Neonatal Hematology for the Primary Care Physician Vlad C. Radulescu, M.D. University of Kentucky

Topics  Normal newborn hematologic parameters  Common causes of anemia in the newborn  Neonatal screening for abnormal hemoglobins  Hemostatic abnormalities  Current use of umbilical cord blood stem cells

Case #1  3 months old infant  32 weeks gestation, birth weight : 2100 g  Spent two weeks in NICU for respiratory distress, feeding difficulties  Feeding well, thriving, appropriate growth  CBC:  WBC 10,500 / fl,  Hgb 9.5g /dl, MCV 95fl,  platelet count 245,000 / fl

Normal Newborn CBC  Hemoglobin  Red blood cell indices : Mean Corpuscular Volume  Peripheral smear

Neonatal changes that impact the red blood cell indices  Sudden increase in tissue oxygenation after birth  Decrease erythropoietin levels  Decreased hemoglobin production  Transition from fetal hemoglobin to adult hemoglobin  Rapid growth

Hemoglobin Data extracted from: The Harriet Lane Handbook, 19 th edition, table 14-1

Hemoglobin Full term Premature g Premature <1200 g Adapted from: Nathan and Oski Hematology of Infancy and childhood, 7 th ed.

Mean Corpuscular Volume Data extracted from: The Harriet Lane Handbook, 19 th edition, table 14-1

Normal Adult Blood Smear

Neonatal Blood Smear

 Hemoglobin, MCV are high at birth and decrease over the first few months of life, more dramatically for the pre-term infant  MCV < 94fl in newborn  2/3 had Bart’s Hemoglobin  Suggestive of alpha thalassemia

Case #1 : normal infant  3 months old infant  32 weeks gestation, birth weight : 2100 g  Spent two weeks in NICU for respiratory distress, feeding difficulties  Feeding well, thriving, appropriate growth  CBC:  WBC 10,500 / fl,  Hgb 9.5g /dl, MCV 95fl,  platelet count 245,000 / fl

Anemia in the Newborn

Hgb. < 13.5 g/dl Blood Loss Hemolysis Failure of production

Anemia in the Newborn  Presentation  Life threatening event  Pallor, difficulty feeding, poor weight gain, tachycardia  Incidental finding  Does it require immediate intervention?  If a transfusion is indicated should any tests be done prior to transfusion  Does the newborn have to be referred to a hematologist?

Evaluation of Anemia in the Newborn  CBC  RBC indices – MCV (Mean Corpuscular Volume)  Reticulocyte count  Elevated – RBC destruction ( hemolysis) or bleed  Decreased – decreased RBC production  Coombs ( direct anti-globulin test)  Positive in immune hemolysis  Maternal and fetal blood type  Identifies mismatched in the ABO and Rh blood types that may represent set-ups for allo-immunization

Anemia through blood loss  Fetal- maternal transfusion  Rupture of the cord  Laceration of the placenta  Internal hemorrhage  Intracranial  Retroperitoneal  Intrathoracic  Intraabdominal

Anemia due to hemolysis  Immune hemolysis  Maternal alloimmunization to fetal RBC antigens  Maternal auto- antibodies ( Lupus)  Non-Immune Hemolysis  Enzymes  G6PD  RBC membrane  spherocytosis  Hemoglobin  Thalassemia, Hgb. SS

Hemolytic Disease of the Newborn  The mother becomes sensitized to antigens present on fetal red blood cells  Fetal- maternal hemorrhage  Prior maternal transfusion  Antigens  Rh  ABO  Kell, Duffy, Kidd  Maternal antibodies cross the placenta  IgG can cross, IgM, IgA can not cross  Transport increases in the 3 rd trimester

Hemolytic Disease of the Newborn  Maternal antibodies bind to fetal RBC and sometimes other tissues  AB, Duffy, Kidd, Kell antigens are expressed on erythroid and non erythroid tissues  Rh, MN, SS antigens expressed only on erythroid tissues  Antibodies bound to RBC induce hemolysis if  they can activate complement  promote cell mediated cytotoxicity

Hemolytic Disease of the Newborn  RhD  Most commonly identified antigenic stimulus  Mother is Rh negative, fetus Rh positive  The incidence has dropped with the use of anti-D antibodies to decrease maternal sensitization  ABO  Mother is type O, fetus is type A, B  Kell, Duffy, Kidd  Maternal sensitization may be due to prior maternal blood transfusions mismatched in the minor blood types

Hemolytic Disease of the Newborn  Diagnosis:  Mismatch between maternal and newborn blood types  History of prior maternal transfusions  Combs ( Direct Antiglobulin Test) positive  Neonatal Hyperbilirubinemia  Managemnt  Anemia  simple or exchange transfusion  Hyperbilirubinemia  Phototherapy  Exchange transfusions

Anemia through decreased production  Physiologic anemia  Anemia of prematurity  Late anemia of the hemolytic disease of the newborn  Bone marrow failure syndromes  Diamond Blackfan sdr.  Fanconi sdr.  Nutritional deficiencies  Infections  Infiltrative processes  Leukemia  Neuroblastoma

Anemia of prematurity  Causes  Low erythropoietin levels  Small circulating blood volumes  Blood loss  Hemolysis  Minimize blood loss  PRBC transfusions  Hgb < 7 g/dl  Apnea & bradycardia  Tachycardia  Tachypnea  Poor weight gain  Respiratory distress  Erythropoietin  Iron supplements

Hemoglobin Screening in Newborns

Goal: early diagnosis of sickle cell disease The first manifestations of sickle cell disease in infants may be life-threatening complications: Pneumococcal sepsis Splenic sequestration

Methodology  High performance liquid chromatography  Identifies different types of hemoglobin  Relevant for sickle cell disease: Hgb S, Hgb C  Incidental findings: Hgb H, Hgb Bart’s, Hgb E, D, etc.

Hemoglobin  Normal variants  Embrionic  Fetal  2  2  Adult 1  2  2  Adult 2  2  2  Abnormal variants  S, D, C, E : abn.  chain  Barts:   H: 

Hemoglobin Switching during development

Normal newborn  Screening test:FA  Hemoglobin electrophoresis:  Hgb F 60-90%  Hgb A110-40%  Hgb A2< 1 %

Sickle Cell Syndromes Screening test Diagnostic possibilities FSHgb SS Hgb S   thalassemia FSC FSD Hgb SC Hgb SD FSA Hgb S   thal. Sickle Cell Trait

Sickle Cell Syndromes: Interventions  Refer to Pediatric Hematology/ repeat testing  Evaluate infant for splenomegaly.  Educate parents/caregivers regarding  risk of sepsis, aggressive management of fevers  splenic sequestration in Sickle Cell disease  Pen V K 125 mg po bid until repeat testing confirms or rules out a sickle cell syndrome

Thalassemia Syndromes Screening test DiagnosisImplications F  Thalasemia major Premature infant Severe anemia, may need transfusions Repeat screening FAB  Thallsemia Variable manifestations depending on the number of affected genes Genetic implications

Globin Genes

Alpha Thalassemia

 Follow-up tests:  CBC, Hemoglobin electrophoresis  Consider alpha globin gene mutation analysis  Family history  Ethnic origin: common in SE Asia  History of anemia or microcytosis  Genetic counseling  Consider Pediatric Hematology referral

Non- Sickle Hemoglobinopathies Screening test DiagnosisImplications FEHemoglobin EE Hgb E  0 Thal. Mild anemia Moderate to severe anemia FCHemoglobin CC Hgb C  0 Thal. Mild anemia Mild Anemia

Carriers of Hemoglobin Variants Screening test Diagnostic possibilities Implications FASSickle Cell TraitGenerally Asymptomatic Genetic implications FACHemoglobin C trait Asymptomatic Genetic implications FAEHemoglobin E trait Asymptomatic / mild anemia Genetic implications FAVVariant Hemoglobin Most likely clinically insignificant

Carriers of Hemoglobin Variants  In general, no medical intervention is needed for the patient  Genetic counseling : asses the risk of having a child with sickle cell disease or thalassemia major  For the patient future children  For the patient’s parents  Evaluation of the carrier state : CBC, Hgb electrophoresis

Hemostatic abnormalities in the newborn

 Case # 2  FT newborn  Covered in petechiae at birth  Birthweight : 3.4kg  Apgar scores: 9, 9  Case # 3  FT male newborn  Birthweight : 3.5kg  Apgar scores: 8, 9  Oozing for 4 hrs. at the site of the heel-stick  Develops unexpected bleeding after circumcision

Hemostatic abnormalities: presentation  Petechial rash  Ecchymoses  Cephalohematoma  Small but prolonged bleeding at the heel-stick site  Hematoma at the IM injection site  Oozing form the umbilicus  Bleeding with circumcision  Intracranial bleeding

Laboratory evaluation  CBC  PT  PTT  Fibrinogen  Platelet Function Analysis  Normal values* 1 day1 month 1 year PT14-16s11-15s11-14s PTT34-44s35-46s28-38s

Neonatal Thrombocytopenia

 Prevalence  Common in the sick newborn  20-40% of NICU admissions  70-80% of very low birth weight premature newborns  Uncommon in the healthy newborn (1-2%)  Timing  <72 hrs – due to prenatal or perinatal factors  >72 hrs - due to postnatal factors  Sepsis  Necrotizing enterocolitis

Thrombocytopenia in the sick newborn  Frequently associated with:  Infection  Asphyxia  Meconium aspiration  Respiratory distress syndrome  Necrotizing enterocolitis  Presence of indwelling catheters  Predictor of poor prognosis  Mortality  Intestinal gangrene in NEC  Frequently leads to bleeding complications

Thrombocytopenia in the well -looking newborn  Maternal history  Drug ingestion  Sulphonamides, valproic acid, carbamazepine, quinindine  Hypertension / Pre-eclampsia  Infections during pregnancy  Maternal ITP/ low maternal platelet count  Previous newborn with thrombocytopenia  Neonatal Allo-immune Thrombocytopenia (NAIT)

Thrombocytopenia in the well -looking newborn  Newborn exam  Normal  NAIT  Maternal ITP  Maternal drug exposure  Congenital abnormalities  Thrombocytopenia absent radii syndrome (TAR)  Fanconi anemia  Hepatosplenomegaly  Infection  Leukemia

Neonatal Allo-Immune Thrombocytopenia ( NAIT)  Mechanism  The mother is exposed to a Platelet antigen they do not posses  The mother produces an IgG. antibody that  crosses the placenta  Induces thrombocytopenia in the newborn  Incidence 1: ,000 birth  May occur with the first pregnancy, more severe with subsequent pregnancies  Manifestations  Thrombocytopenia  Purpura  Internal hemorrhage including intracranial hemorrhage

Neonatal Allo-Immune Thrombocytopenia ( NAIT)  Diagnosis  Identification of maternal and paternal platelet antigens  Maternal and paternal genotyping  Management  Platelet transfusions  IV Immunoglobulins  Subsequent pregnancies  Close monitoring  IV Ig.  Steroids  Cord blood sampling and in utero platelet transfusions

Case # 2  FT newborn  Covered in petechiae at birth  Birthweight : 3.4kg  Apgar scores: 9, 9  Platelet count 10,000  Older brother had thrombocytopenia  Maternal CBC is normal

Abnormal PT and or PTT Coagulation abnormalities:  History  Did the child receive the Vitamin K injection at birth?  Any family history of bleeding disorders?  Von Willebrand disease  Factor VIII or factor IX deficiency

Hemophilia A and B  X linked disorders  Females are carriers  Males have the bleeding disorder  1/3 of cases of Factor VIII deficiency are due to new mutations, thus no family history

Hemophilia A and B  Manifestations  Prolonged bleeding at the heel-stick site  Cephalhematoma  Excessive or prolonged bleeding with circumcision  Hematomas at the IM injection sites

Hemophilia A and B  Laboratory  PT- normal  PTT- prolonged  Mixing studies  PTT corrects with addition of normal plasma  Factor VIII or IX level is low  Management  No arterial sticks  No IM injections  No procedures  Pressure at the site of bleeding  Hematology consult ASAP  Factor concentrates

Case # 3  FT male newborn  Birthweight : 3.5kg  Apgar scores: 8, 9  Oozing for 4 hrs. at the site of the heel-stick  Develops unexpected bleeding after circumcision  PT 60 s, corrects to 29 s on mixing studies  Maternal great-uncle was a “free bleeder”  Fct. VIII level 4%

Umbilical Cord Blood Stem Cell Transplantation  Cord blood stem cells may be used for a bone marrow transplant  Less likely to cause graft versus host disease  Does not need to be fully HLA matched for a successful transplant  Can be collected without any risk for the donor

Private Cord Blood Banking  Service offered to parents by several for profit companies  Autologous transplant  Malignant disorders  rare in children  no graft vs. leukemia/ tumor effect  Allogeneic transplant  First degree relatives with  Malignancies treatable with stem cell transplant  Hemoglobinopathies ( Sickle Cell Disease, Thalassemia)  Congenital Immunodeficiency Disorders  Bone marrow Failure Disorders

 Newborns have distinct  Blood count values  Hemostatic parameters  Differential diagnosis  Disorders of the feto-maternal unit  Immunologic responses of the mother to fetal antigens  Congenital / genetic abnormalities