Nationwide Children s Hospital

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1 Implementing IPF and RET He: Clinical Applications in a Pediatric Setting Gretchen Dennis MT(ASCP) cm, MLS(ASCP) Technical Specialist Routine Hematology Nationwide Children s Hospital 1

2 We have been growing! The nation's largest pediatric expansion officially opened for business on June 20, 2012 Our new, 12 story main hospital adds 750,000 square feet of clinical space a third research building adds 225,000 square feet of research space Focus on Family Centered Care The Magic Forest "A magnificent distraction," Columbus Monthly 2

3 Many unique challenges faced by pediatric institutions Small Sample Volume ~75% samples for CBC with differential come in microtainers, or bullets uL average draw volume received. Can not run in automated mode on analyzers. Samples often shared between multiple departments. Samples usually QNS for add on testing. Iatrogenic anemia always concern. 3

4 Sample Integrity Sample collection can be very challenging. Capillary collection frequently performed. Many samples received clotted or contaminated. Do not have extra sample for trouble shooting or investigation of questionable results. Establishing Reference Ranges Pediatric ranges often different from commonly used adult ranges. Can be a lot of biological variation seen in values throughout childhood. Example: Reticulocyte reference ranges (Birth to 15 Year) Age Range Age Range 0D D D D D D D D D D D D D D D M D M D Y M Y

5 Implementing New Testing Small sample volumes make saving and collecting samples for bias testing challenging. Limited opportunity for extra volume collection due to nature of patient population. Have to work with what we have. Do not have normal population to draw from. Can make establishing normal ranges a challenge. Regardless of the challenge Implementation of new testing is vital in pediatric medicine. Newly implemented RET He and IPF 5

6 RET He Reticulocyte Hemoglobin aka CHr (Advia) Direct cellular measurement of iron availability in the bone marrow. Snap shot or real time view of iron status on the day the testing. Detects iron deficient erythropoiesis Provides an indirect measure of the functional iron available for new red blood cell production over the previous 3 4 days. Ret He on Sysmex Fluorescent flow cytometry in the Reticulocyte channel MFR+HFR=IRF Proprietary algorithm based on forward scatter and side fluorescence of the reticulocytes and RBCs as measured in the RET channel. 6

7 Iron Deficiency True Iron Deficiency Not enough Iron stored in body Iron Deficiency Anemia (IDA) Iron Deficiency w/out anemia (ID) Functional Iron Deficiency iron restricted erythropoiesis Erythropoietin Therapy Surgery patients Anemia of Chronic disease True Iron Deficiency Iron deficiency most common nutritional deficiency in the world Results from: Dietary insufficiency Variable absorption Rapid growth IDA causes impairment of mental and motor development in infants and long term or permanent cognitive defects Iron is essential in neuronal energy metabolism, neurotransmitter metabolism and myelination American Academy of Pediatrics (AAP) and CDC recommend infant screening for IDA at ~12 months old 7

8 Iron Deficiency in Babies 80% iron present in full term newborn is acquired in 3 rd trimester of pregnancy Premies miss this rapid acquisition and are frequently ID Anemia compounded by rapid postnatal growth Usually require frequent phlebotomies resulting in further decreasing Fe stores Despite the use of iron supplemented formulas 14% preterm infants develop ID between 4 and 8 months. Iron Deficiency in Babies Maternal conditions including anemia, gestational diabetes, and maternal hypertension with intrauterine growth restriction can cause low fetal iron stores Full term infants usually born with sufficient iron stores until 4 to 6 months old High Hgb and blood volume rapidly decline in first several months after birth which supports the low iron intake of breast fed children for the 1 st 6 months of life. At 6 months physiologic iron needs increase resulting in an association of increased risk of IDA in exclusively breastfed babies. 8

9 Erythropoietin and Iron therapy When EPO therapy accelerates RBC production, demand can overwhelm the bodies iron delivery system regardless of whole body iron stores EPO frequently causes ID if IV iron therapy is not also given Normal ferritin and Tsat RET He Quicker indicator of response Hemodialysis for ESRD patients and Functional ID KDOQI (kidney disease outcomes quality initiative) guidelines for iron assessment indices Ferritin >200ng/mL RET He >29pg 9

10 Anemia of chronic (inflammation) disease Iron restricted erythropoiesis due to inability to utilize iron stores or oral iron Seen in autoimmune disorders and cancer RET He helpful in diagnosing and monitoring therapy Surgery/Trauma patients Accelerate recovery by ensuring adequate hemoglobin and limiting transfusions Massive blood loss=massive Iron loss Post surgery there is a period of coexisting inflammation which prevents uptake and release of iron. Due to increased iron demands IV iron often needed 10

11 Functional iron deficiency Pre op Pre operative EPO treatment Oral Iron and EPO injections 2/3 responders (Hgb increase >0.8mmol/L over 3 weeks) with average of 1.4mmol/L increase. 1/3 non responders Ret He and Non Responders Need 300mg Iron to get 1.4 mmol/l Hgb increase Daily oral Iron uptake=5mg Max uptake over 3 weeks with oral iron=105mg Have to make up the difference with body iron stores RET He could allow early detection (w/in first week) and intervention (IV instead of oral) of non responders 11

12 Functional iron deficiency First post op week 1L blood loss=500mg iron loss Difficult to compensate by natural means Oral iron has no effect due to hepcidin (inflammation) blocking uptake and distribution. Iron release from body stores inhibited by hepcidin. RET He can help determine the pathophysiologic mechanism of anemia. Why is RET He better than traditional Iron tests? Rapid and automated Non acute phase reactant Allows for much earlier detection of response to treatment for iron deficiency. RET He ~2 days Retic peek response ~ 3 7 days Fe sat, TIBC, Ferritin ~14 days Recommended RET He be used in conjunction with ferritin, serum iron, and transferrin testing for the most accurate clinical picture. 12

13 What about Hgb? Hgb takes the 120 day life span of RBC to show anemia present. Most toddlers with ID do not have anemia Decrease in Hgb (<11g/dL) is a late finding in the development of ID not good predictive screen of ID or early onset IDA CBC + RET He = economical and effective screening tool RET He has been shown to be a very strong predictor of ID in children Easy to obtain 500uL finger stick or bullet adequate No additional blood volume or tubes required No additional cost, reported with Retic. 13

14 Interpreting the Results Our normal range is 26 35pg Low values suggest the patient does not have enough iron available in the bone marrow to support RBC production. High or normal values are unlikely to respond to additional iron therapy. Limitations Thalassemia patients may have falsely low RET He values due to the small size of their RBC s. Use microcytosis hypochromia ratio IDA hypochromia > microcytosis Thalassemia trait microcytosis > hypochromia 14

15 IPF Immature Platelet Fraction Reticulated platelets Indirect measure of BM megakaryocyte activity Indicator of platelet count recovery and rate of thrombopoiesis Used for Assessing Thrombocytopenia Plts IPF = Production Plts IPF = Destruction IPF on Sysmex Retic channel Flow cytometric technique using polymethine and oxazine nucleic acid specific dye Measures fluorescence and forward scattered light Discriminates the mature from IPF via the intensity of fluorescence and forward scattered light Allows for differentiation of newly released platelets that are larger and more physiologically active with elevated RNA 15

16 Thrombocytopenia 3 main etiologies: 1. Centralized decrease of production= normal/decreased IPF Leukemia Aplastic anemia Myelodisplastic syndrome Solid tumors 2. Peripheral increase in destruction=increased IPF ITP DIC Evans syndrome 3. Peripheral abnormal distribution=normal to slightly increased IPF Splenomegoly Liver cirrhosis Portal vein hypertension IPF values in various disease states Briggs, C., et al. British Journal of Hematology IPF (%) 20 N 10 0 Normals ITP AA/PNH BMT chemo MDS DIC Cancer Normals 80 ITP 37 AA/PNH 3 BMT 8 chemo 79 MDS 3 DIC 25 Cancer 16 16

17 IPF Clinical Utility Transfusion assessment Help with diagnosis of, and monitoring progression, activity and treatment of ITP Monitoring bone marrow cell recovery Monitoring chemotherapy and other marrow suppression ITP Differentiate cause of thrombocytopenia R/O centralized decreased production w/o doing BM testing High IPF indicates increased thrombotic production by marrow and indicates a destructive peripheral process taking place. 17

18 Bone Marrow Recovery Following HPC transplantation, IPF recovered significantly earlier than platelet count, ANC, and IRF. A persistently low IPF in this setting would suggest failure of thrombopoietic recovery. Why IPF Fully automated Standardized method Minimally invasive (compared with BM biopsy) More cost effective than flow studies No additional blood volume required Easily ran along side total platelet count Faster response to changes from therapy 18

19 Interpreting the Results Our normal range is % IPF > 9.1% in chemo and BMT patients shows good indication of cellular recovery and BM response Highly elevated IPF values show good indication of increased peripheral destruction in patients with low total platelet counts Limitations False increases in IPF not followed by increase in plt count seen in transplant patients suffering from sepsis Suspect false stimulation by cytokine release False decreases seen following plt concentrate infusion Dilutional effect or transient suppression of thrombopoiesis by the transfused plts 19

20 The implementation Process RET He Correlation testing with Riverside Methodist Hospital (Easy) IPF Clinical correlation through data collection (Not so easy) RET He Implementation Advanced Clinical Parameters (ACP) on CRC Implementation Manual Verification of precision Verified with Insight comparisons and CAP surveys (RT 4) CV L1=1.0, L2=1.2, L3=1.6 Verification with patient samples Correlation Method comparison with Riverside Methodist using 40 samples spanning linear range 20

21 RET He Method Comparison Y=1.039X 1.41, R= RET He Implementation In house policies Ref range validation picograms Noted RET He for pediatric population lower than commonly seen in healthy adult population Our validation confirmed these findings Stability studies 48 hrs 21

22 IPF Implementation Advanced Clinical Parameters (ACP) on CRC Implementation Manual Verification of precision Verified with Insight comparisons and CAP surveys (FH 9) CV L1=4.7, L2=5.0, L3=3.5 Verification with patient samples Correlation No peer or reference method to compare with Clinical Correlation linearity (via the PLT O) IPF Clinical Correlation Verifying accuracy via clinical diagnosis Use residual sample 167 patients with low PLTC Sorted based off of diagnosis 33 peripheral destruction M= decreased production M= abnormal distribution M= other M=11.4 Findings consistent with previous studies 22

23 In house policies IPF Implementation Ref range validation % Clinical correlation findings support range validation Stability studies 12 hrs IPF trends up with time RET He References Brugnara, C., et al. Reticulocyte Hemoglobin Equivalent (Ret He) and Assessment of Iron deficient States. Clinical Laboratory Hematology, 2006, 28: Kuehn, D. et al. Reticulocyte hemoglobin content testing for iron deficiency in healthy toddlers. Mil Med Jan; 177(1):91 5. Semmelrock, M.J. et al. Reticulocyte hemoglobin content allows early and reliable detection of functional iron deficiency in blood donors. Clin Chim Acta. 2012;413(7 8): Baker, R et al. and The Committee on Nutrition. Diagnosis and Prevention of Iron Deficiency and Iron Deficiency Anemia in and Infants and Young Children (0 3 Years of Age). Pediatrics 2010;126; Brugnara, C., et al. Reticulocyte Hemoglobin Content to diagnose iron deficiency in children. JAMA 1999, 281: Ullrich, C., et al. Screening healthy infants for iron deficiency using reticulocyte hemoglobin content. JAMA 2005, 294: Shaker, M., et al. An economic analysis of anemia prevention during infancy. J. Pediatr. 2009, 154(1):

24 RET He References cont. Mast, A., et al. Clinical utility of the reticulocyte hemoglobin content in the diagnosis of iron deficiency. Blood 2002,15;99(4): Mast, A., et al. Reticulocyte Hemoglobin Content. Am J Hematol 2008;83(4), 307. National Kidney Foundation. KDOQI Clinical Practice Guidelines and Clinical Practice Recommendations for Anemia in Chronic Kidney Disease. Am J Kidney Dis. 2006, 47:S1 S146 (suppl 3). Van Wyck, D., et al. Analytical and Biological Variation in Measures of Anemia and Iron Status in Patients Treated With Maintenance Hemodialysis. Am J Kidney Dis. 2010, 56(3): Muusze, R., et al. Successful implementation of an anemia algorithm using Ret He at ZorgSaam Hospital Zeeuws Vlaanderen, the Netherlands. Sysmex Journal International. 2008; 18: Muusze, R. et al. Protocol for Transfusion Free Major Orthopaedic Operations using RET He. Sysmex Journal International. 2009; 19:1, 1 8. IPF References Briggs, C., et al. Immature Platelet Fraction measurement: a future guide to platelet transfusion requirement after Hematopoietic Stem Cell transplantation. Transfusion Medicine 2006;16: Briggs, C., et al. Assessment of an immature platelet fraction (IPF) in peripheral thrombocytopenia. British Journal of Hematology. 2004; Zucker, M., et al. Immature Platelet Fraction as a predictor of platelet recovery following Hematopoietic Progenitor Cell transplantation. Laboratory Hematology 2006, 12: Kickler, T., et al. A Clinical Evaluation of High Fluorescent Platelet Fraction Percentage in Thrombocytopenia. Am J Clin Pathol. 2006;125: Psaila, B., et al. Differences in platelet function in patients with AML and myelodysplasia compared to equally thrombocytopenic patients with immune thrombocytopenia. J Thromb Homeostasis 2011;9(11):2302. Barsam, SJ., et al. Platelet production and platelet destruction: assessing mechanisms of treatment effect in immune thrombocytopenia. Blood 2011; 117(21):5723. Zucker, M.L. et al. Mechanism of thrombocytopenia in chronic hepatitis C as evaluated by the immature platelet fraction. Int J Lab Hematol. 2012, 34(5):

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