HbE workup and treatment

1. Diagnostic workup

• CBC with RBC indices and peripheral smear:
  • Low MCV/MCH, target cells
  • Assess degree of anemia, leukocytes, platelets
• Reticulocyte count
• Iron studies: ferritin and transferrin saturation, with CRP if inflammation is possible.
  • Do not label all microcytosis as iron deficiency or give chronic iron empirically.
  • Iron deficiency can coexist and may alter Hb fraction interpretation.
• Hemolysis assessment if clinically indicated: bilirubin, LDH, haptoglobin.
• Liver and renal function tests, especially before chelation or if jaundice/iron overload is suspected.

• Hemoglobin fractionation by HPLC, capillary electrophoresis, or electrophoresis.
  • HbE may co-elute with HbA2 on some HPLC platforms, so report interpretation matters.
  • In HbE trait, HbE is commonly about 25%-30%, but coexisting alpha-thalassemia or iron deficiency can reduce it.
  • HbE/beta-zero thalassemia usually has no HbA, while HbE/beta-plus thalassemia has variable HbA.
• Molecular testing of HBB when:
  • HbE/beta-thalassemia is suspected
  • phenotype and fractionation are discordant
  • family planning or prenatal diagnosis is being considered
  • a transfused patient has uninterpretable Hb fractionation
• Consider alpha-globin testing if microcytosis is disproportionate or phenotype is unexpected. Thalassemia evaluation should start with red-cell indices/morphology and Hb fraction measurement, while excluding iron deficiency (TIF diagnostic guidance).

• Symptoms: fatigue, exercise intolerance, poor growth/puberty in children, bone pain, transfusion history.
• Examination: splenomegaly, hepatomegaly, jaundice, skeletal changes, leg ulcers.
• Baseline complications screening:
  • Ferritin trend and liver iron concentration by MRI when indicated
  • Cardiac T2* MRI in patients with significant iron burden or chronic transfusions
  • Liver assessment, hepatitis status
  • Endocrine assessment in significant disease: growth/puberty, glucose, thyroid, calcium/vitamin D, gonadal function
  • Echocardiography if symptoms, pulmonary hypertension risk, or significant chronic anemia
  • Bone-density assessment in higher-risk adults
• Obtain extended red-cell phenotype/genotype and antibody screen before first transfusion.

• Test the reproductive partner for HbE, beta-thalassemia, sickle trait/other hemoglobin variants, and alpha-thalassemia as appropriate.
• Refer for genetic counseling if both partners are carriers. HbE plus beta-thalassemia in offspring can produce clinically significant HbE/beta-thalassemia.

2. Treatment

HbE trait or uncomplicated HbEE

• No disease-specific treatment.
• Treat confirmed iron deficiency if present, but do not prescribe iron solely because MCV is low.
• Explain inheritance and arrange partner testing before pregnancy.
• Routine follow-up is usually sufficient.

HbE/beta-thalassemia: treatment is phenotype-based

A. Mild, non-transfusion-dependent disease

• Follow with hematology, usually every 3-6 months initially, then individualized.
• Folic acid may be used when there is ongoing hemolysis/increased erythropoiesis or poor dietary intake.
• Avoid routine iron unless iron deficiency is confirmed.
• Monitor hemoglobin trend, growth/development, spleen size, iron burden, and complications.
• Assess iron overload even without transfusions: increased intestinal iron absorption can cause progressive loading.
• Manage infections promptly and maintain immunizations.

B. When to consider regular transfusion

• Persistent symptomatic anemia or reduced function
• Poor childhood growth, delayed puberty, or poor school/activity tolerance
• Progressive splenomegaly/hypersplenism
• Skeletal changes or extramedullary hematopoiesis
• Pregnancy or cardiopulmonary complications where improved oxygen delivery is needed
• Increasing disease complications despite supportive care

C. Iron overload management

• Monitor serial ferritin, but recognize it does not perfectly predict tissue iron.
• Use liver iron concentration MRI and cardiac T2* MRI when clinically indicated.
• Start iron chelation according to transfusion burden, ferritin trajectory, and MRI-derived iron burden, under a thalassemia specialist.
• Available chelators include deferasirox, deferiprone, and deferoxamine. Choice and dose depend on liver and cardiac iron, renal/hepatic function, adverse effects, age, and adherence.
• Regular adherence is essential, and chelation must be tailored to the individual (TIF iron-chelation guidance).

D. Splenectomy

• Avoid if possible. It is reserved for selected cases of severe hypersplenism or markedly rising transfusion requirement after expert review.
• Before splenectomy: vaccinate against encapsulated organisms and discuss lifelong infection and thrombosis precautions.
• Postsplenectomy patients need monitoring for thrombosis, pulmonary hypertension, infection, and platelet elevation.

E. Disease-modifying and curative options

• Luspatercept may reduce transfusion burden in appropriately selected adults with transfusion-dependent beta-thalassemia, subject to local approval and specialist assessment. Its role is not a substitute for individualized HbE/beta-thalassemia evaluation.
• Allogeneic hematopoietic stem-cell transplantation can be curative for selected patients, particularly younger individuals with a suitable donor.
• Gene-based therapies may be options in some jurisdictions for eligible beta-thalassemia genotypes, but availability, eligibility, and long-term outcomes require specialist-center review.

Avoid

• Repeated iron prescriptions without iron studies.
• Transfusing merely to normalize Hb in otherwise stable mild disease.
• Delaying chelation monitoring after chronic transfusion begins.
• Splenectomy for mild splenomegaly alone.
• Missing partner testing and genetic counseling.

Urgent hematology review