Differential Diagnosis of Hereditary and Acquired Thrombocytopenia By the Immature Platelet Fraction and Thrombopoietin Levels

Abstract Introduction: The differential diagnosis of hereditary and acquired thrombocytopenias can be challenging, especially when between immune thrombocytopenia (ITP) and less well characterized hereditary thrombocytopenias (HT) such as MYH9-related disorders. Fundamental differences in the management of these two conditions add clinical relevance to the search for novel parameters that differentiate these conditions. The immature platelet count (IPF) represents the fraction of platelets with higher RNA content, and in analogy to the reticulocyte count for erythropoiesis is a biomarker of thrombopoietic activity. In a recent report (Miyazaki et al, 2015), IPF values that were more than 5-fold higher than those observed in ITP patients were reported in a population of 15 patients with HT. However, whether this increased values represented a real increase in thrombopoietic activity, or reflected a technical limitation of IPF determination in large platelets could not be clarified. Here, we aimed to evaluate the role of IPF determination in the differential diagnosis between HT and several forms of acquired thrombocytopenia in a larger and more diverse population of patients. We also evaluated thrombopoietin (TPO) levels in HT compared to ITP, to further investigate the mechanisms by which extremely large IPF values are observed in HT. Methods: IPF and mean platelet volume (MPV) were prospectively determined using a Sysmex XE5000 hematologic analyzer (as part of the complete blood count) in a cohort of patients with post-chemotherapy thrombocytopenia (n=56), bone marrow failure (myelodysplastic syndromes and aplastic anemia; n=22), ITP (ITP; n=105) and inherited thrombocytopenias (n=27). The latter population consists of a well-defined cohort of individuals with HT thrombocytopenia characterized by clinical, familial, laboratory and molecular data. TPO levels were determined by ELISA (R&D Systems) in 21 HT patients and 22 ITP patients matched for platelet count and age. A group of 178 healthy volunteers were used to determine normal IPF and MPV values. Results: Median platelet counts were similar in post-chemotherapy patients (CTx) (32.0*109/L), bone marrow failure (BMF) (33.5*109/L), ITP (52.0*109/L) and HT (52.0*109/L) (P=0.15). Similar IPF levels were observed in CTx and BMF patients (5.6%; IQR 3.4-8.8% and 6.5%; IQR 3.5-13.7%. Compared to these two groups, higher IPF values were observed in both ITP (12.3%; 7.0-21.0%) and HT patients (29.8%; 17.5-56.4%) (both P values < 0.05). In addition, IPF were significantly higher in HT compared to ITP (Kruskall-Wallis test and Dunn's post test,P=0.001). MPV values were different between HT and CTx/BMF groups, but could not differentiate ITP from HT. TPO levels. The accuracy of IPF to discriminate HT from all other causes of thrombocytopenia estimated by ROC analysis was 0.88 (CI95%0.8-0.96, p<0.0001). Similar TPO levels were observed in platelet count-matched ITP, HT patients and healthy volunteers without thrombocytopenia. Interestingly, TPO presented marked correlations with both platelet count (Rs = - 0.61, P=0.002) and IPF (Rs= 0.59, P=0.003), even with TPO levels in the same range of healthy individuals. In contrast, no significant correlation could be observed between TPO and IPF or platelet count in HT patients. Conclusions: IPF represents an informative biomarker for the differential diagnosis of hereditary and acquired thrombocytopenias, and accurately differentiates ITP from the most common HT. As expected, TPO levels in patients with ITP were not higher than in individuals with normal platelets counts. The inverse correlation between TPO and platelet count in these patients confirm a blunted TPO response to thrombocytopenia in these patients. Similarly, patients with HT did not present increased TPO levels compared to healthy individuals. Accordingly, increased IPF levels in these patients cannot be attributed to higher TPO levels. Disclosures No relevant conflicts of interest to declare.

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Importance of Flow Cytometry in the Differential Diagnosis of Hairy Cell Leukemia in the State of Rio Grande Do Norte, Brazil

Blood ◽

10.1182/blood-2020-143225 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 14-15

Author(s):

Aldair Sousa Paiva ◽

Alessandra Suelen Jardim Silva ◽

Victor lima Soares ◽

Gustavo Henrique de Medeiros Oliveira ◽

Lenilton Silva DA Silva Júnior ◽

...

Keyword(s):

Bone Marrow ◽

Flow Cytometry ◽

Differential Diagnosis ◽

Peripheral Blood ◽

Complete Blood Count ◽

Conflicts Of Interest ◽

Specific Treatment ◽

Leukemic Cells ◽

Terminal Deoxynucleotidyl Transferase ◽

Cell Leukemia

Introduction:Hairy Cell Leukemia (HCL) is a B-cell non-Hodgkin's Lymphoma (B-NHL) representing about 2% of chronic leukemias, is manifested in adults with an average age of 55 years old or more and the ratio of male: female is 5:1, being more common among white people. It is characterized by the presence of neoplastic lymphocytes with cytoplasmic projections (villous cells), a characteristic commonly observed in other DLPCs such as variant HCL (HCL-v) and splenic villous cell lymphoma (SVCL), being the immunophenotyping by flow cytometry determinant in the differential diagnosis of these neoplasms. HCL is characterized by splenomegaly, hepatomegaly, pancytopenia in peripheral blood (PB) with leukopenia, anemia, neutropenia, monocytopenia, and thrombocytopenia. It has a low number of circulating tumor cells, spleen, liver, and bone marrow (BM) infiltration.Objective:To investigate, by flow cytometry, patients with lymphocytosis and presence of villous lymphocytes in the characterization of HCL and HCV-v and SMZL.Methodology:Were investigated samples of peripheral blood (SP) and bone marrow (MO) from 27 patients previously diagnosed with DLPC and presence of villous lymphocytes which were by flow cytometry with a panel of monoclonal antibodies (MoAb) conjugated to fluorochromes and targeted to T-lymphocytes: CD1a, CD2, CD3, CD5, CD7, subpopulation T-helper (CD3/CD4) and T-cytotoxic (CD3/CD8), in addition to TCR a/b and TCR g/d; Natural Killer cells: CD16-56; B-lymphocytes: CD19, CD20, CD21, CD22, CD23, CD79b, CD200, IgM, IgG, IgD, anti-kappa and anti-lambda, in addition to CD10, TdT (Terminal deoxynucleotidyl Transferase), CD103, CD123, CD11c, CD25, CD38, CD138, CD45 and CD14. At the same time, a complete blood count with differential white blood cell count and investigation of clinical and demographic data such as age, sex and ethnicity / race were also performed.Results:The distribution of patients according to ethnicity and gender, there was a predominance of white individuals and males. The age group most affected was in patients older than 60 years. All patients expressed pan-B antigens on leukemic cells with expression of CD19, CD22 / CD20 (Forte), sIgH, associated with clonal restriction for immunoglobulin light chain (kappa= 20 and lambda= 7), associated with FMC7 expression, HLADR, CD38 and CD45 strong and negativity to CD10, CD138, CD200, CD23, CD5, TdT and related T antigens. Sixteen cases were categorized as HCL, six HCLv and five SVCL. The immunophenotyping of HCL cases was positive for CD103, CD25, CD123 and CD11c. HCLv was negative for CD103 in three cases and CD25 and SVCL negative for CD103, CD123 and CD11c and CD25 in all cases.Conclusions:The precise diagnosis of HCL has fundamental importance because each NHL-B has a specific treatment, besides emphasizing the sensitivity and speed of the IFC regarding diagnosis and follow-up. Disclosures No relevant conflicts of interest to declare.

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Can Immature Platelet Fraction (IPF) be Used to Assess Bleeding Risk in Pediatric Immune Thrombocytopenia (ITP) and to Differentiate ITP from Bone Marrow Failure/Aplastic Anemia? A Retrospective Analysis

Blood ◽

10.1182/blood.v126.23.3474.3474 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3474-3474 ◽

Cited By ~ 1

Author(s):

Karen Lee Bride ◽

Derick Lim ◽

Michele Paessler ◽

Michele P Lambert

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Immune Thrombocytopenia ◽

Bone Marrow Failure ◽

Bleeding Risk ◽

Medical Laboratory ◽

Bleeding Complications ◽

Severe Thrombocytopenia ◽

Immature Platelet Fraction ◽

Time Of Presentation

Abstract Immune Thrombocytopenia (ITP) usually presents with isolated, severe thrombocytopenia with very low platelet count (generally less than <30 x 109/L) in the absence of other hematologic abnormalities. However, ITP is a diagnosis of exclusion without any definite diagnostic test that can confirm the diagnosis at the time of presentation and clinicians occasionally worry at the time of presentation about other bone marrow processes that may present with thrombocytopenia, which would require considerably different therapy. In light of current guidelines suggesting that observation is likely to be safe in pediatric patients with low platelet counts without significant bleeding, identifying patients at risk for severe hemorrhage is even more important to help guide therapy. In addition, appropriately differentiating ITP from other diagnoses may also prevent inappropriate administration of ineffective therapies. The immature platelet fraction (IPF) is a measure of platelet turnover measuring RNA containing, large platelets by fluorescently labeling the platelets and utilizing flow cytometric gates programmed into the Sysmex XN-3000 hematology analyzer. We examined the medical laboratory records of 134 patients who had an IPF performed over the past 4 months for correlation between IPF and bleeding manifestations. In ITP patients who presented with significant bleeding symptoms (defined as epistaxis which was more than brief, oral bleeding more than palatal petechiae or GI or intracranial hemorrhage), the IPF was significantly lower than in those who presented with no bleeding or cutaneous bleeding only (bruising and petechiae): IPF=4.3%±1.6 SEM in bleeding patients versus 21.8%±1.8 SEM in not bleeding patients; p<0.0001. In two patients with life threatening hemorrhage and ITP (GI bleeding with drop in hemoglobin requiring both PRBC transfusion and treatment to raise the platelet count; ICH resulting in mortality), the IPF was low at the time of initial hemorrhage, but increased after ITP therapy (GI Bleed: plt 1K, IPF 5.3% increased to 20.3% after IVIG; ICH plt 6K, IPF 1.8% increased to 12.8% after IVIG and prednisone). We also examined first platelet count and IPF in 127 patients with ITP and 21 patients with BMF/AA who presented to our institution since October 2013. In this cohort of patients, the IPF in patients with ITP was significantly higher than in the BMF/AA patients and an IPF of >5.3 was associated with a negative predictive value of 80% for BMF/AA (IPF 16.6%±1.2 SEM in ITP vs. 2.9%±1.4 SEM in BMF/AA). In summary, we demonstrate that the IPF is a useful and simple adjunct in diagnosis of ITP which can help differentiate the patients most likely to have ITP from those who may need further diagnostic evaluation and require treatment to prevent bleeding complications. Further studies will focus on the ability of the IPF to prospectively predict the bleeding risk of patients and categorize patients. Disclosures Lambert: GSK: Consultancy; NovoNordisk: Honoraria; Hardin Kundla McKeon & Poletto: Consultancy.

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Diamond-Blackfan Anemia: Erythropoiesis Lost in Ribosome Biosynthesis

Blood ◽

10.1182/blood.v118.21.sci-2.sci-2 ◽

2011 ◽

Vol 118 (21) ◽

pp. SCI-2-SCI-2

Author(s):

Stefan Karlsson ◽

Johan Flygare ◽

Pekka Jaako ◽

David Bryder

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Molecular Mechanisms ◽

Conflicts Of Interest ◽

Bone Marrow Failure ◽

Macrocytic Anemia ◽

Hematopoietic Progenitors ◽

Hematopoietic Stem ◽

Diamond Blackfan Anemia

Abstract Abstract SCI-2 Diamond-Blackfan anemia (DBA) is a rare congenital erythroid hypoplasia that presents early in infancy. The classic hematologic profile of DBA consists of macrocytic anemia with selective absence of erythroid precursors in a normocellular bone marrow, normal or slightly decreased neutrophil, and variable platelet count. During the course of the disease some patients show decreased bone marrow cellularity that often correlates with neutropenia and thrombocytopenia. DBA is a developmental disease since almost 50% of the patients show a broad spectrum of physical abnormalities. All known DBA disease genes encode for ribosomal proteins that collectively explain the genetic basis for approximately 55% of DBA cases. Twenty-five percent of the patients have mutations in a gene encoding for ribosomal protein S19 (RPS19). All patients are heterozygous with respect to RPS19 mutations suggesting a functional haploinsufficiency of RPS19 as basis for disease pathology. Despite the recent advances in DBA genetics, the pathophysiology of the disease remains elusive. Cellular studies on patients together with successful marrow transplantation have demonstrated the intrinsic nature of the hematopoietic defect. DBA patients have a variable deficit in burst-forming unit-erythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) progenitors. The frequency of immature hematopoietic progenitors in DBA patients is normal but their proliferation is impaired in vitro. Generation of animal models for RPS19-deficient DBA is pivotal to understand the disease mechanisms and to evaluate novel therapies. Several DBA models have been generated in mice or zebrafish. Although these models have provided important insights on DBA, they are limited in a sense that the hematopoietic phenotype and molecular mechanisms are likely to be influenced by the level of RPS19 downregulation. We have generated mouse models for RPS19-deficient DBA by taking advantage of transgenic RNAi. These models are engineered to contain a doxycycline-regulatable RPS19-targeting shRNA, allowing a reversible and dose-dependent downregulation of RPS19 expression. We demonstrate that the RPS19-deficient mice develop a macrocytic anemia together with leukocytopenia and variable platelet count and the severity of the phenotype depends on the level of RPS19 downregulation. We show further that a chronic RPS19 deficiency leads to irreversible exhaustion of hematopoietic stem cells and subsequent bone marrow failure. Overexpression of RPS19 following gene transfer rescues the proliferative and apoptotic phenotype of RPS19-deficient hematopoietic progenitors in vitro, demonstrating that the phenotype is specifically caused by the RPS19 deficiency. Expression analysis of RPS19-deficient hematopoietic progenitors reveals an activation of the p53 pathway. By intercrossing the DBA mice with p53 null mice we demonstrate that inactivation of p53 in vivo results in a variable rescue of the hematopoietic phenotype depending on the level of RPS19 downregulation. Therefore, we conclude that increased activity of p53 plays a major role in causing the DBA phenotype but that other hitherto unidentified pathways also play a role, specifically in patients that have low levels of functional RPS19. Disclosures: No relevant conflicts of interest to declare.

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Splenectomy in a Child of X-Linked Thrombocytopenia with Thalassemia and Bone Marrow Fibrosis : Hemoglobin and Platelet Count Were Improved

Blood ◽

10.1182/blood.v124.21.1367.1367 ◽

2014 ◽

Vol 124 (21) ◽

pp. 1367-1367

Author(s):

Yang Wan ◽

Xiaofan Zhu ◽

Xiaojuan Chen ◽

Wenbin An ◽

Peihong Zhang ◽

...

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Bone Marrow Biopsy ◽

Peripheral Blood ◽

Clinical Characteristics ◽

Blood Count ◽

Complete Blood Count ◽

Conflicts Of Interest ◽

Bone Marrow Fibrosis ◽

Marrow Fibrosis

Abstract X-linked thrombocytopenia with thalass emia (XLTT)(OMIM 314050)was first described by Thompson in 1977(Thompson et al. J Blood 1977 50(2):303-16). This rare inherent disorder was caused by a nucleotide change G>A at position 647, which leads to an amino acid substitution of arginine to glutamine (R216Q) in the gene of GATA-1 on the band p11-12 ohuman X chromosome(Raskind et al. Blood 2000, 95(7):2262-8 ;Yu et al.J Blood 2002,100(6): 2040-2045). GATA-1, belonging to the GATA family of transcription factors plays a crucial role in the development of several hematopoietic cell lines ( Ferreira et al. J Mol Cell Biol 2005,25(4): 1215-1227) . The missense mutation(R216Q) in XLTT affects GATA-1 binding to palindromic DNA sites (Yu et al.J Blood 2002,100(6): 2040-2045). The clinical characteristics of XLTT are mild thrombocytopenia, splenomegaly, reticulocytosis, hemolytic anemia and unbalanced hemoglobin (Hb) chain synthesis resembling ¦Â-thalassemia (Raskind et al. Blood 2000, 95(7):2262-8 ; Balduini et al. J Thromb Haemost 2004, Jan;91(1):129-40). About 7 families of XLTT were reported before (Millikan et al.J Semin Thromb Hemost 2011,37(6): 682-689; Danielsson et al. J Lakartidningen 2012 ,109(34-35): 1474-1477).Bone marrow fibrosis is described only in tow Swedish families ( Danielsson et al. J Lakartidningen 2012 ,109(34-35): 1474-1477).But there is limited data about the treament and prognosis of the diesase. Here we describe the full clinical characteristics of a boy of XLTT who was treated by splenectomy. The patient was first admitted at the age of 1year and 8 months in 2011.The chief complain was skin petechia and pale for more than one month. The boy had lower weight but no visible malformation. Feeding difficult and lag of language development were also complained.His Liver was 2.3cm below the right ribs and spleen was 3.2cm below the left. Peripheral blood count showed hemoglobin 8 g/dL, MCV76.7fl, MCH21.8 pg,MCHC284 g/L and reticulocyte count 0.1764¡Á1012/L. Peripheral blood smear demonstrated marked anisopoikilocytosis, polychromasia and nucleated RBCs.Platelet count was 64¡Á109/L with normal morphology.Wight blood cell was normal in number and morphology.elevated to 0.226(normal range 0-0.025) while HBA2 and hemoglobin electrophoresis was normal. Bone marrow biopsy and aspirate smear revealed a hypercellular marrow with dysplasia of erythrocyte series and megakaryoblasts (Figure 1 A). Polynuclear erythroblast ,micromegakaryocytes and hypolobated megakaryocytes could be easily seen (Figure 1 B). Fibrosis proliferation was obvious (Figure 1 A). Genetic analysis discovered a mutantion of GATA-1(R216Q)and excluded mutations of hemoglobin gnens and JAK-2. Patient was treated with dexamethasone and thalidomide which got little effect. The baseline hemoglobin was 6-8 g/dL.Platelet count ranged from 30 to 70¡Á109/L. Splenectomy was done at the age of 5years and 4 months because of constantly RBC transfusion and splenomegaly. Fibrosis proliferation and extramedullary hematopoiesis in spleen were proved by biopsy (Figure 1 C,D).The boy's complete blood count was recovered 4 months after splenectomy. Hemoglobin rose to11.6 g/dL and platelet count was 337¡Á109/L. HBF was still high at 0.226. Multifocal fibrosis proliferation still existed in bone marrow biopsy but with no myelodysplasia (Figure 1 E,F). Hepatomegaly didn't progress. He has good quality of life,and normal growth and intelligence development. Splenectomy can be a therapeutic strategy of X-linked thrombocytopenia with thalassemia. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

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Measurement of the Absolute Immature Platelet Number Reflects Marrow Production and Is Not Impacted by Platelet Transfusion

Blood ◽

10.1182/blood.v120.21.3425.3425 ◽

2012 ◽

Vol 120 (21) ◽

pp. 3425-3425

Author(s):

Taha Bat ◽

Susan F. Leitman ◽

Katherine R Calvo ◽

Donna Chauvet ◽

Cynthia E. Dunbar

Keyword(s):

Bone Marrow ◽

Platelet Transfusion ◽

Conflicts Of Interest ◽

Bone Marrow Failure ◽

High Dose Chemotherapy ◽

High Dose ◽

Immature Platelet Fraction ◽

Platelet Number ◽

The Impact

Abstract Abstract 3425 Background The ability to distinguish increased platelet destruction from platelet hypo-production is important in the care of patients with bone marrow failure syndromes and patients receiving high dose chemotherapy. The measurement of immature circulating platelets based on RNA content using an automated counter is now feasible. This study evaluated the impact of recent platelet transfusion on measurement of immature platelet parameters. Study Design and Methods The immature platelet fraction (IPF) and absolute immature platelet number (AIPN) were measured using the Sysmex XE-5000 analyzer prior to and following platelet transfusion in 9 transfusion-dependent patients with marrow failure secondary to aplastic anemia, myelodysplasia or transplantation conditioning. IPF and AIPN were also measured serially over 5 days of storage in 3 plateletpheresis components collected from normal donors. Results Platelet transfusion did not significantly change the mean AIPN in transfused patients. In contrast, IPF decreased significantly from 6.6 ±4.6% at day -1 to 2.3 ±1.4% at day 0 before returning to 4.3 ±2.3% at day +1. In the platelet component, AIPN and IPF% increased significantly over 5 days of storage, most likely due to an artifact of the staining and detection process for stored platelets, no longer detected in vivo once the platelets were transfused. Conclusion Platelet transfusion decreases the IPF due to the resultant increase in circulating platelet count. However, platelet transfusion does not change the circulating absolute immature platelet number (AIPN), validating this assay as a reflection of ongoing platelet production by the bone marrow in various clinical settings, regardless of proximity to platelet transfusion. Disclosures: No relevant conflicts of interest to declare.

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Ethylenediaminetetraacetic Acid‑Dependent Pseudothrombocytopenia in Patient Previously Treated as Dengue Fever

Berkala Kedokteran ◽

10.20527/jbk.v17i1.10250 ◽

2021 ◽

Vol 17 (1) ◽

pp. 65

Author(s):

Hendra Wana Nur’amin ◽

Muhammad Darwin Prenggono ◽

Wivina Riza Devi

Keyword(s):

Bone Marrow ◽

Platelet Count ◽

Dengue Fever ◽

Complete Blood Count ◽

Ethylenediaminetetraacetic Acid ◽

Bone Marrow Aspiration ◽

Normal Platelet ◽

Low Platelet Count ◽

Bleeding Manifestation ◽

Secondary Hospital

Abstract: One of the most widely used anticoagulants for a complete blood count is ethylenediaminetetraacetic acid (EDTA). Pseudothrombocytopenia (PTCP) may be caused by EDTA, this condition may lead to inappropriate diagnosis and treatment. We report a 25-year-old female with unspecific headache and joint pain with very low platelet count since 1 month before hospital admission. She was diagnosed with Dengue fever infection and got some platelet transfusion from the previous secondary hospital. She was carried out for a blood test with another anticoagulant (sodium citrate) and bone marrow aspiration. The results showed that she had normal platelet count and bone marrow cellularity. When a patient was identified with thrombocytopenia without any bleeding manifestation, hematology disease, and family history, PTCP should be taken into consideration to prevent unnecessary intervention. Keywords: platelet, pseudothrombocytopenia, ethylenediaminetetraacetic acid, Dengue fever

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New Bone Marrow Failure Genes: DNAJC21 and ERCC6L2

Blood ◽

10.1182/blood.v130.suppl_1.sci-22.sci-22 ◽

2017 ◽

Vol 130 (Suppl_1) ◽

pp. SCI-22-SCI-22

Author(s):

Inderjeet Dokal

Keyword(s):

Bone Marrow ◽

Dna Damage ◽

Nuclear Export ◽

Conflicts Of Interest ◽

Excision Repair ◽

Bone Marrow Failure ◽

Retinal Dystrophy ◽

Ribosomal Subunit ◽

Genotoxic Stress ◽

Biallelic Mutations

A significant number of cases with bone marrow failure present with one or more extra-hematopoietic abnormality. This suggests a constitutional or genetic basis, and yet many of them remain uncharacterized. Through exome sequencing, we have recently identified two sub groups of these cases, one defined by germline biallelic mutations in DNAJC21 (DNAJ homolog subfamily C member 21) and the other in ERCC6L2 (excision repair cross complementing 6 like-2). Patients with DNAJC21 mutations are characterized by global bone marrow failure in early childhood. They can also have a variable number of extra-hematopoietic abnormalities such as short stature and retinal dystrophy. The encoded protein associates with ribosomal RNA (rRNA) and plays a highly conserved role in the maturation of the 60S ribosomal subunit. Lymphoblastoid patient cells exhibit increased sensitivity to the transcriptional inhibitor actinomycin D and reduced levels of rRNA. Characterisation of mutations has revealed impairment in interactions with cofactors (PA2G4, HSPA8 and ZNF622) involved in 60S maturation. DNAJC21 deficiency results in cytoplasmic accumulation of the 60S nuclear export factor PA2G4, aberrant ribosome profiles and increased cell death. Collectively these findings demonstrate that biallelic mutations in DNAJC21 cause disease due to defects in early nuclear rRNA biogenesis and late cytoplasmic maturation of the 60S subunit. Patients harbouring biallelic ERCC6L 2 mutations are characterized by bone marrow failure (in childhood or early adulthood) and one or more extra-hematopoietic abnormality such as microcephaly. Knockdown of ERCC6L2 in human cells significantly reduces their viability upon exposure to the DNA damaging agent irofulven but not etoposide and camptothecin suggesting a role in nucleotide excision repair. ERCC6L2 knockdown cells and patient cells harbouring biallelic ERCC6L2 mutations also display H2AX phosphorylation that significantly increases upon genotoxic stress, suggesting an early DNA damage response. ERCC6L2 is seen to translocate to mitochondria as well as the nucleus in response to DNA damage and its knockdown induces intracellular reactive oxygen species (ROS). Treatment with the ROS scavenger, N-acetyl-cysteine, attenuates the irofulven-induced cytotoxicity in ERCC6L2 knockdown cells and abolishes its traffic to mitochondria and nucleus in response to this DNA damaging agent. Collectively, these observations suggest that ERCC6L2has a pivotal rolein DNA repair and mitochondrial function. In conclusion, ERCC6L2 and DNAJC21 have an important role in maintaining genomic stability and ribosome biogenesis, respectively. They bring into focus new biological connections/pathways whose constitutional disruption is associated with defective hematopoiesis since patients harbouring germline biallelic mutations in these genes uniformly have bone marrow failure. Disclosures No relevant conflicts of interest to declare.

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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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The Immature Platelet Fraction in HIV Patients with Thrombocytopenia.

Blood ◽

10.1182/blood.v110.11.2095.2095 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2095-2095

Author(s):

Brian T. Garibaldi ◽

Rupal B. Malani ◽

Hsin-Chieh Yeh ◽

Deborah Michell ◽

Evan J. Lipson ◽

...

Keyword(s):

Diabetes Mellitus ◽

Bone Marrow ◽

Platelet Count ◽

Peripheral Blood ◽

Reticulocyte Count ◽

Control Group ◽

P Value ◽

Hiv Patients ◽

Immature Platelet Fraction ◽

The Mean

Abstract Thrombocytopenia is a common clinical feature of HIV infection. Given the number of possible etiologies of thrombocytopenia in a patient with known HIV, a peripheral blood test effective in determining the likely pathophysiologic basis of the thrombocytopenia would be a valuable clinical tool. Immature platelets are released early from the bone marrow in response to increased platelet turnover. These platelets contain residual megakaryocyte mRNA and have been termed reticulated platelets. A new assay, the Immature Platelet Fraction (IPF), measures the reticulated platelet count in peripheral blood. Patients with increased destruction of platelets from such conditions as ITP consistently have a higher IPF percent, while patients with decreased platelet production have a low or normal IPF percent. The goal of our study was to determine the performance characteristics of the IPF assay in HIV patients with thrombocytopenia and to see if the IPF percent could be used to help elucidate the etiology of low platelet counts in this group of patients. All adult patients admitted to the Johns Hopkins Hospital with a diagnosis of HIV and a platelet count less than 150,000 were eligible for enrollment. 62 patients were identified from February 2007 to June 2007. 34 control samples were obtained from inpatients with HIV who were not thrombocytopenic. In addition, 81 samples were available from non-HIV historical controls with normal platelet counts. The mean platelet count in the HIV thrombocytopenic group was 92,000 while the mean platelet count in the HIV control group was 254,000 (p value <.001). The mean platelet count in the non-HIV historical control group was 274 (p=.34 when compared to the HIV control group). The mean IPF percent in the HIV thrombocytopenic group was 10.2% as compared to 6.8% in the HIV control group (p=.001). The mean IPF in historical non-HIV controls was 3.1% (p<.001 for both the HIV thrombocytopenic and the HIV control group). Univariate analyses were conducted to identify potential individual predictors of a high IPF percent. Backward selection was then performed using multivariate linear models with a threshold Wald test p-value of 0.05. ITP, diabetes mellitus and cirrhosis were significantly associated with a higher IPF percent with a co-efficient (95% confidence interval) of 6.98 (3.05–10.91), 4.73 (1.39–8.06), and 14.18 (9.7–18.66), respectively. CD4 count, HIV viral load, hepatitis C and reticulocyte count were not correlated with IPF percent. Our results suggest that patients with HIV have increased platelet turnover as compared to patients without HIV. Thrombocytopenic patients with HIV have increased platelet turnover relative to both non-thrombocytopenic HIV patients and to historical non-HIV controls. History of ITP, diabetes mellitus, and cirrhosis are predictive of an elevated IPF percent. Reticulocyte count is not correlated to IPF percent, suggesting that a low reticulocyte count is not a reliable marker for decreased bone marrow production in HIV thrombocytopenia. It is unlikely that the IPF assay alone can be used to determine the pathophysiologic basis of thrombocytopenia in any single patient with HIV. Further work needs to be done to clarify the utility of the IPF assay in this group of patients.

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

Blood ◽

10.1182/blood.v114.22.1091.1091 ◽

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.

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