Hemolytic Anemia

Sickle Cell Anemia (SCA)

• Homozygous S disease has no hemoglobin A present.
• Elevated hemoglobin F (15–20%) is linked to a milder clinical outcome.
• Patients with S-beta+-thalassemia and SS alpha-thalassemia experience less severe symptoms than those with pure sickle cell anemia.
• Diagnosis essentials include recurrent pain episodes, positive family history of hemolytic anemia, irreversibly sickled cells on blood smear, and predominant hemoglobin S on electrophoresis.

Autoimmune Hemolytic Anemia

• Acquired hemolytic anemia is caused by IgG autoantibodies.
• Peripheral blood smear shows spherocytes and reticulocytosis.
• Positive Coombs test confirms diagnosis.
• Roughly half of cases are idiopathic; can also occur with SLE, rheumatic disorders, CLL, or lymphomas.
• Distinction from drug-induced hemolytic anemia is essential; drug-induced involves autoantibodies against membrane-drug complexes.

Clinical and Laboratory Findings

• Autoimmune hemolytic anemia can lead to rapidly developing, potentially life-threatening anemia.
• Symptoms include fatigue, dyspnea, and possible angina or heart failure; jaundice and splenomegaly are common findings.
• Severe hemolysis can result in cardiovascular collapse.
• Anemia severity varies, with hematocrit potentially dropping below 10%.
• Reticulocytosis and spherocytes appear on blood smear; indirect bilirubin is elevated and haptoglobin is decreased.

Treatment Strategies

• Prednisone (1–2 mg/kg/day) is standard for treatment; response is similar in DAT-negative and DAT-positive cases.
• Incompatible blood transfusions may be necessary due to cross-match challenges.
• Immunosuppressive agents like cyclophosphamide, vincristine, and azathioprine are options.
• Plasmapheresis is effective in acute hemolysis cases; high-dose IVIG may help control hemolysis.
• Splenectomy is indicated if prednisone fails or if recurrence occurs during tapering.
• Rituximab is used for refractory cases.

Hemolytic Anemias Overview

• Hemolytic anemias reduce red blood cell survival, can be episodic or continuous, leading to anemia when the bone marrow's compensatory mechanisms fail.
• Classified into intrinsic defects (hereditary) and extrinsic factors (immune-mediated, infections, microangiopathic hemolytic anemia).
• Common laboratory features include decreased haptoglobin, elevated indirect bilirubin, and increased LDH.

Thalassemia Essentials

• Family history and history of microcytic anemia are common.
• Affected individuals exhibit disproportionate microcytosis to anemia, normal or elevated RBC count, and abnormal red blood cell morphology.
• Variants include alpha-thalassemia trait, hemoglobin H disease, beta-thalassemia minor, major, and intermedia.
• Thalassemias are characterized by reduced synthesis of globin chains, leading to hypochromic microcytic anemia.

Sickle-Thalassemia Insights

• Homozygous sickle cell anemia combined with alpha-thalassemia results in less vigorous hemolysis and higher hemoglobin levels due to decreased sickling.
• Sickled red cells result in the release of ATP; ATP conversion to adenosine contributes to further sickling.
• Free hemoglobin scavenges nitric oxide, leading to endothelial dysfunction and vascular complications.
• Factors increasing sickling include dehydration of red blood cells and formation of deoxyhemoglobin S, typically from acidosis and hypoxemia.

Clinical Findings in Sickle Cell Anemia

• Symptoms include jaundice, gallstones, splenomegaly, and chronic skin ulcers.
• Severe anemia can occur during hemolytic or aplastic crises, often triggered by infection or folate deficiency.

Test your knowledge on Sickle Cell Anemia and Autoimmune Hemolytic Anemia with this quiz. Explore the essential diagnostic criteria, clinical findings, and differences between various types of hemolytic anemias. Perfect for students and healthcare professionals looking to deepen their understanding of hematology.