Treatment and Outcome of the Patients with Donor-Type Aplasia after Bone Marrow Transplantation in Children with Aplastic Anemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4782-4782 ◽  
Author(s):  
Kumhee Jeong ◽  
Joo Hyun Cho ◽  
Kyeong Ryeol Cheon ◽  
Hae In Jang ◽  
Hee Jo Baek ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Aplastic Anemia ◽  
Graft Failure ◽  
Conflicts Of Interest ◽  
Graft Function ◽  
Cell Number ◽  
Hematopoietic Stem ◽  
Stem Cell Rescue ◽  
Donor Type

Abstract Hematopoietic stem cell transplantation (HSCT) from an HLA-matched donor is the treatment of choice for children with aplastic anemia (AA). However, graft failure (GF), either primary or secondary, remains an important and life-threatening complication. Recently, donor-type aplasia, defined as bone marrow aplasia with full donor chimerism among secondary GF, has been identified after HSCT. Clinical characteristics of donor-type aplasia after HSCT and its treatment and outcome in children with AA were retrospectively reviewed. Forty-two children with AA underwent allogeneic HSCT with 10-year overall survival rate of 85.7%. While primary GF developed in 1 (2.4%), secondary GF was seen in 12 at a median of 8 months (range: 2.0-28.5 months). Among them, 11 developed a donor-type aplasia with the cumulative incidence of 26.2%. Low infused cell number (P=0.002), immunosuppressive therapy (IST) prior to HSCT (P=0.003) and preceding transfusion >40 times (P=0.008) were associated with the development of donor-type aplasia. The survival of patients with donor-type aplasia was 81.8%. Six patients were treated with stem cell rescue as follows: peripheral blood stem cell (PBSC) boost, 3; PBSC boost followed by secondary HSCT, 2; and secondary HSCT, 1. All but 1 who had a longest interval from 1st HSCT to stem cell rescue (54.4 months) showed restoration of graft function. The remaining 5 patients were managed with conservative measures including transfusions. No one showed spontaneous improvement with the median follow-up of 30.1 months (range, 4.2 to 43.0 months). Two patients died of graft failure and infection. Altogether, 4 patients still remain transfusion-dependent. Donor-type aplasia after HSCT for AA is not uncommon. Stem cell rescue, either with PBSC boost or secondary HSCT after conditioning should be attempted to obtain sustained graft function. For those who do not have availability for stem cell rescue, a novel treatment, such as thrombopoietin receptor agonist, should be considered for the future. Disclosures No relevant conflicts of interest to declare.

scholarly journals Impaired Hematopoiesis after Allogeneic Hematopoietic Stem Cell Transplantation: Its Pathogenesis and Potential Treatments

Hemato ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 43-63
Author(s):  
Masahiro Imamura
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Hematopoietic Stem Cells ◽  
Graft Failure ◽  
Graft Function ◽  
Hematopoietic Stem ◽  
Poor Graft Function ◽  
Bone Marrow Niches

Impaired hematopoiesis is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Bone marrow aplasia and peripheral cytopenias arise from primary and secondary graft failure or primary and secondary poor graft function. Chimerism analysis is useful to discriminate these conditions. By determining the pathogenesis of impaired hematopoiesis, a timely and appropriate treatment can be performed. Hematopoietic system principally consists of hematopoietic stem cells and bone marrow microenvironment termed niches. Abnormality in hematopoietic stem and progenitor cells and/or abnormality in the relevant niches give rise to hematological diseases. Allo-HSCT is intended to cure each hematological disease, replacing abnormal hematopoietic stem cells and bone marrow niches with hematopoietic stem cells and bone marrow niches derived from normal donors. Therefore, treatment for graft failure and poor graft function after allo-HSCT is required to proceed based on determining the pathogenesis of impaired hematopoiesis. Recent progress in this area suggests promising treatment manipulations for graft failure and poor graft function.

Hematopoeitic Stem Cell Transplant in Aplastic Anemia: Is It Time to Revise the Treatment Alogirthm

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2395-2395
Author(s):  
Ashish O. Gupta ◽  
Steven L Shein ◽  
Jignesh D Dalal
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Aplastic Anemia ◽  
Graft Failure ◽  
Inpatient Admission ◽  
Unknown Etiology ◽  
Unrelated Donor ◽  
Cell Transplant ◽  
Hematopoietic Stem ◽  
Increasing Trend

Abstract Background: Aplastic anemia (AA) is a rare bone marrow failure (BMF) syndrome of unknown etiology characterized by hypocellular bone marrow and severe persistent pancytopenia. Pediatric AA is more common in adolescent age group with better outcomes as compared to adults. Current treatment modalities include immunosuppressive therapy (IST) or matched related bone marrow transplant, when possible. There is a high risk of disease relapse with IST and clonal evolution into myelodysplastic syndrome. There is limited pediatric data on outcomes with different treatment options. Methods: Retrospective database analysis of Pediatric Health Information Systems (PHIS) database was performed to evaluate healthcare outcomes of pediatric patients (age less than 21 years) with AA from January 1, 2006 to December 31, 2015. PHIS is an administrative quality-controlled database from 43 not-for-profit children's hospitals. ICD-9 code 284.9 was used to identify patients with acquired AA. Appropriate procedure and pharmacy billing codes were used to obtain information regarding transplants and various drugs used. SAS based statistical software was used to perform analysis. Results: A total of 5127 inpatient admissions were noted for AA during the study period. An overall increasing trend of transplant was observed from 2006-2015 (Figure 1). Almost equal inpatient admission rate was noted in males and females, with a slightly higher rate amongst males who underwent transplant (55% vs 45%). Inpatient admission was more common amongst whites in both transplant (n=407, 8%) and non-transplant groups (n=4717, 92%; Table 1). Overall inpatient mortality was about 2% with a similar mortality in those who underwent transplant (5%). Cyclosporine (n= 1785, 38%) and steroids were most common immunosuppressive drugs used in non-transplant group. In the transplant group (Table 2), graft failure (20%) was the most common complication, while Cyclophosphamide (77%), Fludarabine (53%) and anti-thymocyte globulin (31%) based conditioning was most commonly used. Transplant itself was an independent risk factor for mortality (p=0.04) along with graft failure (p=0.02). Steroids (92%) and Cyclosporine (73%) were the most common immunosuppression used. Conclusion: Hematopoietic stem cell transplants have good outcomes in pediatric AA patients. With an increasing trend of HSCT in these patients, successful outcomes with other transplant options such as match unrelated donor transplants should be considered. Treatment algorithm for Pediatric AA needs to be revised to include other transplant sources. Disclosures No relevant conflicts of interest to declare.

FLT Imaging Reveals Kinetics and Biology of Engraftment after Myeloablative HSCT

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1147-1147
Author(s):  
Kirsten M Williams ◽  
Jennifer L. Holter Chakrabarty ◽  
Liza Lindenberg ◽  
Steve Adler ◽  
Juan Gea-Banacloche ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Graft Failure ◽  
Conflicts Of Interest ◽  
Bone Marrow Failure ◽  
Cord Blood Transplantation ◽  
Prospective Trial ◽  
High Morbidity ◽  
Hematopoietic Stem

Abstract Bone marrow failure is associated with high morbidity and mortality after hematopoietic stem cell transplantation (HSCT) due to complications associated with prolonged neutropenia. Using the positron emission tomography (PET) imaging probe, 3’-deoxy-3 18F-fluorothymidine (18FLT), we illustrate HSC homing very early after myeloablative HSCT in adults in vivo. In our prospective trial, NCT01338987, we imaged 14 patients undergoing myeloablative transplantation with Cytoxan and total body irradiation and evaluated corresponding uptake of radiotracer 18FLT in osseous structures throughout the bone marrow compartment following full myeloblation, early engraftment, and hematopoietic reconstitution. 18FLT was safe and did not delay engraftment. Objective increases in 18FLT uptake measured by standardized uptake value (SUV) revealed evidence of stem cell homing to medullary bone marrow sites within 5 days of donor cell infusion. In patients without relapse (n=11), mean thoracic spine SUV was greater among patients with rapid (<21 days) as compared to slow engraftment (≥21 days). Using SUV, we could differentiate full ablation (SUV of 0.65) from early engraftment at day +5-6 (SUV 1.1, p <0.05). 18FLTsignal increases revealed a consistent pattern of marrow recovery that recapitulated fetal ontogeny, claiming sites of hematopoiesis that are normally dormant in adults. These findings were substantiated with in vitro cellular recovery data. 18FLT SUV could also predict marrow recovery after secondary graft failure without additional HSC infusion. In summary, our data show that 18FLT reveals homing, kinetics, and biology of hematopoietic engraftment in adults in vivo.18FLT could predict engraftment very early after HSCT and could be of value to predict primary or secondary graft failure in high risk populations, such as recipients of cord blood transplantation or haplo-identical transplantation. Disclosures No relevant conflicts of interest to declare.

scholarly journals Inducible SBDS Deficiency Impairs Bone Marrow Niche Function to Engraft Donor Hematopoietic Stem Cell after Transplantation

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3199-3199
Author(s):  
Ji Zha ◽  
Lori Kunselman ◽  
Hongbo Michael Xie ◽  
Brian Ennis ◽  
Jian-Meng Fan ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Mouse Model ◽  
Board Of Directors ◽  
Hematopoietic Stem Cell ◽  
Graft Failure ◽  
Advisory Committees ◽  
Hematopoietic Stem ◽  
Bm Niche ◽  
Deficient Mice

Hematopoietic stem cell (HSC) transplantation (HSCT) is required for curative therapy for patients with high-risk hematologic malignancies, and a number of non-malignant disorders including inherited bone marrow failure syndromes (iBMFS). Strategies to enhance bone marrow (BM) niche capacity to engraft donor HSC have the potential to improve HSCT outcome by decreasing graft failure rates and enabling reduction in conditioning intensity and regimen-associated complications. Several studies in animal models of iBMFS have demonstrated that BM niche dysfunction contributes to both the pathogenesis of iBMFS, as well as impaired graft function after HSCT. We hypothesize that such iBMFS mouse models are useful tools for discovering targetable niche elements critical for donor engraftment after HSCT. Here, we report the development of a novel mouse model of Shwachman-Diamond Syndrome (SDS) driven by conditional Sbds deletion, which demonstrates profound impairment of healthy donor hematopoietic engraftment after HSCT due to pathway-specific dysfunctional signaling within SBDS-deficient recipient niches. We first attempted to delete Sbds specifically in mature osteoblasts by crossing Sbdsfl/flmice with Col1a1Cre+mice. However, the Col1a1CreSbdsExc progenies are embryonic lethal at E12-E15 stage due to developmental musculoskeletal abnormalities. Alternatively, we generated an inducible SDS mouse model by crossing Sbdsfl/flmice with Mx1Cre+ mice, and inducing Sbds deletion in Mx1-inducible BM hematopoietic and osteolineage niche cells by polyinosinic-polycytidilic acid (pIpC) administration. Compared with Sbdsfl/flcontrols, Mx1CreSbdsExc mice develop significantly decreased platelet counts, an inverted peripheral blood myeloid/lymphoid cell ratio, and reduced long-term HSC within BM, consistent with stress hematopoiesis seen in BMF and myelodysplastic syndromes. To assess whether inducible SBDS deficiency impacts niche function to engraft donor HSC, we transplanted GFP+ wildtype donor BM into pIpC-treated Mx1CreSbdsExc mice and Sbdsfl/flcontrols after 1100 cGy of total body irradiation (TBI). Following transplantation, Mx1CreSbdsExc recipient mice exhibit significantly higher mortality than controls (Figure 1). The decreased survival was related to primary graft failure, as Mx1CreSbdsExc mice exhibit persistent BM aplasia after HSCT and decreased GFP+ reconstitution in competitive secondary transplantation assays. We next sought to identify the molecular and cellular defects within BM niche cells that contribute to the engraftment deficits in SBDS-deficient mice. We performed RNA-seq analysis on the BM stromal cells from irradiated Mx1CreSbdsExc mice versus controls, and the results revealed that SBDS deficiency in BM niche cells caused disrupted gene expression within osteoclast differentiation, FcγR-mediated phagocytosis, and VEGF signaling pathways. Multiplex ELISA assays showed that the BM niche of irradiated Mx1CreSbdsExc mice expresses lower levels of CXCL12, P-selectin and IGF-1, along with higher levels of G-CSF, CCL3, osteopontin and CCL9 than controls. Together, these results suggest that poor donor HSC engraftment in SBDS-deficient mice is likely caused by alterations in niche-mediated donor HSC homing/retention, bone metabolism, host monocyte survival, signaling within IGF-1 and VEGF pathways, and an increased inflammatory state within BM niches. Moreover, flow cytometry analysis showed that compared to controls, the BM niche of irradiated Mx1CreSbdsExc mice contained far fewer megakaryocytes, a hematopoietic cell component of BM niches that we previously demonstrated to be critical in promoting osteoblastic niche expansion and donor HSC engraftment. Taken together, our data demonstrated that SBDS deficiency in BM niches results in reduced capacity to engraft donor HSC. We have identified multiple molecular and cellular defects in the SBDS-deficient niche contributing to this phenotype. Such niche signaling pathway-specific deficits implicate these pathways as critical for donor engraftment during HSCT, and suggest their potential role as targets of therapeutic approaches to enhance donor engraftment and improve HSCT outcome in any condition for which HSCT is required for cure. Disclosures Olson: Merck: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Miltenyi: Honoraria.

23 Years of Management: A Retrospective Review of Treatment for Aplastic Anemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1091-1091
Author(s):  
Connie M Piccone ◽  
Marie Boorman Martin ◽  
Zung Vu Tran ◽  
Kim Smith-Whitley
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Retrospective Review ◽  
Pediatric Patients ◽  
Conflicts Of Interest ◽  
Bone Marrow Failure ◽  
Complete Response ◽  
Primary Objective ◽  
Hematopoietic Stem ◽  
Transfusion Independence

Abstract Abstract 1091 Poster Board I-113 Introduction Aplastic anemia (AA) is a syndrome of bone marrow failure characterized by peripheral pancytopenia and marrow hypoplasia. In the past, AA was considered to be a fatal disease; however, current therapies, including bone marrow transplantation or immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporine (CSA), are curative in the majority of patients. IST is effective at restoring hematopoietic stem cell production, but relapse and evolution to myelodysplastic syndromes remain clinical challenges. Additionally, there is no real consensus regarding optimal CSA levels, duration of CSA treatment, or the optimal use of growth factors and their relationship to the development of clonal disease. Objectives The primary objective was to review treatment management for severe AA in pediatric patients in order to elucidate treatment differences and review morbidity and mortality as they relate to treatment variation. Study Design/Methods A retrospective review of pediatric patients treated at the Children's Hospital of Philadelphia for AA (both severe and moderate) over a 23 year period was performed. Results A total of 70 patients with AA were treated at our institution from 1985 to July 2008. Exclusions included: 6 patients who received some type of initial treatment at outside institutions, 4 patients who had missing records, and 2 patients who had a diagnosis of moderate AA. Thus, a total of 58 patient records were included in the analysis. Of the total patients reviewed, 60% were male and 40% were female. 34.5% of patients were African-American, and 57% were diagnosed in 2000 or later. The mean age at diagnosis was 9.5±5.8 years. 52% fell into the category of very severe AA based on published diagnostic criteria, 45% had severe AA, and 2 patients (3%) had moderate AA. 15.5% of patients developed AA in the setting of acute hepatitis. More than half of the patients treated with IST had a complete response (CR). The average time to CR was 15±15 months. Average duration of CSA treatment was 15±13 months and 8.6±10.7 months for growth factor. Two patients (3.5%) died, one from complications unrelated to AA and one from infectious complications post-BMT after initial IST failure. Average time to transfusion independence for all patients was 8±11 months (with a range of 0-54 months). Not surprisingly, the time to transfusion independence was significantly associated with IST failure (p=0.010). Patients who failed treatment had an average time to transfusion independence of 17±16 months as compared to those who were complete responders who had an average time to transfusion independence of 3±3 months. Additionally, there was a significant association between IST failure and CSA levels (p=0.014). Patients who had nontherapeutic CSA levels overall had an increased rate of treatment failure. Of those patients who were nontherapeutic, 56% were noncompliant with CSA administration. There was no significant association between IST failure and bone marrow cellularity (p=0.251). PNH was diagnosed in 5% of patients; there were no patients with evidence of myelodysplastic syndrome (MDS). Two of the 3 patients with PNH failed initial IST. Another 2 patients had evidence of a cytogenetic abnormality (16q deletion), but never progressed to MDS. (Note: averages presented as mean±SD) Conclusions/Methods With current IST regimens, AA is curative in the majority of pediatric patients. IST failure was associated with nonadherence to CSA treatment. For patients with confirmed clonal disease, it is possible that IST failure and the ultimate development of clonal disease are related. Disclosures No relevant conflicts of interest to declare.

Long-Term Clinical Outcome of Children with Acquired Aplastic Anemia in Brazil.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4216-4216
Author(s):  
Marlene Pereira Garanito ◽  
Vicente Odone Filho ◽  
Marcela Vieira dos Santos ◽  
Elvira Velloso ◽  
Frederico L. Dulley ◽  
...  
Keyword(s):  
Stem Cell ◽  
Stem Cell Transplantation ◽  
Aplastic Anemia ◽  
Immunosuppressive Therapy ◽  
Cell Transplantation ◽  
Survival Probability ◽  
Conflicts Of Interest ◽  
Time History ◽  
Hematopoietic Stem ◽  
Significant Difference

Abstract Abstract 4216 Introdution/ Backgound Acquired Aplastic Anemia (AAA) is a rare hematologic disorder characterized by pancytopenia and hypocelular bone marrow. The pathophysiology is immune mediated in most cases. Environmental exposures to drugs, viruses and toxins, are thought to trigger the aberrant immune response in some patients. However, 50 to 74 percent of cases are classified as idiopathic. The highest frequency occurs in young population (15 to 25 years) with a second peak at age of 65 to 69 years. Immunosuppressive therapy is the best treatment in children with AAA who do not have a suitable donor for allogeneic stem cell transplantation. Materials and methods We reviewed the medical records of patients diagnosed with severe (SAA) and very severe acquired aplastic anemia (vSAA) at the Department of Pediatrics, Instituto da Criança – Hospital das Clínicas, University of Sào Paulo, Brazil from December, 1992 to December, 2007. We analyzed the clinical characteristics of the patients at diagnosis and the response to immunosuppressive therapy (IST) and hematopoietic stem cell transplantation (HSCT). Results In this study, 47 patients (27 boys and 20 girls), younger than 16 years, were diagnosed with vSAA (n= 21) or SAA (n=26). The median age was 7,71 years, ranging from 0.5 to 16 years and the average time history (beginning of signs and symptoms related to the disease and diagnosis) of the disease was 4,82 months, ranging from 0,25 to 48 months. Of the 47 patients, 45 had idiopathic AAA and 2 had hepatitis-associated. The median follow-up was 6,91 years for the patients treated with IST and 3,10 years for the patients who underwent to HSCT. One patient died before any treatment. For the eight patients who underwent to allogenic HLA-matched HSCT the 5-years-survival probability was 50%. For the 38 patients treated with IST, ten of them received cyclosporine and a short course of corticosteroids (CsA/CE) and 28 received antithymocyte globulin plus cyclosporine (ATG/CSA). The 5 years survival probability was 40% and 55%, respectively (p:0,0054). According to the severity of AAA, we did not show a significant difference in survival (p:0,32). Eight patients received second treatment after 1 year and 6 months (6 ATG from different species and CsA, 1 CsA and 1 thalidomide) and the probably of survival at 5 years was 60%. Among the 18 patients who responded to IST, four relapsed (22%). Two patients developed acute myeloid leukemia at 5 and 12 years after diagnosis. Conclusion Our results both for patients undergoing HSCT, as well as patients undergoing IST are lower in comparison to other hematological centers. Probably, this discrepancy is related to the prolonged time of disease when patients are admitted to our service. Unfortunately, the difficulty of access to specialized centers for diagnosis and early treatment in our country is a reality and this fact contributes to the delay to the beginning of treatment. Disclosures: No relevant conflicts of interest to declare.

Diagnosis of Fanconi Anemia in An Asymptomatic Adult with Mosaicism and a Molecular Explanation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4213-4213
Author(s):  
Blanche P. Alter ◽  
Neelam Giri ◽  
William Hogan ◽  
Monique Johnson ◽  
Susan Olson ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dna Repair ◽  
Stem Cell ◽  
Aplastic Anemia ◽  
Hematopoietic Stem Cell ◽  
Nonsense Mutation ◽  
Chromosome Breakage ◽  
Splice Mutation ◽  
Hematopoietic Stem ◽  
History Of

Abstract Abstract 4213 INTRODUCTION Fanconi Anemia (FA) is a primarily autosomal recessive disorder with a defective DNA repair pathway associated with mutations in any of 13 genes. The majority of patients reported in the literature have one or multiple congenital anomalies, including low birth weight, short stature, café au lait spots, abnormal radii and/or thumbs, structural renal abnormalities, microcephaly, and deafness, among others. About 25% of reported patients had few or none of these findings. The hazard of severe aplastic anemia peaks at 10 years of age, and patients have very high risks of acute myeloid leukemia and specific solid tumors, such as head and neck and gynecologic squamous cell carcinomas. Only six patients have been reported who were diagnosed between 40 and 50 years of age. However, patients may present as adults with neoplasms, or remain asymptomatic and undiagnosed. METHODS We report the diagnosis of FA in the oldest known patient, an asymptomatic 55 year old woman (Case 2), identified only because she was a potential stem cell donor for her 42 year old sister (Case 1) with severe aplastic anemia. RESULTS Case 1 had a history of thrombocytopenia at 26, and anemia and thrombocytopenia during pregnancy; physical exam was normal except for a slightly deformed thumb; blood lymphocyte chromosome aberrations were increased with both diepoxybutane (DEB) and mitomycin C (MMC). The patient died following an HLA-matched bone marrow transplant from a non-FA brother. Case 2, the other of two siblings of Case 1 who were HLA matches, had higher than normal chromosome breakage in blood (3 cells with multiple radials with MMC) but not in the FA range; skin fibroblasts were diagnostic of FA, confirming hematopoietic somatic mosaicism. She had a normal appearance, a history of hypothyroidism and mitral valve prolapse, five pregnancies with five children (one miscarriage, one set of twins), a near normal blood count (Hb 13.3 g/dl, MCV 99 fl, WBC 3500/ul, and platelets 139,000/ul), and was a regular blood donor. Bone marrow cellularity and morphology were normal, but cytogenetics showed a small clone (46,XX,add(11)(q23)[6]/46,XX[14]). Complementation analysis of Case 1 indicated group A (FA-A), and molecular analysis identified two mutations in the FANCA gene. One mutation, p.S1208S (c.3624C>T) was a splice site mutation occurring in exon 36 and has been previously described. The second mutation was a novel nonsense mutation in exon 23, p.S674X (c.2021C>A). Five siblings had normal breakage results; four were heterozygous for the nonsense mutation and one was negative for both mutations. Case 2, with mosaicism for FA, had the familial splice mutation in both blood and fibroblasts, and the familial nonsense mutation in fibroblasts, but was skewed heavily toward wild-type in blood. cDNA studies confirmed that the predicted splice mutation created an alternate splice site resulting in multiple transcripts, including exon skipping, which varied in different tissues. The molecular mechanism for the loss of the nonsense mutation in the blood is most likely due to back mutation at a hot spot, which occurred in a hematopoietic stem cell which then had a selective growth advantage. CONCLUSIONS Reversion of one FANCA mutation probably occurred in a hematopoietic stem cell which was selected for and repopulated the peripheral blood. A plausible explanation for the lack of FA clinical features is the leaky splice mutation which may provide sufficient levels of protein for normal function in DNA repair. Family members should be tested for FA by chromosome breakage analysis in blood (and/or fibroblasts to identify those who may be mosaics). Those who have FA are at risk of syndrome-specific solid tumors, as well as aplastic anemia, myelodysplastic syndrome, and leukemia, if a non-gene corrected hematopoietic stem cell were to emerge. Even if asymptomatic, they should not be used as stem cell transplant donors for siblings with FA, because they may fail to repopulate the recipient marrow. FA is undoubtedly underdiagnosed in adults at this time. Disclosures: No relevant conflicts of interest to declare.

Poor Graft Function in Recipients of T Cell Depleted (TCD) Allogeneic Hematopoietic Stem Cell Transplants (HSCT) Is Mostly Related to Viral Infections and Anti-Viral Therapy.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3147-3147 ◽  
Author(s):  
Roni Tamari ◽  
Sheetal Ramnath ◽  
Deborah Kuk ◽  
Craig S. Sauter ◽  
Doris M Ponce ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
T Cells ◽  
Stem Cell ◽  
Peripheral Blood ◽  
Viral Infections ◽  
Graft Function ◽  
Hematopoietic Stem ◽  
Allogeneic Hsct ◽  
Poor Graft Function

Abstract Abstract 3147 Introduction: Poor graft function (PGF) without immune rejection, defined as persistent cytopenias with hypocellular marrow and full donor myeloid chimerism, can be a life-threatening complication after allogeneic HSCT. It is commonly caused by viral infectious, myelosuppressive drugs like antivirals, and graft-vs-host disease (GvHD). Treatment options include supportive therapy with transfusions and growth factors and in severe cases administration of additional hematopoietic stem cells (HSCs) from the same donor without conditioning (stem cell boost). The incidence, natural history, and the indications for stem cell boost therapy are not well defined. Aims: To assess the incidence, etiologies, and indications for stem cell boost for PGF in a homogeneous group of patients with advanced MDS and AML who underwent TCD HSCT from matched or mismatched related or unrelated donors after conditioning with the same myeloablative regimen. Patients and methods: Poor graft function was defined as persistent neutropenia (ANC <1,000 μL and G-CSF administration x3 in 30 days), thrombocytopenia (platelets <50,000 μL or platelets transfusion × 4 in 30 days), and/or hemoglobin <8 g//dL after engraftment with hypocellular BM and full donor myeloid chimerism. Severe PGF was defined as ANC <500 μL, red cell transfusion-dependent anemia with reticulocytopenia of < 20,000 μL, and platelets <20,000 μL. The patient population in which this study was done included 42 patients enrolled between 09/2009 and 05/2012 in a phase 2 trial of palifermin peri-transplant to reduce transplant-related mortality. The median age was 57.5 years (1–65). All patients received the same myeloablative conditioning regimen with busulfan, melphalan, fludarabine, rabbit ATG and palifermin peri-transplant. G-CSF mobilized donor peripheral blood stem cells underwent CD34+ selection and depletion of T cells using CliniMACS immunomagnetic selection columns (Milteny Biotec). Donors were HLA matched (31; 13 related and 18 unrelated) or mismatched unrelated (11). Chimerism was determined in bone marrow as well as neutrophils, B cells, and T cells by short tandem repeat analysis on DNA extracted from bone marrow and peripheral blood cell subsets. Results: Forty-one patients were evaluable for this analysis; 1 patient was not included as he rejected the allograft shortly after engraftment. There were 8 cases of PGF with a cumulative incidence (CI) at 1 year of 18% (13% HLA matched, 33% HLA mismatch). The etiology was infection in 7 cases, and unknown in the 8th case. This patient presented with presumed autoimmune anemia and thrombocytopenia associated with a hypercellular marrow and did not respond to multiple lines of therapies. Her marrow became later hypocellular and met the criteria for PGF. None of the PGF cases in this series was associated with GvHD at the time of diagnosis of PGF. The infectious etiologies included: 6 viral infections and 1bacterial sepsis + myelosuppressive drugs. The most common viral etiology associated with PGF was CMV (50%). The 1-year CI of PGF in CMV seropositive patients was 25% and in CMV seronegative patients was 14%. Of note, HHV6 viremia was detected in patients with PGF. HHV6 is not routinely monitored, however, making it difficult to establish a causative role. All patients had moderate PGF at diagnosis and 3 cases had worsening of cytopenias and met the criteria for severe PGF. To date, 3 PGF patients have died from EBV-PTLD, adenovirus infection or GVHD (developed after CMV treatment with liposomal cidofovir), 3 continue to suffer from PGF and 2 patients are alive with recovered good blood counts after eradication of CMV. Of the 3 patients with persistent PGF, one received a TCD boost with no response, and 2 continued to be treated for CMV viremia. A stem cell boost was indicated if pancytopenia persisted despite eradication of cause of the PGF. In this small series, there were not enough events to evaluate association between PGF and CD34 cell dose, CD3 cell dose or day 100 T-cell chimerism. Conclusions: In this homogenous population of patients with MDS who underwent TCD allogeneic HSCT, the incidence of PGF is about 20%. The most common cause was viral infection with predominance of CMV. Therefore, strategies to prevent CMV reactivation in patients undergoing allogeneic HSCT has the potential to reduce the risk of PGF and avoid the need for infusion of additional stem cells. Disclosures: No relevant conflicts of interest to declare.

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