The Challenge of Diagnosing Fanconi Anemia in Patients with Bone Marrow Failure (BMF): A Study in 82 BMF Patients.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 991-991 ◽  
Author(s):  
Fernando O. Pinto ◽  
Thierry Leblanc ◽  
Gwenaelle Le Roux ◽  
Jerome Larghero ◽  
Bruno Cassinat ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Bone Marrow Failure ◽  
Somatic Mosaicism ◽  
Chromosome Breakage ◽  
Clinical Findings ◽  
Group 3 ◽  
Group 2 ◽  
Rule Out ◽  
Group 1

Abstract The Bone Marrow Failure (BMF) syndromes comprise a variety of distinct acquired or inherited clinical entities. Early distinction between syndromes has clear implications in the disease management and outcome. Fanconi anemia (FA), the most frequent cause of inherited BMF, is usually associated with congenital abnormalities, progressive cytopenia, chromosome fragility, and cancer susceptibility. However, due to a high clinical variability and/or the potential emergence of revertant hematopoietic cells (somatic mosaicism), identifying patients with FA or ruling out this diagnosis can be challenging. If undiagnosed, FA patients who initially present with bone marrow failure will die of toxicity after standard-dose conditioning regimens for HSCT. In this study, we evaluated FA diagnosis in patients with BMF but no clear initial evidence of FA, using of a combination of classical and innovative tests in blood and fibroblasts. A cohort of 82 patients with BMF and no strong clinical evidence of FA was analysed (patients with a clear FA diagnosis were not included). Based on the likelihood of an underlying inherited condition associated with the BMF, we classified patients in 3 groups: those likely to have idiopathic aplastic anemia (IAA) [n=38, group 1], those likely to have a constitutional condition other than FA [n=26, group 2], and those likely to have IAA but who had isolated clinical findings which could also be present in FA [n=18, group 3]. Chromosome breakage test and analysis of the FA/BRCA pathway by FANCD2 immunoblot were performed in PBL in all patients [n= 82]. To overcome potential somatic mosaicism, skin primary fibroblasts were analysed [n= 52]. Also, to rule out FA/BRCA downstream groups, we developed a new flow cytometry test based on MMC-sensitivity in fibroblasts. In total, 6 patients with FA were identified: 1/38 in group 1 (aplastic anemia at 10 yo, no positive clinical findings), 2/26 in group 2 (one with MDS at 48 yo with precocious menopause and vocal cord neoplasia at 38 yo; one with hypoplastic MDS at 50 yo), and 3/18 in group 3 (one with short stature and aplastic anemia at 37 yo; one with MDS and borderline physical abnormalities at 26 yo; and one with a single cafe-au-lait spot and aplastic anemia at 10 yo). Chromosomal breakage tests in PBL were sufficient to diagnose 4 of these FA patients (further classified as FA core using FANCD2 immunoblot). Additional fibroblast analyses were necessary to identify 2 more FA patients (both with complete somatic mosaicism) and, importantly, to definitely exclude FA diagnosis in other patients. In conclusion, underdiagnosing FA is rare if careful history and physical exam are done together with chromosome breakage test in PBL. However, in clinical situations where the suspicion of FA persists despite negative breakage tests, then fibroblasts should be tested. Because no cases of FA were found among patients with IAA and negative breakage tests in PBL, we suggest that FA screening can be limited to this technique in this population (group 1). The strategy here presented allowed us to identify a few unexpected FA cases in a cohort of BMF patients, and importantly, to definitely rule out FA in others, with clear clinical impact for patients who undergo HSCT.

Unexpected Fanconi Anemia Diagnosis in Patients with Bone Marrow Failure.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1056-1056
Author(s):  
Fernando O. Pinto ◽  
Thierry Leblanc ◽  
Gwenaelle Le Roux ◽  
Helene Dastot ◽  
Moema Santos ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aplastic Anemia ◽  
Clinical Features ◽  
Fanconi Anemia ◽  
Bone Marrow Failure ◽  
Somatic Mosaicism ◽  
Chromosome Breakage ◽  
Large Set ◽  
Chromosomal Breakage ◽  
Group A

Abstract Early diagnosis of Fanconi Anemia (FA) in patients with bone marrow failure is critical for optimal clinical management. However, the remarkably high clinical variability and the potential emergence of revertant hematopoietic cells (somatic mosaicism) can obscure and delay the diagnosis of FA. Here we addressed FA diagnosis in a prospective series of adult and pediatric patients who presented with bone marrow failure without clear overall clinical picture of FA. Sixty-six patients were classified into three groups: (1) bone marrow failure likely to be congenital, based on dysmorphic features or a family history [n=18], (2) aplastic anemia likely to be idiopathic [n=32], (3) patients with intermediate clinical features not classified into the former groups [n=16]. Of note, FA patients with typical clinical features were not included in the present study. FA diagnosis was evaluated using chromosome breakage test and FANCD2 immunoblot in PHA-stimulated-PBL. In addition, skin primary fibroblasts were analysed in order to overcome potential hematopoietic FA reversion. For that purpose, and considering that chromosome breakage tests are barely efficient in fibroblasts, we used FANCD2 immunoblot and also developped a new flow cytometry test based on MMC-sensitivity in fibroblasts (to detect downstream FA/BRCA groups). Using these approaches, we detected FA in 4 previously undiagnosed patients: a 35-years old patient from the congenital-like group; a 10-years old patient presenting as an idiopathic aplastic anemia without any FA signs; and two patients from the intermediate group: a 10-years old patient with an isolated thrombocytopenia, and a 50-years old patient presenting with pancytopenia/MDS and complete hematopoietic reversion. Importantly, FA diagnosis was definitely excluded in all other patients. In conclusion, we could identify a few unexpected FA cases in a series of patients with bone marrow failure. Therefore, the comprehensive use of a large set of tests is useful for accurate FA diagnosis. Classical chromosomal breakage tests in PBL appeared to be sufficient to exclude FA in idiopathic aplastic anemia, whereas fibroblast analysis can be necessary to definitely diagnose or exclude FA in other patients.

Decreased Rejection and Improved Survival of First and Second Marrow Transplants for Severe Aplastic Anemia (A 26-Year Retrospective Analysis)

Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2742-2749 ◽  
Author(s):  
Anne Stucki ◽  
Wendy Leisenring ◽  
Brenda M. Sandmaier ◽  
Jean Sanders ◽  
Claudio Anasetti ◽  
...  
Keyword(s):  
Aplastic Anemia ◽  
Graft Rejection ◽  
Marrow Transplant ◽  
Severe Aplastic Anemia ◽  
Probability Of Survival ◽  
Gvhd Prophylaxis ◽  
Group 3 ◽  
Group 2 ◽  
American Society ◽  
Group 1

Abstract Between 1970 and 1996, 333 patients with severe aplastic anemia underwent HLA-matched related marrow transplant after conditioning with cyclophosphamide (CY). Thirty-five percent of patients transplanted between 1970 and 1976 (group 1), 12% of those transplanted between 1977 and 1981 (group 2), and 9% of patients transplanted between 1982 and 1997 (group 3) had graft rejection. Graft rejection occurred later among group 3 patients (median, 180 days) than among those in groups 1 and 2 (medians, 28 and 47 days, respectively; P < .001 group 3 v 2). In group 3, 92% of rejecting patients underwent a second transplant, compared with 78% and 77% in groups 1 and 2, respectively. Group 1 patients received various conditioning regimens before second transplant, whereas most patients of groups 2 and 3 received CY combined with antithymocyte globulin (ATG). Graft-versus-host disease (GVHD) prophylaxis after second transplant consisted of methotrexate (MTX) for all group 1 and 2 patients, whereas group 3 patients received MTX combined with cyclosporine (CSP). Over the three time periods studied, first graft rejection decreased from 35% to 9%, and the proportion of rejecting patients undergoing second transplants increased from 77% to 92%. The 10-year probability of survival after second transplants increased from 5% to 83%. Multivariate analysis showed MTX/CSP GVHD prophylaxis to be a significant factor accounting for the increase in patient survival after second transplant. © 1998 by The American Society of Hematology.

scholarly journals Screening for MELAS mutations in young patients with stroke of undetermined origin

2007 ◽  
Vol 65 (2b) ◽  
pp. 371-376 ◽  
Author(s):  
Adriana Bastos Conforto ◽  
Fabio Iuji Yamamoto ◽  
Sueli Mieko Oba-Shinjo ◽  
Julio Guy C. Pinto ◽  
Maurício Hoshino ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Healthy Subjects ◽  
Young Patients ◽  
Clinical Findings ◽  
Melas Syndrome ◽  
Mitochondrial Mutations ◽  
A3243g Mutation ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

PURPOSE: It has been suggested that mitochondrial disease may be responsible for a substantial proportion of strokes of indetermined origin. We have preliminarily screened for MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) mutations in young patients with cryptogenic strokes. METHOD: The mitochondrial mutations A3243G and T3271C were investigated in 38 subjects aged less than 46 years. Group 1: 15 patients with cryptogenic strokes; Group 2: 3 patients with diagnosis of MELAS syndrome, including stroke-like episodes; Group 3: 20 healthy subjects. RESULTS: The A3243G mutation was absent in all subjects in Groups 1 and 3 but was present in all subjects in Group 2. CONCLUSION: Our results do not support screening for these mutations to diagnose oligosymptomatic forms of MELAS in cryptogenic strokes in the absence of other features of the syndrome. We suggest that clinical findings should guide mitochondrial genetic testing.

Mobilization of Stem Cells from the Bone Marrow Is Required for Neovascularization of Ischemic Limbs in Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4233-4233
Author(s):  
Jeong-A Kim ◽  
Chang -Hoon Lee ◽  
Jin-A. Yoon ◽  
Woo-Sung Min ◽  
Chun-Choo Kim
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hind Limb ◽  
Limb Ischemia ◽  
Hind Limb Ischemia ◽  
Ischemic Limb ◽  
Group 3 ◽  
Group 2 ◽  
Surgically Induced ◽  
Group 1

Abstract We examined whether the injection of bone marrow mononuclear cells (BM-MNCs) or mesenchymal stem cells (MSCs) might augment angiogenesis and collateral vessel formation in a mouse model of hind limb ischemia. C57BL/6 BM-MNCs were isolated by centrifugation through a Histopaque density gradient and MSCs were obtained from C57BL/6 bone marrow and cultured in low-glucose DMEM media. Unilateral hind limb ischemia was surgically induced in C57BL/6 mice (control; n=4), and autologous BM-MNCs (Group 1; n=4, 1.8±0.2 x107/animal) or MSCs (Group 2; n=4, 1.0±0.14 x106/animal) or BM-MNCs and MSCs (Group 3; n=4, 2.3±0.1 x107 and 1.1±0.21 x106/animal) were transplanted into the ischemic tissue. Six weeks after transplantation, the group 1, group 2 and group 3 had a higher capillary/muscle ratio (0.82±0.12 vs 0.85±0.08 vs 0.97 ±0.03) than control (0.46±0.12, p<0.05) (Fig. 1). This result suggested that direct local transplantation of autologous BM-MNCs or MSCs seems to be a useful strategy for therapeutic neovascularization in ischemic tissues. Next, we evaluated whether bone marrow derived stem cells were participated in the process of local injected stem cells forming new vessels. In general, mobilizing stem cells from bone marrow to local site, MMP-9 has been known as an important molecule. So we used the MMP-9 deficient KO mice and wild type, 129SvEv mice were used in the experiments. Autologous BM-MNCs and MSCs were transplanted into the ischemic limb in MMP-9 (−/−) (n=4) after unilateral hind limb ischemia was surgically induced and then the same experiments was done in MMP-9 (+/+) mice (n=4). The number of the injected BM-MNCs and MSCs was 2.2±0.05 x107 and 0.87±0.17 x106/animal in MMP-9 (−/−). And the number of the injected BM-MNCs and MSCs was 2.1±0.17 x107 and 0.98±0.09 x106/animal in MMP-9 (+/+). No difference was seen in the BM-MNCs and MSCs were injected or not (0.52±0.07 vs 0.49±0.03,) in MMP-9 (−/−). But, in the case that BM-MNCs and MSCs were injected, the higher capillary/muscle ratio was seen in MMP-9 (+/+) compared to control (0.86 ±0.09 vs 0.49±0.03, P<0.05) (Fig 2). This data indicated that the mobilization of bone marrow derived stem cells would have an important role in the neovasculrization although the stem cells were injected directly into the muscle of ischemic limb. Figure Figure Figure Figure

scholarly journals Feline Leukemia Virus-associated Enteritis—A Condition with Features of Feline Panleukopenia

1987 ◽  
Vol 24 (1) ◽  
pp. 1-4 ◽  
Author(s):  
M. Reinacher
Keyword(s):  
Bone Marrow ◽  
Leukemia Virus ◽  
Feline Leukemia Virus ◽  
Lymphoid Tissues ◽  
Post Mortem ◽  
The Third ◽  
Histopathological Alterations ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Infection with feline leukemia virus (FeLV) was demonstrated immunohistologically in 218 necropsied cats suffering from enteritis. The animals were divided into three groups according to histopathological criteria. The first group exhibited the signs of feline panleukopenia in intestine, lymphoid tissues, and bone marrow. Only 1.6% of these animals were FeLV-infected. The animals of the second group had histopathological alterations as seen in cats suffering from feline panleukopenia, but these were found only in the intestine and not in lymphoid tissues or bone marrow. Of these 71.9% were infected with FeLV. The third group consisted of all other cats suffering from enteritis of which 6.3% were FeLV-positive. The association between FeLV infection and the lesions seen in the animals of group 1 (feline panleukopenia) and group 3 (other types of enteritis) is statistically not significant whereas the alterations exhibited by the cats of group 2 are significantly FeLV-associated. Cats with FeLV-associated enteritis (group 2) are of a mean age of about 2.5 years and are significantly older than animals with feline panleukopenia which are of a mean age of about half a year. Thus a FeLV-associated enteritis exists as a histopathologically recognizable condition which sometimes might be mistaken for feline panleukopenia in routine post-mortem investigations.

scholarly journals Cyclophosphamide cardiotoxicity: an analysis of dosing as a risk factor

Blood ◽  
1986 ◽  
Vol 68 (5) ◽  
pp. 1114-1118 ◽  
Author(s):  
MA Goldberg ◽  
JH Antin ◽  
EC Guinan ◽  
JM Rappeport
Keyword(s):  
Heart Failure ◽  
Bone Marrow ◽  
Congestive Heart Failure ◽  
Aplastic Anemia ◽  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Severe Combined Immunodeficiency ◽  
Group 2 ◽  
Group 1

Abstract Patients who undergo bone marrow transplantation are generally immunosuppressed with a dose of cyclophosphamide (CYA) which is usually calculated based on the patient's weight. At these high doses of CYA, serious cardiotoxicity may occur, but definitive risk factors for the development of such cardiotoxicity have not been described. Since chemotherapeutic agent toxicity generally correlates with dose per body surface area, we retrospectively calculated the dose of CYA in patients transplanted at our institution to determine whether the incidence of CYA cardiotoxicity correlated with the dose per body surface area. Eighty patients who were to receive CYA 50 mg/kg/d for four days as preparation for marrow grafting underwent a total of 84 transplants for aplastic anemia, Wiskott-Aldrich syndrome, or severe combined immunodeficiency syndrome. Fourteen of 84 (17%) patients had symptoms and signs consistent with CYA cardiotoxicity within ten days of receiving 1 to 4 doses of CYA. Six of the 14 patients died with congestive heart failure. The dose of CYA per body surface area was calculated for all patients and the patients were divided into two groups based on daily CYA dose: Group 1, CYA less than or equal to 1.55 g/m2/d; Group 2, CYA greater than 1.55 g/m2/d. Cardiotoxicity that was thought to be related to CYA occurred in 1/32 (3%) of patients in Group 1 and in 13/52 (25%) patients in Group 2 (P less than 0.025). Congestive heart failure caused or contributed to death in 0/32 patients in Group 1 v 6/52 (12%) of patients in Group 2 (P less than 0.25). There was no difference in the rate of engraftment of evaluable patients in the two groups (P greater than 0.5). We conclude that the CYA cardiotoxicity correlates with CYA dosage as calculated by body surface area, and that patients with aplastic anemia and immunodeficiencies can be effectively prepared for bone marrow grafting at a CYA dose of 1.55 g/m2/d for four days with a lower incidence of cardiotoxicity than patients whose CYA dosage is calculated based on weight. This study reaffirms the principle that drug toxicity correlates with dose per body surface area.

Serum Transferrin Receptor Value as a Universal Indicator of Erythropoietic Activity.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3682-3682
Author(s):  
Young Soo Lee ◽  
Chul Soo Kim ◽  
Jong Weon Choi
Keyword(s):  
Bone Marrow ◽  
Transferrin Receptor ◽  
Bone Marrow Cells ◽  
Reticulocyte Count ◽  
Serum Transferrin Receptor ◽  
Group 4 ◽  
Universal Indicator ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Abstract The serum transferrin receptor (sTfR) is thought a sensitive and quantitative parameter of tissue iron deficiency as well as an indicator of erythropoietic activity. This study was aimed at the verification of a hypothesis that sTfR is a general indicator of erythropoiesis regardless whatever the cause is. A total of 173 patients in heterogeneous diseases who underwent bone marrow study as a workup for anemia were measured for sTfR, reticulocyte maturity index (RMI), erythroid element proportion of bone marrow cells, and other hematologic parameters (hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, red cell distribution width, absolute reticulocyte count). By immunoenzymometric method sTfR was measured using IDeATMcTfR kids (Orion Diagnostica, Orion, Finland). Reticulocyte count and proportion was measured manually by one expert examiner after standard blood smear and stain. Reticulocyte subpopulation was automatically analyzed by flow cytometry using R-3000 TM (Sysmex, TOA, Japan). RMI was calculated from the equation of (medium fluorescent reticulocyte fraction + high fluorescent reticulocyte fraction) X 100 / low fluorescent reticulocyte fraction. Correlation analysis was done among the variables including sTfR, RMI, erythroid element proportion of bone marrow cells, and other hematologic parameters using SAS 6.12 soft ware. The analysis was carried out for the whole 173 patients to see the general trends and repeated for 4 groups of disease category, arbitrarily divided to group 1 (n=33, iron deficiency or or disease with no predisposition to anemia of chronic disease), group 2 (n=53, hematologic malignancies), group 3 (n=44, solid tumors), and group 4 (n=43, chronic or infectious disease) to see if the trends may be affected by specific diseases. The results showed a solid correlation of sTfR with RMI as well as erythroid precursors in bone marrow, not only in the whole patient population (e.g. sTfR vs RMI, R=0.587, p=0.0001) but also in individual groups (e.g. sTfR vs RMI, R=0.48, p=0.005 in group 1, R=0.69, p=0.0001 in group 2, R=0.58, p=0.0001 in group 3, R=0.81, p=0.0001 in group 4). These findings indicated the significance of sTfR is valid under any clinical setting as a universal indicator of hematopoietic activity. The sTfR can be used as a useful parameter for monitoring of erythropoiesis in a variety disease.

WT1 Levels At Diagnosis and POST-Induction Provide Prognostic Information in Adult De Novo AML. Results From the Spanish Cetlam Group.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2524-2524
Author(s):  
Josep F Nomdedeu ◽  
Montserrat Hoyos ◽  
Maite Carricondo ◽  
Elena Bussaglia ◽  
Camino Estivill ◽  
...  
Keyword(s):  
Bone Marrow ◽  
De Novo ◽  
High Dose ◽  
Prognostic Impact ◽  
Post Induction ◽  
Group 3 ◽  
Group 2 ◽  
De Novo Aml ◽  
Intermediate Dose ◽  
Group 1

Abstract Abstract 2524 WT1 monitoring is an almost universal target to follow de novo AML. Its exppression in myeloid malignancies is upregulated in parallel to the blast percentage. Recently, WT1 determination has been standardized as result of an European Leukemia Net initiative. Early reports have demonstrated that the best results are obtained when peripheral blood is used to establish clinical predictions. Pediatric studies in AML have shown that raised WT1 levels after induction associate with unfavourable outcome. Despite all the mentioned, WT1 quantitation has not yet gained widespread use, in part because some AML show normal WT1 levels at diagnosis. To investigate the prognostic impact of the normalized bone marrow WT1 levels at diagnosis and post-induction in a consecutive series of de novo AML patients enrolled in the CETLAM group trials. Available bone marrow samples at diagnosis (586 cases) and post induction (367 cases) were obtained in each participating center and sent to the CETLAM repository center at the Hospital de la Santa Creu i Sant Pau for complete immunophenotype and molecular analyses. One μg of RNA was reverse transcribed to cDNA in a total reaction volume of 20μl containing Cl2Mg 5mM, 10× Buffer, DTT 10mM, dNTP's 10mM each, random hexamers 15μM, RNAsin 20 units (Promega) and 200 units of MMLV enzyme. WT1 expression levels were determined by real-time quantitative polymerase chain reaction (RQ-PCR) in an ABI PRISM 7700® Genetic Analyzer (Applied Biosystems, Foster City, CA) using the primers and conditions described by the ELN group (Cilloni et al J. Clin. Oncol 2009;27:5195-201). For WT1 copy number titration, the IPSOGEN® (Marseille, France) plasmid was employed. Results were expressed as copies and four normal bone marrow samples were used as test controls. Patients were treated between 2004 and 2011 according to the CETLAM03 protocol. Adults up to 70 years of age received induction chemotherapy with idarubicin, intermediate-dose cytarabine and etoposide, followed by consolidation with mitoxantrone and intermediate-dose ara-C. Subsequently, patients with favourable cytogenetics at diagnosis received one cycle of high-dose cytarabine.G-CSF priming during induction and consolidation was used. Patients with favorable cytogenetics and high leukocyte counts at diagnosis were treated with autologous transplantation instead of high-dose cytarabine. Furthermore, patients with a normal karyotype but an adverse molecular profile (FLT3 mutations or MLL rearrangements) were allocated to the treatment for unfavorable cases; this included allogeneic transplantation from an HLA-identical donor. Overall survival (OS) was measured from the date of enrolment until the date of death. Leukemia-free survival (LFS) for patients who achieved a CR was calculated from the date of CR to relapse or death. OS and LFS were plotted by the Kaplan-Meier method; differences between curves were analyzed by the log-rank test. The probability of relapse was calculated using cumulative incidence estimates and taking into account the competing risk of death in remission. A WT1 cut-off value of 5065.2 copies at diagnosis was obtained. Two hundred and four samples had WT1 levels greater than this value, whereas 382 samples showed levels below this cut-off. These groups had statistically different OS 55±3 vs 33±5 p<0.001, LFS 52±3 vs 30±6 p:0.004 and CIR 34±3 vs 56±6 p<0.001. As regards the post-induction results, four groups were established: Group 0 (135 patients) with WT1 levels between 0 and 17.5 copies, Group 1 (107 patients) with WT1 values ranging from 17.6 to 76 copies, Group 2 (54 patients) with WT1 between 76.1 and 170.5 copies and Group 3 (71 patients) with WT1 levels after induction greater than>170.6 copies. These groups showed statistically significant differences(p<0.001) in terms of OS: Group 0 59±4 months, Group 1 50±5 months, Group 2 45±7 months and Group 3 23±6 months. LFS was also statiscally different: Group 0: 58±4, Group 1: 46±5, Group 2: 39±8 and Group 3:19±8 (all p<0.001). Lastlly, CIR was markedly different between the four groups: Group 0:25±4, Group 1: 44±5, Group 2: 46±8 and Group 3: 68±8(p<0.001) . WT1 quantitation at diagnosis and post-induction provide a simple and well standardized measurement of the prognostic risk of adult AML patiens. Larger series need to be analyzed to ascertain whether this determination could be incorporated to initial AML risk stratification. Disclosures: No relevant conflicts of interest to declare.

Leukemic and Hematopoietic Stem Cells Compete for the Same Functional Marrow Niche in a MLL-AF9 Murine Leukemia Model

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4897-4897
Author(s):  
Ronan G. Desmond ◽  
Taha Bat ◽  
Olena Kamenyeva ◽  
Benjamin Mizukawa ◽  
James C. Mulloy ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Murine Model ◽  
Leukemic Cells ◽  
Hematopoietic Stem ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Abstract Abstract 4897 Much is known regarding the location, cellular composition, signaling pathways, and functional role of the normal hematopoietic stem cell (HSC) niche in the bone marrow microenvironment. Microenvironmental cells including osteoblasts, other specialized mesenchymal cells, and vascular endothelial cells exert control over HSC self-renewal, differentiation, and engraftment. Niche occupancy appears to be competitive and limiting in terms of controlling the number of HSCs per organism. Leukemia stem cells (LSCs), through their inherent properties of quiescence and resistance to chemotherapeutic agents, are thought to be one of the principal mechanisms underlying disease relapse in patients. Much less is known regarding the interaction of LSCs and the marrow microenvironment. It is not clear whether LSCs localize to the same niches as HSCs, compete with HSCs for niche occupancy, or share dependence on niche signals, and whether those signals affect tumor responses to chemotherapy. Using a human pre-B ALL xenograft mouse model, Colmone et al (Science 2008) recently showed that leukemic cells may alter the normal microenvironment, resulting in initial homing of transplanted normal HSPCs in distinct atypical niches. Shiozawa et al (JCI 2011) showed that metastatic prostate cancer cells, a tumor type known to target bone, impeded HSC engraftment in a murine model, suggesting competition for the same niche. To investigate the relationship between HSC and LSC niche localization and functional occupancy, we used murine progenitor cells transduced with an MLL-AF9 vector expressing GFP in a murine syngeneic competitive transplantation model. MLL-AF9 cells are highly enriched for LSCs, particularly the c-kit+ compartment (Somervaille Cancer Cell 2006). We found that between approximately 21% and 24% of cells were c-kit+ by FACS in 2 separate experiments. In our model, mice transplanted with unsorted MLL-AF9 cells (1×107) died of AML with a latency of 11–14 days. We cotransplanted a fixed number of MLL-AF9-GFP cells (1×106) with increasing numbers of normal mouse whole bone marrow (WBM) cells, derived from dsRed transgenic mice to facilitate distinction from the GFP+ MLL-AF9 cells, into mice irradiated with 1000 rads: 1×105 [group 1], 1×106 [group 2], 1×107 [group 3], 5×107 [group 4]. Control groups received 1×105 and 1×106 normal WBM cells only. Survival was monitored daily. The control group receiving 1×105 cells only all died with median time to death of 16.5 days from lack of count recovery, those receiving 1×106 cells are still alive 35 days after transplant, indicating that 1×106 cells is adequate to rescue from irradiation. Mice were bled weekly until death and samples were analyzed by flow cytometry. Complete blood counts, blood smears, and splenic sections were obtained from these mice. As expected, there were no circulating blasts detected 7 days post transplant and all mice were healthy. However, 14 days after transplant the percentages of GFP+ leukemic cells detected in the blood were inversely proportional to the number of normal dsRed WBM cells transplanted (group 1 vs. group 2 vs. group 3 vs. group 4 mean percentage of GFP+ cells, 83.97 v 66.53 v 18.73 v 9.275 p< 0.0001). At day 15, mice from group 1, but not from groups 2 to 4, became moribund and were sacrificed. Spleens in this group were heavier than in those mice transplanted with 1×105 normal WBM cells alone and 2 out of 3 showed leucocytosis compared to leucopenia in all mice in the group transplanted with normal cells alone. When mice in the other groups had blood samples taken for analysis while moribund, GFP+ cells were greater than 80% suggesting that mice in group 1 died from complications relating to leukemic infiltration. Confocal microscopy confirmed the colocalization of normal HSPCs and MLL-AF9-GFP LSCs in the niche. Most interestingly, survival was proportional to the numbers of normal WBM cells transplanted, with a continuous delay in leukemic death proportional to the number of normal WBM cells cotransplanted with the same dose of MLL-AF9 cells (Figure 1). Hence, this murine model of leukemia suggests that normal and leukemic cells compete for the same functional niche, that manipulation of the niche could impact on response to anti-leukemic therapies, and that cell dose in the context of stem cell transplantation for leukemia may have an impact on outcome via niche competition. Figure 1 Figure 1. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Epidemiology Unknown: Developing an Approach to Identify Potential Smoldering Multiple Myeloma Cases

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4722-4722
Author(s):  
Raleigh A. Fatoki ◽  
Diane M. Carpenter ◽  
Adnan Khan ◽  
Ryan Stevenson ◽  
Joan C. Lo ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Cancer Registry ◽  
Research Funding ◽  
Physician Visit ◽  
Lytic Lesions ◽  
Group 3 ◽  
Race Ethnicity ◽  
Group 2 ◽  
Group 1

Abstract Background Smoldering Multiple Myeloma (SMM) is an asymptomatic clonal plasma cell disorder that identifies patients at risk for progression to Multiple Myeloma (MM). The standard of care for SMM has traditionally been observation, but some cancer centers are now treating high-risk SMM before progression to MM. The diagnostic criteria for SMM have also changed in recent years, and current estimates of SMM are derived from large MM databases and observations from tertiary centers. The goal of this study was to develop an approach for identifying SMM cases in a large integrated healthcare delivery system to better characterize the epidemiology of SMM in community-based populations. Methods This retrospective, observational study was conducted in Kaiser Permanente Northern California (KPNC) using KPNC SEER-based Cancer Registry data and information from the electronic health record (EHR). Potential SMM cases from 1/1/2010 to 12/31/2018 were identified using three approaches: Group 1 - identified via the KPNC Cancer Registry based on indicators of 'asymptomatic myeloma', 'evolving myeloma', and 'smoldering myeloma'; Group 2 - identified via the KPNC Cancer Registry as MM cases who had a physician visit note containing the word 'smoldering' but did not begin treatment within 1 year of diagnosis; Group 3 - identified via the KPNC Cancer Registry as MM cases who had a physician visit note containing the word 'smoldering' but did begin treatment within 1 year of diagnosis. Chart review was performed for these potential SMM cases (Groups 1-3) to document initial bone marrow biopsy results (bone marrow plasma cell percentage, BMPC) and skeletal findings (presence or absence of lytic bone lesions) around the time of biopsy. When BMPC was reported as a range, the highest value was captured. Patient demographics (age, sex and race/ethnicity) were obtained from the EHR. Bivariate analyses were performed using the chi-squared test and the Wilcoxon-Mann-Whitney nonparametric test. For binomial comparisons by mode of potential SMM case identification, Groups 1 and 2 were combined and compared to Group 3. Results A total of 471 potential SMM cases were identified, including 178 (37.8%) via Group 1, 35 (7.4%) via Group 2, and 258 (54.8%) via Group 3 (Figure). The median age was 71 years (interquartile range, IQR 62-78) and 40.0% were female. The racial/ethnic distribution included 57.1% White, 17.6% Black, 10.8% Hispanic, 13.6% Asian, and 0.9% other/unknown race. There were no significant differences across groups (Group 1+2 vs Group 3) with respect to age (p=0.07), sex (p=0.85), or race/ethnicity (p=0.81). There were 442 (93.8%) who underwent bone marrow biopsy. Among those with BMPC data, the median BMPC for Group 1 was 20.0% (IQR 10.0%-28.0%); for Group 2 was 25.0% (IQR 12.5%-50.0%), for Group 3 was 28.0% (IQR 15.0%-50.0%) (p&lt;0.001 comparing Groups 1+2, combined median 20.0%, IQR 10.0%-30.0%, vs Group 3, 28.0%, IQR 15.0%-50.0%). The proportion with BMPC ≥60% was 4%, 13%, and 22% for Groups 1, 2, and 3, respectively (Figure). There were 413 (87.7%) who had skeletal imaging (n=405, 86.0% with available results) within 6 months of diagnosis. Of those with imaging results available to view, n=68 were found to have lytic lesions; 7.6% among Group 1, 6.9% among Group 2, 24.9% among Group 3 (p&lt;0.001 comparing Groups 1+2, 7.5%, vs Group 3, 24.9%). Discussion This study used a multifaceted approach to identify potential SMM cases from a large real-world clinical population in an integrated health system. We used an approach similar to prior SMM epidemiological studies and also included those with physician visit notes specifically containing the word 'smoldering' within the text. The vast majority of our cohort had BMPC between 10 and 60%, but those who received treatment within 1 year had greater BMPC and a higher proportion of lytic lesions. This suggests those who received treatment, Group 3, may have actually had a MM diagnosis, and physician visit notes containing the word 'smoldering' may have been intended to communicate something other than a SMM diagnosis. Further analyses will determine the effectiveness of each approach by confirming SMM cases according to the International Myeloma Working Group diagnostic criteria with incorporation of laboratory data and additional clinical findings. Among confirmed cases of SMM, the rate of progression to MM and the severity of end-organ damage at time of progression will be assessed. Figure 1 Figure 1. Disclosures Lo: Novartis: Research Funding; Bristol-Myers-Squibb: Research Funding; CSL-Bering: Research Funding.

Sign in / Sign up

Export Citation Format

Share Document