Questions and Answers
What type of autoantibodies does methyldopa induce against RBC?
Primary cold agglutinin is caused by IgG antibodies.
False
What is a common symptom associated with paroxysmal cold hemoglobinuria?
Mild jaundice
Which of the following infections can precipitate acute hemolytic crises in G6PD deficiency?
Signup and view all the answers
PIGA is required for ___ synthesis.
Signup and view all the answers
Which drug is known to cause immune hemolytic anemia by binding to RBC membranes?
Signup and view all the answers
What is the treatment option for paroxysmal nocturnal hemoglobinuria?
Signup and view all the answers
Match the following symptoms with their associated conditions:
Signup and view all the answers
What are the classifications of hemolytic anemia?
Signup and view all the answers
What are the clinical manifestations of hemolytic anemia?
Signup and view all the answers
What laboratory findings indicate hemolytic anemia?
Signup and view all the answers
What disorders can cause hemolytic anemia?
Signup and view all the answers
The primary defect in hereditary spherocytosis involves the _____ skeleton of red blood cells.
Signup and view all the answers
Describe intravascular hemolysis.
Signup and view all the answers
What is an osmotic fragility test used for?
Signup and view all the answers
Which of the following is a cause of acquired hemolytic anemia?
Signup and view all the answers
Sickle cell disease is considered a type of acquired hemolytic anemia.
Signup and view all the answers
Match the type of hemolytic anemia with its cause.
Signup and view all the answers
Study Notes
Classification of Hemolytic Anemia
- Hemolytic anemia is classified into hereditary and acquired forms.
-
Hereditary causes:
- Membrane defects, such as hereditary spherocytosis and hereditary elliptocytosis.
- RBC metabolism defects, including G6PD deficiency and thalassemia.
-
Acquired causes:
- Immune hemolytic anemia (Autoimmune, Alloimmune, drug-associated).
- Secondary causes include infections and red cell fragmentation syndromes.
- Intravascular (RBC lysed in circulation) vs. Extravascular (RBC destruction by macrophages in the spleen).
Causes and Clinical Manifestations
-
Intravascular Hemolysis:
- Mechanisms: Mechanical forces, biochemical agents, physical agents damage RBCs.
- Clinical features: Hemoglobinemia, hemoglobinuria, hemosiderinuria, loss of iron, low haptoglobin.
-
Extravascular Hemolysis:
- Macrophage-mediated destruction of abnormal RBCs.
- Clinical features: Hyperbilirubinemia, jaundice, splenomegaly, bilirubin-rich gallstones, low haptoglobin.
Laboratory Findings
-
Increased RBC Breakdown:
- Elevated serum bilirubin, urine urobilinogen, faecal stercobilinogen.
- Absent haptoglobin, indicative of free hemoglobin.
-
Increased RBC Production:
- Reticulocytosis, erythroid hyperplasia evident in the bone marrow.
-
Damaged RBCs:
- Abnormal morphology, osmotic fragility tests, and specific enzyme, protein, and DNA tests.
Pathogenesis and Specific Disorders
-
G6PD Deficiency:
- An inherited enzyme defect affecting RBC metabolism.
- Symptoms include neonatal jaundice, acute hemolytic anemia during oxidative stress (e.g., infections, certain foods).
- Bite cells and Heinz bodies observed on blood smear.
-
Autoimmune Hemolytic Anemia (AIHA):
- Caused by antibodies binding to RBCs, leading to their destruction.
- Warm AIHA characterized by IgG antibodies, while cold AIHA involves IgM antibodies.
- Diagnosis via direct antiglobulin test (DAT) that shows antibody coating on RBCs.
-
Hereditary Spherocytosis:
- Genetic condition causing spherical RBCs due to defects in membrane proteins (spectrin, ankyrin).
- Clinical features: Jaundice, splenomegaly, and cholelithiasis are common.
- Investigations reveal dark spherocytes and increased osmotic fragility.
-
Hereditary Elliptocytosis:
- Mutations in spectrin cause elliptical RBCs and can lead to milder hemolytic anemia.
- Presents with microspherocytes and poikilocyte features on smear.
-
South-East Asian Ovalocytosis:
- Genetic mutation providing resistance to malaria but can cause hemolytic anemia.
Treatment Options
-
General Treatment:
- Blood transfusions for symptomatic anemia.
- Folate supplementation in hereditary forms.
- Splenectomy may be indicated for cases with excessive spleen-mediated RBC destruction.
-
For Autoimmune Hemolytic Anemia:
- Treatment often includes corticosteroids and immunosuppressive therapy.
- Rituximab is used for refractory cases.
-
For G6PD Deficiency:
- Avoidance of oxidant stress triggers, supportive care such as transfusions during crises.### Aggressive Lymphoma and Immune Hemolytic Anemia
-
May transform into aggressive lymphoma but is usually self-limiting.
-
Complement factors detectable on RBCs in lab tests as IgM is eluted off in the cold agglutinin.
Treatment Approaches
- Keep the patient warm to promote circulation.
- Treatment includes alkylating agents, rituximab, splenectomy, and corticosteroids.
Drug-Induced Immune Hemolytic Anemia
- Penicillin: Antibodies directed against drug-RBC membrane complex.
- Quinidine: Causes complement deposition through drug-protein (antigen)-antibody complex.
- Methyldopa: Autoimmune antibodies bind to RBCs, inducing hemolysis.
Red Cell Fragmentation Syndromes
- G6PD deficiency can precipitate acute hemolytic crises due to infections.
- Meningococcal septicaemia, malaria, and Clostridium perfringes lead to intra and extravascular hemolysis.
- Oxidative intravascular hemolysis associated with drugs like sulfasalazine and dapsone.
Chemical and Physical Agents
- High copper levels in Wilson's disease lead to acute hemolytic anemia.
- Chemical poisoning from lead, chlorate, or arsine results in severe hemolysis.
- Burns can cause spherocytosis and acanthocytosis.
Secondary Hemolytic Anemia
- Liver diseases associated with hemolysis include:
- Zieve’s syndrome: Alcohol-induced.
- Wilson’s disease: Copper oxidation of RBC membrane.
- Chronic immune hepatitis can lead to autoimmune hemolytic anemia (AIHA).
- End-stage liver disease impacts RBC membranes due to lipid changes.
- In kidney diseases, hemolysis may occur due to Hemolytic Uremic Syndrome (HUS) and Thrombotic Thrombocytopenic Purpura (TTP).
Paroxysmal Nocturnal Hemoglobinuria (PNH)
- X-linked disorder caused by a mutation in the PIGA gene, essential for phosphatidylinositol glycan (PIP) synthesis.
- Chronic intravascular hemolysis leads to hemosiderinuria and free hemoglobin.
- RBCs become sensitive to complement lysis, resulting in venous thrombosis complications.
- Flow cytometry shows the loss of CD55 and CD59 expression.
- Treatments include Eculizumab, iron therapy, and stem cell transplant as a definitive approach.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the classification of hemolytic anemia into hereditary and acquired forms, along with their causes and clinical manifestations. It delves into specific conditions and the mechanisms of both intravascular and extravascular hemolysis, highlighting significant clinical features. Test your knowledge on this vital aspect of hematology.
