Sideroblastic Anemia Overview

Sideroblastic Anemia

• Siderocytes: Mature red blood cells containing iron granules (Pappenheimer bodies), considered abnormal.
• Sideroblasts: Immature nucleated red blood cells in the bone marrow containing small amounts of iron in the cytoplasm, considered normal.
• Sideroblastic Anemia: Characterized by iron accumulation within mitochondria of immature red blood cells in the bone marrow. Iron forms a ring around the nucleus in these cells, called ringed sideroblasts, considered abnormal.

Types of Sideroblastic Anemia

• Primary Sideroblastic Anemia: Cause unknown, not reversible.
• Secondary Sideroblastic Anemia: Commonly due to alcohol, anti-tuberculosis drugs, and lead poisoning.
• Alcohol and anti-tuberculosis drugs: Inhibit vitamin B6 (pyridoxine).
• Lead poisoning: Inhibits multiple steps in the protoporphyrin pathway.

Lead Poisoning

• Lead poisoning: Inhaled or ingested lead results in abnormal lead levels.
• Symptoms: Neurologic issues and lead lines on the gums.
• Treatment: Chelation therapy using EDTA.

ACD Pathogenesis

• Lactoferrin: Iron-binding protein in the granules of neutrophils, binds iron with higher affinity than transferrin.
• Infection or inflammation: Neutrophils release lactoferrin into the plasma, which scavenges available iron.
• Lactoferrin binds to: Macrophages and liver cells (due to their lactoferrin receptors).

Cytokines

• Cytokines: Produced by macrophages during inflammation.
• Effect of cytokines: Contribute to anemia of chronic disease by inhibiting erythropoiesis.

Lab Diagnosis

• Blood findings:
  • Early stage: Normocytic, hypochromic.
  • Late stage: Hypochromic, microcytic.
  • Low serum iron, low TIBC, normal or high serum ferritin.
  • Increased reticulocyte count.
  • Decreased hemoglobin and hematocrit.
• Leukocytosis: Elevated white blood cell count.
• Abundant storage of iron in macrophages: Observed using Prussian blue staining.

This quiz explores the key concepts of sideroblastic anemia, including the definitions and differences between siderocytes and sideroblasts. It also covers the types of sideroblastic anemia, their causes, and the impact of lead poisoning on health. Test your understanding of these crucial topics in hematology!