Biomedical subjects

R Szydlo

Publications and source records attributed to R Szydlo.

16 recordsLinked to original sources

PubMed2001

Early detection of BCR-ABL transcripts by quantitative reverse transcriptase-polymerase chain reaction predicts outcome after allogeneic stem cell transplantation for chronic myeloid leukemia.

The reverse transcriptase-polymerase chain reaction (RT-PCR) has become widely used for monitoring minimal residual disease after allogeneic stem cell transplantation (SCT) for chronic myeloid leukemia (CML). However, most of these studies were performed using qualitative RT-PCR, and the interpretation of the results obtained has been conflicting. The correlation of a quantitative RT-PCR test performed early after SCT (at 3 to 5 months) and long-term outcome of CML patients surviving for more than 6 months was studied. Between January 1991 and June 1999, data from 138 CML patients who received allografts were evaluated. Early RT-PCR results were classified as (1) negative if there were no BCR-ABL transcripts detected (n = 61), (2) positive at low level if the total number of BCR-ABL transcripts was less than 100 per microg RNA and/or the BCR-ABL/ABL ratio was less than 0.02% (n = 14), or (3) positive at high level if transcript levels exceeded the thresholds defined above (n = 63). Three years after SCT the cumulative incidence of relapse was 16.7%, 42.9%, and 86.4%, respectively (P =.0001). The relationship between BCR-ABL transcript level and probability of relapse was apparent whether patients had received sibling or unrelated donor SCT and also whether or not the transplantation was T cell depleted. The results suggest that quantitative RT-PCR performed early after SCT is useful for predicting outcome and may help to define the need for further treatment.

Actuarial Analysis↗

PubMed2001

Stem cell transplantation for chronic myeloid leukaemia: the role of infused marrow cell dose.

INTRODUCTION: Allogeneic stem cell transplantation is a potentially curative option for patients with CML. The optimal donor is an HLA-identical sibling but transplants using unrelated volunteers can also be successful. The factors influencing survival after allogeneic SCT for CML are reasonably well defined. Recently however, the Seattle group have emphasised the influence of a high marrow cell dose on outcome following volunteer unrelated donor SCT for high risk acute leukaemia. MATERIALS AND METHODS: We have sought to define factors impacting on transplant related mortality (TRM) in a population of CML patients after allografting with matched sibling or alternative stem cell donors at a single centre over a 20-year period, with emphasis on infused marrow cell dose. Factors entered into a multivariate analysis were: recipient age, recipient CMV serostatus, disease phase, donor sex, cell dose and frequency of CTLP reactivity. RESULTS: In multivariate analysis four factors had an adverse effect on TRM when using a VUD: low marrow cell dose (<3.65 x 10(8) TNC/kg, relative risk 2.05, CI 1.08-3.90, P = 0.029), late disease phase (relative risk 1.68, CI 1.03-2.74, P = 0.038), patient CMV seropositivity (relative risk 1.98, CI 1.25-3.13, P = 0.004) and high frequency of CTLP (relative risk 1.93, CI 1.18-3.13, P = 0.008). For HLA-identical sibling donor transplants the only factor that adversely impacted on TRM was late disease phase (P = 0.0004 in univariate analysis). CONCLUSION: High infused cell dose is a new modifiable factor associated with reduced TRM following allogeneic SCT using an unrelated donor for the treatment of CML. The data support the recommendation that bone marrow harvest teams should aim to collect the highest possible number of nucleated cells for recipients of unrelated donor transplants.

Adult↗

PubMed2000

Effect of short-term interferon therapy on the outcome of subsequent HLA-identical sibling bone marrow transplantation for chronic myelogenous leukemia: an analysis from the international bone marrow transplant registry.

Allogeneic bone marrow transplantation (BMT) is the only curative therapy for chronic myelogenous leukemia (CML), though several studies indicate that prolonged survival can result from interferon-alpha (IFN-alpha) treatment. IFN-alpha is now often used as initial therapy for CML, before donor availability is known. Because identifying potential donors can take several weeks to months, it is important to know whether IFN-alpha adversely affects outcome of a subsequent BMT. If it does, initiation of IFN-alpha therapy might be delayed until donor availability is determined and avoided in patients for whom BMT is planned. We studied 873 patients who received HLA-identical sibling BMT for chronic-phase CML in 153 centers participating in the International Bone Marrow Transplant Registry. The object was to compare outcome in the 664 who received only hydroxyurea before BMT with outcome in the 209 who received IFN-alpha with or without hydroxyurea. The median duration of IFN-alpha therapy was 2 months (range, 1 to 39 months). Cox proportional hazards analysis was used to compare engraftment, graft-versus-host disease (GVHD), nonrelapse mortality, relapse, survival, and leukemia-free survival after adjustment for other prognostic variables. We found a higher risk of nonengraftment among patients given IFN-alpha than among those given hydroxyurea alone (2% versus 0.2%; P = 0.01). Patients who received IFN-alpha had a lower risk of relapse (relative risk, 0.17; 95% confidence interval, 0.04-0.70). Probabilities of GVHD, nonrelapse mortality, survival, and leukemia-free survival were similar in the two treatment groups. These results suggest that a short course of IFN-alpha does not adversely affect survival after a subsequent HLA-identical sibling BMT for chronic-phase CML. (Blood. 2000;95:410-415)

Actuarial Analysis↗

PubMed2000

High-dose busulphan alone as cytoreduction before allogeneic or autologous stem cell transplantation for chronic myeloid leukaemia: a single-centre experience.

Transplant-related morbidity and mortality remain a major problem following stem cell transplantation (SCT). The use of high-dose single-agent busulphan before allogeneic or autologous SCT may be a reasonable compromise between maintaining cytoreductive efficacy and minimizing toxicity in patients with chronic myeloid leukaemia (CML). Seventy patients with CML have received busulphan as the only cytoreductive therapy before SCT on 79 occasions. The probability of survival of the 14 allogeneic recipients (all of whom were undergoing a second transplant from the original donor) was 78% at 5 years. Sixty-five autologous SCT were performed in 56 patients, of whom 40 were in late chronic phase. The actuarial 3-year post-autograft survival was 54% for these 56 first autografts. For patients in chronic phase, the 3-year survival was 76% compared with 30% at 2 years for those with advanced phase disease. Busulphan therapy was well tolerated, and except for mild mucositis little toxicity was experienced. None of these patients developed hepatic veno-occlusive disease (VOD). Nine patients (one allogeneic and eight autologous recipients) received several doses of an intravenous formulation of busulphan with very low toxicity. High-dose busulphan alone appears sufficient to provide adequate cytoreduction and immunosuppression in second allogeneic transplants and is also effective as cytoreduction before autologous SCT in patients with CML.

Adolescent↗

PubMed2000

Non-random involvement of chromosome 13 in patients with persistent or relapsed disease after bone-marrow transplantation for chronic myeloid leukemia.

Chronic myeloid leukemia (CML) patients with persistent or relapsed disease following bone-marrow transplantation (BMT) usually show both clonal and non-clonal cytogenetic changes in addition to the Philadelphia (Ph) translocation. These changes are presumably due to conditioning prior to transplantation and are generally not thought to be of clinical significance. We have examined the additional cytogenetic changes found in Ph+ve cells after BMT in 47 CML patients. Forty patients showed clonal changes. The involvement of each chromosome was compared statistically with expected values assuming that further chromosome changes are random and related to chromosome size. In clones that comprised 50% or more of the Ph+ve metaphases, chromosome 13 was involved in 12 of 22 clones (55%); this was highly significant when compared with the theoretical expected value of 3.2 (14.5%) (P < 0.001). The chromosome 13 rearrangements comprised both translocations and deletions. By means of FISH with a panel of 13q YAC clones, the breakpoints in 6 of these patients were investigated, but no common site of translocation was identified. The YAC panel was then used on material from 6 patients with chromosomal deletions. A common region of deletion was identified at 13q12-14, suggesting the presence of one or more tumor suppressor genes. We conclude that chromosome 13 deletions are non-randomly overrepresented in Ph+ve metaphases following BMT for CML. Genes Chromosomes Cancer 27:278-284, 2000.

Bone Marrow Transplantation↗

PubMed1999

A comparison of prophylactic vs pre-emptive ganciclovir to prevent cytomegalovirus disease after T-depleted volunteer unrelated donor bone marrow transplantation.

The prophylactic and pre-emptive use of ganciclovir (GCV) both reduce significantly the incidence of CMV disease after sibling BMT but it is unclear which of these strategies is best for volunteer unrelated donor (VUD) BMT patients. We reviewed 49 consecutive patients, who received a T-depleted VUD BMT (from March 1990 to March 1996) for the treatment of CML in chronic phase, and were CMV seropositive before transplant or had a CMV seropositive donor. Patients were conditioned with cyclophosphamide (120 mg/kg for 2 days) and total body irradiation (13.2-14.4 Gy). Prophylaxis for GVHD was cyclosporin A and methotrexate with ex vivo or in vivo T cell depletion. Twenty-seven patients received pre-emptive GCV if CMV infection was detected by short-term culture before day +120 post BMT. Twenty-two patients received prophylactic GCV from engraftment until day +120 post BMT. The probabilities of CMV infection and disease occurring by 1 year post-BMT were greater in the pre-emptive GCV group than in the prophylactic GCV group (73.8% and 64.0% vs 53.1% and 30.0%, respectively; P=0.04 and 0.07). The incidence of death from CMV disease was similar in both groups (3/12 (25%) vs 3/10 (30%), respectively) and there was no difference in 1 year survival (55.6% vs 54.2%, respectively). New strategies are urgently required for the prevention of CMV disease after T-depleted VUD BMT.

Adult↗

PubMed1999

Abnormal patterns of immunoglobulin heavy chain gene DNA fingerprinting during chronic phase chronic myeloid leukemia.

Using IgH DNA fingerprinting we have previously demonstrated clonal immunoglobulin heavy chain (IgH) gene rearrangements during chronic phase (CP) chronic myeloid leukemia (CML) in patients destined to develop lymphoid blast crisis (L-BC). In view of this we decided to follow a cohort of CP CML patients to determine the frequency with which abnormal IgH fingerprints are found and their relationship, if any, to treatment regimen. Thirty three, initially CP, CML patients were studied on 111 occasions over a 16 month period using consensus PCR amplification of the third complementarity determining region (CDR3) of the IgH gene and high resolution polyacrylamide gel electrophoresis (IgH DNA fingerprinting). Of these 33 patients, thirteen received interferon-alpha (IFN) containing regimens and 15 non-IFN containing regimens throughout the study period. Five patients received variable therapy. During the period of observation 7 patients experienced disease progression: 5 accelerated phase, I L-BC and I myeloid blast crisis (M-BC). Abnormal IgH fingerprints were seen in 29 of the 111 (26%) specimens analysed. The 28 patients who received uniform therapy (IFN or non-IFN) over the 16 months were classified as "normal" (n = 18, normal pattern on all occasions) or "abnormal" (n = 10, abnormal on 1 or more occasions). Analysis by patient group (normal vs abnormal) showed that fingerprint abnormalities were associated with an elevated peripheral blood lymphocyte count (p = 0.0001) but not with changes in the total white cell count. Comparison of the IFN vs. non-IFN groups showed the former all had normal patterns whereas 10 of 15 non-IFN therapy patients were abnormal (p = 0.00023). The peripheral blood lymphocyte counts in the normal vs abnormal patients within the non-IFN group were not significantly different. The patient who developed L-BC demonstrated a persistent IgH fingerprint pattern abnormality from 7 months prior to the diagnosis of L-BC. The M-BC patient had a normal pattern at all times. We conclude that: (1) abnormal IgH fingerprints are found in a significant number of CP CML patients; (2) in this cohort the use of IFN was associated with normal CP CML IgH fingerprints, and (3) detection of abnormal IgH fingerprints may be highly predictive for the lineage of impending blast crisis.

DNA Fingerprinting↗

PubMed1998

Interleukin 3 (IL-3), but not stem cell factor (SCF) increases self-renewal by human erythroid burst-forming units (BFU-E) in vitro.

Interleukin 3 (IL-3) and stem cell factor (SCF) are both important regulators of early haemopoietic cell development. Here, we have compared their effects or the kinetics of erythroid burst formation by BFU-E in normal adult bone marrow. We grew the BFU-E in the presence of erythropoietin (Epo) alone, Epo + IL-3 or Epo + SCF and scored the numbers of subcolonies in individual bursts after 14 days. The data were plotted as the cumulative distribution of the numbers of subcolonies per erythroid burst then linearised by logarithmic transformation. Analysis of the data revealed that IL-3 increases the numbers of subcolonies in BFU-E whilst SCF increases the size of the subcolonies themselves. Experiments involving combinations of Epo + IL-3 + SCF and the delayed addition of IL-3 or SCF indicated that the actions of IL-3 and SCF are largely independent of one another. We conclude that: (1) IL-3 acts at an earlier stage of erythroid differentiation than SCF, and (2) it may be possible to classify haemopoietic growth factors according to their effects on cell kinetics in vitro.

Cells, Cultured↗

PubMed1998

Adoptive immunotherapy for relapse of chronic myeloid leukemia after allogeneic bone marrow transplant: equal efficacy of lymphocytes from sibling and matched unrelated donors.

Lymphocyte transfusion from the marrow donor (DLT) is well established as an effective therapy for relapse of CML post allogeneic BMT. Reports thus far have been mostly limited to patients who received DLT from a matched sibling donor. We compared the efficacy and toxicity of DLT in 30 patients who were treated with cells from their HLA-identical sibling (n = 18) or from their phenotypically HLA-matched unrelated marrow donor (n = 12). The overall probability of obtaining a cytogenetic remission was 69% (95%CI: 51-83%) and was not significantly different between the two groups. The disease stage at the time of DLT was the only factor associated with cytogenetic remission by multivariate analysis; patients treated in cytogenetic or molecular relapse (n = 11) were seven times more likely (RR = 7.4, 95%CI: 2.4-22.4, P = 0.0005) to respond compared to patients treated for hematologic relapse (n = 19). There was a trend towards more acute GVHD II-IV in the unrelated donor group (58 vs 39%, P = 0.09), but the probability of developing extensive chronic GVHD was not significantly different (56 vs 39%, P = 0.4). We conclude that transfusion of donor cells from HLA-matched volunteer donors does not appreciably increase the risk of GVHD compared with transfusion of cells from HLA-identical siblings in patients with CML who relapse following allogeneic BMT. Conversely, there is no evidence for an increased graft-versus-leukemia effect after DLT from volunteer donors.

Adult↗

PubMed1997

Factors influencing the outcome of bone marrow transplants using unrelated donors.

The use of unrelated donors for bone marrow transplantation (BMT) is associated with an increased morbidity and mortality when compared with HLA-identical donors, primarily due to an increased rate of graft-versus-host disease, but also to increased susceptibility to infections and graft failure. HLA matching for donors and recipients is the single most important factor influencing the outcome of BMT. However, unrelated donor selection generally relies on matching only for HLA-A, -B and -DR antigens without considering potential incompatibility for other HLA loci, such as HLA-C, -DQ and -DP. In addition, other factors that affect the outcome of BMT need to be taken into consideration in selecting the best unrelated donor. In this review, we will focus on the effects of HLA-associated factors in determining the result of a transplant procedure. We will also mention other relevant factors, drawing on our experience of laboratory studies performed at The Anthony Nolan Research Institute and clinical studies at the Hammersmith Hospital in London.

Bone Marrow Transplantation↗

PubMed1997

Results of allogeneic bone marrow transplants for leukemia using donors other than HLA-identical siblings.

PURPOSE: To compare outcomes of bone marrow transplants for leukemia from HLA-identical siblings, haploidentical HLA-mismatched relatives, and HLA-matched and mismatched unrelated donors. PATIENTS: A total of 2,055 recipients of allogeneic bone marrow transplants for chronic myelogenous leukemia (CML), acute myelogenous leukemia (AML), and acute lymphoblastic leukemia (ALL) were entered onto the study. Transplants were performed between 1985 and 1991 and reported to the International Bone Marrow Transplant Registry (IBMTR). Donors were HLA-identical siblings (n = 1,224); haploidentical relatives mismatched for one (n = 238) or two (n = 102) HLA-A, -B, or -DR antigens; or unrelated persons who were HLA-matched (n = 383) or mismatched for one HLA-A, -B, or -DR antigen (n = 108). HLA typing was performed using serologic techniques. RESULTS: Transplant-related mortality was significantly higher after alternative donor transplants than after HLA-identical sibling transplants. Among patients with early leukemia (CML in chronic phase or acute leukemia in first remission), 3-year transplant-related mortality (+/-SE) was 21% +/- 2% after HLA-identical sibling transplants and greater than 50% after all types of alternative donor transplants studied. Among patients with early leukemia, relative risks of treatment failure (inverse of leukemia-free survival), using HLA-identical sibling transplants as the reference group, were 2.43 (P < .0001) with 1-HLA-antigen-mismatched related donors, 3.79 (P < .0001) with 2-HLA-antigen-mismatched related donors, 2.11 (P < .0001) with HLA-matched unrelated donors, and 3.33 (P < .0001) with 1-HLA-antigen-mismatched unrelated donors. For patients with more advanced leukemia, differences in treatment failure were less striking: 1-HLA-antigen-mismatched relatives, 1.22 (P = not significant [NS]); 2-HLA-antigen-mismatched relatives, 1.81 (P < .0001); HLA-matched unrelated donors, 1.39 (P = .002); and 1-HLA-antigen-mismatched unrelated donors, 1.63 (P = .002). CONCLUSION: Although transplants from alternative donors are effective in some patients with leukemia, treatment failure is higher than after HLA-identical sibling transplants. Outcome depends on leukemia state, donor-recipient relationship, and degree of HLA matching. In early leukemia, alternative donor transplants have a more than twofold increased risk of treatment failure compared with HLA-identical sibling transplants. This difference is less in advanced leukemia.

Age Factors↗

PubMed1996

Cytomegalovirus antibody avidity in allogeneic bone marrow recipients: evidence for primary or secondary humoral responses depending on donor immune status.

The reconstitution of the human cytomegalovirus (CMV) antibody response in CMV seropositive bone marrow transplant patients was investigated by comparing 11 patients whose donors were CMV seropositive with 8 whose donors were CMV seronegative. Evidence for primary or secondary responses to CMV was sought by determining IgG antibody avidity using an avidity index method, and antibody titre over a period of up to 3 years after transplant. For the patients whose donors were CMV seropositive, the results showed the characteristics of a secondary response, i.e., rising antibody titres of high avidity immediately after transplant. In contrast, the patients with CMV seronegative donors showed evidence of a primary antibody response usually occurring at about 250 days after transplant, i.e., rising antibody levels initially of low avidity maturing to high avidity over the following 100 to 200 days. It is concluded that a secondary response and hence transfer of humoral immunity had occurred in those patients whose donor was CMV seropositive, whereas a delayed primary response occurred in those patients whose donor was CMV seronegative.

Antibodies, Viral↗

PubMed1993

Choice of pretransplant treatment and timing of transplants for chronic myelogenous leukemia in chronic phase.

We analyzed the outcome of 450 HLA-identical sibling bone marrow transplants for chronic myelogenous leukemia (CML) in chronic phase performed between 1985 and 1990 and reported to the International Bone Marrow Transplant Registry (IBMTR). All patients received either hydroxyurea (n = 292) or busulfan (n = 158) to treat their CML before transplant. The median interval between diagnosis and transplant was 10 months (range, 1 to 191). Patients treated with hydroxyurea had a higher probability (95% confidence interval) of leukemia-free survival (LFS) at 3 years than those treated with busulfan (61% [51% to 70%] v 45% [36% to 55%], P < .0003). Probability of LFS was also higher in patients transplanted within 1 year of diagnosis (61% [53 to 68%] v 47% [38% to 57%], P < .001). After adjustment for patient and transplant covariables in a multivariate analysis, prior chemotherapy and duration of disease pretransplant were independently associated with LFS. These data support the use of hydroxyurea rather than busulfan and transplant within 1 year of diagnosis for patients with CML and an HLA-identical sibling.

Actuarial Analysis↗

PubMed1993

Phenotypic characterization of normal and CML CD34-positive cells: only the most primitive CML progenitors include Ph-neg cells.

We studied the sequence of acquisition of CD33, CD38 and HLA-DR antigens on CD34+ cells from marrow and blood of Ph-chromosome positive CML patients and normal marrow. We examined the Ph status of the various CML cell populations. The mean proportions of normal and CML CD34+ cells expressing CD33 and CD38 were not significantly different. However, a significantly greater proportion of CML CD34+ cells expressed HLA-DR antigens compared with normal CD34+ cells and the level of HLA-DR expression per CML cell was abnormally high. When the sequence of acquisition of these antigens on normal and CML CD34+ cells was evaluated using 3-colour fluorescence analysis, the results suggested that HLA-DR was expressed earlier than CD38 or CD33 and these findings were confirmed by following the acquisition of CD38 and CD34+/DR+/CD38-subpopulation during liquid culture. We performed cytogenetic studies on CD34+ subpopulations in 6 cases. In 4 cases there were some Ph-negative metaphases detectable in the CD34+/DR-subpopulation (range 12.5 to 60%). In the CD34+/DR+ fractions, however, all 6 patients had only Ph-positive metaphases and only 1/5 patients had detectable Ph-negative metaphases in the CD34+/CD38-subpopulation. We conclude that expression of HLA-DR antigens may precede the expression of CD38 on CD34+ cells during normal stem cell differentiation. In CML DR may be expressed aberrantly and Ph-negative cells are found predominantly in the DR negative subpopulation.

ADP-ribosyl Cyclase↗

PubMed1992

HLA-identical sibling donor bone marrow transplantation for chronic myeloid leukaemia in first chronic phase: influence of GVHD prophylaxis on outcome.

We have analysed the results of treating 140 consecutive patients with chronic myeloid leukaemia (CML) in chronic phase by bone marrow transplantation (BMT) using marrow from HLA-identical siblings performed between February 1981 and July 1991. Three different regimens were used sequentially to prevent graft-versus-host disease (GVHD): cyclosporin A (CsA) alone (n = 39), T-cell depletion of donor marrow (n = 51) and CsA with methotrexate (MTX) (n = 50). Eighty-four patients (61%) survive at a median of 49 months from BMT (range 3-120). The actuarial overall and leukaemia-free survivals at 5 years were 52% and 41% respectively. The actuarial probabilities of leukaemia-free survival and haematological relapse at 2 years for the CsA only group were 65% and 4%, for the T-cell depletion group 40% and 41% and for the CsA/MTX group 68% and 6% respectively. For the T-cell depletion group the probability of leukaemia-free survival was significantly lower (P less than 0.001) and the probability of relapse significantly higher (P less than 0.001) than for other methods of GVHD prophylaxis; differences between the other two groups were not significant. Previous reports that T-cell depletion with Campath-1M results in a high rate of relapse are confirmed. Patients in the CsA/MTX group have been monitored with cytogenetic and polymerase chain reaction studies for residual BCR/ABL transcripts. We conclude that the combination of CsA/MTX is currently the best available approach to prevention of GVHD after BMT for CML and in our hands it is not associated with a major risk of relapse.

Adolescent↗

PubMed1992

Unrelated donor marrow transplants for severe acquired aplastic anemia.

This report is divided into two parts. The first part is a retrospective analysis of 40 unrelated transplants [UD-BMT] for severe acquired aplastic anemia [SAA], performed at five transplant centers between 1981 and 1990. The second is an interim analysis of 15 UD-BMT for SAA compared with a matched cohort of 16 sibling transplants [ID-BMT] carried out since February 1989 using prospectively collected data provided by the IMUST Study Group. In the retrospective study the actuarial survival was 28% [+/- 15] with a median follow-up of 1485 [266-3890] days post BMT. Univariate analysis showed a considerable survival advantage for patients younger than 15 years at BMT [p = 0.03]. More recently patients entered in the IMUST Study showed an actuarial survival of 50% [+/- 27] for UD-BMT compared with 58% [+/- 31] for ID-BMT recipients. These data suggest that UD-BMT is a realistic option for paediatric patients with SAA. Although numbers are very small there is some indication from IMUST Study data that better patient selection and intensive BMT protocols may also improve the results of UD-BMT in young adult patients with SAA.

Adolescent↗