What is the interpretation and management of a CBC showing microcytic anemia with low hemoglobin, hematocrit, MCV, MCH, and MCHC, and elevated RDW?

Interpretation of CBC: Microcytic Hypochromic Anemia

This CBC shows iron deficiency anemia, characterized by low hemoglobin, low MCV, low MCH, low MCHC, and elevated RDW. 1

Laboratory Findings Analysis

• Hemoglobin 10.3 g/dL (low): Indicates anemia in a female patient (reference range 11.1-15.9 g/dL) 1
• Hematocrit 35.3% (normal): Within reference range (34.0-46.6%) but at the lower end 1
• MCV 78 fL (low): Indicates microcytosis (reference range 79-97 fL) 1
• MCH 22.8 pg (low): Indicates hypochromia (reference range 26.6-33.0 pg) 1
• MCHC 29.2 g/dL (low): Further confirms hypochromia (reference range 31.5-35.7 g/dL) 1
• RDW 15.5% (high): Indicates increased variation in red cell size (reference range 11.7-15.4%) 2
• Platelets 337 x10³/μL (normal): Within reference range (150-450 x10³/μL) 1

Diagnostic Interpretation

The combination of low MCV, low MCH, low MCHC, and elevated RDW strongly suggests iron deficiency anemia 2, 1:

• Low MCV (microcytosis) with high RDW is characteristic of iron deficiency anemia 2
• The elevated RDW (>14.0%) with low MCV helps differentiate iron deficiency from thalassemia, which typically shows low MCV with normal RDW 2
• The pattern of hypochromia (low MCH and MCHC) further supports iron deficiency 1

Recommended Next Steps

1. Confirm iron deficiency with additional testing 1:

   • Serum ferritin (most sensitive test for iron stores)
   • Serum iron and total iron binding capacity (TIBC)
   • Transferrin saturation (should be <15% in iron deficiency)

2. If iron studies are equivocal or normal, consider alternative causes of microcytic anemia 2:

   • Hemoglobin electrophoresis to rule out thalassemia
   • Consider anemia of chronic disease (would show normal/high ferritin with low serum iron)
   • Evaluate for sideroblastic anemia (rare genetic disorders)

3. Investigate underlying cause of iron deficiency 1:

   • Evaluate for blood loss (menstrual, gastrointestinal)
   • Assess dietary intake
   • Consider malabsorption disorders
   • Age-appropriate cancer screening if indicated

Treatment Approach

1. Oral iron supplementation as first-line therapy 1:

   • Ferrous sulfate 325 mg (65 mg elemental iron) 1-3 times daily
   • Take on empty stomach with vitamin C to enhance absorption
   • Monitor for gastrointestinal side effects

2. If no response to oral iron after 4-8 weeks 1:

   • Reassess compliance
   • Consider ongoing blood loss
   • Evaluate for malabsorption
   • Consider parenteral iron if oral therapy fails

3. Follow-up CBC in 2-4 weeks to assess response to therapy 1

Important Considerations

• Reticulocyte count may help assess bone marrow response to iron therapy 1
• In patients with inflammation, serum ferritin up to 100 μg/L may still be consistent with iron deficiency 2
• The combination of low MCV and high RDW has high specificity for iron deficiency anemia 2
• If iron deficiency is confirmed, the source of blood loss must be identified, especially in men and non-menstruating women 1