Sickle Cell disease

• Sickle cell disease genetics =

  • autosomal codominant - mutation on chromosome 11
  • People who are heterozygous for BetaS allele carry the sickle cell trait
  • Homozygous for BetaS allele = sickle cell disease
  • gene defect = single nucleotide mutation of beta-globin gene
  • Glutamic acid being substituted by valine in position 6
• Sickling causes =

  Recurrent infarcts

  Location = brain + eyes + lungs + liber + kidneys + bones

  Triggered by

  • hypoxia
  • dehydration
  • infection
  • stress
• Cells involved in sickling =

  • neutrophils
  • platelets
  • endothelial cells
  • macrophages

  Severe inflammatory process

  • hypoxia
  • tissue damage
  • high CRP
• Adult Hb is formed at 6-8 months

  Start hydroxyurea as syrup if sickle cell diesease
• Stop sickling =

  Stabilsiation of HbS

  Rehydration

  reduce number of neutrophils - hydroxyurea
• HbSS = sickle cell

  HbSc = trait
• Medical complications of sickle cell =

  VOC - acute sickiling

  Stroke in children

  Retinal detachment + proliferative retinopathy

  pulmonary hypertension

  bone infarcts + fat emboli
• Management of vaso-cclusive crisis =

  • morphine
  • oxygen
  • hydration
  • antibiotics
• Sickle cell disease presentation =

  Acute chest syndrome = antibiotics + exchange

  Stroke = exchange transfusion

  Spleen sequestration = splenectomy

  priapism = hydration + exchange transfusion + urology

  papillary necrosis = hydration + exchange transfusion
• Treatment of sickle cell disease =

  Allogenic stem cell transplant + gene therapy (affects fertility)= cure

  Hydroxyurea - reduce HbSS

  Regular exchange transfusions
• Prevention of sickle cell disease =

  Penicillin V twice daily

  Folic acid

  Vitamin D

  Vaccinations