From the Guidelines
Low hemoglobin (Hb) with low MCV, MCH, and MCHC indicates microcytic hypochromic anemia, most commonly caused by iron deficiency. According to the most recent and highest quality study 1, treatment typically involves oral iron supplementation such as ferrous sulfate 325 mg taken 1-2 times daily between meals with vitamin C to enhance absorption.
Key Considerations
- Therapy should continue for 3-6 months even after hemoglobin normalizes to replenish iron stores.
- Common side effects include constipation, nausea, and black stools.
- If oral iron isn't tolerated or effective, intravenous iron formulations may be necessary.
Diagnostic Approach
- A comprehensive workup including ferritin, iron studies, and possibly endoscopy or colonoscopy may be needed depending on age and risk factors, as suggested by 1.
- Other less common causes of this blood picture include thalassemia, anemia of chronic disease, sideroblastic anemia, and lead poisoning, which require different treatments based on the specific diagnosis.
Underlying Cause Identification
- It's essential to identify and address the underlying cause of iron deficiency, which could be blood loss (menstruation, gastrointestinal bleeding), poor dietary intake, malabsorption, or increased requirements during pregnancy.
- Serum ferritin concentration is the most powerful test for ID, with a concentration of <12 μg/dl being diagnostic of ID, as stated in 1.
From the Research
Low Hemoglobin with Low MCV, MCH, and MCHC
- Low hemoglobin (Hb) levels with low mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) are indicative of microcytic anemia 2, 3.
- Microcytic anemia is characterized by the presence of small, often hypochromic, red blood cells in a peripheral blood smear and is usually defined by a low MCV (less than 83 micron 3) 2.
- The most common causes of microcytic anemia are iron deficiency anemia (IDA) and α-thalassemia 3.
Causes of Microcytic Anemia
- Iron deficiency anemia (IDA) is the most common cause of microcytic anemia, resulting from defective synthesis of hemoglobin in the erythroid precursors 2, 3.
- α-thalassemia is another common cause of microcytic anemia, which can be isolated or associated with iron deficiency 3.
- Other causes of microcytic anemia include anemia of chronic disease, thalassemia, and sideroblastic anemia 2.
Diagnostic Parameters
- Hematological parameters such as MCV, MCH, MCHC, and red blood cell distribution width (RDW) can be useful in differentiating between different types of microcytic anemia 3.
- Serum ferritin measurement is a reliable indicator of iron stores, and a level of less than 10,15, or 20 μg/L is considered diagnostic of empty iron stores 4.
- MCH is slightly more accurate than MCV and MCHC in diagnosing empty iron stores in children and young adults 4.