Platelet Factor 4 Levels Inversely Correlate with Platelet Transfusion Needs In Pediatric Patients Treated for Standard Risk Acute Lymphoblastic Leukemia

Abstract Abstract 725 Platelet factor 4 (PF4) is a chemokine found almost exclusively in megakaryocytes and platelets. PF4 has been previously shown to be a negative paracrine inhibiting megakaryopoiesis in vitro in humans and mice. We confirmed this finding and also found an inverse correlation between PF4 and steady-state platelet counts in mice. In both chemotherapy- and radiation-induced thrombocytopenia, platelet PF4 levels inversely correlated with platelet count recovery after bone marrow injury, and blocking this effect ameliorated the thrombocytopenia. We now asked whether platelet PF4 levels are of clinical relevance on human platelet biology in patients undergoing chemotherapy. We selected pediatric patients who had completed treatment for standard risk acute lymphoblastic leukemia at the Children's Hospital of Philadelphia, as this was a fairly large population that have reached remission after relatively uniform therapy. Enrolled patients had completed therapy since January 1999. Blood samples were obtained and medical records were retrospectively reviewed for platelet counts, platelet transfusion requirements and duration of therapy during delayed intensification (DI). DI was chosen for investigation as a preliminary study showed that 35% of our patients require platelet transfusion during DI and need for transfusion at that point in therapy is unlikely to be related to primary underlying bone marrow disease. To date, 68 subjects have been enrolled. Sixty-two subjects had evaluable PF4 levels. PF4 levels were independent of age and sex. Leukemia survivors did not have significantly different PF4 levels when compared to a pediatric control population. There was a direct relationship between measured total PF4 level and platelet count (Pearson r 0.36, p<0.006) although contrary to animal studies, there was no correlation between PF4 per platelet and platelet count. Transfusion data from the first 22 patients have been evaluated. Patients who did not require platelet transfusion during DI had markedly lower PF4 per platelet (6.35 ± 1.85 SE) when compared to patients who required transfusion (13.26 ± 1.89 SE, p<0.02). In addition, duration of therapy (for girls) was inversely correlated with PF4 per platelet (r 0.689, p=0.04), consistent with animal data in which platelet count recovery was inversely correlated with PF4 per platelet. These data suggest that PF4 may be an important in vivo regulator of human platelet counts in the setting of bone marrow injury. Further clinical studies will confirm these findings and begin to explore potential interventions to allow for intensified chemotherapy regimens in subjects at risk for more severe chemotherapy-induced thrombocytopenia based on their level of this negative paracrine of megakaryopoiesis. Disclosures: No relevant conflicts of interest to declare.

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Platelet Factor 4 Regulates Platelet Count In Vivo: Implications for Platelet Recovery after Cytotoxic Therapy.

Blood ◽

10.1182/blood.v106.11.3144.3144 ◽

2005 ◽

Vol 106 (11) ◽

pp. 3144-3144

Author(s):

Michele P. Lambert ◽

M. Anna Kowalska ◽

Mortimer Poncz

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Mononuclear Cells ◽

Physiological Role ◽

Platelet Factor 4 ◽

Cytotoxic Therapy ◽

Platelet Factor ◽

Platelet Recovery ◽

Platelet Counts

Abstract Platelet factor 4 (PF4), a platelet-specific CXC chemokine, was the first reported negative autocrine regulator of megakaryopoiesis in vitro. To define the physiological role(s) of PF4, we established mice that either were deficient in murine (m) PF4 (mPF4−/−) or that over-expressed human (h) PF4 (hPF4+/+). These mice had a level of PF4 ~6-fold greater than that present in human platelet controls. All lines studied had been backcrossed onto a C57Bl/6J background for >10 generations. Platelet counts in these animals correlated inversely with PF4 determined expression, beginning with a low platelet count of 702 ± 57 x 103/μL in the hPF4+/+ mice < hPF4+ < wildtype (WT) < mPF4+/− < mPF4−/− mice in which the platelet count was 1,404 ± 117 x 103/μL. The half-life of the platelets from the hPF4+/+ was identical to that of WT mice. Cultured bone marrow mononuclear cells (BMMNC) in serum-free media showed that each line had identical efficiency in growing megakaryocyte colonies, suggesting that megakaryocyte progenitor cells in these different genetic lines were intrinsically normal. Megakaryocyte colony numbers derived from WT BMMNC were reduced by the addition of recombinant PF4 or supernatant from irradiated bone marrow of hPF4+ mice, but not from mPF4−/− mice, suggesting that megakaryocyte lysis in vivo during cytoreductive therapy may contribute to the subsequent thrombocytopenia by releasing PF4. Additionally, a rabbit polyclonal anti-mPF4 antibody (Ab) was able in culture to significantly reverse this inhibitory effect of PF4 on megakaryopoiesis. Preliminary cytoreductive studies using either 600 cGy or 150 mg/kg of 5-fluorouracil (5-FU) intraperitoneally (IP) were performed. In irradiation studies, mPF4−/− mice began to recover on the same day as WT littermates, but they clearly had higher platelet counts at their nadir, with a drop to only 42 ± 7% of baseline vs. 32 ± 6% in the WT mice (n =12 in each arm, p = 0.06). By Day 13, 9 of 12 mPF4−/− mice had recovered to >75% of baseline, while only 3 of 12 WT mice had recovered (p <0.001). hPF4+ mice (n = 7) were studied after 5-FU treatment. Compared to WT littermates (n = 9), the hPF4+ recovered later (15.6 ± 2.2 vs. 11.2 ± 1.5 days, p < 0.0003), and clearly had significantly greater drop to 30 ± 6% vs. 56 ± 9% of baseline (p < 0.00001). By day 15, all of the WT mice had recovered, but only 43% of hPF4+ mice had returned to >75% of baseline platelet count (p = 0.009). To examine if anti-mPF4 Ab was protective of cytotoxic therapy-induced thrombocytopenia, WT mice were treated with 180 mg/kg of 5-FU and were given either anti-mPF4 Ab (25 mg/kg, IV, x 2) or an equal volume of vehicle. By day 5, the Ab-treated group had a platelet count of 45 ± 6% vs. 32 ± 4% in the untreated (n > 13 per arm, p = 0.015). Platelet counts remained higher in the Ab-treated arm throughout the study. By day 10 after intervention, 9 of 16 mice of the Ab-treated arm had platelet counts over 75% of the baseline, while only 3 of 13 control mice did (p < 0.001). Thus, it appears that PF4 is an important negative autocrine regulator of platelet count in vivo. Excessive release of PF4 following cytotoxic therapy may be a mediator of treatment-related thrombocytopenia. Strategies directed to alleviate the consequence of released PF4 may have clinical benefit in ameliorating this thrombocytopenia.

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The Abrogated Thrombopoietin (TPO) Signal Transduction In Pediatric Patients Suffering From Thrombocytopenia-Absent Radii Syndrome Is Restored In Adult Patients, Suggesting An Additional, c-Mpl-Jak2-Independent Mechanism for Platelet Biogenesis.

Blood ◽

10.1182/blood.v116.21.1561.1561 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1561-1561

Author(s):

Janine Fiedler ◽

Gabriele Strauss ◽

Martin Wannack ◽

Silke Fleischhauer ◽

Kerstin Seidel ◽

...

Keyword(s):

Signal Transduction ◽

Bone Marrow ◽

Platelet Count ◽

Pediatric Patients ◽

Precursor Cells ◽

Adult Patients ◽

Negative Regulator ◽

Healthy Children ◽

Comparable Amount ◽

Platelet Counts

Abstract Abstract 1561 Thrombocytopenia-absent radii syndrome (TARS) is a rare congenital disorder defined by low platelet count and bilaterial aplasia of radii. Additionally, patients have perinatal eosinophilia and leukocytosis and are often anemic during the first years of life. At this time, a moderate, but enigmatic increase in platelet counts has been described, but patients remain thrombocytopenic and eventually continue to suffer from severe episodes of bleeding. Megakaryocytes, the immediate precursor cells of platelets, are scarce in the bone marrow and precursor cells fail to produce megakaryocytic colonies in response to thrombopoietin (TPO). Recently, we demonstrated that all TARS patients harbor a microdeletion on chromosome 1q21 which spans 120–200 kb, comprising 12–18 annotated genes. The deletion is also present in some unaffected parents (carriers) indicating that it is essential but not sufficient for generating the TARS phenotype. We analyzed 158 platelet counts of 33 patients over time and found that platelets increase within 2 years of life in most of our patients, but even in adult patients counts do not reach the lower norm. Thus, we performed an extended analysis of TPO signal transduction in platelets from 20 TARS patients. Overall, Jak2 kinase - despite being expressed in comparable amount - does not become phosphorylated in response to TPO when patients were below age 20, confirming our previous results also performed on young patients. Intriguingly, in platelets isolated from patients over age 20, Jak2 did become phosphorylated. As TPO activates several distinct pathways, we looked for the consequences of this bipartite TPO-responsiveness, including the activation of the alternate januskinase Tyk2, the STAT, the MAPK/ERK, and the Akt pathways. As expected, when Jak2 was not phosphorylated, Tyk2 and all downstream pathways were inactive. In contrast, in the presence of phosphorylated Jak2 (pJak2), all downstream pathways were activated, emphasizing the key role of Jak2 for TPO responsiveness. Platelets from either 20 healthy children or 11 carriers showed normal TPO signaling, excluding that the effect was due to a general age-dependence or a mere consequence of the microdeletion. Densitometric analyses confirmed our overall visual results. Expression levels of the TPO-receptor c-Mpl was not altered in 2 young and 2 adult patients compared to carriers, healthy children and adult controls, arguing against a compensatory upregulation in older patients. Furthermore, we sequenced all coding regions of Jak2 mRNA derived from patient-derived lymphoblastic cell lines (LCL) of one young and one adult patient and could not find any mutations. As bone marrow biopsies are typically not performed, changes in bone marrow cellularity or composition are not directly accessible. Recently, the immature platelet fraction (IPF) has been considered a surrogate marker for megakaryopoiesis. Interestingly, while there was no correlation between platelet count and IPF in 16 patients with TARS, we found a negative correlation between IPF with age. In 9 pediatric patients IPF was elevated (4.6%) compared to the median of 100 pediatric controls (2.7%), while in 7 adult TARS patients the mean IPF was 2.4%. These data provide circumstantial evidence that changes in megakaryopoiesis might drive the change in platelet biogenesis and TPO signaling. Plasma levels of stromal derived factor 1, a chemokine that contributes to restore platelet production in the absence of functional TPO signaling, were within the normal range in 6 patients with TARS. Real-time analysis of mRNA expression in LCL of genes within the microdeleted region indicates comparable expression in 2 unaffected parents with 2 controls, while 3 patients and 2 carriers showed the expected reduced expression. This includes the expression of PIAS3, a negative regulator of the Jak-STAT pathway. PIAS3 protein level, however, was normal in platelet lysates of TARS patients, making a key function for thrombocytopenia in TARS unlikely. Taken together, our data show an unexpected age-dependent change in TPO-signaling in platelets of TARS patients. As this change occurs much later than the amelioration of platelet counts, we suggest that an unknown factor influences platelet biogenesis during childhood. Disclosures: No relevant conflicts of interest to declare.

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Conditional Knockout of LRP1 in Murine Megakaryocytes and Its Affects on Platelet Factor 4 Biology in Megakaryocytes

Blood ◽

10.1182/blood.v124.21.4150.4150 ◽

2014 ◽

Vol 124 (21) ◽

pp. 4150-4150

Author(s):

Michele P Lambert ◽

Liqing Xiao ◽

Mortimer Poncz

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Steady State ◽

Platelet Factor 4 ◽

Conditional Knockout ◽

Platelet Factor ◽

Paracrine Effects ◽

Animal Survival ◽

Count Recovery

Abstract We have previously shown that platelet factor 4 (PF4, CXCL4), which is synthesized almost exclusively by megakaryocytes undergoes release intramedullary after which it can undergo reuptake into alpha-granules, but also can be an important negative paracrine regulator of megakaryopoiesis, effecting platelet recovery post-radiation or chemotherapy. Animals that express high levels of human (h) PF4 in addition to their normal levels of murine (m) PF4 (hPF4+) have increased sensitivity to radiation- and chemotherapy-induced thrombocytopenia when compared to wild type (WT) mice or to mice that lack endogenous PF4 (mPF4-/-). Both PF4 reuptake and the negative paracrine effects are at least partially dependent upon the presence of low-density lipoprotein receptor related protein-1 (LRP1) on the surface of megakaryocytes as shown using shRNA suppression of megakaryocyte LRP1 levels. To further understand the role of LRP1 in megakaryopoiesis, we studied LRP1 expressed on primary megakaryocytes in murine models. Homozygous knockout for LRP1 constitutively is embryonically lethal and heterozygous deficiency of LRP1 is insufficient to have an observed effect on PF4 biology. We now established a megakaryocyte-specific knockout of LRP1 using a floxed LRP1 mouse previously described by Rohlman et al, mated to the Cre- PF4 promotor-driven Cre recombinase (Cre+) mice previously described by Tiedt et al. Megakaryocytes from mice that were LRP1fl/fl/Cre+ had no detectable LRP1 mRNA or LRP1 surface protein expression by flow cytometry, while LRP1fl/fl/Cre- mice were essentially identical to WT mice. Baseline platelet counts in LRP1fl/fl/Cre+ and LRP1fl/fl/Cre- mice did not different from each other, and there was no difference in bone marrow derived megakaryocyte ploidy. PF4 available in platelet releasate of LRP1fl/fl/Cre+ platelets was also significantly less than in LRP1fl/fl/Cre- platelets (208 ± 42 vs. 362 ± 47 IU/106 platelets, p=0.002) consistent with a role of LRP1 in PF4 reuptake into megakaryocytes in the steady-state and demonstrating that >42% of PF4 may be released during PF4 megakaryopoiesis and requires megakaryocyte LRP1 expression. In siru cultured LRP1fl/fl/Cre+ megakaryocytes exposed to exogenous hPF4 has a lower level of total PF4 levels than LRP1fl/fl/Cre- megakaryocytes (191 ± 7 vs. 236 ± 17 IU/106 cells, respectively (p=0.03)). A similar effect was seen in liquid bone marrow culture assays. Finally, while LRP1fl/fl/Cre+/hPF4+ mice had similar platelet count recovery after irradiation compared to LRP1fl/fl/Cre+/WT mice, treatment of these mice with a heparin-derivative (ODSH) shown to significantly improve platelet count recovery and animal survival in both WT and hPF4+ mice had no effect on either platelet count recovery or animal survival in animals that were also LRP1fl/fl/Cre+. These data demonstrate that nearly half of the total PF4 in megakaryocytes undergoes recycling in vivo and that LRP1 is important for this phenomenon in the steady-state. LRP1 is also important in the negative paracrine effect of PF4 in stress megakaryopoiesis though LRP1 may affect megakaryocyte biology by non-PF4-dependent pathways as well. Whether the two observations – PF4 uptake and negative paracrine effects – are mechanistically related or are distinct LRP1-dependent pathways now needs to be elucidated. Disclosures Xiao: ECRI Institute: Employment.

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Probability of Eventual CR After Course 1 of Induction Therapy for Newly-Diagnosed AML As a Function of Platelet and Neutrophil Recovery.

Blood ◽

10.1182/blood.v120.21.2598.2598 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2598-2598

Author(s):

Laura F Newell ◽

Hu Xie ◽

John M. Pagel ◽

Ravinder K Sandhu ◽

Pamela S Becker ◽

...

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Induction Chemotherapy ◽

Induction Therapy ◽

Blood Count ◽

Newly Diagnosed ◽

Platelet Recovery ◽

Platelet Counts ◽

Bone Marrow Blasts ◽

Count Recovery

Abstract Abstract 2598 Background: After initial induction chemotherapy for acute myeloid leukemia (AML), it is commonplace that reinduction or intensified therapy is not indicated if the bone marrow has <5% blasts, even despite persistently low neutrophil (ANC) and/or platelet counts. This practice suggests that complete remission (CR), i.e. ANC >1000/μl and platelet count >100,000/μl per standard criteria (Cheson BD, et al. J Clin Oncol. 1990;8(5):813-9), might still occur and that the lack of blood count recovery may not bear prognostic significance. However, the time to CR after the first induction has been shown to be inversely related to subsequent duration of disease-free survival (DFS) and survival (OS), independent of age, treatment, and cytogenetics (Estey EH, et al. Blood. 2000;95(1):72-7). Additionally, the level of ANC and platelet recovery at time of CR is prognostic, with significantly better DFS among patients with higher counts (Yanada M, et al. Leuk Res. 2008;32(10):1505-9). Newly-diagnosed AML patients often present with below normal neutrophil and platelet counts, suggesting that persistence of such cytopenias after induction may be a clinical indicator of minimal residual disease (MRD) in the marrow. We therefore examined whether blood count recovery affected the probability of subsequent CR in patients with <5% bone marrow blasts. Methods: We included 85 patients who, by day 21 or thereafter of induction therapy for newly-diagnosed AML, had not met blood count criteria for CR despite a bone marrow in the prior week with <5% blasts by morphology. Patients were classified by type of induction therapy based on cytarabine dosing. G-CSF was not systematically administered. Marrows were planned for day 21 after chemotherapy and/or weekly thereafter to assess for disease status and evidence of marrow recovery. Because patients were often managed as outpatients, counts and marrows were not uniformly available and thus “day 28” included days 21–28, “day 35” included days 29–35, etc. If a patient had more than one marrow evaluation after day 21, we included only the first one. Results: Overall cohort CR rate was 64%. Eventual CR rate was significantly affected by platelet count, with 44% eventual CR for patients with platelets <30,000, 66% CR for platelets 30,000–100,000, and 95% CR for platelets >100,000. The effect of ANC recovery on eventual CR was less dramatic, with an OR 0.4 (0.2–1.0, p=0.049), for ANC <0.1 vs. >0.1 in the univariate analysis. By day 28, patients with either ANC or platelet recovery were significantly more likely to obtain CR than patients with neither count recovery (89% vs. 51%), OR 8.05 (2.2–30, p=0.002). In the multivariate analysis, (a) lack of platelet recovery to >30,000 was associated with significantly lower incidence of CR, OR 0.26 (0.1–0.8, p=0.02), and was independent of cytogenetic risk, antecedent hematologic disorder, and induction regimen, and (b) there was a suggested association between earlier count recovery and CR (>28 days vs. day 21–28), OR 0.31 (0.1–1.0, p=0.051). Conclusion: Persistence of low peripheral blood counts, despite the presence of <5% bone marrow blasts, is predictive of low eventual CR rates after induction chemotherapy. These results suggest that initiation of further and possibly different therapy, rather than continued observation, should be investigated in this setting. Disclosures: Becker: Sanofi: Research Funding.

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A Novel Approach to the Assessment of Variations in the Human Platelet Count

Thrombosis and Haemostasis ◽

10.1055/s-0037-1613840 ◽

2000 ◽

Vol 83 (03) ◽

pp. 480-484 ◽

Cited By ~ 70

Author(s):

John James ◽

Dianne Brown ◽

Gordon Whyte ◽

Mark Dean ◽

Colin Chesterman ◽

...

Keyword(s):

Platelet Count ◽

Seasonal Variation ◽

Individual Variation ◽

Human Platelet ◽

First Report ◽

Platelet Counts ◽

Novel Approach ◽

Platelet Number ◽

Genetically Determined

SummaryThis is the first report of a method to assess the significance of numerical changes in the platelet count based upon a result exceeding the normal intra-individual variation in platelet numbers. Serial platelet counts from 3,789 subjects were analysed to determine the intra-individual variation in platelet numbers. A platelet count difference of 98 × 109/L in males was found to represent a change that would occur by chance in less than 1 in 1,000 platelet count determinations. Tables to determine the significance of platelet number variations, given N previous observations, are provided at two probability levels. The repeatability of the platelet count was calculated as 0.871 (males) and 0.849 (females) indicating that the heritability of platelet count is high and that the platelet count is predominantly genetically determined. A seasonal variation in platelet count was found with a ‘winter’ versus ‘summer’ difference of 5.10 × 109/L (males) and 5.82 × 109/L (females).

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Characteristics and Financial Impact of Potentially Inappropriate Platelet Transfusion in the Inpatient Hospital Setting

Blood ◽

10.1182/blood-2019-125949 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 2096-2096

Author(s):

Eric Mou ◽

Colin Murphy ◽

Jason Hom ◽

Lisa Shieh ◽

Neil Shah

Keyword(s):

Platelet Count ◽

Patient Care ◽

Platelet Transfusion ◽

Bypass Surgery ◽

Hospital Setting ◽

Financial Impact ◽

Platelet Counts ◽

Cardiac Bypass ◽

Platelet Defects ◽

Platelet Transfusions

Introduction Platelets are transfused prophylactically to prevent hemorrhage in a variety of patient populations. However, guidelines indicate that prophylactic platelet transfusions in patients with platelet counts above 50k/uL are usually not indicated, with notable exceptions including those undergoing neurological or cardiac bypass surgery. Common minor procedures such as paracentesis, central line placement, and lumbar puncture have been safely performed at platelet counts below 50k/uL. Despite this evidence, our institution incurred approximately 10 million dollars (USD) in direct platelet costs in 2017, with nearly 40% of platelet transfusions are occurring when the patient's platelet count exceeded 50k/uL. Given the significant financial impact of, and potential adverse effects associated with inappropriate platelet transfusion, we implemented a best practice advisory (BPA) in our electronic medical record (EMR) in order to better characterize patterns of platelet transfusion orders in patients with platelet counts >50k/uL. Methods An EMR-embedded BPA was activated in the inpatient hospital setting of a large, tertiary care academic medical center on May 1, 2019, and triggered whenever a platelet transfusion order was placed on an admitted patient whose most recent documented platelet count was >50k/ul. To inform the comparative impact of BPA alerts on provider behavior, alerts were randomized at the patient level to trigger either in standard or silent fashion. For standard alerts, the BPA appeared on-screen, informing the provider that their platelet transfusion order was potentially inappropriate and citing supportive evidence. Providers had the option of following or overriding the alert (Figure 1). In case of alert override, a pre-specified or free text justification was requested. Pre-specified options included upcoming neurosurgery, cardiac bypass surgery, known qualitative platelet defects, or patients taking antiplatelet drugs. Charge data were based on charges for platelet transfusion orders as listed in the hospital charge master. Results From May 1, 2019 to July 30, 2019, the alert fired 181 times (Figure 2). Alerts were silently triggered in 64 (35%) cases. Of the 117 active alerts, 23 (20%) were followed and 94 (80%) were overridden. The most common reasons for alert override included prophylactic transfusions ahead of non-cardiac and non-neurosurgical operations (18%), upcoming cardiac bypass surgery (18%), qualitative platelet defects (12%), active central nervous system (CNS) bleeding (12%), and active non-CNS bleeding (7%). The estimated cost savings associated with followed alerts was $18,170 USD. Discussion Our BPA was effective in reducing instances of platelet transfusion orders by 20% over a three-month period, translating to an estimated annual savings of nearly $70,000 USD in hospital charges. Conversely, the 80% alert override rate indicates that platelet transfusion in patients with platelet counts >50k/uL remains common, occurring in a variety of contexts. Potentially appropriate reasons for platelet transfusions included orders in the setting of cardiovascular bypass surgery, active CNS bleeding, or qualitative platelet defects, representing circumstances in which platelet thresholds are often set higher than 50k/uL. Alternatively, 25% of alert overrides occurred in potentially inappropriate contexts, including patients undergoing non-cardiovascular/non-neurosurgical procedures and patients with non-CNS active bleeding, settings where routinely targeting a platelet threshold >50k/uL is not supported by evidence. As a result of our study's randomized design, future directions include comparative analyses between patient care encounters in which alerts were silently versus visibly triggered, allowing for rigorous determination as to whether providers' interaction with our BPA influences subsequent rates of potentially inappropriate platelet utilization as compared to a control group. Overall, our findings show that platelets are frequently ordered in potentially inappropriate settings, and that reducing these orders imparts significant financial savings. These results provide an impetus for interventions directed at educating providers on appropriate platelet ordering practices, in order to further reduce unnecessary expenditures and optimize patient care. Disclosures No relevant conflicts of interest to declare.

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CD2 antigen expression on leukemic cells as a predictor of event-free survival after chemotherapy for T-lineage acute lymphoblastic leukemia: a Children's Cancer Group study

Blood ◽

10.1182/blood.v88.11.4288.4288 ◽

1996 ◽

Vol 88 (11) ◽

pp. 4288-4295 ◽

Cited By ~ 3

Author(s):

FM Uckun ◽

PG Steinherz ◽

H Sather ◽

M Trigg ◽

D Arthur ◽

...

Keyword(s):

Bone Marrow ◽

Acute Lymphoblastic Leukemia ◽

High Risk ◽

Lymphoblastic Leukemia ◽

Antigen Expression ◽

Leukemic Cells ◽

Event Free Survival ◽

Free Survival ◽

Cancer Group ◽

Standard Risk

Abstract We examined the prognostic impact of CD2 antigen expression for 651 patients with T-lineage acute lymphoblastic leukemia (ALL), who were enrolled in front-line Childrens Cancer Group treatment studies between 1983 and 1994. There was a statistically significant correlation between the CD2 antigen positive leukemic cell content of bone marrow and probability of remaining in bone marrow remission, as well as overall event-free survival (EFS) (P = .0003 and P = .002, log-rank tests for linear trend). When compared with patients with the highest CD2 expression level (> 75% positivity), the life table relative event rate (RER) was 1.22 for patients with intermediate range CD2 expression level (30% to 75% positivity) and 1.81 for “CD2-negative” patients (< 30% positivity). At 6 years postdiagnosis, the EFS estimates for the three CD2 expression groups (low positivity to high positivity) were 52.8%, 65.5%, and 71.9%, respectively. CD2 expression remained a significant predictor of EFS after adjustment for the effects of other covariates by multivariate regression, with a RER of 1.47 for CD2- negative patients (P = .04). Analysis of T-lineage ALL patients shows a significant separation in EFS after adjustment for the National Cancer Institute (NCI) age and white blood cell (WBC) criteria for standard and high-risk ALL (P = .002, RER = 1.67). The determination of CD2 expression on leukemic cells helped identify patients with the better and poorer prognoses in both of these risk group subsets. For standard risk T-lineage ALL, CD2-negative patients had a worse outcome (P = .0007, RER = 2.92) with an estimated 5-year EFS of 55.9% as compared with 78.3% for the CD2-positive patients. Thus, CD2 negativity in standard risk T-lineage ALL identified a group of patients who had a worse outcome than high-risk T-lineage ALL patients who were CD2 positive. The percentage of CD2 antigen positive leukemic cells from T- lineage ALL patients is a powerful predictor of EFS after chemotherapy. This prognostic relationship is the first instance in which a biological marker in T-lineage ALL has been unequivocally linked to treatment outcome.

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Three-Drug Induction and BFM-Type Intensive Consolidation Chemotherapy for Treatment of Standard Risk Childhood Acute Lymphoblastic Leukemia Defined Also by DNA index. The Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) Study ALL-9501.

Blood ◽

10.1182/blood.v104.11.1951.1951 ◽

2004 ◽

Vol 104 (11) ◽

pp. 1951-1951

Author(s):

Maurizio Arico’ ◽

Valentino Conter ◽

Maria Grazia Valsecchi ◽

Marie France Pinta Boccalatte ◽

Elena Barisone ◽

...

Keyword(s):

Bone Marrow ◽

Acute Lymphoblastic Leukemia ◽

Lymphoblastic Leukemia ◽

Malignant Neoplasm ◽

Small Subset ◽

Unrelated Donor ◽

Minimal Risk ◽

Dna Index ◽

Standard Risk

Abstract In this study, we tried to select a very small subset of children with acute lymphoblastic leukemia (ALL) at minimal risk of treatment failure - identified to not only by early response in vivo, one of the strongest predictors in the I-BFM-SG experience, but also by age, blood count and in particular high DNA content - which we treated with a reduced-intensity BFM schedule. The AIEOP-ALL 9501 study enrolled patients with standard-risk (SR) ALL, defined as: <20,000 WBC/mm3, age 1 to <6 years, non-T immunophenotype, DNA index between 1.16 and 1.6, non t(9;22), no extramedullary leukemia, good response to prednisone (PGR, defined as <1,000/mmc blasts in the peripheral blood after 7 days of prednisone and one injection of IT-MTX), CR at the end of induction therapy. Follow-up was updated at December,31st 2003 and median follow-up was 5.9 years. Treatment consisted of a modified BFM schedule: 3-drug (VCR + PDN + Erwinia ASP), 43-day induction, no phase IB, 4x2 g/m2 MTX, reinduction with protocol II followed by 6MP+MTX continuation therapy up to 2 years; CNS directed therapy consisted of IT-MTXx18. Between May 95 and August 2000, 137 patients were identified as SR (7.8% of the ALL-95 population), of whom 102 received the SR protocol and are here reported.Of them, 1 died in remission of septicemia, and 1 had developed a second malignant neoplasm (T-ALL after initial B-lineage ALL); 11 patients relapsed (bone marrow, n=8; central nervous system, n=1; marrow + testis, n=1; eye, n=1) and their re-treatment included chemotherapy only (n=3, 1 dead) or plus bone marrow transplant (n=8) either autologous (n=2) or allogeneic from matched (n=4, 1 dead) or partially matched (n=2) unrelated donor. The remaining 89 are in first CR; the probabilities (and related standard errors) of survival and event-free survival (EFS) were 97.0% (1.7) and 86.7% (3.5) at 5 years, 95.3% (2.4) and 86.7% (3.5) at 7 years, respectively. There was no difference in the outcome between the 56 females [7 events, 7-yrs EFS, 87.3 (4.5)] and the 46 males [6 events, 85.9 (5.4)]. Although most of the relapsed patients were rescued, the long-term EFS in this small, very selected group of patients remains inferior to expectance. Thus, alternative selection criteria, for instance related to minimal residual disease as in current AIEOP-ALL 2000, should be considered in order to address the issue of treatment reduction.

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Intermittent Low Dose Interleukin 11 Can Lead to Transfusion Independence in Patients with Chronic Myelo-Monocytic Leukemia and Thrombocytopenia.

Blood ◽

10.1182/blood.v104.11.3939.3939 ◽

2004 ◽

Vol 104 (11) ◽

pp. 3939-3939

Author(s):

Chirag Shah ◽

Teresa C. Gentile

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Platelet Transfusion ◽

Low Dose ◽

Transfusion Requirement ◽

Bone Marrow Failure ◽

Monocytic Leukemia ◽

Significant Toxicity ◽

History Of ◽

Interleukin 11

Recombinant Interleukin- 11 (IL-11) is a thrombopoietic cytokine that stimulates megakaryocytopoiesis in vitro and platelet production in vivo. It attenuates post chemotherapy thrombocytopenia at a dose of 50 mcg/ kg/ day subcutaneously (SC). Unfortunately, prolonged administration is associated with significant toxicity including peripheral and pulmonary edema at this dose. Administration of low dose IL-11 at 10 mcg/kg/day SC has shown efficacy in bone marrow failure states without significant toxicity. We report two cases of chronic myelo-monocytic leukemia (CMML) with transfusion dependent thrombocytopenia who received intermittent low dose IL-11 without significant toxicity. Case Reports- Patient 1 is a 79-year-old male with history of CMML with pancytopenia of three years duration. Recently he required transfusion of platelets with his platelet counts falling to less than 15 x 109/L. His cytogenetic study showed normal karyotype, 46 XY. He required platelet transfusion at every 14 days. He initially was started on IL-11 at 10mcg/kg/day, 5 days per week.. His platelet count increased to above 30 x 109/L and he became transfusion independent within two weeks. Unfortunately on this schedule he developed edema and mild CHF. IL-11 was stopped for two weeks and upon resolution of toxicity, restarted at 10 mcg/kg/day on Monday, Wednesday and Friday. He has remained transfusion independent without recurrence of edema at 5 months on this schedule. Patient 2 was a 63-year-old male with previous history of chronic lymphocytic leukemia and diffuse large B cell lymphoma who developed CMML with severe pancytopenia. His karyotype was 46, XY, −7, +21. His platelet count was consistently less than 10 x 109/L. He required platelet transfusion twice a week. He was started on IL-11 at 10mcg/kg/day for 5 days per week, two weeks on and two weeks off. His platelet count increased to as high as 64 x 109/L after 2nd cycle. His platelet transfusion requirement decreased from every 3rd day to every 10th-14th day. He experienced no peripheral or pulmonary edema. Conclusion: Administration of low dose IL-11 in other bone marrow failure states has been reported but its use has not been described in CMML. Our observation in these 2 patients suggests that IL-11 has efficacy in CMML and is very well tolerated at low doses on an intermittent administration schedule. IL-11 may decrease the transfusion requirement in transfusion dependent patients. Further studies are needed to evaluate overall impact on larger number of patients who require regular platelet transfusion.

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Early Evaluation of Bone Marrow Minimal Residual Disease by Flowcytometry on Day 15 Is Feasible on a Multicenter Basis and Bears Strong Prognostic Value in Childhood Acute Lymphoblastic Leukemia. The AIEOP-BFM Experience.

Blood ◽

10.1182/blood.v110.11.1423.1423 ◽

2007 ◽

Vol 110 (11) ◽

pp. 1423-1423

Author(s):

Giuseppe Basso ◽

Giuseppe Gaipa ◽

Maria Grazia Valsecchi ◽

Marinella Veltroni ◽

Michael Dworzak ◽

...

Keyword(s):

Bone Marrow ◽

Acute Lymphoblastic Leukemia ◽

Lymphoblastic Leukemia ◽

Childhood Acute Lymphoblastic Leukemia ◽

Reference Laboratory ◽

Intermediate Risk ◽

Early Measurement ◽

Relapse Risk ◽

Standard Risk ◽

Risk Of Relapse

Abstract Early measurement of blast clearance is a relevant prognostic indicator in childhood acute lymphoblastic leukemia (ALL). To this purpose we measured, by four-colour flowcytometry (FC), the percentage of blast cells in bone marrow samples from Italian patients enrolled in the multicentre AIEOP-BFM ALL 2000 trial. Samples were collected on day 15 (after 14 days of steroids, and one dose of IT-MTX, vincristine, daunorubicine, asparaginase) and shipped overnight to the reference laboratory. The data were compared to PCR-MRD performed, by study design, on day +33 and +78 BM samples. We report the results of patients enrolled between December 2000 and October 2004. The 561 patients studied were not different from the remaining ones (with no available material) including their cumulative incidence of relapse (SE): 17.3% (1.9) vs. 18.1% (1.5) in 850 patients not studied. According to the results of FC-MRD, 5 groups were defined: negative (blast count <0.01%, n=143), <0.1% (n=94), <1% (n=149), 1–10% (n=119), >10% (n=56). Their cumulative 5-year risk of relapse was: 4.1% (1.9), 9.3% (4.0), 14.3% (3.2), 26.5% (5.5), 53.7% (7.4), respectively. By PCR-MRD, the same patients were stratified as follows: 177 were standard risk and had 5-year risk of relapse of 4.1% (1.7), 233 at intermediate risk had a relapse risk of 24.2% (3.4), 37 at high risk had a relapse risk of 58.1% (9); the remaining 124 patients (21.6%) were not stratified by PCR-MRD due to lack of 2 sensitive (≥10−4) markers. Of 177 patients classified as standard risk by PCR (double negative), 110 fell within the 2 subgroups with lower FC-MRD (<0.1%), 46 had <1%, 19 had <10%, only 2 >10% of blasts. Of the 233 patients stratified as PCR-MRD intermediate risk (d78 <10−3), FC-MRD related groups had the following probabilities of EFS: 93.5% (3.6; n=47), 83.3%(8.0; n=30), 80.5%(5.1; n=70), 66.5%(10.8; n=57), 39.2%(11.8; n=29). We conclude that very early measurement of FC-MRD on day 15 bone marrow is feasible in our multicentre cooperative setting. On the basis of our data we suggest the following risk groups: standard, when <0.1% blasts on day 15 BM; intermediate for 0.1 to <10%; high, for >10% blasts. These groups had a risk of relapse of 6.2% (1.9), 19.5% (3), and 53.7% (7.4), respectively. Since it is fast, reproducible, relatively cheap and applicable to virtually all patients, our group decided to apply it prospectively on all ALL patients to integrate PCR-based stratification. Our findings showed that: early (d15) MRD detection by FCM identifies different patients than PCR on d33 and d78; FCM may be very useful to identify earlier the highly sensitive ALL with low relapse risk (even though long-term follow-up is still missing), whereas later timepoints may be accessible for PCR and the identification of HR patients.

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