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Biomedical subjects

M M Abecasis

Publications and source records attributed to M M Abecasis.

11 recordsLinked to original sources
PubMed2007

Congenital amegakaryocytic thrombocytopenia--report of a new c-mpl gene missense mutation.

A 44-month old girl with congenital amegakaryocytic thrombocytopenia, already with pancytopenia, underwent an unrelated allogeneic cord blood transplantation with recovery of normal blood cell counts. The patient was a compound heterozygote for two c-mpl missense mutations inherited from both parents, one of them, a G578A exon 4 mutation leading to a cysteine to tyrosine replacement of codon 193, previously unreported.

Child, Preschool↗
PubMed1999

Defibrotide as salvage therapy for refractory veno-occlusive disease of the liver complicating allogeneic bone marrow transplantation.

A 30-year-old woman developed veno-occlusive disease of the liver during an allogeneic BMT for acute leukemia. Treatment with recombinant human tissue plasminogen activator and heparin resulted in an incomplete and transient response followed by progressive disease. The patient was then given defibrotide (DF), a mammalian tissue-derived polydeoxyribonucleotide developed for the treatment of a number of vascular disorders, which has thrombolytic and anti-thrombotic properties. No significant bleeding or other major toxicities were observed during treatment and she made a full recovery. At 6 months after the onset of VOD her liver function tests and color flow Doppler ultrasound scan are normal. Our experience supports the preliminary results already obtained with DF. Its efficacy should be evaluated in a prospective randomized fashion.

Adult↗
PubMed1997

IBMTR Severity Index for grading acute graft-versus-host disease: retrospective comparison with Glucksberg grade.

Acute graft-versus-host disease (GVHD) severity is graded by pattern of organ involvement and clinical performance status using a system introduced by Glucksberg and colleagues 21 years ago. We examined how well Glucksberg grade predicted transplant outcome and constructed a Severity Index not requiring subjective assessment of performance in 2881 adults receiving an HLA-identical sibling T-cell-depleted (n = 752) or non-T-cell-depleted (n = 2129) bone marrow transplant for leukaemia between 1986 and 1992. Relative risks (RR) of relapse, treatment-related mortality (TRM) and treatment failure (TF) (relapse or death) were calculated for patients with (Glucksberg Grade I, II or III/IV acute (GVHD) versus those without acute GVHD and for patients with distinct patterns of organ involvement regardless of Glucksberg grade. Using data for non-T-cell-depleted transplants, a Severity Index was developed grouping patients with patterns of organ involvement associated with similar risks of TRM and TF. Higher Glucksberg grade predicted poorer outcome; however, patients with the same grade but different patterns of skin, liver or gut involvement often had significantly different outcomes. The revised Severity Index groups patients in four categories, A-D. Compared to patients without acute GVHD, RRs (95% confidence interval) of TF were 0.85 (0.69, 1.05) for patients with Index A, 1.21 (1.02, 1.43) with B, 2.19 (1.78, 2.71) with C, and 5.69 (4.57, 7.08) with D. Prognostic utility of the Index was tested in patients receiving T-cell-depleted transplants; similar RRs of TF were observed. An acute GVHD Severity Index is proposed to enhance design and interpretation of clinical trials in the current era of allogeneic blood and bone marrow transplantation.

Adolescent↗
PubMed1996

Haploidentical cord blood transplant contaminated with maternal T cells in a patient with advanced leukaemia.

Myeloablative treatment followed by lymphohaematopoietic reconstitution with stem cells from umbilical cord blood (UCB) can cure children with leukaemia. The clinical experience of UCB transplantation with HLA 2- and 3-antigen mismatched siblings is rather limited and there are no reports of such patient being given UCB significantly contaminated with maternal T lymphocytes. In this study, we report our experience in treating a child with chronic myeloid leukaemia in blast crisis who was transplanted using UCB cells from mismatched sibling donor containing a significant number of maternal T cells. The patient received 1.17 x 10(8) nucleated cells/kg after conditioning with Ara-C, busulphan, TBI and cyclophosphamide. GVHD prophylaxis was with cyclosporine and an anti-CD25 monoclonal antibody. Although engraftment was somewhat slow it was complete as documented by cytogenetic analysis and DNA studies. Results of minimal residual disease monitoring by RT-PCR for the hybrid BCR/ABL gene showed no evidence of leukaemic mRNA post-transplant. Acute GVHD, skin only, developed on day +14 but promptly responded to low-dose steroids. The technique used for UCB collection may have cell contamination found. In spite of these potential disadvantages: advanced disease, HLA antigen disparate donor and significant maternal T cell contamination, the transplant was successful and at a follow-up of 14 months the child is well with no evidence of chronic GVHD. Immune naivety of cord blood and lack of immunological reactivity of maternal T cells in this context may have played a significant role in the outcome of this case.

Chimera↗
PubMed1995

Allogeneic marrow grafts from donors with congenital chromosomal abnormalities in marrow cells.

To determine whether siblings with chromosomal abnormalities in marrow cells which are associated with cellular defects (e.g. Down syndrome or heterozygosity for Fanconi syndrome) are suitable donors for allogeneic bone marrow transplants, we have reviewed the patient files at the Fred Hutchinson Cancer Research Center (FHCRC) and carried out a survey among member centres of the International Bone Marrow Transplant Registry (IBMTR). The 57 of 253 (23%) member centres which responded to the survey reported seven transplants from donors with the following conditions: Down syndrome (n = 2), suspected heterozygotes for Fanconi syndrome (n = 3), and 47,XXX syndrome (n = 2), among a total of 5,561 allogeneic transplants from HLA-identical siblings. Adding the three cases seen at the Fed Hutchinson Cancer Research Center among 2,927 HLA-identical sibling transplants during 1992 resulted in 10 transplants among 8,488 cases transplanted overall: four with Down syndrome, four suspected of being heterozygous for Fanconi syndrome, and two trisomy X. Three out of four grafts from siblings with Down syndrome had complications, including poor graft function (n = 2) and graft failure (n = 1). Two of four recipients of marrow from presumed Fanconi syndrome heterozygotes presented with poor graft function and a third recipient developed graft failure after initial evidence of engraftment. The two patients given marrow from siblings with 47,XXX syndrome engrafted uneventfully. The experience reported here shows a low frequency of encountering an HLA-identical sibling donor who has chromosomal abnormalities in marrow cells consistent with Down syndrome or heterozygosity for Fanconi syndrome, about one case among 1,000 transplants. The much higher than expected incidence of graft problems with marrow from such a donor would make it reasonable to look either for an alternative marrow donor or consider an autologous transplant, in case a sibling marrow donor with Down syndrome or heterozygosity for Fanconi syndrome is encountered, although a donor with trisomy X seems acceptable.

Adolescent↗
PubMed1989

[Bone marrow transplantation: current perspectives].

Bone marrow transplantation was introduced over thirty years ago in the treatment of several immuno-hematological conditions. During the last decade, there has been a substantial increase in the number of transplanted patients. However, results over the last five years have not significantly improved. Clinical indication conditioning regimens and related complications are reviewed and new developments pointed out.

Bone Marrow↗
PubMed1989

[Bone marrow transplant: current perspectives].

Bone marrow transplantation was introduced over thirty years ago in the treatment of several immuno-hematological conditions. During the last decade, there has been a substantial increase in the number of transplanted patients. However, results over the last five years have not significantly improved. Clinical indication conditioning regimens and related complications are reviewed and new developments pointed out.

Bone Marrow Transplantation↗