Hemoglobin Electrophoresis Results Interpretation
What This Result Means
Your hemoglobin electrophoresis shows a slightly elevated Hemoglobin A (98.3%) and a LOW Hemoglobin A2 (1.7%), which is BELOW the normal range of 2.0-3.2%. Despite the conclusion stating "negative thalassemia screen," the low HbA2 level is clinically significant and requires further evaluation, as it may indicate iron deficiency anemia, certain types of alpha-thalassemia, or other conditions.
Understanding the Abnormal Values
The Low HbA2 (1.7%) is the Key Finding
A low HbA2 level below 2.0% is NOT normal and contradicts the "negative thalassemia screen" conclusion. 1 The normal reference range for HbA2 is 2.0-3.2%, and your result falls below this threshold.
Low HbA2 levels are specifically associated with:
- Iron deficiency anemia - This is the most common cause of low HbA2 2. The lowest HbA2 levels occur with the most severe iron deficiency anemia 2
- Hemoglobin H disease (a form of alpha-thalassemia) 2
- Hereditary persistence of fetal hemoglobin 2
Clinical Significance
The slightly elevated HbA (98.3% vs reference 96.7-97.8%) is a minor deviation that occurs when HbA2 is reduced - the percentages must add up to approximately 100%.
What You Need to Do Next
Immediate Testing Required
You need iron studies to determine if iron deficiency is causing the low HbA2 1:
- Serum ferritin (most important test - values <15 μg/L confirm iron deficiency; <30 μg/L suggest low iron stores) 1
- Transferrin saturation (<30% suggests iron deficiency) 3
- Complete blood count with MCV and MCH to assess for microcytosis and hypochromia 1
If Iron Deficiency is Confirmed
Iron deficiency must be investigated for its underlying cause 3, 1:
- In men and postmenopausal women: Gastrointestinal blood loss is the most common cause and requires upper endoscopy with small bowel biopsy AND colonoscopy to exclude GI malignancy 3
- In premenopausal women: Menstrual blood loss is most common, but GI investigation should still be considered if symptoms are present 1
- Celiac disease screening should be performed (found in 3-5% of iron deficiency cases) 1
If Iron Studies are Normal
If iron deficiency is excluded, consider:
- Alpha-thalassemia genetic testing (particularly Hemoglobin H disease) 2
- Repeat HbA2 measurement after correcting any iron deficiency, as iron deficiency can suppress HbA2 levels even in beta-thalassemia carriers 2
Critical Pitfall to Avoid
Do not accept the "negative thalassemia screen" conclusion at face value when HbA2 is below the normal range. 1 Low HbA2 requires investigation just as elevated HbA2 does. Iron deficiency can mask beta-thalassemia trait by lowering HbA2 into the normal or low range 2, 4. If you have iron deficiency, HbA2 should be rechecked after iron repletion to ensure beta-thalassemia trait is not being missed.
Ethnic Considerations
If you are from Mediterranean, Middle Eastern, or Asian descent, thalassemia screening is particularly important given higher prevalence in these populations 5, 1.