Hemolytic anemia
Fazel Elahi (MD) Oncologist &Hematologist Production of Erythrocytes: Erythropoiesis Erythrocytes (RBCs) Components of Whole Blood
Plasma (55% of whole blood)
Buffy coat: leukocyctes and platelets (<1% of whole blood) Formed elements Erythrocytes 1 Withdraw blood 2 Centrifuge (45% of whole blood) and place in tube Erythropoietin Mechanism
Start Normal blood oxygen levels Stimulus: Hypoxia due to decreased RBC count,
decreased availability of O2 to blood, or increased Increases tissue demands for O2 O2-carrying ability of blood
Reduces O2 levels in blood
Erythropoietin Kidney (and liver to a Enhanced stimulates red smaller extent) releases erythropoiesis bone marrow erythropoietin increases RBC count Structure of Hemoglobin Hemolysis:
Any condition characterized by a significantly decreased erythrocyte life span RBC destrution
Hemolysis Ineffective erythropoesis hematoma
Haemolysis may be predominantly extravascular (i.e. phagocytic uptake) or intravascular (i.e. in the blood stream
Definition A haemolytic anaemia is an anaemia resulting from an increased rate of red cell destruction. This results in a shortening of the red cell life span Erythropoiesis in the bone marrow can expand by up to 6-fold to compensate for accelerated red cell destruction, but anaemia results when red cell destruction exceeds erythropoiesis Increased erythropoiesis leads to a reticulocytosis classification
Intavascular or Extravascular
Inheritance or Aquired
Extrinsic or Intrinsic HEMOLYTIC ANEMIA Causes
INTRACORPUSCULAR HEMOLYSIS Membrane Abnormalities Metabolic Abnormalities Hemoglobinopathies EXTRACORPUSCULAR HEMOLYSIS Nonimmune Immune Classification
The haemolytic anaemias can be classified as inherited or acquired Inherited haemolytic anaemias can be subclassified into
I. Haemoglobin defects II. Red cell membrane defects III. Red cell enzyme defects HEMOLYTIC ANEMIA Membrane Defects
Microskeletal defects Hereditary spherocytosis Membrane permeability defects Hereditary stomatocytosis Increased sensitivity to complement Paroxysmal nocturnal hemoglobinuria Hereditary hemolyisis
Hemoglobinopathy (alfa,beta thal, S,S beta ,C ,SC…..) Membran disorders ( HS ,HE, HPP, STOMATOCYTOSIS …) Enzyme defect: 1-Glycolytic pathway 2-Pentose phosphate pathway 3-Nucleotid metabolism INHERITED HAEMOLYTIC ANAEMIAS
HAEMOGLOBIN DEFECTS Thalassaemia Sickle cell anaemia Other haemoglobin defects
MEMBRANE DEFECTS Hereditary spherocytosis Other membrane defects
ENZYME DEFECTS G6PD deficiency Other enzyme defects All Hereditary etiology of hemolysis have intrinsic defect
Only nonhereditary intrinsic defect (PNH)
In some of intrinsic defect hemolysis one extrinsic factor cause hemolysis or aggrevated hemolysis (G6PD) Acquired haemolytic anaemias
immune or non-immune
The entire classification encompasses a very large number of different haemolytic disorders ACQUIRED HAEMOLYTIC ANAEMIAS
IMMUNE Auto-immune haemolytic anaemia Allo-immune haemolysis
NON-IMMUNE Microangiopathic haemolytic anaemias Infections Drugs and toxins Acquired membrane disorders Mechanical and physical agents Aquired
Immunohemolytic Microangiopathic Traumatic Infectious agent Chemical agent Physical agent Spur cell anemia PNH hypophosphATEMIA Vit .E deficency EXTRACORPUSCULAR HEMOLYSIS Nonimmune
Mechanical Infectious Chemical Thermal Osmotic Microangiopathic Hemolytic Anemia Causes
Vascular abnormalities Thrombotic thrombocytopenic purpura Renal lesions Malignant hypertension Glomerulonephritis Preeclampsia Transplant rejection Vasculitis Polyarteritis nodosa Rocky mountain spotted fever Wegener’s granulomatosis Microangiopathic Hemolytic Anemia
Vascular abnormalities
AV Fistula Cavernous hemangioma Intravascular coagulation predominant Abruptio placentae Disseminated intravascular coagulation Hemolysis
Acute
Chronic
Acute on chronic Clinical finding
Acute haemolysis presents with :
Fatigue, Pallor, Jaundice, Fever, Chills, Low back pain, Splenomegaly and Congestive cardiac failure
Haemoglobinuria results if the haemolysis is predominantly intravascular Clinical finding
Chronic haemolysis : (e.g. thalassemia, sickle cell anaemia etc)
Present with pallor, jaundice, splenomegaly and congestive cardiac failure; but in addition there may be gallstones, bony deformities and pathological fractures due to marrow erythroid expansion with thinning of the bone cortex Causes of Intravascular Haemolysis
Infection : Malaria, clostridium perfringen sepsis G6PD deficiency Severe auto-immune haemolytic anaemia Paroxysmal nocturnal haemoglobinuria Paroxysmal cold haemoglobinuria Transfusion : ABO mismatched blood, infected blood Burns Cardiac prosthesis Intravascular haemolysis
Elevated plasma haemoglobin (haemoglobinaemia) urinary haemoglobin (haemoglobinuria) serum LDH urinary haemosiderin
Elevated unconjugated bilirubin and reduced haptoglobins are found in both intra- and extravascular haemolysis Chronic intravascular haemolysis
Results in iron deficiency due to the loss of haemoglobin, haemosiderin and ferritin in the urine Extravascular haemolysis
Red cells are destroyed by phagocytosis by macrophages in the spleen, liver and bone marrow
This uptake system is often referred as the reticulo-endothelial system (R.E.S). In this situation, free haemoglobin is not liberated into the bloodstream Detecting reasons of hemolysis
Duration and severity Jundice (acholuric ) Splenomegaly Cholelithiasis (black stone) Leg ulcer Skeletal abnormality Fever , shaking chills Pain ( limb, back,abdominal,headache ) Malaise ,vomiting ,hypotention Shock ,oliguria, aneuria History ( famalial , personal , drugs ) Physical exam lab test : 1- Sign of accelerated RBC destruction 2- Sign of accelerated erythropoesis Normal blood film: There is a slight degree of anisocytosis (variation in cell size). The width of central pallor is less than one- third of the diameter of the cell. Laboratory finding
Peripheral blood film
Increased red cell destruction e.g. jaundice, unconjugated hyperbilirubinaemia, elevated serum lactate dehydrogenase (LDH), reduced haptoglobins
Increased erythropoiesis e.g. reticulocytosis, polychromasia, radiological changes of erythroid hyperplasia in chronic haemolysis The biochemical profile is characteristic of a pre- hepatic jaundice with unconjugated hyperbilirubinaemia and elevated LDH, but normal hepatocellular enzymes
There are a relatively small number of causes of intravascular haemolysis Therefore, tests for intravascular haemolysis are useful because the differential diagnosis for haemolysis can be considerably simplified if it can be shown that predominantly intravascular haemolysis is taking place RBC MORPHOLOGY HAEMOLYTIC ANAEMIA
Spherocytes hereditary spherocytosis, immune haemolysis, sepsis
Fragmentation DIC, artificial heart valves, malignancy, TTP, HUS Agglutination immune haemolysis
Target cells liver disease, thalassaemia, haemoglobin C Sickle cells S/S, S/C, S/Thal Blister cells G6PD deficiency Acanthocytes liver disease, pancreatitis, abetalipoproteinaemia Prickle cells pyruvate kinase deficiency post-splenectomy blood film ,nucleated red cells, Howell- Jolly bodies, acanthocytes, target cells, mild to moderate leukocytosis and thrombocytosis
This film is from a splenectomised patient who was in chronic renal failure, and therefore also shows burr cells. Reticulocytes are larger than mature red cells and stain purplish with Romanowsky stains (e.g. May Grunwald Giemsa). Reticulocytosis leads to a rise in the MCV (mean cell volume). The reticulocyte count is a simple test that provides a rough guide to the rate of red cell production
The reticulocyte count does not neccessarily reflect true erythroid activity because of premature or delayed release of reticulocytes from the marrow and variable rates of reticulocyte maturation in response to different conditions Reticulocyte count
(reference range 0. 2 - 2.0%)
Number of reticulocytes per litre
(10-100 x 109/L) Reticulocyte count: methylene blue stain BMA Erythroid Hyperplasia (haemoglobinaemia): Reddish plasma in severe intravascular haemolysis Urinary haemosiderin May persist for several weeks after an acute haemolytic episode, and may therefore be useful in detecting a bout of recent haemolysis Urinary haemosiderin: Perl's iron stain of urine cellular debris Sign of RBC destruction
Uncongugated bilirubin increased Urobilinogen “ “ “ LDH LDH2>LDH1 “ “ “ Haptoglobin deceased GHb glycosylated hemoglobin “ RBC life span (t ½ Cr ) “ Carbon menoxide increased Free haemoglobin binds with high affinity to a serum glycoprotein, haptoglobin and the complex is cleared by the reticulo-endothelial system (R.E.S.), resulting in a low or absent serum haptoglobin.
Albumin combines with haem to form methaemalbumin which gives a brown colour to the plasma. Methaemalbumin can be biochemically detected by Schumm's test
(LDH) is released from red cells during haemolysis and this contributes to a rise in serum LDH, which is a useful marker for intravascular haemolysis.
Massive deposition of free haemoglobin in the renal tubules can cause acute oliguric renal shutdown, a medical emergency, as seen in the haemolytic transfusion reaction. Intravascular hemolysis
HEMOGLOBINEMIA HEMOGLOBINURIA HEMISIDRINURIA METHEMOGLOBINEMIA METHEMALBUMINEMIA HEMOPEXIN decreased Urine hemosiderrin Spacific Lab test
Antiglobulin (coomb”s ) test Osmotic fragility test Autohemolysis Heat stability test (denaturation procedure ) Heinz body formation Isopropanol precipitation test Sickling test Retic with incubation (H.inclusion) Identifying Enzyme deficency Hemoglobin & globin chain study PNH Test HAM& sucrose lysis test ,flucytometry Glutathion stability test Ascorbate - cyanid test Sign of accelerated erythropoesis
Retic NRBC (erythroblastosis) Polychromatophilia Macrocytosis Basophilic stipling Leukocytosis (PMN rise), leukopenia Thrombocytosis ,thrombocytopenia, large Plt Erythrophagocytosis Autoagglutination BM erythroid hyperplasia , megaloblastic change Effective erythropoesis (PITR ,EITR ) Macrocyte Tin-macrocyte ,leptocyte ,wafer cell Target cell .codocyte Spherocyte , microspherocyte Elliptocyte ovalocyte Stomatocyte I,II,III, spertostomatocyte spheroechinocyte IV (dense crenated spher ,prickle cell ) Acanthocyte.spur cell Echinocyte .Burr cell,Crenated cell,berry cell type I,II,III Schistocyte ,helmet ,fragmented RBC Sickle cell ,Drepantocyte, boat shape RBC Keratocyte ,Horn cell Tear drop ,tennis racket, dacrocyte Basophilic stippling Heinz body ,howell jolly body Agglutination ,heophagocytosis Cabot Ring Reticulocyte Manual Count by Supravital Stain: Normal Count Reticulocytes: Elevated Count Hemolytic crisis
Aplastic crisis
Megaloblastic crisis Compensated hemolytic state
A state of hemolysis in which the resulting increased erythrocyte production is able to keep up with accelerated RBC destruction, thus averting any anemia Hemolytic anemia
A state of hemolysis in which increased erythrocyte production is insufficient to keep up with accelerated RBC destruction, thus producing anemia
This anemia is characterized as normochromic/normocytic, except when sufficient outpouring of the larger reticulocytes produces a resulting elevation of the MCV Diagnosis of hemolytic anemia is performed in four steps Step -1
1- Establish that anemia exists Step - 2 Marrow response Hemolysis is demonstration of an attempted marrow response to erythrocyte destruction
. Reticulocyte count . Absolute retic count (in cells/µL) . Reticulocyte production index (RPI) Step - 3
Look for erythrocyte detritus/their component catabolites, such as free hemoglobin, methemoglobin, methemalbumin, bilirubin, and urobilinogen, as well as the specific binding proteins for these catabolites, such as haptoglobin and hemopexin. Step - 4
The first distinction to make is to determine whether the hemolysis is (extravascular hemolysis) or(intravascular hemolysis)
Both types produce indirect hyperbilirubinemia, urobilinogen in stool and urine, decreased serum haptoglobin, and reticulocytosis intravascular hemolysis produces hemosiderin in the urine sediment, free hemoglobin in the serum (which may be grossly visible), and free denatured hemoglobin in the urine. helmet-shaped schizocytes (or "schistocytes"), which can be seen on the routine peripheral blood film
Extravascular hemolytic anemias may produce spherocytes, Leptocyte (hypochromic microcytic red cell), Blood smear Poikilocyte (DIC), Blood smear, Tear Drop Cell, Blood smear Basophilic Stippling, Blood smear Pappenheimer's body, Blood smear Howell-Jolly's body, Blood smear Rouleaux Formation, Blood smear Malaria, Blood smear Thalassemia, Bone marrow Schizocytes
FREQUENCY
Internationally: Hemolytic anemia represents approximately 5% of all anemias. RACE
. Sickle cell disorders are found primarily in Africans, African Americans, some Arabic peoples, and Aborigines in southern India
. Several variants of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency exist. The A variant generally is found in West Africans and African Americans. Approximately 10% of African Americans have at least 1 gene for this variant
. The Mediterranean variant occurs in individuals of Mediterranean descent and in some Asians SEX
Most cases of hemolytic anemia are not specific to any gender. Autoimmune hemolytic anemia (AIHA) is slightly more likely to occur in females than in males. G-6-PD deficiency is a X-linked recessive disorder. Males usually are affected, and females are carriers AGE
Hemolytic anemia can occur at any age. Hereditary disorders usually are evident early in life AIHA is more likely to occur in middle-aged and older individuals Peripheral smear and morphological examination
Identifies polychromasia, indicating RBC immaturity reticulocytosis
Demonstrates spherocytes, suggesting congenital spherocytosis or AIHA
Can identify schistocytes (fragmented red cells), suggesting TTP, HUS, or mechanical damage
Can help diagnose a concomitant underlying hematological malignancy associated with hemolysis (ie, CLL) Reticulocyte count
An increased reticulocyte count is a criterion for hemolysis but is not specific for hemolysis
An increase may be caused by blood loss or a bone marrow response to iron, vitamin B-12, or folate deficiencies
The reticulocyte count may be normal or low in patients with bone marrow suppression despite ongoing severe hemolysis Lactic acid dehydrogenase
Serum LDH is a criterion for hemolysis. LDH is not specific because it is ubiquitous and can be released from the neoplastic cells of the liver or other damaged organs.
Although an increase in LDH isozyme 1 and 2 is more specific for RBC destruction, these enzymes also are increased in patients with myocardial infarction. Serum haptoglobin
. A low serum haptoglobin is a criterion for moderate-to-severe hemolysis
. A decrease is more likely in intravascular hemolysis than in extravascular hemolysis, but it is an acute phase reactant
. The presence of concomitant infection, other reactive states, or chronic hemolysis may mask the diagnosis by raising haptoglobin levels Indirect bilirubin
Unconjugated bilirubin is a criterion for hemolysis, but it is not specific because an elevated bilirubin also may indicate Gilbert disease
With hemolysis, the level of indirect bilirubin usually is less than 4 mg/dL
Higher levels of indirect bilirubin indicate compromised hepatic function or cholelithiasis and hemolysis Changes in the LDH and serum haptoglobin levels are the most sensitive general tests because the indirect bilirubin is not always increased Imaging Studies:
Use ultrasound to estimate spleen size. The physical examination occasionally does not detect significant splenomegaly.
Chest radiograph is used to evaluate cardiopulmonary status Other Tests:
ECG and other studies are used to evaluate cardiopulmonary status Prognosis:
Depends upon the underlying cause for hemolysis
Patient Education:
The patient must be able to identify symptoms and signs of hemolysis recurrence and seek prompt medical attention if they occur. There are numerous fragmented RBC's seen here. Some of the irregular shapes appear as "helmet" cells. Such fragmented RBC's are known as "schistocytes" and they are indicative of a microangiopathic hemolytic anemia (MAHA) or other cause for intravascular hemolysis. This finding is typical for disseminated intravascular coagulopathy (DIC) The CBC of a patient with microangiopathic hemolytic anemia (MAHA) demonstrates a markedly increased RDW (red cell distribution width) due to the marked variation in size and shape of the RBC population. Erythrocyte Inclusions with Wright’s Stain
Inclusion Composition Appearance Condition
Basophilic Precipitated Evenly dispersed Lead poisoning stippling ribosomes fine or coarse granules thalassemia other anemia Howell-Jolly Nuclear Dense, round Post splenectomy bodies fragment blue granule Pappenheimer Iron-containing Small blue granules Anemias bodies granules in clusters Organism Small blue inclusion Malaria Babesiosis Basophilic Stippling Howell-Jolly Body Malaria RBC Inclusions: Composite Erythrocyte Distribution Abnormalities
Rouleaux formation Stacking of RBCs due to increased plasma proteins coating RBCs
Agglutination Antibody-mediated clumping; temperature dependent Rouleaux Formation Agglutination Reaction Variations in RBC Size and Shape
Anisocytosis Variations in size (e.g. microcytes)
Poikilocytosis Variations in shape (e.g. target cells)
Hypochromia Increased central pallor due to decrease in hemoglobin Variations in RBC Size and Shape
Anisocytosis Variations in size (e.g. microcytes)
Poikilocytosis Variations in shape (e.g. target cells)
Hypochromia Increased central pallor due to decrease in hemoglobin Hypochromic Microcytic RBC Normal Hypochromic microcytic Hypochromia without Anisocytosis: Thalassemia Trait Severe Hypochromia: Iron Deficiency Anemia Mixed Population: Treated Iron Deficiency Anemia Microcytic Hypochromia: Alpha Thalassemia (a-/--) Microcytic Hypochromia: Beta Thalassemia Major Microcytic Hypochromia: Beta Thalassemia Major Macrocytic Anemia: Macro- Ovalocytes Shape Abnormalities of Erythrocytes Terminology Description Condition
Target cells Central hemoglobin; target-shaped Liver disease; thalassemia: Abnormal Hgb; iron deficiency Echinocyte Short spicules, equally-spaced Uremia, hypokalemia, artifact Acanthocyte Spiculated, irregular Liver disease (alcohol), Post-splenectomy Spherocyte Spherical, no central pallor HS, Immune hemolytic anemia Schistocyte Fragmented RBC, helmet cells MAHA, burns
Ovalocyte Oval/elliptical shaped Hereditary elliptocytosis, Megaloblastic anemia Sickle cell bipolar spiculated shape Hgb S-containing “banana” shaped hemoglobinopathy Teardrop cell single elongated extremity Myelophthistic changes Bite cells Irregular gap in membrane G6PD deficiency Target Cells
Diagnostic possibilities Liver disease Hemoglobinopathy Thalassemia Iron deficiency Post-splenectomy Lipid disorders Echinocytes (Burr Cells) Acanthocytes (Spur Cells) Morphologic Changes in Liver Disease
Target Spur Cells Cells Hepatorenal Syndrome: Burr + Spur Cells Spherocytes Spherocytes: Autoimmune Hemolytic Anemia Spherocytes: Hereditary Spherocytosis Schistocytes: Microangiopathic Hemolytic Anemia Elliptocytes: Hereditary Elliptocytosis Sickle Cell Anemia: Hgb SS Hemoglobin SC Disease Hemoglobin S-Beta Thalassemia Teardrop Cells Bite Cells Heinz Bodies