Objectives 8,9, 13, 17, 19, 20-24, 28

What percentages are associated with Sickle Cell Disease?

• HbS > 80%

• HbA: none

• HbF: 1-20%

• A2: 2-20%

What percentages are associated with Sickle Cell Trait?

• HbA 60%

• HbS 40%

What percentages are associated with Hemoglobin C disease?

• HbC: 95%

• HbA: none

• HbF: <7%

• HbA2: negligible

What percentages are associated with Hemoglobin C trait disease?

• HbC: 30-40%

• HbA: 60-70%

What percentages are associated with Hemoglobin SC disease?

• near equal amounts HbS and C

• No HbA

• small HbF

What percentages are associated with Thalassemia Major?

• HbgF: 70-90%

• and Hgb A2

• No Hgb A

What percentages are associated with Thalassemia Minor?

• HbA: 92-95%

• HbA2: 3.5-7%

What happens if you are using electrophoresis with and alkaline pH?

• HbS migrates to the same position as HbD and HbG

• for HbSS- see a major band in the S/D/G region

  • you can not automatically say “that is definitely HbS”

  • because HbD and HbG migrate in same area

What happens if you are using electrophoresis at an acidic pH?

• helps distinguish HbS from HbD / HbG

• acid electrophoresis helps establish HbS band

In an acidic pH, what band does HgD migrate with in electrophoresis?

• HbA

What does HbC disease look like in electrophoresis?

• has its own migration behavior and is identified by electrophoresis for HbCC

  • approx 95% HbC

• for HbAC

  • approx: 30-40% HbC + 60-70% HbA

What is B-thalassemia Major?

• severe form associated with homozygous disease

What lab findings indicate B-thalassemia major?

• ↑ retics

• ineffective erythropoiesis

• low haptoglobin

• ↑ LDH

• ↓ Hgb/HCT

What can be seen on a peripheral blood smear with B-thalassemia?

• target cells

• teardrop cells

• elliptocytes'

• basophilic stipplings

• HJ bodies

• pappenheimer bodies

• heinz bodies

• nucleated RBCs

• anisocytosis, poikilocytosis, hypochromia, macrocytosis

What is associated with B thalassemia Intermedia?

• less severe than major

• may require occasional RBC transfusions

• can develop severe infections

• can develop gallstones

What is associated with B-thalassemia minor?

• least severe form (trait)

• CBC

  • RBC count = normal

  • minimal/ineffective erythropoiesis

  • mild microcytosis/ hypochromia

  • MCV< 75

  • MCHC < 32

• smear

  • target cells, elliptocytes, basophilic stipplings

What is used to treat Sickle Cell Disease?

• RBC transfusions

• analgesics

• Desferrioxamine

• Stem Cell transplant - matched, unrelated donor < 20%

• Hydroxyurea - increases Hgb F

• CRISPR gene editing

What is used to treat Thalassemia major?

• hematopoietic stem cell transplant

  • ONLY cure

• 10-15 ml/Kg of RBCs transfusion every 2-5 weeks

• iron chelation

• hydroxurea

• Desferroxamine

Why is Hydroxyurea useful to sickle cell patients?

• it stimulates production of Hgb F

  • useful in this disease because Hgb F does NOT participate in the same sickling process as HbS

Associate Iron Overload With Thalassemia Major and Sickle Cell Disease.

• iron overload is a major concern cause pt need regular RBC transfusions

• repeated RBC transfusions → iron overload

  • iron overload i treated with → chelation

What are features of “Sickle like” B-thalassemia?

• combines a sickle hemoglobin abnormality with thalassemia abnormality

  • Hgb S: 50-80%

  • HgbA: 20-50%

  • ↑ Hgb F

    • indicates decreased severity of the sickling process

    • microcytosis

What are morphological features of Sickle-Thalassemia?

• Thalassemia

  • micro/hypo

  • target cells

  • anicocytosis/poikilocytosis

  • basophilic stipplings

• Sickling disorders

  • sickle cells, target cells, abnormal RBC forms

• sickling morphology + thalassemia microcytic / hypochromic morphology

What lab findings indicate Hgb CC disease?

• normocytic / normochromic

• target cells, microspherocytes, schistocytes

• RBC indicies normal

• mod ↑ in retics

• nRBCs may be present

• negative Hgb solubility test

• electophoresis - acidic pH

  • Hgb C: 95%

  • HbA = none

  • HgbF < 7%

What lab findings indicate Hgb C Trait (AC)?

• 30-40% Hgb C

• 60-70% Hgb A

• target cells on smear

• mild hypochromia

What percentages indicate B Thalassemia Major?

• Hgb F: 70-90%

• and HgbA2

• NO HbA

What percentages indicate Thalassemia Minor?

• Hgb A: 92-95%

• Hgb A2: 3.5-7%

• Hgb F: 1-5%

What are the RBC indices (MCV,MCHC) of Sickle Cell Disease (Hgb S)?

• normocytic / normochromic

What are the RBC indices (MCV,MCHC) of Hgb C disease

• normocytic / normochromic

What are the RBC indices (MCV,MCHC) of Hgb C Trait (AC)

• normocytic / normochromic

• has mild hypochromia

What are the RBC indices (MCV,MCHC) of Hgb SC Disease

• normocytic / normochromic

What are the RBC indices (MCV,MCHC) of Thalasemia?

• microcytic / hypochromic

Describe the peripheral blood smear in Hemoglobin C Trait.

• target cells on smear

• mild hypochromia

Describe the peripheral blood smear in Sickle Cell Trait.

• PB: normal , few target cells

• siderotic granules and HJ bodies possible

  • due to rapid RBC turnover

• possible shift to left

  • ↑ immature WBC and PLTs