From the Guidelines
Low MCH is most likely indicative of iron deficiency anemia, and treatment with oral iron supplementation is recommended. This condition is characterized by red blood cells containing less hemoglobin than normal, typically defined as less than 27 picograms per cell 1. The British Society of Gastroenterology guidelines suggest that MCH is a reliable marker of iron deficiency, as it is less dependent on storage and the counting machine used, and a reduction is seen in both absolute and functional iron deficiency 1.
Causes and Diagnosis
The causes of low MCH include iron deficiency anemia, thalassemia, chronic disease, or lead poisoning. To diagnose iron deficiency anemia, serum markers such as low ferritin, low transferrin saturation, and low iron are used 1. Serum ferritin (SF) is the most specific test for iron deficiency in the absence of inflammation, with an SF level of <15 μg/L indicative of absent iron stores 1.
Treatment
Treatment for iron deficiency anemia typically involves oral iron supplementation, with standard dosing being ferrous sulfate 325 mg (containing 65 mg elemental iron) taken 1-3 times daily between meals with vitamin C to enhance absorption. Patients should have their hemoglobin levels monitored after 4-8 weeks of treatment, and therapy typically continues for 3-6 months after hemoglobin normalizes to replenish iron stores 1.
Dietary Changes and Alternative Treatments
Dietary changes to include iron-rich foods like red meat, spinach, and beans can complement treatment. If oral iron is not tolerated or effective, intravenous iron formulations may be necessary 1. It's essential to identify and address the underlying cause of iron deficiency, such as blood loss from menstruation, gastrointestinal bleeding, or malabsorption.
Key Considerations
When interpreting MCH results, it's crucial to consider the presence of chronic disease, thalassemia, or vitamin B12/folate deficiency, as these conditions can affect the sensitivity and specificity of MCH as a marker of iron deficiency 1. Hb electrophoresis is recommended in those with microcytosis and normal iron studies, particularly if there is an appropriate ethnic background 1.
From the Research
Low MCH
- Low MCH (Mean Corpuscular Hemoglobin) is often associated with iron deficiency anemia (IDA) 2
- IDA is defined as low Hb or hematocrit associated with microcytic and hypochromic erythrocytes and low RBC count due to iron deficiency 2
- The diagnosis, management, and treatment of patients with ID and IDA change depending on age and gender and during pregnancy 2
- Iron deficiency is the reduction of total body iron stores due to impaired nutrition, reduced absorption secondary to gastrointestinal conditions, increased blood loss, and increased needs as in pregnancy 2
Causes and Prevalence
- Blood loss is the most common cause of acute iron depletion and anemia worldwide 2
- IDA most commonly affects women of reproductive age, the developing fetus, children, patients with chronic and inflammatory diseases, and the elderly 2
- IDA is the most frequent hematological disorder in children, with an incidence in industrialized countries of 20.1% between 0 and 4 years of age and 5.9% between 5 and 14 years 2
Treatment and Management
- Guidelines for the diagnosis and treatment of iron deficiency anemia using intravenous iron vary across different therapeutic areas 3
- Approximately 60% of the guidelines have not been updated in ≥5 years and consequently do not reflect current evidence on the safety and efficacy of IV iron 3
- There is no relevant information on low MCH in the study on total condylar knee prosthesis 4