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D H Pamphilon

Publications and source records attributed to D H Pamphilon.

At least 19 recordsLinked to original sources
PubMed2001

An optimised biphasic culture system for the generation of functional dendritic cells from patients with acute lymphoblastic leukaemia at presentation and in clinical remission.

We have tested the hypothesis that functional dendritic cells (DC) may be generated from patients with acute lymphoblastic leukaemia (ALL). We evaluated the production of DC from blast cells taken at presentation from nine children with ALL. Blast cells were expanded in serum-free medium supplemented with Flt3L, G-CSF, GM-CSF, IL-3, IL-6 and SCF for 7 days and subsequently stimulated with Flt3L, GM-CSF and TGF-beta for a further 14 days, with the addition of TNF-alpha for the final 48 h of culture. Cultured cells had the morphological appearance of DC and expressed the DC-associated antigens CD1A (range 2-87%) and CD83 (15-44%). Expression of the co-stimulatory molecules CD80 and CD86 was increased and the majority of these cells retained their expression of CD34 (73+/-4%) and HLA-DR (79+/-5%). Seven of the nine ALL had a leukaemia-specific abnormality and DC generated from five of these seven cases were derived from the leukaemic clone. Leukaemic DC derived from four HLA-A*02-positive ALL pulsed with CMV-associated peptides could induce significant proliferation of peptide-specific CD8+ T cells. This specificity was verified using tetrameric complexes of HLA class l/antigenic peptide. DC could also be generated from cells taken at times of complete remission of ALL and from normal controls using these culture conditions. These findings show that functional DC can be generated both from ALL blasts and from patients in remission; these might be utilised in future for immunotherapeutic strategies in the treatment of ALL.

Adolescent↗
PubMed2001

The clinical features, risk factors and outcome of thrombotic thrombocytopenic purpura occurring after bone marrow transplantation.

In this study, we retrospectively analysed the clinical features, risk factors and outcome of 22 patients with thrombotic thrombocytopenic purpura (TTP) occurring after allogeneic stem cell transplantation. All but two of these patients received stem cells from unrelated donors (UDs), two-thirds were female, three-quarters were adults and leukaemia was the major reason for transplant. The incidence of TTP was 20 out of 332 patients (6%) with UD transplants and two out of 104 recipients (2%) of matched sibling allografts (P = 0.16). In order to ascertain basic demographic risk factors for the development of TTP, we compared the 22 patients with 434 patients who did not develop TTP. Compared with patients who did not develop TTP, patients with TTP were nearly three times older (P < 0.001) and were more than twice as likely to be female (P = 0.001). Because > 90% of patients were recipients of UD marrow, we then compared the 20 UD-bone marrow transplantation (BMT) patients with 60 randomly selected UD-BMT patients who did not develop TTP. On univariate analysis, age and female gender were again significant risk factors, as was grade II-IV acute graft-versus-host disease (GvHD) (P = 0.002), and there was a trend towards an association with chronic GvHD (P = 0.083). However, after logistic regression analysis, only age and sex remained significant (P < 0.001 and 0.009 respectively). We report an 86% mortality with only three survivors out of 22 patients, and one of these remains thrombocytopenic and red cell transfusion dependent, possibly in part because of graft hypoplasia. Six out of 17 patients responded to plasmapheresis, but the majority of them ultimately succumbed because of TTP, often in association with GvHD or fungal infection.

Adolescent↗
PubMed2000

T cell-depleted unrelated donor bone marrow transplantation for acute myeloid leukemia.

The outcome for 39 patients with acute myeloid leukemia (AML) in remission who had CAMPATH 1M T cell-depleted unrelated donor bone marrow transplantations (BMTs) is described. Conditioning was mainly with cyclophosphamide (120 mg/kg) and total body irradiation (TBI) (14.4 Gy), but 5 patients received busulfan in place of TBI and 200 mg/kg cyclophosphamide. All patients received cyclosporin, and short-course methotrexate was given to recipients of mismatched grafts. The patient population was predominantly pediatric (median age, 10 years), but one third of the patients was aged 15 years or above. Twenty-five patients were in second complete remission (CR2), and 14 had high-risk CR1 disease (primarily failed remission induction or antecedent myelodysplastic syndrome, often with complex cytogenetic abnormalities). Both recipient and donor were cytomegalovirus seronegative in 15 of 37 cases (38%); 51% of patients were matched for HLA class I and II. Grade II to IV acute graft-versus-host disease (GVHD) occurred in 24% of patients; chronic GVHD occurred in 5 of 31 evaluable patients (16%), 4 extensive and 1 limited. Relapse occurred in 5 cases (13%); 1 of these 5 patients survives, 24 months after a second unrelated donor transplantation. Two of these relapses were associated with secondary graft failure (incidence rate, 5%). All patients engrafted primarily. Severe viral infection was the major transplant-associated complication, with 12 episodes in 9 patients, 5 of them lethal. Twenty-five patients survive at a median follow-up of 44 months (range, 2-102 months), with estimated actuarial overall and disease-free survival rates at 44 months of 61% (SE 8%) and 57% (SE 8%), respectively. Nineteen patients are more than 2 years post-BMT and may be cured. The functional status of long-term survivors is excellent, with 19 of 21 patients who survive 6 months or more in full-time employment or full-time students. These encouraging results suggest that in patients lacking a sibling donor, unrelated donor BMT for AML in remission achieves survival figures as good as or better than those reported on patients with autologous stem cell transplantation, and that T-cell depletion of grafts is associated with a low relapse rate and an excellent functional status. However, only a randomized study comparing unrelated donor BMT and auto-grafting will resolve which of these treatment strategies is better for patients with AML.

Acute Disease↗
PubMed2000

Outcome and clinical course of 100 patients with adenovirus infection following bone marrow transplantation.

We conducted a retrospective review of the clinical features and outcome of adenovirus infection in 572 consecutive patients transplanted in a single centre over a 10 year period. One hundred patients (17%) had a total of 105 episodes of adenovirus infection diagnosed at a median of 18 days post transplant (range 2-150 days). The incidence was higher in children than adults (21% vs 9%, P < 0.001) and in unrelated donor vs matched sibling donor transplants (26% vs 9%, P < 0.001). Diarrhoea and fever were the most common presenting features. Reflecting these symptoms, the most common site of isolation was the stool. Serotypes 1, 2 and 7 were the most frequently seen (total of 41/68 or 60% of evaluable cases). In six patients (6%) adenovirus infection was the direct cause of death occurring at a median of 72 days post transplant (range 18-365 days). Five of these six patients had pulmonary involvement and four had associated graft-versus-host disease (GVHD). Three further patients were considered to have severe adenoviral disease (total incidence 9%). Isolation of virus from multiple sites correlated with a poor outcome (P < 0.001). Comorbid viral infection was common in this group with 50% of all patients having other viruses isolated (predominantly polyoma virus and cytomegalovirus). We conclude that adenovirus is commonly isolated after bone marrow transplant and is a cause of significant morbidity but was a rare cause of mortality (6/572 = 1%) in our patient group as a whole. The relative infrequency of severe infection will make it difficult for the transplant physician to decide which patients should receive experimental antiviral drugs such as ribavirin and cidofovir or immunomodulatory therapy with donor white cell infusions.

Adenovirus Infections, Human↗
PubMed2000

Differential leucocyte subpopulation analysis of leucodepleted red cell products.

Donor leucocytes are responsible for many adverse transfusion effects. Clinical reactions may be attributed to specific leucocyte subsets. In this study leucocyte subpopulations were identified and quantified pre- and post-leucodepletion by integral filtration using novel Optipac(R) configurations incorporating either WBF-1 (Pall Medsep) or RS2000 (Asahi) whole blood filters. Leucocytes were analysed by flow cytometry using direct, four-colour, membrane immunofluorescence with monoclonal antibodies specific for CD 3, 14, 16, 19 and 45. Filtration reduced the leucocyte load by 3-4 log10, consistently giving products with < 2 cells microL-1. Subset distributions were also affected with the proportion of neutrophils and monocytes increased and the lymphocyte/monocyte ratio inverted. These effects were independent of the preprocessing hold conditions, filter used and buffy coat (BC) removal. All filtered red cell products contained 75-80% neutrophils, 16-20% monocytes and 2-7% lymphocytes. Results presented here demonstrate that whole blood filtration, and BC removal, significantly reduce the content and substantially alter the subpopulation distribution of the donor leucocytes remaining in leucodepleted red cell products.

Blood Preservation↗
PubMed1999

Children with acute lymphoblastic leukemia who receive T-cell-depleted HLA mismatched marrow allografts from unrelated donors have an increased incidence of primary graft failure but a similar overall transplant outcome.

Disparity for HLA in unrelated donor bone marrow transplantation (BMT) increases the risk of graft rejection and graft-versus-host disease (GVHD) and may compromise transplant outcome. We have compared the outcome of matched and mismatched transplants from unrelated donors in 137 children with acute lymphoblastic leukemia (ALL). Their disease status was complete remission (CR)-1, 24 patients; CR-2, 88 patients; CR-3, 18 patients; CR-4, 2 patients; and relapse, 5 patients. CAMPATH monoclonal antibodies were used for T-cell depletion and cyclosporin A was given to 134 children together with short-course methotrexate in 43, mainly when there was HLA disparity. Fifty-two donor/recipient pairs were HLA-mismatched, 41 at HLA-A and -B and 11 at HLA-DR and -DQ loci. Overall graft failure was increased in recipients of marrow mismatched at either HLA-A, -B, -DR, or -DQ (15.7% v 4.8%; P =.057) mainly because there was a higher proportion of children with primary graft failure (11. 8% v 1.2%; P =.012). The presence of an HLA-C locus mismatch did not independently increase the likelihood of graft failure. There was no significant difference in the incidence of acute GVHD >/= grade 2 between the matched and mismatched groups (P =.849). For patients in CR-2, the risk of relapse post-BMT was significantly lower if leukemic relapse occurred off-treatment (P =.005). The Kaplan-Meier overall and leukemia-free survival (LFS) estimates for recipients of matched and mismatched BMT, respectively, at 36 months were 49% versus 42% (P =.380) and 45% versus 40% (P =.654). Although HLA mismatching results in an increased occurrence of primary graft failure with T-cell-depleted allografts, it allows more donors to be identified rapidly for children with ALL without compromising overall transplant outcome.

Adolescent↗
PubMed1999

The outcome of 26 patients with respiratory syncytial virus infection following allogeneic stem cell transplantation.

Respiratory syncytial virus (RSV) is known to cause acute lung injury in the immunocompromised host, especially recipients of bone marrow allografts. Specific prognostic factors for the development of severe life-threatening disease remain to be identified as does the optimum treatment of established disease. Over a 5-year period the incidence and outcome of RSV in BMT recipients was analysed retrospectively. Prognostic factors assessed included type of transplant, engraftment status at the time of infection, the presence of lower respiratory tract disease, viral genotype and treatment received. During the study period, 26 of 336 (6.3%) allogeneic stem-cell recipients were identified as having RSV. Five patients (19.2%) died as a direct result of RSV. One patient died secondary to an intracranial bleed with concomitant RSV. There were four patients with graft failure (two primary and two secondary) attributable to the presence of RSV, two of whom subsequently died of infections related to prolonged myelosuppression. The presence of lower respiratory tract infection and a poor overall outcome was the only statistically significant association. Unrelated donor transplants and AML as the underlying disease appeared to be associated with a poorer outcome. Engraftment status, viral genotype and RSV treatment received did not correlate with outcome. We conclude that future studies are required to identify early sensitive and reproducible prognostic factors of RSV in the immunocompromised host. The roles of intravenous and nebulised ribavirin need to be clarified by prospective controlled trials.

Adolescent↗
PubMed1999

Infections in adults undergoing unrelated donor bone marrow transplantation.

This study retrospectively reviews infections over a 7-year period in 60 consecutive adults (median age 25 years) undergoing their first unrelated donor bone marrow transplant (UD-BMT). T-cell depletion was employed in 93%. More than half the patients had one or more severe, potentially life-threatening, infections. There was a high incidence of invasive fungal infections (Aspergillus 17, Candida four), despite the use of itraconazole or amphotericin prophylaxis. Ten Aspergillus infections occurred beyond 100 d. Two patients (11%) with invasive aspergillosis survived. Clustering of infections was noted, with invasive fungal infections significantly associated with bacteraemias (OR 3.73, P=0.06) and multiple viral infections (OR 4.25, P=0.05). There were 21 severe viral infections in 16 patients, with CMV disease occurring in four patients only; viral pneumonitis was predominantly due to 'community respiratory' viruses. Most early bacteraemias (68%) were due to Gram-positive organisms. The majority of episodes of Gram-negative sepsis were caused by non-fastidious non-fermentative bacteria, such as Pseudomonas spp. and Acinetobacter spp., historically regarded as organisms of low pathogenicity. In patients with successful engraftment and minimal graft-versus-host disease, late infections suggestive of continued immune dysfunction (shingles, recurrent lower respiratory infections, Salmonella enteritis and extensive warts) were common.

Adolescent↗
PubMed1999

Prevention of transfusion-transmitted cytomegalovirus infection.

Cytomegalovirus (CMV) is a double-stranded DNA virus which can be transmitted by blood transfusion. Its seroprevalence in adults ranges from 40% to 100% depending on geographical and socioeconomic conditions. Seropositive individuals have latent CMV infection with viral DNA present in peripheral blood leucocytes. CMV can be associated with considerable morbidity and mortality in susceptible individuals, e.g. CMV-seronegative bone marrow allograft patients. Evidence, from a number of reports, suggests that provision of leucodepleted blood components may be as effective as the use of components from CMV-seronegative donors in preventing CMV infection and disease. This is relevant in the UK because Blood Transfusion Services are implementing universal leucodepletion of cellular blood components to minimize the theoretical risk of transmission of new variant Creutzfeldt-Jakob disease. This review examines data on the biology of CMV, discusses options for testing and summarizes the impact of CMV-seronegative and leucodepleted blood components on transfusion-transmitted CMV.

Antibodies, Viral↗
PubMed1999

Evaluation of plasma and red cells obtained after leucocyte depletion of whole blood.

We evaluated whole blood integral filtration to produce leucocyte-depleted red cells and plasma by using the WBF1 whole blood filter (Pall Medsep). Whole blood units were filtered after either warm (2-4 h at room temperature) or cold (12-24 h at 4 degrees C) holds. Filtered and control units were processed using either a bottom-and-top or top-top method. Red cells were tested weekly for 6 weeks, and plasma 3 monthly for 12 months. All filtered red-cell packs contained < 5 x 10(6) leucocytes/unit with 71 of 72 containing < 1 x 10(6) leucocytes/unit. No clinically significant differences in red-cell storage parameters were seen, although haemolysis was less and pO2/pCO2 values were better maintained in filtered units. Plasma units contained < 2.5 x 10(3) leucocytes/unit with no significant loss of factor VIII except in the warm hold units processed by the top-top method. There was no evidence of complement or coagulation activation with significant removal of preformed C3a in cold hold units. Plasma storage parameters were maintained at control levels for 12 months.

Erythrocyte Count↗
PubMed1998

Minimal residual disease status before allogeneic bone marrow transplantation is an important determinant of successful outcome for children and adolescents with acute lymphoblastic leukemia.

The efficacy of allografting in acute lymphoblastic leukemia (ALL) is heavily influenced by remission status at the time of transplant. Using polymerase chain reaction (PCR)-based minimal residual disease (MRD) analysis, we have investigated retrospectively the impact of submicroscopic leukemia on outcome in 64 patients receiving allogeneic bone marrow transplantation (BMT) for childhood ALL. Remission BM specimens were taken 6 to 81 days (median, 23) before transplant. All patients received similar conditioning therapy; 50 received grafts from unrelated donors and 14 from related donors. Nineteen patients were transplanted in first complete remission (CR1) and 45 in second or subsequent CR. MRD was analyzed by PCR of Ig or T-cell receptor delta or gamma rearrangements, electrophoresis, and allele-specific oligoprobing. Samples were rated high-level positive (clonal band evident after electrophoresis; sensitivity 10(-2) to 10(-3)), low-level positive (MRD detected only after oligoprobing; sensitivity 10(-3) to 10(-5)), or negative. Excluding 8 patients transplanted in CR2 for isolated extramedullary relapse (all MRD-), MRD was detected at high level in 12 patients, low level in 11, and was undetectable in 33. Two-year event-free survival for these groups was 0%, 36%, and 73%, respectively (P <.001). Follow-up in patients remaining in continuing remission is 20 to 96 months (median, 35). These results suggest that MRD analysis could be used routinely in this setting. This would allow identification of patients with resistant leukemia (who may benefit from innovative BMT protocols) and of those with more responsive disease (who may be candidates for randomized trials of BMT versus modern intensive relapse chemotherapy).

Adolescent↗
PubMed1998

Second allogeneic bone marrow transplants from unrelated donors for graft failure following initial unrelated donor bone marrow transplantation.

Graft failure is a common and severe complication of unrelated donor bone marrow transplantation (UD-BMT). However, there are few reports of a second UD-BMT in this setting. We describe 12 patients with graft failure (five primary, seven secondary) who had a second transplant, five from their original donor and seven from a different donor. Their median age was 9 years. Two patients died before day 10 of regimen-related toxicity. Nine of 10 evaluable patients engrafted in a median of 17 days. Secondary graft failure was seen in one patient. Transplant-related morbidity was significant. Six of nine developed acute GHVD, there were five severe infections and five patients developed Bearman grade 3 or 4 extramedullary toxicity. Overall, five patients survive at a median of 38 months after the second BMT and two are in continuous complete remission. Second transplants from unrelated donors for graft failure can result in prolonged survival.

Adolescent↗
PubMed1998

Influence of ultraviolet-B irradiation on engraftment, graft-versus-host disease and graft-versus-leukemia effect in a rat model for allogeneic bone marrow transplantation.

Ultraviolet-B (UVB) irradiation is known to inhibit lymphocyte activity and consequently to reduce the incidence of graft-versus-host disease (GVHD) in experimental models for allogeneic bone marrow transplantation (BMT). GVHD is frequently associated with morbidity and mortality, but also with the beneficial graft-versus-leukemia (GVL) effect, demonstrated by a reduction in the incidence of leukemia relapse. In this study, we investigated whether UVB treatment of allogeneic T cells could prevent GVHD while sparing the beneficial GVL effect following allogeneic BMT in the Brown Norway myelocytic leukemia (BNML) rat model analogous to human acute myelocytic leukemia (AML). The dose of UVB required to abolish lethal GVHD in the rat allogeneic BMT model (WAG/Rij donors into BN recipients) was 4000 J/m2. However, this UVB dose simultaneously abrogated all GVL activity mediated by the T cells in the graft, while the radio-protective capacity of rat BM cells was strongly reduced. The number of allogeneic BM cells required to protect lethally irradiated BN rats was increased 50 to 100-fold. It is concluded that UVB acts as a non-selective form of T cell inactivation, and that UVB pretreatment of an allogeneic marrow graft is unlikely to be useful clinically as a preventive measure for GVHD, since other means of reduction of the number of functional T cells are less damaging to bone marrow stem cells.

Animals↗
PubMed1998

Double T cell depletion of bone marrow using sequential positive and negative cell immunoaffinity or CD34+ cell selection followed by Campath-1M; effect on CD34+ cells and progenitor cell recoveries.

An advantage of CD34+ cell selection over antibody purging is that a component allograft is produced comprising a stem cell enriched and an unadsorbed fraction, the latter containing T cells which may be used for post-transplant immunotherapy. Initial reports with PBSC allografts suggested that T cell depletion (TCD) by CD34+ cell selection and post-graft cyclosporin A +/- methotrexate was insufficient prophylaxis against acute GVHD. We compared sequential TCD (of a CD34+ cell-selected fraction) using a second (CD2) immunoaffinity step or Campath-1M monoclonal antibody and complement. Since a high stem cell 'dose' enhances engraftment across HLA barriers and improves overall post-transplant outcome, the recovery of CD34+ cells and progenitors were assessed. Sequential positive (CD34+) and negative (CD2+) immunoaffinity selection resulted in a 3.4 log depletion of T cells as compared to a 4.05 log depletion when CD34+ cell selection was followed by Campath-1M treatment. Recoveries of CD34+ cells, CFU-GM and BFU-E following double depletion using CD34+ cell selection plus CD2+ cell depletion were 28, 25 and 17% as compared to 20, 18 and 16% when CD34+ cells were treated with Campath-1M. The unadsorbed fraction contained 85% of the original T cells, from which donor leukocyte infusions in the range of 10(5) to 10(7) CD3+ cells per kg body weight of the recipient were harvested. Despite the advantages of component allografts, the loss of stem/progenitor cells may restrict sequential TCD steps unless single BM harvests are supplemented and/or replaced with mobilised PBSCs.

Alemtuzumab↗
PubMed1998

The outcome of children requiring admission to an intensive care unit following bone marrow transplantation.

We report the results of a retrospective study of the role of intensive care unit (ICU) admission in the management of 367 children who underwent bone marrow transplantation (BMT) at a tertiary referral institution. 39 patients (11%) required 44 ICU admissions for a median of 6 d. 70% received marrow from unrelated donors, half of which were mismatched; 80% had leukaemia and two-thirds were considered high-risk transplants. Respiratory failure was the major reason for admission to ICU. 75% of admissions required mechanical ventilation (for a median of 5 d) and 20 patients had lung injury as defined by the criteria of the Seattle group. None of 11 patients with proven viral pneumonitis survived (P = 0.06) and only one of 20 patients with lung injury survived (P < 0.01). Six of seven patients with a primary neurological problem survived (P < 0.001); these appear to represent a good outcome group. Age, the presence of graft-versus-host disease, the use of inotropes, isolated renal or hepatic impairment, and paediatric risk of mortality (PRISM) score were not predictive of outcome. In total, 12 patients (27% of admissions) survived and were discharged from hospital 30d or more after admission and eight (18%) survived >6 months. ICU admission can be beneficial to selected children post-BMT but it may be less useful in proven viral pneumonitis. Where mechanical ventilation is required, the duration of this support should be limited unless there is rapid improvement.

Acute Disease↗
PubMed1998

Minimal residual disease status as a predictor of relapse after allogeneic bone marrow transplantation for children with acute lymphoblastic leukaemia.

We have analysed the behaviour of minimal residual disease (MRD) after allogeneic bone marrow transplantation (allo-BMT) in 71 children with acute lymphoblastic leukaemia (ALL). The method relied on PCR of IgH, TCRdelta and/or TCRgamma gene rearrangements followed by electrophoretic size resolution and allele-specific oligoprobing. Patients were similarly conditioned; 55 received marrow from unrelated donors and 16 from related donors. MRD was assessed at various time-points up to 24 months after BMT. Three children were not evaluable due to transplant-related mortality. MRD was detected in 28/32 patients (88%) who relapsed post-BMT; 16 were positive at all times and 12 were initially negative but became positive at a median of 3 months (range 1.5-11) prior to relapse. In contrast, only eight of 36 (22%) patients who remained in continuing complete remission (CCR) (median follow-up 43 months, range 20-94) showed MRD at any time after BMT (P<0.0001). In these eight patients MRD was found up to 9 months after transplant and at low levels (0.01-0.001%). All eight (median follow-up 39 months, range 24-87) had at least two MRD-negative samples tested subsequently and five of the eight had evidence of grade I-II acute graft-versus-host disease (GvHD), raising the possibility of a graft-versus-leukaemia effect. In general, any evidence of MRD after allo-BMT is a poor prognostic sign. However, if immunotherapy were to be targeted towards patients with evidence of persisting MRD after BMT, the method described would expose only a small proportion of patients to unnecessary additional toxicity.

Adolescent↗