Etiology, Investigations, and Differential Diagnosis of Microcytic Hypochromic Anemia

Anemia of Chronic Disease: Mechanisms and Distinguishing Features

Introduction

Microcytic hypochromic anemia is a hematological disorder characterized by small red blood cells with reduced hemoglobin concentration. It can result from various causes, including iron deficiency, chronic diseases, and genetic abnormalities.

Etiology

• Iron Deficiency Anemia: Due to inadequate iron intake, chronic blood loss, or malabsorption.
• Thalassemia: A genetic disorder affecting hemoglobin synthesis.
• Anemia of Chronic Disease (ACD): Occurs in chronic inflammatory conditions, impairing iron metabolism.
• Sideroblastic Anemia: Due to defective heme synthesis leading to abnormal iron accumulation in erythroblasts.

Investigations

Proper diagnosis requires a combination of laboratory tests:

• Complete Blood Count (CBC): Shows low hemoglobin, microcytic RBCs.
• Serum Iron Studies: Measures iron, ferritin, and transferrin saturation.
• Peripheral Blood Smear: Evaluates RBC morphology.
• Hemoglobin Electrophoresis: Used for thalassemia diagnosis.
• Bone Marrow Examination: Helpful in sideroblastic anemia cases.

Differential Diagnosis

• Iron Deficiency Anemia vs. ACD: ACD typically presents with normal or elevated ferritin levels, unlike iron deficiency anemia.
• Thalassemia vs. Iron Deficiency: Thalassemia patients show normal or elevated RBC count with target cells on smear.
• Sideroblastic Anemia: Presence of ring sideroblasts in the bone marrow is a key distinguishing feature.

Treatment Approaches

• Iron supplementation for iron deficiency anemia.
• Blood transfusions or chelation therapy for thalassemia.
• Managing underlying inflammatory conditions in anemia of chronic disease.
• Pyridoxine therapy for certain sideroblastic anemias.

Conclusion

Microcytic hypochromic anemia has diverse causes and requires meticulous evaluation for accurate diagnosis and appropriate management. Understanding the distinguishing features of anemia of chronic disease is crucial for targeted interventions.