ORCID Profile
0000-0003-3135-0401
Current Organisations
NHLBI Division of Intramural Research
,
Peter MacCallum Cancer Centre
,
Royal Melbourne Hospital
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Publisher: American Society of Hematology
Date: 22-03-2022
DOI: 10.1182/BLOODADVANCES.2021004537
Abstract: Poor graft function (PGF), defined by the presence of multilineage cytopenias in the presence of 100% donor chimerism, is a serious complication of allogeneic stem cell transplant (alloSCT). Inducers or potentiators of alloimmunity such as cytomegalovirus reactivation and graft-versus-host disease are associated with the development of PGF, however, more clinical studies are required to establish further risk factors and describe outcomes of PGF. The pathophysiology of PGF can be conceptualized as dysfunction related to the number or productivity of the stem cell compartment, defects in bone marrow microenvironment components such as mesenchymal stromal cells and endothelial cells, or immunological suppression of post-alloSCT hematopoiesis. Treatment strategies focused on improving stem cell number and function and microenvironment support of hematopoiesis have been attempted with variable success. There has been limited use of immune manipulation as a therapeutic strategy, but emerging therapies hold promise. This review details the current understanding of the causes of PGF and methods of treatment to provide a framework for clinicians managing this complex problem.
Publisher: American Society of Hematology
Date: 29-03-2018
Publisher: Wiley
Date: 06-06-2018
DOI: 10.1111/EJH.13089
Abstract: Core-binding factor acute myeloid leukaemia (CBF AML) defined by t(8 )(q22 q22) or inv(16)(p13q22)/t(16 )(p13 q22) has a favourable prognosis however, 30%-40% of patients still relapse after chemotherapy. We sought to evaluate the risk factors for relapse in a de novo CBF AML cohort. A retrospective review of patients from four Australian tertiary centres from 2001 to 2012, comprising 40 t(8 ) and 30 inv(16) AMLs. Multivariate analysis identified age (P = .032) and white cell count (WCC)>40 (P = .025) as significant predictors for inferior OS and relapse, respectively. Relapse risk was higher in the inv(16) group vs the t(8 ) group (57% vs 18%, HR 4.31, 95% CI: 1.78-10.42, P = .001). Induction therapy had no bearing on OS or relapse-free survival (RFS) however, consolidation treatment with >3 cycles of intermediate-/high-dose cytarabine improved OS (P = .035) and RFS (P = .063). Five patients demonstrated post-treatment stable q PCR positivity without relapse. >3 consolidation cycles of intermediate-/high-dose cytarabine improves patient outcomes Age and inv(16) CBF AML subtype are predictors of inferior OS and RFS, respectively. Stable low-level MRD by qPCR does not predict relapse Similar OS in the inv(16) cohort compared to the t(8 ) cohort, despite a higher relapse rate, confirms salvageability of relapsed disease.
Publisher: Informa UK Limited
Date: 07-08-2020
Publisher: Frontiers Media SA
Date: 24-09-2021
DOI: 10.3389/FIMMU.2021.749094
Abstract: Allogeneic stem cell transplantation (alloSCT) is utilised to cure haematological malignancies through a combination of conditioning regimen intensity and immunological disease control via the graft versus tumour (GVT) effect. Currently, conventional myeloablative chemotherapeutic or chemoradiation conditioning regimens are associated with significant side effects including graft versus host disease (GVHD), infection, and organ toxicity. Conversely, more tolerable reduced intensity conditioning (RIC) regimens are associated with unacceptably higher rates of disease relapse, partly through an excess incidence of mixed chimerism. Improvement in post-alloSCT outcomes therefore depends on promotion of the GVT effect whilst simultaneously reducing conditioning-related toxicity. We have previously shown that this could be achieved through BCL-2 inhibition, and in this study, we explored the modulation of JAK1/2 as a strategy to lower the barrier to donor engraftment in the setting of RIC. We investigated the impact of short-term treatment of BCL2 (venetoclax) or JAK1/2 (ruxolitinib) inhibition on recipient natural killer and T cell immunity and the subsequent effect on donor engraftment. We identified striking differences in mechanism of action of these two drugs on immune cell subsets in the bone marrow of recipients, and in the regulation of MHC class-II and interferon-inducible gene expression, leading to different rates of GVHD. This study demonstrates that the repurposed use of ruxolitinib or venetoclax can be utilised as pre-transplant immune-modulators to promote the efficacy of alloSCT, whilst reducing its toxicity.
Publisher: Informa UK Limited
Date: 31-01-2021
Publisher: Springer Science and Business Media LLC
Date: 23-07-2022
DOI: 10.1038/S41409-022-01761-Z
Abstract: The development of non-relapse cytopenias (NRC) is a relatively common occurrence post allogeneic stem cell transplant (alloSCT). Whilst there have been attempts to classify post alloSCT cytopenias by transplantation groups, ambiguity of definitions in prior publications compounded by a lack of availability of high-quality evidence, provide challenges to clinicians attempting to manage these complex patients. In this review we describe 3 cases of NRC, (1) Graft Failure with graft rejection representing cytopenias with minimal donor chimerism (2) Poor Graft Function representing cytopenias with complete donor chimerism and (3) Cytopenias with mixed donor chimerism. This case-based review will evaluate the currently available evidence regarding the pathophysiology of each entity as well as the evidence for current therapies with the aim of providing guidance to clinicians managing these complex patients.
Location: United States of America
No related grants have been discovered for Ashvind Prabahran.