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D Pamphilon

Publications and source records attributed to D Pamphilon.

At least 19 recordsLinked to original sources
PubMed2006

Factors affecting volume reduction and red blood cell depletion of bone marrow on the COBE Spectra cell separator before haematopoietic stem cell transplantation.

The COBE Spectra is used to volume/red blood cell (RBC) deplete BM before transplantation or cryopreservation. We have audited our results to identify the effect of transit time, refrigerated storage, age and cellular composition on mononuclear cells (MNC) and CD34+ cell recoveries, volume/RBC depletion and neutrophil engraftment. In total, 88 consecutive collections from autologous (n = 25) and allogeneic (n = 63) donors were included. The mean collection volume was 1250 +/- 398 ml with RBC content of 341 +/- 113 ml. The MNC and CD34+ cell recoveries were 83.3 +/- 18.5 and 88.1 +/- 18.9%, respectively, volume depletion was 88.2+/-4.4% and RBC depletion 98.3 +/- 1.8%. Neutrophil engraftment was achieved in 20.1 +/- 6.4 days. Factors affecting MNC and CD34+ cell recoveries were transit time (P = 0.0060), overall age (P < 0.0210) and MNC/CD34+ cell concentrations (P < 0.0313). The presence of crenated RBC also reduced CD34+ cell recovery (P = 0.0028). Refrigerated storage did not adversely affect cell recovery (P > 0.8161) or neutrophil engraftment (P = 0.8959). This study demonstrates that time in transit, overall age, MNC and CD34+ cell concentrations and RBC condition were important factors affecting processing. RBCs show artefacts soon after collection at ambient temperatures and these may interfere with the separation and collection of MNC/CD34+ cells. Refrigeration at 4-6 degrees C during transit and storage may reduce formation of RBC artefacts and maximize MNC and CD34+ cell recoveries.

Antigens, CD34↗
PubMed2006

Topical issues in unrelated donor haematopoietic stem cell transplants: a report from a workshop convened by the Anthony Nolan Trust in London - 2005.

Over more than three decades, The Anthony Nolan Trust (ANT) has provided an unrelated donor (UD) for over 4000 children and adults lacking a suitable family member donor, and has remained at the forefront of developments in haematopoietic stem cell transplantation (HSCT) and bone marrow register management. These three decades have seen major changes in clinical practice of UD-HSCT, including new indications, increased use of alternative haematopoietic cell sources, significant improvement of the outcome as a result of better support care, less-toxic conditioning regimens, and better donor selection, and expansion to older patients with higher comorbidities. In order to foster our goal of improving UD-HSCT availability and outcome in a progressively more complex clinical scenario, a new initiative from ANT was launched in 2005 to convene an experts workshop to address the topical issues in this field. Four consecutive panels addressed factors influencing donor selection and transplant outcome, the use of cord blood, regulatory and accreditation issues, and future developments in this field. This report summarizes the discussions held in this workshop, which will likely develop into a periodic event where transplant clinicians, scientists and registry members will meet to share their experience and vision in the field of UD-HSCT.

Donor Selection↗
PubMed2004

Therapeutic efficacy of pooled buffy-coat platelet components prepared and stored with a platelet additive solution.

Despite the introduction of platelet additive solutions for the preparation of pooled platelet components, only a few studies of limited scope have evaluated the clinical efficacy of platelets stored in these solutions. The current report presents an analysis of data to evaluate the response to the transfusion of pooled buffy-coat components suspended in storage solution with reduced (35%) plasma content in comparison with 100% plasma products. During the euroSPRITE clinical trial of platelet components treated with a pathogen inactivation process, control treatment group platelet components were prepared in 100% allogeneic donor plasma (plasma control) or in platelet additive solution (T-Sol) mixed with plasma (T-Sol control). Control group thrombocytopenic patients received either plasma control or T-Sol control platelet components. One-hour and 24-h platelet count increments (CIs) and corrected count increments (CCIs) were analysed for these two types of preparation. In addition, haemostatic assessments were conducted for each transfusion. One-hour and 24-h mean platelet CIs and post-transfusion haemostatic scores were not significantly different for patients receiving platelet components suspended in 100% plasma and T-Sol plasma mixtures. Pooled buffy-coat platelet components prepared in reduced plasma content mixtures provided therapeutic platelet CIs with effective haemostasis.

Blood Component Transfusion↗
PubMed2001

Improved outcome of alternative donor bone marrow transplantation in children with severe aplastic anaemia using a conditioning regimen containing low-dose total body irradiation, cyclophosphamide and Campath.

The increasing success of human leucocyte antigen (HLA)-matched sibling donor (MSD) transplants and combination immunosuppressive treatments have dramatically improved the prognosis of severe aplastic anaemia (SAA) in children and young adults. For patients who lack a MSD there is a significant minority who fail immunosuppressive therapy or suffer from a severe constitutional aplastic anaemia in which immunosuppression would be ineffective. Alternative donor bone marrow transplantation (AD-BMT) has only had limited success in this context. We report the successful outcome of AD-BMT in eight consecutive patients aged 7 months to 15 years, six of whom had acquired aplastic anaemia who had previously failed to respond to immunosuppression, and two of whom had a severe (non-Fanconi) constitutional aplastic anaemia. All eight patients had received multiple red cell and platelet transfusions. We used a new combination of agents for pretransplant conditioning aiming to maximize immunosuppression and minimize toxicity, consisting of Campath-1G or -1H, cyclophosphamide and low-dose total body irradiation (LD TBI) or fludarabine. Toxicity was minimal and all eight children are alive, well and free of disease at a median follow-up of 32 months. We suggest that this approach could facilitate the successful treatment of children with SAA in whom immunosuppressive therapy has failed or is not appropriate.

Alemtuzumab↗
PubMed2001

Marrow transplants from unrelated donors for patients with aplastic anemia: minimum effective dose of total body irradiation.

Patients with aplastic anemia who do not have suitably HLA-matched, related donors generally receive immunosuppressive treatment as first-line therapy and are considered for transplantation from an unrelated donor only if they fail to respond to immunosuppressive treatment. In this setting, rates of transplantation-related morbidity and mortality have been high. We conducted a prospective study to determine the minimal dose of total body irradiation (TBI) sufficient to achieve sustained engraftment when it is used in combination with 3 cycles of 30 mg/kg of antithymocyte globulin (ATG) and 4 cycles of 50 mg/kg of cyclophosphamide (CY). We also wanted to determine the tolerability and toxicity of the regimen. The starting dosage of TBI was 3 x 200 cGy given over 2 days following CY/ATG. The TBI dose was to be escalated in increments of 200 cGy if graft failure occurred in the absence of prohibitive toxicity, and de-escalated for toxicity in the absence of graft failure. Twenty-one female and 29 male patients aged 1.3 to 46.5 years (median age, 14.4 years) underwent transplantation at 14 medical centers. The time interval from diagnosis to transplantation was 2.8 to 264 months (median, 14.5 months). All patients had been transfused multiple times and all had received 1 to 11 courses (median, 4 courses) of immunosuppressive treatment and other modalities of treatment. In 38 cases, the donors were HLA-A, -B and -DR phenotypically matched with the patients, and, in 12 cases, the donor phenotype differed from that of the recipient by 1 HLA antigen. Recipients of mismatched transplants were considered separately for TBI dose modification, and this study is still ongoing. Seven patients did not tolerate ATG and were prepared with 6 x 200 cGy of TBI plus 120 mg/kg of CY. Of the HLA-matched recipients prepared with CY/ATG/TBI, all 20 who received 3 x 200 or 2 x 200 cGy of TBI achieved engraftment, and 10 are alive. Of the 13 patients who received 1 x 200 cGy of TBI, 1 failed to engraft, and 8 are alive. Each of 10 patients who received an HLA-nonidentical transplant achieved engraftment, and 3 of 6 who were given 3 x 200 cGy of TBI, and 4 of 4 who were given 2 x 200 cGy are alive. Pulmonary toxicity occurred in 8 of 30 patients who were given 3 x 200 or 2 x 200 cGy of TBI concurrently with ATG and CY at 200 mg/kg, and in 2 of 13 patients who received 1 x 200 cGy of TBI, a pattern that suggests a decrease in toxicity with TBI dose de-escalation. Overall, the highest probability of survival (73%) was observed among patients who underwent transplantation within 1 year of diagnosis, compared with patients who underwent transplantation after a longer period of disease. In addition, younger patients (aged < or = 20 years) were more likely to survive than older patients (aged > 20 years). Thus, for patients with an HLA-matched, unrelated donor, a TBI dose of 200 cGy (in combination with CY/ATG) was sufficient to allow for engraftment without inducing prohibitive toxicity. As in previous studies, patient age and pretransplantation disease duration remain important prognostic factors.

Adolescent↗
PubMed2000

Pediatric marrow transplantation for acute leukemia using unrelated donors and T-replete or -depleted grafts: a case-matched analysis.

A retrospective, case-matched analysis of the short-term toxicity, risk of GVHD and relapse as well as outcome in pediatric unrelated marrow transplantation was conducted by comparing recipients of T-replete and -depleted grafts in a two-center setting. Both groups contained 30 patients with acute leukemia matched by age at transplant, gender, primary diagnosis and disease status. Acute (90% vs 53%) and chronic (48% vs 0%) GVHD were more common among recipients of T-replete grafts. No significant differences in graft rejection/failure or viral infections were encountered between the two groups. Relapses were more prevalent (37% vs 15%) among recipients of T-depleted grafts. Outcome (EFS) was similar in the two groups. Consequently, in the analysis of transplant outcome, the higher risk of procedure-related, toxic complications among pediatric recipients of T-replete marrow grafts appears to be balanced by an increased risk of relapse among the recipients of T-depleted grafts.

Acute Disease↗
PubMed1999

Direct detection of bacteria in cellular blood products using bacterial ribosomal RNA-directed probes coupled to electrochemiluminescence.

Various techniques for detecting bacteria in blood products exist; however, none has been widely accepted. Our method permits direct bacterial detection in both platelet concentrates (PC) and packed red blood cells (RBC). This novel procedure targets bacterial ribosomal RNA (rRNA) but does not utilize culture or nucleic acid amplification. The assay comprises five steps: (1) release of bacterial rRNA by cell lysis with a combination of detergents and high heat; (2) hybridization of bacterial rRNA using a biotin- and a ruthenium (ORIGEN)-labelled oligonucleotide probe pair; (3) capture of labelled rRNA with streptavidin-coated magnetic beads; (4) concentration of labelled rRNA/bead complexes out of solution and onto an electrode surface with a magnet; (5) detection of ruthenium-labelled bacterial rRNA by application of voltage and consequent generation of the electrochemiluminescent (ECL) signal. Results using PC and RBC samples, spiked with clinically relevant gram-negative and -positive bacterial species, consistently demonstrated a linear relationship between ECL signal (equates to rRNA level) and colony forming units (CFU) mL(-1). Signals were generated in the range of 1400-80000 and 3500-500000 ECL units for unwashed and washed samples, respectively. This is equivalent to 10(5)-10(8)CFU mL(-1). These data demonstrate that therapeutic blood products significantly contaminated with bacteria may be identified prior to issue.

Bacteria↗
PubMed1999

A new apheresis procedure for the preparation of high-quality red cells and plasma.

BACKGROUND: Multicomponent apheresis is an alternative way of preparing blood components that avoids the delay between collection and separation seen with standard whole-blood techniques. STUDY DESIGN AND METHODS: An apheresis device has been modified to facilitate the combined collection of a unit (250 mL) of red cells (RBCs) and a high-volume unit (475 mL) of plasma. The procedure, using 8-percent ACD-A, has been tested in two European blood centers. Each center performed 20 procedures for in vitro evaluation of collected RBCs and plasma and 10 procedures for evaluation of in vivo RBC recovery. All RBCs were white cell reduced by filtration. One-half of the RBC units were stored in the additive solution Adsol and one-half in another such solution (Erythro-Sol). RESULTS: The target volumes of RBCs and plasma were obtained in 27 minutes (range, 20-44 min) by using three to six cycles in a single-needle procedure. Saline (275 mL) was used to replace fluid volume withdrawn in excess of standard whole-blood donation. No side effects occurred, with the exception of minor signs of hypocalcemia. RBC ATP was well maintained (>65% at Day 42) during storage; 2,3-DPG was less well maintained, with virtually none remaining at Day 21 in either Adsol or Erythro-Sol. The RBC in vivo recoveries, after 42 days of storage at 4+/-2 degrees C determined by the single-label method, were 86.7+/-7.2 percent (Erythro-Sol) and 84.4+/-8.1 percent (Adsol). Mean plasma factor VIII levels were >100 percent in all test groups. CONCLUSION: A novel automated technique for the simultaneous collection and preparation of RBCs and plasma has been evaluated. The apheresis procedure was acceptable and well tolerated by donors, and it resulted in high-quality blood components. Further optimization of the system should yield a practicable component suitable for routine use in blood banks.

Blood Component Removal↗
PubMed1998

Cytomegalovirus infection in recipients of related and unrelated donor bone marrow transplants: no evidence of increased incidence in patients receiving unrelated donor grafts.

Recent reports suggest an increased incidence of cytomegalovirus (CMV) infection in recipients of unrelated donor (UD) bone marrow transplantation (BMT). In this study we have collated the incidence of CMV infection and disease in sequential UD (n = 119) and related donor (RD; n = 79) BMT performed in a single institution over a 7-year period. Low-risk patients (CMV seronegative recipient and donor) accounted for 51% of UD BMT (n = 61) and 62% of RD BMT (n=49), with CMV excretion documented in one RD BMT only. The remaining high-risk patients received identical prophylaxis regimens with aciclovir and intravenous immunoglobulin (IVIG). Two groups consisting of 58 UD BMT (median age 9.0 years, range 0.7-45.3 years) and 30 RD BMT (median age 13.6 years. range 1.6-47.6 years) were analysed. CMV reactivation/re-infection was documented in 15 UD BMT (26%) and 10 RD BMT (33%) (P = 0.72), and CMV disease in four UD BMT (8%) and four RD BMT (13%) (P = 0.533). In this series the risk of CMV excretion and disease following UD BMT was similar to that following RD BMT.

Acyclovir↗
PubMed1996

Patterns of hematopoietic chimerism following bone marrow transplantation for childhood acute lymphoblastic leukemia from volunteer unrelated donors.

Hematopoietic chimerism was analyzed in serial bone marrow samples taken from 28 children following T-cell depleted unrelated donor bone marrow transplants (UD BMT) for acute lymphoblastic leukemia (ALL). Chimeric status was determined by polymerase chain reaction (PCR) of simple tandem repeat (STR) sequences (maximal sensitivity, 0.1%). At least two serial samples were examined in 23 patients. Of these, two had evidence of complete donor engraftment at all times and eight showed stable low level mixed chimerism (MC) (<1% recipient hematopoiesis). All 10 of these patients remain in remission with a minimum follow-up of 24 months. By contrast, 13 patients demonstrated a progressive return of recipient hematopoiesis. Five of these relapsed (4 to 9 months post BMT), one died of cytomegalovirus pneumonitis and seven remain in remission with a minimum follow-up of 24 months. Five children were excluded from serial analysis as two serial samples were not collected before either relapse (3) or graft rejection (2). We conclude that as with sibling transplants, ex vivo T depleted UD BMT in children with ALL is associated with a high incidence of MC. Stable donor engraftment and low level MC always correlated with continued remission. However, detection of a progressive return of recipient cells did not universally correlate with relapse, but highlighted those patients at greatest risk. Serial chimerism analysis by PCR of STRs provides a rapid and simple screening technique for the detection of relapse and the identification of patients with progressive MC who might benefit from detailed molecular analysis for minimal residual disease following matched volunteer UD BMT for childhood ALL.

Adolescent↗
PubMed1996

Matched and mismatched unrelated donor bone marrow transplantation for juvenile chronic myeloid leukaemia.

Juvenile chronic myeloid leukaemia (JCML) is a rare haematological condition of childhood curable only by bone marrow transplantation (BMT). We report our experience using matched and mismatched unrelated donor BMT for JCML in five patients. Although the procedure is hazardous in terms of toxicity and relapse, two patients are alive and disease-free 28 and 49 months post BMT.

Bone Marrow Transplantation↗
PubMed1994

Plasma half-lives and bioavailability of human monoclonal Rh D antibodies BRAD-3 and BRAD-5 following intramuscular injection into Rh D-negative volunteers.

Two human MoAbs, BRAD-3 (an IgG3 anti-D) and BRAD-5 (an IgG1 anti-D), were produced from Epstein-Barr virus (EBV)-transformed B lymphoblastoid cell lines grown in hollow fibre bioreactors. Six Rh D-negative male volunteers were injected intramuscularly with anti-D; two received BRAD-3 (approx. 1500 micrograms, 2600 IU), two were given BRAD-5 (300 micrograms, 2000 IU), and two had polyclonal anti-D immunoglobulin (500 IU, approx. 100 micrograms anti-D). Levels of anti-D in plasma samples taken up to 42 days later were measured by a sensitive AutoAnalyser method. The half life of BRAD-5 (mean 22.2 days) was greater, and that of BRAD-3 (mean 10.2 days) less than that of polyclonal anti-D (mean 15.6 days). The bioavailability (plasma uptake) of the MoAbs (mean 33.9%) was less than that of the polyclonal anti-D (mean 60.3%). BRAD-3 and BRAD-5 may be suitable for use in antenatal and post-natal prophylaxis against Rh D haemolytic disease of the newborn.

Antibodies, Monoclonal↗