7/7/2019

The CBC and Me: Identifying and Evaluating Abnormalities

Bradley DeNardo, MD Assistant Professor of Pediatrics Division of Pediatric /Oncology The Warren Alpert Medical School of Brown University

Disclosure

• No conflicts of interest to disclose.

Learning Objectives

1. Describe the diagnostic testing and clinical approach to pediatric .

2. Identify WBC abnormalities suspicious for hematologic disease.

3. Recognize common disorders that result in or thrombocytosis.

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Blood Basics

• Adult blood: • Components of Blood: • Blood volume: 5-6L • Formed elements: blood cells • 7% body weight • Erythrocytes • Circulates the entire body in 20-60 • Leukocytes seconds • • Plasma • Childhood blood: • 90% water • 10% solutes • Total blood volume: body weight • Neonate: 85 ml/kg • 1 month: 105 ml/kg • >2 months: 70-80 ml/kg • Serum = plasma without clotting factors

Blood Basics

• Hematopoiesis: • Continuous production of blood cell population.

• Bone marrow cavities and canals.

• Mediated: • Growth factors • Hematopoietic stem cells

Blood Basics

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Blood Basics

Blood Basics: The CBC

• Other values: • Indices: • MCV • MCH • MCHC • RDW

• MPV

Blood Basics: The CBC

Manual Automated

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Blood Basics: The Red Blood Cell

• Biconcave disc • 7.8 μm diameter • Highly flexible membrane • 100-120 day lifespan • 3.9-6 million cells/μl • Produce 2.4 million RBCs/second

• Simple interior: • Lack of nucleus • Lack of organelles • Enzymes for glycolysis •

Blood Basics: Hemoglobin

• Iron-containing metalloprotein. • Structure • Responsible for O transport. • Heme Group: 2 • Protoporphyrin IX • 35% of total RBC content. • Single atom of Iron • 96% by dry content • Globin: • Polypeptide chain

• Heme + Globin = Hemoglobin Chain: • 16,000 g/mol • Variety of different chains

• Hemoglobin Protein: • 4 loosely bound hemoglobin chains

Blood Basics: Hemoglobin

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Blood Basics: The Newborn Screen

Pediatric Anemia

• Defining Anemia: • Reduction in RBC mass. • Reduction in Hgb concentration.

• Varies substantially: • Age • Race • Gender

• Anemia: • Hct or Hgb below the 2.5th%

Classifying Pediatric Anemia: Size (MCV)

• Microcytic (<70) • Normocytic (70-80) • Macrocytic (>85) • Iron deficiency • Infection • Vitamin B12/folate deficiency • Lead intoxication • Acute blood loss • Hypothyroidism • • Anemia of • Drug-induced • inflammation • Post-splenectomy • Anemia of • Drug-induced • Diamond-Blackfan inflammation • Renal disease • Bone marrow failure • Zinc deficiency • TEC • Bone marrow • infiltration • : • Liver disease • • Reticulocytosis Autoimmune • • Membrane defect • Enzyme defect • MAHA

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Classifying Pediatric Anemia: Cause (Retic) ↓ Reticulocytes ↑ Reticulocytes ↑↓ Reticulocytes • Decreased Production • Increased Destruction • RBC Loss • Iron deficiency • Hemoglobinopathy • Thalassemia • Hemolytic anemia: • Hemorrhage • Lead intoxication • Autoimmune • Acute blood loss • B12/folate/zinc • Membrane defect • Chronic blood loss • • Enzyme defect Infection • • Drug-induced • MAHA Liver disease • Anemia of Inflam. • Blood loss • Bone marrow disease • Hypersplenism • Hypothyroidism • Renal disease • Sideroblastic anemia • DBA and TEC

Classifying Pediatric Anemia: Age

• Birth to 3 months • 3 to 6 months • 9 months to teens • Blood loss • Hemoglobinopathy • Nutritional deficiency • Alloimmune hemolysis • Infection • All others…. • • ABO incompatibility • Congenital infection • Intrinsic hemolytic anemia • Twin-to-twin transfusion

Newborn Anemia

• Physiologic Anemia on Infancy • ↑ tissue oxygenation • ↓ erythropoietin

• Anemia in newborns: • Hgb <13.5: birth-4 weeks • Hgb <9: weeks 6-9 • Signs of hemolysis • Signs of anemia • Irritability • Poor feeding

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Approaching Anemia: Clinical

• Age • Symptoms: • Dietary history: • severity and duration • Formula or breastfed • Sex • Cow versus goat milk • X-linked diseases: G6PD • Acute: • Age of onset deficiency • lethargy, tachycardia, pallor • Daily volume • Postmenarchal female • Chronic: • Pica • Iron-rich food intake • Race/Ethnicity • none or minimal sx’s • Thalassemia: • PMHx • Mediterranean • Hemolysis: • Newborn jaundice • Southeast Asian • jaundice • Newborn screen • Hemoglobin S and C • change in urine color • Prior CBC’s • African descent • Scleral icterus • Underlying medical conditions • Hispanic populations • : • Drug/toxin exposure • Incidental or symptomatic? • GI • Family History • Chronic epistaxis • CCY or splenectomy • menstrual • Gallstones

Approaching Anemia: Exam

• Assessing pallor

• Assessing hemolysis

• Clues

Approaching Anemia

Clinical Assessment Hemoglobin

MCV Reticulocytes

Macrocytic >85 Absolute Reticulocyte Count Reduced Production ARC = % Retic x RBC Normocytic 70-80 Increased Destruction ARC <100 x109 Microcytic <70 INADEQUATE RESPONSE RBC Loss

ARC >100 x109 APPROPRIATE RESPONSE

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MCV <70 Microcytic Anemia Reticulocyte <3% ARC <100,000

• Iron Deficiency Anemia • IDA versus Thalassemia • Thalassemia • Red Cell Distribution Width (RDW) • Low RDW: Thal • High RDW: IDA • Less Common • Lead Intoxication • RBC Count • • Anemia of Inflammation (<20%) >5 million: Thal • <5 million: IDA • Congenital Sideroblastic Anemia • Zinc Deficiency • Mentzer Index = MCV/RBC • <11: Thal minor • >13: IDA

Iron Deficiency Anemia

• Causes: Nutritional deficiency • Other Causes: • Infants • Blood loss: • Exclusive BF without iron supplementation • Menorrhagia • Formula with insufficient iron • Chronic epistaxis • Early transition to cows milk • Occult GI bleeding (IBD)

• Toddlers • Reduced iron absorption: • Excessive cows milk intake • Celiac disease • >24 ounces/day • Autoimmune gastritis • H. pylori gastritis • Adolescents • Alternative diets: vegetarians, vegans • Rare genetic conditions: • Endurance athletics • IRIDA • Obesity • SLC11A2 mutation

Iron Metabolism

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Iron Deficiency Anemia

• Diagnosis: • Age <3 yo, typical presentation: • CBC sufficient.

• Age >3 yo or atypical presentation • CBC • Iron Studies

• Iron Studies • Serum iron: 1% measured iron • Ferritin: 99% measured iron • TIBC: transferrin. • Iron Saturation = serum iron/TIBC

Iron Deficiency Anemia • Treatment • Clinical Manifestations: • Oral supplementation • Neurocognitive • 3-6 mg/kg elemental iron • Exercise capacity • Once daily • Febrile seizures • Between meals without dairy • Pica • With water or juice (vitamin C) • Cerebral vein • Dietary changes • Restless leg syndrome • Limit cows milk: 6-20 oz/day • ? Infection and immunity • Discontinue the bottle!

• Nonanemic iron deficiency: • Treating Teens: • • Easy in athletes 65-130 mg once daily (1-2 tabs 1xD) • • Cognitive function in adolescents Combine with ascorbic acid

MCV 70-80 Hemolytic Anemia Reticulocyte >3% ARC >100,000

• Intrinsic: • Extrinsic: • Lab Studies • • Autoimmune • Membrane Defects • Warm-reactive Reticulocytosis • • Cold agglutinin • Hyperbilirubinemia • Hereditary Elliptocytosis • Paroxsymal Cold Hemoglobinuria • ↑ LDH • Enzyme Defects • SLE • ↓ Haptoglobin • G6PD deficiency • Evan’s syndrome • Plasma-free Hgb • Pyruvate Kinase • Alloimmune deficiency • Rh disease of NB • Urine • • ABO incompatibility • Hemoglobinuria • Microangiopathic • Bilirubinuria • Sickle cell disease • HUS • Hemoglobin E • TTP • Peripheral smear • Hemoglobin C • DIC • Mechanical • Thalassemia • Congenital heart disease •

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Pure Red Blood Cell Aplasia

Transient Erythroblastopenia of Diamond Blackfan Anemia (DBA) Childhood (TEC) • Congenital • Acquired • ribosomal protein mutations • Unknown etiology • Presents <1 yo (90%) • Presents 1-4 yo (80%) • No prior illness • Hgb 2-6 • Preceding viral illness • Retic <1% • Hgb 3-9 • MCV: macrocytic • Retic <1% • Elevated Hgb F • MCV normal • Congenital abnormalities (30-50%) • Normal Hgb F • Life-long condition • No anatomic abnormalities • Transfusion support • Steroid therapy • Spontaneous resolution • Risk of malignancy • Weeks to months • Rare need for transfusion

White Blood Cell Abnormalities

• • Lymphocytosis: ALC >4000

• • Lymphocytopenia: ALC <1500

• Abnormal WBC forms in periphery

Absolute Count (ANC) WBC x %/100

Neutropenia

• Definitions: • Prevalence of in U.S. • Mild ANC 1000-1500 • African-American: 4.5 to 10.5% • Moderate ANC 500-1000 • Haiti: 8.5% • Severe ANC <500 • Barbados/Trinidad: 6.4% • Jamaica: 2.7% • Infancy: • Mexican: 0.38% • 0-7 days ANC <5000 • Caucasian: 0 to 0.79% • 14 days to 1 yr ANC <1000

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Benign Familial Neutropenia

• African-American: ANC <2000 • West Indians, Arab Jordanians, Yemenite Jews

• Traced to common West African allele: • SNP in DARC gene • Receptor for inflammatory cytokines

• Normal bone marrow reserve of • Defective release from the marrow

• Neutropenia is benign • No propensity to infection

Neutropenia: Causes

• Acquired • Congenital • Postinfectious • Kostman Syndrome (SCN) • Drug-induced • Shwachman-Diamond Syndrome • Nutritional • WHIM Syndrome • Vit B12/folate deficiency • GATA2 Deficiency • Copper deficiency • Chediak-Higashi Syndrome • Immune • Glycogen Storage Disease Type 1b • Alloimmune neonatal • GCSF receptor mutation • Chronic autoimmune • Collagen vascular disease • Immunodeficiency • • Hypersplenism • Bone marrow disorders • • • Chemotherapy • Chronic Idiopathic

Neutropenia: Approach

• Does neutropenia indicate a serious underlying disease?

• Is the patient at increased risk of infection because of neutropenia?

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Neutropenia: Approach

Clinical Concern Incidental/Reassuring History Urgent Hematology Referral: • Recurrent oral ulcers and gingivitis • No concerning infectious history • bone marrow biopsy • Perirectal ulcers • genetic sequencing • Associated viral syndrome • Recurrent Staph and Strep • No oral/gingival issues • Oropharyngeal and Otitis Fever: • Respiratory • Confirmed with repeat CBC: • Cellulitis • Immediate ER evaluation • Pseudoneutropenia: cell clumping • Bacteremia • Hematology consultation • Sample left standing • • Unusual organisms • Inpatient: antimicrobials Presence of anticoagulant • Chronic diarrhea/FTT Serial PE with CBC and ESR • Chronic inflammation: ↑ ESR • every 1-2 weeks • Recurrent fevers every 21 days • gradually decreasing interval

Fever: • CBC and blood culture • ER eval if clinical concern

Neutropenia: Clinical Scenarios

Healthy Infant/Toddler Older Child/Teenager • Post-infectious • Absent protracted/recurrent infection • Transient, mild-moderate ANC • ANC >800 • Viral etiology • Absent oral symptoms • RSV, Influenza, Parvo, EBV, HHV6 • Typically benign etiology • Onset: within 72hrs of illness start • Followed with serial CBC • Resolves: after 3-8 days • Lab eval with any febrile illnesses

• Benign Neutropenia of Childhood • • Chronic autoimmune neutropenia Recurrent infection • Prolonged, moderate-severe ANC • Diagnostic evaluation • Not associated with severe infections • ANA, complement • Age 5-15 months • Anti-neutrophil antibodies • • Resolves: after months-years Ig levels and vaccine titers • HIV • Nutritional studies

Lymphocytosis

• Definitions: • Reactive versus Clonal • Age >12 yo ALC >4000 • Clonal Lymphocytosis: Rare • Age <12 yo ALC >8000 • Acute Leukemia • Hereditary Polyclonal B cell Lymphocytosis • Lymphocyte subsets • CLL • T cells (CD3+) 60-80% • Monoclonal B cell Lymphocytosis • Lymphoproliferative disease of LGL • B cells (CD20+) 10-20% • Reactive • NK cells (CD56+) 5-10%

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Reactive Lymphocytosis

• Mononucleosis • Hypersensitivity reactions • EBV, CMV • • HHV6, Adenovirus Drug-induced • Infectious Lymphocytosis • Serum sickness • Coxsackie, poliovirus, entero • Stress-induced • WBC 20-100: 60-90% T-cells • Cardiac emergencies • Last 4-10 weeks • Status epilepticus • Other viruses • Mumps, varicalla, influenza, • Trauma hepatitis, rubella, measles • Post-splenectomy • Pertussis • Cat Scratch • Toxoplasmosis • Babesiosis

Lymphocytosis: Evaluation

• CBC • Ruling Out Clonality • Peripheral smear • Lymphocyte subsets • Lymphocyte morphology • Clonal lg rearrangements • Clonal TCR rearrangements • EBV titers • Kappa/lambda light chain expression

• Ruling Out Malignancy • Morphology • Flow cytometry • Bone marrow biopsy • Associated anemia, neutropenia, thrombocytopenia

Eosinophilia

• Definitions: • Childhood: • : AEC >500 • Neoplastic hypereosinophilia is VERY rare • Hypereosinophilia: AEC >1500 • Hypereosinophilia Syndrome • Secondary causes of eosinophilia are COMMON: • AEC >1500 • Asthma, atopic disease: mild-moderate • End-organ damage (cardiac, neuro, pulm) • Food allergy, eosinophilic esophagitis • Infection: toxocariasis, filariasis • Differential Diagnosis: • Medications • Primary immunodeficiencies: • Neoplastic Eosinophilia • ALPS • Leukemia/ with eosinophilia • HyperIgE Syndrome • Primary hypereosinophilia syndrome • DOCK8 deficiency • Secondary • IPEX

• Severity of AEC • Diagnostic evaluation HES is necessary: • Does not predict etiology • Persistent AEC >1500 • Does not predict risk of end-organ damage • AEC 500-1500 with concern for organ dysfunction

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Platelets

• Normal range: 150-450,000 • Lifespan: 8-10 days • Function: primary hemostasis

Thrombocytopenia

• Definition: • Bleeding Risk • General <150,000 • Inversely proportional to platelet count • ITP <100,000 • Risk begins: Plts <100

• Symptoms: • Surgical bleeding Plts <50 • Cutaneous: • Spontaneous bleeding Plts <20 • Superficial ecchymoses • Petechiae • Mucosal • Younger platelets: ↑ hemostatic • Epistaxis • More bleeding risk: disorders of platelet • Gingival bleeding production • Wet • Less bleeding risk: disorders of platelet • GI/GU bleeding destruction •

Thrombocytopenia: Causes

Increased Platelet Destruction Decreased Platelet Production • Immune-mediated • Infection • Immune Thrombocytopenia (ITP) • EBV, CMV • Drug-induced • Parvo, varicella, rickettsia • Activation/Consumption • HIV • Microangiopathic HA • Bacterial sepsis • TTP, HUS, DIC • Major surgery, trauma • Nutritional deficiency • Kasabach-Merritt • B12/folate • Mechanical Destruction • Iron • ECMO, bypass, dialysis, apheresis • Bone marrow disease • Sequestration/Trapping • • Hypersplenism Aplastic anemia • : Type 2B, pseudo-vWF • Malignancy • Genetic

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Congenital Thrombocytopenia: MPV

• Small Plts (<7) • Normal (7-11) • Giant Plts (>11) • Wiskott-Aldrich • Bone Marrow Failure • Bernard-Soulier • X-linked • Syndrome Thrombocytopenia • • MYH9-related disorders • Shwachman-Diamond • Paris-Trousseau • Congenital Amegakaryocytic • Thrombocytopenia (CAMT) Gray platelet • Thrombocytopenia-absent radius syndrome (TAR) • Amegakaryocytic thrombocytopenia with radioulnar synostosis

Spurious Thrombocytopenia

• Platelet clumping • Automated CBC: counted as leukocyte • False reading: thrombocytopenia

• Causes: • Improper blood collection • Delayed processing • Inadequate anticoagulation • Pseudothrombocytopenia • 0.1% population • EDTA-dependent antibodies Verify Thrombocytopenia: Repeat CBC

Immune Thrombocytopenia (ITP)

• Most common cause of symptomatic thrombocytopenia • 1-6 cases/100,000 children • Peak incidence: 2-5 years

• Sudden onset of severe thrombocytopenia: • Defined: Plts <100,000 • 80%: Plts <20,000 • 45%: Plts <10,000

• Triggers: • Preceding viral illness: 60% cases • Within 4 weeks of onset • MMR vaccination

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Immune Thrombocytopenia (ITP)

• Symptoms: • Diagnosis: Clinical/Exclusion • Mucocutaneous bleeding • Typical presentation: • Lack of systemic symptoms • Age 1-10 • Rare: serious hemorrhage (3%) • acute onset, otherwise healthy • Prolonged epistaxis • Plts <100,000 • Intracranial hemorrhage (0.5%) • CBC otherwise normal • GI/GU hemorrhage • Peripheral smear: no hemolysis or blasts • Negative DAT (Coomb’s) • Response to treatment

• Indications for bone marrow biopsy: • Systemic symptoms, LAD, HSM • Atypical labs: cytopenias • Lack of response to treatment • Chronic ITP >12 months

Approach to Mild-Moderate Thrombocytopenia • Repeat CBC: • Persistent thrombocytopenia: • Spurious thrombocytopenia • Lasting >2-3 months • No clear etiology • Viral suppression: most common • Diagnostic dilemma: Hematology referral • Associated viral symptoms • Mild-moderation thrombocytopenia • Diagnostic evaluation: • Monitor serial CBC’s over 2-4 weeks • Anti-Platelet Antibodies and DAT • Chronic ITP • Evan’s syndrome • Presumptive ITP • Rheumatology evaluation • Otherwise healthy • Collagen vascular disorders • Preceding illness • SLE • Monitor for spontaneous resolution • Bone marrow biopsy: • Malignancy/MDS • Bone marrow failure syndrome • Genetic sequencing • MYH9 disorders • Congenital thrombocytopenia

Mild 450-700 Moderate 700-900 Thrombocytosis Severe 900-1000 Extreme >1000

Reactive/Secondary Essential/Primary • Stimulated megakaryopoiesis • Myeloproliferative disease • >600/million children • 1/million children • Transient • Chronic • Plts <800 • Plts >1000 • MPV large • MPV small or large • Normal morphology • Abnormal morphology • ↑ CRP/ESR, vWF Ag, fibrinogen • ↑ PT/PTT, Anti-Phosphlipid Ab’s • No bleeding/clotting • Associated bleeding/clotting • No • Splenomegaly

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Take Home Points

• Systematic approach to pediatric anemia: directs diagnosis. • Age • Size of RBC’s (MCV) • Bone marrow response (reticulocytes)

• Urgency of evaluating neutropenia depends on degree of clinical concern: • Infectious history • Oral health: gingivitis, ulcers

• Isolated thrombocytopenia in childhood is almost always benign in etiology: • Viral suppression • Immune thrombocytopenia

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