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Sickle Cell Anemia
Aka: Sickle Cell Anemia, Sickle Cell Trait
- Epidemiology: Sickle Cell Trait (A/S) Incidence
- Americans of African Descent: 1 in 12
- Also Seen in Greeks, Italians, Turks, Saudi Arabians
- Pathophysiology
- Normal Hemoglobin A replaced by Hemoglobin S (Hb S)
- Substitution of Valine for glutamic acid
- Occurs at the 6th position of the beta-chain
- Types
- Sickle Cell Trait (A/S)
- No Anemia
- Hemoglobin S represents 25-40% of their Hemoglobin
- Under normal circumstances, RBCs do not hemolyze
- Sickle Cell Anemia (S/S)
- Initially infant's RBCs mainly contain fetal Hb F
- Within months the abnormal Hb S replaces the Hb F
- Imaging
- Transcranial Doppler Ultrasound
- Evaluate transcranial blood-flow velocity
- Start screening at age 2 years
- See Cerebrovascular Accident in Sickle Cell Anemia
- Management
- Blood Transfusion Indications
- Acute indications
- Multi-organ failure syndrome
- Major surgical procedures (including Tonsillectomy)
- Cerebrovascular Accident in Sickle Cell Anemia
- Progressive Acute Chest Syndrome
- Chronic indications
- Prevention in children at high risk of CVA
- Cerebrovascular Accident in Sickle Cell Anemia
- Pulmonary Hypertension
- Chronic Heart Failure
- Hydroxyurea
- Increases production of fetal Hemoglobin (HbF)
- Indicated for 3 or more crises per year, over age 18
- Reduces Sickle Cell Anemia mortality
- Steinberg (2003) JAMA 289:1645-51
- Depo Provera in women with Sickle Cell Anemia
- Lowers number of crises by 70%
- DeAbood (1997) Contraception
- Hematopoietic Cell Transplantation
- Curative in 85-90% of cases
- Mortality: 5-10% (related to rejection, infection)
- Prevention
- Periodic Evaluation
- Hematology
- Ophthalmology beginning at age 10 years
- Liver Function Tests
- Renal Function tests
- Pulmonary Function Tests
- Nutritional Supplements
- Folic Acid 1 mg/day
- Prophylactic Antibiotics
- See Asplenic
- Penicillin V 150 mg bid (increase at age 3 years)
- Given from 2 months old to age 5
- May substitute with Bicillin LA every 3 weeks
- Extend course if complications
- Splenectomy
- Invasive pneumococcal infection
- Immunizations (In addition to standard CDC)
- See Asplenic
- Pneumococcal Vaccines
- 7-Valent Conjugate Vaccine (Prevnar, PCV)
- Give as per CDC Primary Series guidelines
- 23-Valent Pneumococcal Vaccine (PPV)
- Give first dose at 2 years or older
- Repeat in 3-5 years if under age 10 years
- Haemophilus influenzae B Vaccine
- Hepatitis B Vaccine
- Influenza Vaccine annually (6 months or older)
- Meningococcal Vaccine (age 2 years or older)
- Complications
- Sickle Cell Crisis
- Hematuria in Sickle Cell Anemia
- Most common Sickle Cell Anemia complication
- Pulmonary Hypertension (in up to 30% of patients)
- Acute Chest Syndrome
- Hand Foot Syndrome in Sickle Cell Anemia
- Priapism in Sickle Cell Anemia
- Cerebrovascular Accident in Sickle Cell Anemia
- Avascular Necrosis of Femoral Head
- Splenic Sequestration and Infarct
- See Asplenic
- Acute splenic enlargement (especially in under age 5 years, before auto-infarction)
- Presents with Anemia, Abdominal Pain, splenic distention
- Chronic organ damage
- Lung
- Kidney (Chronic Renal Failure)
- Liver
- Skin (Chronic skin ulcers)
- Congestive Heart Failure
- Eye complications
- Proliferative retinopathy
- Retinal Infarcts
- Retinal Detachment
- Vitreous Hemorrhage
- Biliary disorders
- Cholelithiasis
- Intrahepatic cholestasis
- Jaundice (Unconjugated Hyperbilirubinemia)
- Resources
- Sickle Cell Disease Association of America
- http://www.sicklecelldisease.org
- Phone: (800) 421-8453
- Sickle Centers
- http://www.rhofed.com/sickle
- Emory Sickle Cell Anemia Page
- http://www.scinfo.org
- References
- Mehta (2006) Am Fam Physician 74:303-14
- Steinberg (1999) N Engl J Med 340:1021-30
- (2002) Pediatrics 109:526-35