphic, dependent on whether they encode one or other NK ligand. To determine whether susceptibility to the common (CD10+) form of childhood ALL (c-ALL) is associated with NK1 or NK2, we carried out a molecular analysis of 94 childhood c-ALL patients and 136 infant controls. We found no difference in the frequency of NK1 and NK2 alleles, phenotypes or genotypes between the patients and controls, suggesting that this does not explain the role of the HLA-C locus in susceptibility to childhood c-ALL.

Female↗
PubMed1998

Paroxysmal cold haemoglobinuria of childhood: a review of the management and unusual presenting features of six cases.

We report six cases of children presenting with paroxysmal cold haemoglobinuria occurring in a 3-year period in the north-west of England. In all six cases the onset of the illness was dramatic and its duration brief. We note the prominent red cell agglutination was evident in the blood film, the absence of a prompt reticulocyte response and a negative classical direct Donath Landsteiner test in each of these cases. The Direct Coombs Test (DCT) was positive when anticomplement reagents were used but high titres of free autoantibody were not demonstrated in the serum.

Child, Preschool↗
PubMed1997

Randomized comparison of DAT versus ADE as induction chemotherapy in children and younger adults with acute myeloid leukemia. Results of the Medical Research Council's 10th AML trial (MRC AML10). Adult and Childhood Leukaemia Working Parties of the Medical Research Council.

The relative efficacy and toxicity of the chemotherapeutic agents thioguanine (6TG) and etoposide (VP16) were assessed by a randomized comparison of the DAT (daunorubicin, cytarabine, thioguanine) versus ADE (daunorubicin, cytarabine, etoposide) regimens in the Medical Research Council's 10th acute myeloid leukaemia trial (MRC AML 10), which was open to patient entry from May 1988 to April 1995. In this, the largest reported trial of AML therapy to date, 1,857 eligible patients, mostly less than 56 years old, were randomized: 929 (including 143 children under 15 years old) were allocated to DAT and 928 (143 children) to ADE. The two groups were well matched for presentation features. The complete remission (CR) rate was 81% with DAT and 83% with ADE (P = .3). The percentages of remitters achieving remission after 1, 2, or more than 2 courses were 70%, 22%, and 8% for DAT and 74%, 21%, and 5% for ADE. The percentages failing to achieve a CR due to resistant disease were 11% with DAT versus 9% with ADE (P = .07). There was a slightly higher death rate in CR during consolidation chemotherapy with ADE (9%) than with DAT (6%) (P = .06). Patients receiving DAT took slightly but significantly longer to recover from neutropenia and thrombocytopenia but the median number of days in hospital were similar in each group. ADE patients experienced slightly more severe nonhematologic toxicity. There was also no significant difference between the groups in the longer-term measures of efficacy: disease-free survival at 6 years from CR was 42% (+/-4) for DAT and 43% (+/-4) for ADE (P = .8); relapse rate at 6 years was 50% (+/-4) for DAT and 49% (+/-5) for ADE (P = .6); survival at 6 years was 40% (+/-4) for both DAT and ADE (P = .9). Subgroup analysis failed to show any benefit for etoposide in patients with monocytic or myelomonocytic disease, or in any other diagnostic subgroup. In conclusion, DAT and ADE both achieve high remission rates and good long-term survival, and are equally effective chemotherapy regimens for the treatment of AML patients aged up to 55 years.

Acute Disease↗
PubMed1997

Clearance of marrow infiltration after 1 week of therapy for childhood lymphoblastic leukaemia: clinical importance and the effect of daunorubicin. The Medical Research Council's Working Party on Childhood Leukaemia.

At the commencement of UKALL XI, a national MRC trial for childhood lymphoblastic leukaemia (ALL), the therapy included a bolus of daunorubicin (DR) on the first 2 d of the protocol. This component of treatment was subsequently withdrawn because of concern about long-term cardiotoxicity. All children both before and after this change of policy had their marrow status at the end of the first week assessed by central review as part of the trial to examine the clinical importance of the rate of disease clearance. This also afforded an opportunity to observe the effect of DR on gross residual disease at an early stage of therapy. 1419 children were studied: 342 received DR ('recipients'), 1077 did not. 44% of the recipients completely cleared their marrow of blast cells after 8 d compared with 13% of the non-recipients (chi2 = 158.2, P < 0.0001). The difference in the proportion with massive residual disease (>80% blasts) was less impressive but there was still a difference in favour of DR recipients (DR 9%, no DR 15%; chi2 = 7.7, P = 0.006). The rate of disease clearance correlated with disease-free survival for both recipients and non-recipients, but there was no significant difference in outcome when comparing the two groups with each other, either in terms of disease-free or relapse-free survival. DR accelerated the rate of blast cell disappearance from the marrow but the difference this made to disease free survival is small or non-existent. It appears to be the relative speed of response to a given therapeutic regimen that is prognostically important rather than the absolute rate of response when comparing one treatment with another.

Antibiotics, Antineoplastic↗
PubMed1997

A randomized comparison of liposomal versus conventional amphotericin B for the treatment of pyrexia of unknown origin in neutropenic patients.

One hundred and thirty-four adults and 204 children were randomized in two prospective, parallel comparative multicentre trials to receive either conventional amphotericin B 1 mg/kg/d (c-AMB), liposomal amphotericin B 1 mg/kg/d(L-AMB1) or liposomal amphotericin B 3 mg/ kg/d (L-AMB3). Patients were entered if they had a pyrexia of unknown origin (PUO) defined as temperature of 38 degrees C or more, not responding to 96 h of systemic broad-spectrum antibiotic treatment, and neutropenia (< 0.5 x 10(9)/l). The safety and toxicity of liposomal amphotericin B was compared with that of conventional amphotericin B. Efficacy of treatment was assessed, with success defined as resolution of fever for 3 consecutive days (< 38 degrees C) without the development of any new fungal infection. Clinical and laboratory parameters were collected for safety analysis. In both the paediatric and adult populations, L-AMB treated patients had a 2-6-fold decrease in the incidence (P < or = 0.01) of test-drug-related side-effects, compared to c-AMB. Severe trial-drug-related side-effects were seen in 1% of L-AMB treated patients, in contrast to 12% of patients on c-AMB (P < 0.01). Nephrotoxicity, in the patient subset not receiving concomitant nephrotoxic agents, defined as a doubling from the patients baseline serum creatinine level, was not observed in the L-AMB1 arm whereas the incidence was 3% in patients on L-AMB3 and 23% in those on c-AMB (P < 0.01). Moreover, time to develop nephrotoxicity was longer in both L-AMB arms than c-AMB (P < 0.01). Severe hypokalaemia was observed less frequently in both L-AMB arms (P < 0.01). Analysis was by intention-to-treat and included all patients randomized. Success was defined by a minimum of 3 consecutive days with fever (< 38 degrees C) continuing to study end indicated by recovery of neutrophils to 0.5 x 10(9)/l. Addition of systemic antifungal therapy or development of systemic fungal infection were failures as was persistent fever to study end. Efficacy assessments indicated success in 49% of the total group treated with c-AMB, 58% of patients responded to L-AMB1 and 64% to L-AMB3. A statistically significant difference was found between c-AMB and L-AMB3 (P = 0.03) but a Kaplan-Meier analysis of time to differvescence of fever showed there was no significant difference between the arms. It was concluded that liposomal amphotericin at either 1 or 3 mg/kg/d was significantly safer than conventional amphotericin B in children and adults. The main aim of this open-label study was to compare safety between the three trial arms. However, we provide evidence for an equivalent or possibly superior efficacy of liposomal amphotericin with regard to resolution of fever of unknown origin. Subsequent trials should compare amphotericin preparations in defined fungal infections.

Adult↗
PubMed1996

Molecular analysis of HLA-DQB1 alleles in childhood common acute lymphoblastic leukaemia.

Epidemiological studies suggest that childhood common acute lymphoblastic leukaemia (c-ALL) may be the rare outcome of early post-natal infection with a common infectious agent. One of the factors that may determine whether a child succumbs to c-ALL is how it responds to the candidate infection. Since immune responses to infection are under the partial control of (human leucocyte antigen) HLA genes, an association between an HLA allele and c-ALL could provide support for an infectious aetiology. To define the limit of c-ALL susceptibility within the HLA region, we have compared HLA-DQB1 allele frequencies in a cohort of 62 children with c-ALL with 76 newborn controls, using group-specific polymerase chain reaction (PCR) amplification, and single-strand conformation polymorphism (SSCP) analysis. We find that a significant excess of children with c-ALL type for DQB1*05 [relative risk (RR): 2.54, uncorrected P=0.038], and a marginal excess with DQB1*0501 (RR: 2.18; P=0.095). Only 3 of the 62 children with c-ALL have the other susceptibility allele, DPB1*0201 as well as DQB1*0501, whereas 15 had one or the other allele. This suggests that HLA-associated susceptibility may be determined independently by at least two loci, and is not due to linkage disequilibrium. The combined relative risk of the two groups of children with DPB1*0201 and/or DQB1*0501 is 2.76 (P=0.0076). Analysis of amino acids encoded by exon 2 of DQB1 reveal additional complexity, with significant (P<0.05) or borderline-significant increases in Gly26, His30, Val57, Glu66-Val67 encoding motifs in c-ALL compared with controls. Since these amino acids are not restricted to DQB1*0501, our results suggest that, as with DPB1, the increased risk of c-ALL associated with DQB1 is determined by specific amino acid encoding motifs rather than by an individual allele. These results also suggest that HLA-associated susceptibility to c-ALL may not be restricted to the region bounded by DPB1 and DQB1.

Alleles↗
PubMed1996

Acute myeloid leukaemia.

There has been considerable progress in the understanding and treatment of childhood acute myeloid leukaemia over the past two decades. In particular, cyto- and molecular genetics offer the potential for more specific diagnosis of what is basically a heterogeneous disease. To date treatment has been based on a steady increase in cytotoxic chemotherapy with or without the addition of bone marrow transplantation. Randomised therapeutic trials are difficult to perform in what is a rare disease. The best way forward is for paediatric trial groups worldwide to collaborate in developing common, or parallel, therapeutic protocols.

Acute Disease↗