HEREDITARY/ACQUIRED HEMOLYTIC ANEMIA

HEMOLYTIC ANEMIAS Hemolytic anemias = reduced red-cell life span

Classification of Hemolytic anemias I Classification of Hemolytic anemias I. Red cell abnormality (Intracorpuscular factors) A. Hereditary 1. Membrane defect (spherocytosis, elliptocytosis) 2. Metabolic defect (Glucoze-6-Phosphate- Dehydrogenaze (G6PD) deficiency, Pyruvate kinase (PK) deficiency) 3. Hemoglobinopathies (unstable hemoglobins, thalassemias, sickle cell anemia ) B. Acquired 1. Membrane abnormality-paroxysmal nocturnal hemoglobinuria (PNH)

II. Extracorpuscular factors A. Immune hemolytic anemias 1 II. Extracorpuscular factors A. Immune hemolytic anemias 1. Autoimmune hemolytic anemia - caused by warm-reactive antibodies - caused by cold-reactive antibodies 2. Transfusion of incompatible blood B. Nonimmune hemolytic anemias 1. Chemicals 2. Bacterial infections, parasitic infections (malaria), venons 3. Hemolysis due to physical trauma - hemolytic - uremic syndrome (HUS) - thrombotic thrombocytopenic purpura (TTP) - prosthetic heart valves 4. Hypersplenism

SOME TYPES OF HHA eg. SICKLE CELL DISEASE THALASSEMIAS G6PD DEFICIENCY HEREDITARY SPHEROCYTOSIS

THALASSEMIAS MICROCYTIC, HYPOCHROMIC, HEMOLYTIC ANEMIA MOST COMMON IN AFRICAN, MEDITERRANEAN, MIDDLE EASTERN, & SOUTHEAST ASIAN DESCENT MULTIPLE VARIANTS

THALASSEMIAS CHARACTERIZED BY DEFECTIVE SYNTHESIS OF GLOBIN CHAINS, UNABLE TO PRODUCE NORMAL ADULT HEMOGLOBIN TRAIT THOUGHT TO BE PROTECTIVE AGAINST MALARIA AS WELL

HEMOGLOBIN NORMAL ADULT RBC CONSISTS OF 3 FORMS OF Hb: - HbA - 2 α and 2 β globin chains - HbA2 – 2 α and 2 δ globin chains - HbF - 2 α and 2 γ globin chains THALASSEMIAS α and β

THALASSEMIAS TYPES OF DZ CHARACTERIZED BY DEFFERING EXTREMES OF ANEMIA DEPENDS ON AMOUNT OF INEFFECTIVE ERYTHROPOIESIS AND PREMATURE DESTRUCTION OF CIRCULATING RBC’S HYPOXIA IN SEVERE CASES

G6PD DEFICIENCY MOST COMMON HUMAN ENZYME DEFECT X-LINKED DISORDER AFFECTS 15% OF U.S. BLACK MALES DECREASE IN GLUTATHIONE LEVELS

G6PD DEFICIENCY HEINZ BODIES SEEN ON PERIPHERAL BLOOD SMEAR NEONATAL JAUNDICE 1-4 DAYS AFTER BIRTH IN SEVERE VARIANTS INCREASE INCIDENCE OF PIDMENTED GALLSTONES AND SPLENOMEGALY

G6PD DEFICIENCY ACUTE HEMOLYTIC CRISIS DUE TO: - BACTERIAL/VIRAL INFECTION - OXIDANT DRUGS (SULFAMETHOXAZOLE) - METABOLIC ACIDOSIS (DKA) - RENAL FAILURE - INGESTION OF FAVA BEANS

G6PD DEFICIENCY DIAGNOSIS – QUANTITATIVE ASSAY DETECTING LOW ENZYME TREATMENT – SUPPORTIVE AND PREVENTATIVE

HEREDITARY SPHEROCYTOSIS RBS MEMBRANE DEFECT MOST COMMON HEREDITARY ANEMIA FROM PTS OF NORTHERN EUROPEAN DESCENT AUTOSOMAL DOMINANT MUTATIONS IN SPECTRIN AND ANKYRIN (MEMBRANE PROTEINS)

HEREDITARY SPHEROCYTOSIS SPHEROCYTES – IN PERIPHERAL BLOOD SMEAR SPHEROCYTES UNABLE TO PASS THROUGH THE SPLEEN SEVERE CASES REQUIRE A SPLENECTOMY

HEREDITARY SPHEROCYTOSIS NEONATAL JAUNDICE IN 1ST WEEK OCCURS IN 30-50% OF HS PTS ANEMIA, SPLENOMEGALY, JAUNDICE, AND TRANSFUSIONS NEEDED VARY DEPENDING ON SEVERITY OF DZ

Hereditary microspherocytosis 1 Hereditary microspherocytosis 1. Pathophysiology - red cell membrane protein defects (spectrin deficiency) resulting cytoskeleton instability 2. Familly history 3. Clinical features - splenomegaly 4. Laboratory features - hemolytic anemia - blood smear-microspherocytes - abnormal osmotic fragility test - positive autohemolysis test - prevention of increased autohemolysis by including glucose in incubation medium 5. Treatment - splenectomy

Sickle-Cell Anemia

Hemoglobin Composed of: 1 Heme and 4 Globin Chains 4 Types of Globin Chains: Alpha, Beta, Delta, Gamma

Sickle Cell Disease Cannot make Beta Chains Valine substituted for glutamate in 6th position of beta chain

Sickle Cell Disease Affects people of African descent Affects 72,000 people in the US 2 million people are carriers Occurs once in every 375 African American births

Sickle Cell Anemia Sickle Cell anemia is an inherited red blood cell disorder. Normal red blood cells are round like doughnuts, and they move through small blood tubes in the body to deliver oxygen. Sickle red blood cells become hard, sticky and shaped like sickles used to cut wheat. When these hard and pointed red cells go through the small blood tube, they clog the flow and break apart. This can cause pain, damage and a low blood count, or anemia.

The origin of the disease is a small change in the protein hemoglobin The change in cell structure arises from a change in the structure of hemoglobin. A single change in an amino acid causes hemoglobin to aggregate.

Hemoglobin is a carrier protein HbO2 CO2 deoxy Hb (CO2) Tissues Lungs

Hemoglobin changes structure for efficient oxygen uptake and delivery HbO2 deoxy Hb (CO2) Strong binding state R state Weak binding state T state

The small change in hemoglobin structure leads to aggregation Subunits Normal hemoglobin (Hb A) Sickle cell hemoglobin (Hb S)

Genetic Inheritance

Symptoms in Children Start to appear at 6 months Dactylitis (swelling of hands and feet) Heart Enlargement Growth Retardation Delayed Sexual Development

Dactylitis

Sickle Cell Crisis Severe pain caused by blocked blood flow Triggered by Infection, Dehydration, Fatigue, or Emotional Stress Can last up to 5 days

Splenic Sequestration Spleen tried to remove abnormal cells Becomes enlarged and causes pain Autosplenectomy occurs Usually not seen in adults

Symptoms of Anemia Tiredness Headaches Dizziness Faintness Shortness of breath

Other Symptoms Chronic, low-level pain in joints and bones Abdominal pain Retina Damage Gallstones Leg Ulcers (adults) Chest pain

Leg Ulcers

Blood Picture Sickle, Target and/or nRBCs Decreased Hemoglobin Increased retic count White cell count increased WBC shift to the left

Hgb Electrophoresis Amino acids in globin chains have different charges Separates hemoglobin according to charge 90% Hgb S, 10% Hgb F, small fraction of Hgb A2

Prognosis No cure Life expectancy: 42 years men 48 years women 85% reach the age of 20 50% reach age 50 Causes of death: Infection, heart failure

Treatment Pain Medication Increase fluids Blood Transfusion Bone Marrow Transplant

Acquired Hemolytic Anemia

Introduction Increased RBC Destruction – Short RBC life span <120 days. Normocytic normochromic, reticulocytosis Anemia, Jaundice, marrow hyperplasia Splenomegaly, bilirubin gall stones Unconjugated “acholuric” (pale urine) Common types - AIHA, MAHA

Types of acquired HA AutoImmune Haemolytic Anemias (+ve DAT) Alloimmune haemolytic anemias Drug-induced immune haemolytic anemias Red cell fragmentation syndromes Infections Chemical & physical agents Secondary Haemolytic anemias Paroxysmal Nocturnal Haemoglobinuria (PNH)

Pathogenesis of Jaundice: Hb Globin-Iron-Haem Bilirubin  Glucoronide–Conjugation  Bile  Gut Stercobilinogen & Stercobilin (ex.in stool) Urobilinogen & Urobilin (ex. In urine)

Ketabolism of Hb:

Classification : Auto Immune AIHA - Alloimmune Non-Immune Warm antibody type Cold antibody type Alloimmune Transfusion reactions Hemolytic disease of new born Non-Immune Microangiopathic hemolytic anemia Infections – Malaria, clostridia, Burns, Toxins, snake & spider bites.

Laboratory Diagnosis: RBC Breakdown: Hyperbilirubinemia Urobilinogen, stercobilinogen serum haptoglobins RBC Production: Reticulocytosis, *MCV Marrow hyperplasia* Damaged RBC Morphology, fragility, survival

Laboratory Diagnosis: Additional features of Intravascular Hemolysis: Hb-naemia and Hb-nuria Haemosiderinuria Methaemoglobinemia

DRUG RELATED HA ALPHA-METHYLDOPA LEVODOPA PROCAINAMIDE SULFA DRUGS PENICILLIN CEFTRIAXONE CEFOTETAN QUINIDINE

MICROANGIOPATHIC SYNDROMES THROMBOCYTOPENIC PURPURA HEMOLYTIC UREMIC SYNDROME

TTP & HUS - PATHOPHYS PLATELET AGGREGATION IN THE MICROVASCULATURE CIRCULATION VIA MEDIATION OF von WILLEBRAND’S FACTOR LEADS TO THROMBOCYTOPENIA AND FRAGMENTATION OF RBC’S AS THEY PASS THROUGH THESE OCCLUDED ARTERIOLES AND CAPILLARIES

THROMBOCYTOPENIC PURPURA (TTP) PLATLET COUNTS < 20,000 MORE COMMON IN WOMEN AGES 10-60 FEVER, NEUROLOGIC DEFICITS, HEMORRAGE, AND RENAL INSUFFICIENCY UNTREATED – 80-90% MORTALITY

TTP SCHISTOCYTES OR HELMET CELLS SEEN OF PERIPHERAL SMEAR INCREASED BUN/Cr LEVELS

TTP PREGNANCY IS THE MOST COMMON PRECIPITATING EVENT FOR TTP PREECLAMPSIA SIMILAR TO TTP; DELIVERY TX FOR PREECLAMPSIA, NOT CURE TTP

TTP – ER TREATMENT PREDNISONE 1-2mg/kg/day INITIALLY PLASMA EXCHANGE TRANSFUSION IS FOUNDATION FOR TX (INFUSE FRESH FROZEN PLASMA IF TRANSFUSION UNAVAILABLE AVOID PLATELET TRANSFUSION NEVER USE ASPIRIN

TTP – ER TREATMENT PT MAY NEED SPLENECTOMY AZATHIOPRINE AND CYCLOPHOSPHAMIDE FOR THOSE WHO FAIL OR CANNOT TOLERATE STEROIDS

HUS DZ OF EARLY CHILDHOOD PEAK INCIDENCE BETWEEN 6mo-4yr OFTEN FOLLOWS BACTERIAL/VIRAL ILLNESS MORTALILY 5-15%, WORSE IN OLDER CHILDREN & ADULTS

HUS CHARACTERIZED BY -ACUTE RENAL FAILURE -MICROANGIOPATHIC HA -FEVER -THROMBOCYTOPENIA (NOT AS SEVERE AS TTP)

HUS THE MOST COMMON CAUSE OF ACUTE RENAL FAILURE IN CHILDHOOD E.Coli O157:H7 COMMON CAUSE MICROTHORMBI ARE CONFINED MAINLY TO KIDENYS, WHERE TTP MORE WIDESPREAD

HUS – ER TREATMENT MILD HUS < 24hr OF URINARY SX NEELS ONLY FLUID/ELECTROLYTE CORRECTION AND SUPPORT CARE STEROID THERAPY HEMODIAYLSIS IF ACUTE RENAL FAILURE PRESENT ABX TX CONTROVERSIAL WHEN E.Coli PRESNENT; DO NOT USE ANTIMOLITY DRUG, INCREASE RISK OF DEVELOP HUS

HELLP SYNDROME HEMOLYSIS ELEVATED LIVER ENZYMES LOW PLATLET COUNTS

HELLP SYNDROME 1 IN 1OOO PREGNANCIES SEEN IN PRESENCE OF ECLAMPSIA, PREECLAMPSIA, AND PLACENTAL ABRUPTION MAY EXTEND UP TO 6 DAYS POSTPARTUM

HELLP SYNDROME RUQ AND EPIGASTRIC PAIN – SEEN IN 90% OF PTS (POSSIBLE HEPATIC RUPTURE) DX BASED ON LAB DATA DECREASED SERUM HAPTOGLOBIN LEVEL MOST SENSITIVE

HELLP SYNDROME - TX PROMPT DELIVERY OF INFANT SUPPORTIVE CARE FOR SEIZURES AND HTN CRISIS STEROIDS MAY HELP FETAL LUNGS, BUT NO BENEFIT TO HELLP SYNDROME

Warm AIHA Cold Idiopathic Secondary Spherocytes IgG antibody, C3d Autoimmune lymphoma, drugs Spherocytes IgG antibody, C3d Direct Coombs - 37° Anti c / anti e Idiopathic Secondary Infections Lymphoma RBC clumps IgM antibody Cold Ag. Titre 4° DAT +ve compl* Anti I / i

Warm AIHA Cold Idiopathic Secondary Idiopathic Secondary PCH (anti-P) SLE, Autoimmune disorders. CLL Lymphoma Drugs – Mdopa. Idiopathic Secondary Infections Lymphoma PCH (anti-P)

Warm AIHA IgG, C3d, rarely other Ab. Destruction in Spleen & RES Loss of partial membrane – spherocytes Clinical Features: Spleenomegaly

Autoimmune hemolytic anemia caused by warm-reactive antibodies: I Autoimmune hemolytic anemia caused by warm-reactive antibodies: I. Primary II. Secondary 1. acute - viral infections - drugs ( -Methyldopa, Penicillin, Quinine,Quinidine) 2. chronic - rheumatoid arthritis, systemic lupus erythemat. - lymphoproliferative disorders (chronic lymphocytic leukemia, lymphomas, WaldenstrÖm’s macroglobulinemia) - miscellaneous (thyroid disease, malignancy )

Autoimmune hemolytic anemia caused by cold-reactive antibodies: I Autoimmune hemolytic anemia caused by cold-reactive antibodies: I. Primary cold agglutinin disease II. Secondary hemolysis: - mycoplasma infections - viral infections - lymphoproliferative disorders III. Paroxysmal cold hemoglobinuria

Alloimmune Haemolysis: Antibody from another person. Transfusion reactions Haemolytic disease of Newborn (HDN) RH-D, RH neg mother, + father, 2nd baby Kleihauer test HbF, ABO – IgG in O mother, mild*, 1st baby- agglutination & spherocytes, DAT neg/mild + Post transplantation induced.

Paroxysmal nocturnal hemoglobinuria 1 Paroxysmal nocturnal hemoglobinuria 1. Pathogenesis - an acquired clonal disease, arising from a somatic mutation in a single abnormal stem cell - glycosyl-phosphatidyl- inositol (GPI) anchor abnormality - deficiency of the GPI anchored membrane proteins (decay-accelerating factor =CD55 and a membrane inhibitor of reactive lysis =CD59) - red cells are more sensitive to the lytic effect of complement - intravascular hemolysis 2. Symptoms - passage of dark brown urine in the morning

3. PNH –laboratory features: - pancytopenia - chronic urinary iron loss - serum iron concentration decreased - hemoglobinuria - hemosiderinuria - positive Ham’s test (acid hemolysis test) - positive sugar-water test - specific immunophenotype of erytrocytes (CD59, CD55) 4. Treatment: - washed RBC transfusion - iron therapy - allogenic bone marrow transplantation

Microangiopathy:

Spherocytes:

AIHA Cold ab type: Clumping.

Assesment of HA Clinical features: - pallor - jaundice - splenomegaly

Laboratory features: 1. Laboratory features - normocytic/macrocytic, hyperchromic anemia - reticulocytosis - increased serum iron - antiglobulin Coombs’ test is positive 2. Blood smear - anisopoikilocytosis, spherocytes - erythroblasts - schistocytes 3. Bone marrow smear - erythroid hyperplasia

Diagnosis of hemolytic syndrome: 1. Anemia 2. Reticulocytosis 3 Diagnosis of hemolytic syndrome: 1. Anemia 2. Reticulocytosis 3. Indirect hyperbilirubinemia

Autoimmune hemolytic anemia - diagnosis - positive Coombs’ test Treatment: - steroids - splenectomy - immunosupressive agents - transfusion