Sickle-cell disease is an autosomal recessive condition which occurs due to replacement of glutamic acid by valine in Beta-globin gene at position 6 of chromosome 11 (Missense mutation). This mutation results in loss of elasticity of RBC.
Under low oxygen saturation, this RBC aggregates and polymerize into sickle configuration. This sickled cell are sequestered and removed by macrophage of spleen. Sometimes, this sickled cell stuck in micro-vasculature and causes ischemic damage to distal tissue (pain due to vaso-occlusive crisis).
Highest prevalence among african population.
Signs and Symptoms
Splenomegaly (spleen is most commonly affected)
Auto-splenectomy (doesn't mean that spleen disappeared, it is large and non-functional).
After auto-splenectomy, there is an increase in risk of encapsulated bacterial infections with Streptoccocus Pneumoniae (most common), Hemophilus Influenza, Neisseria Meningitidis and other, so give proper vaccination to all sickle cell patients
Anemia or Aplastic crisis (Can be associated with G6PD or Parvo virus infection)
Painful vaso-occlusive crisis (recurrent episodes of dactylitis and leg ulcers, stroke, acute chest syndrome, necrosis of distal tissue.
Best initial test is peripheral smear that will show sickle cells along with normal RBC [Image 1]
Hemoglobin electrophoresis is best confirmatory test
Annual retinal examination and evaluation of stroke risk by transcranial doppler is suggested
Acute attack - Oxygen, hydration, pain control. Exchange transfusion for severe vaso-occlusive crisis.
Hydroxyurea - Increases HbF(fetal hemoglobin) and thus decreases recurrences, usually given to patients with more than 2 vasocclusive crisis/year
Erythropoietin - Increases RBC production
Folate - Given to everybody because it play an important role in DNA formation
Immunization for encapsulated bacteria along with Penicillin. Give antibiotics (Ceftriaxome or Levofloxacin) immediately if sickle cell patient have fever.
Authored by: Bhavik Patel, MD and Priyank Chauhan, MD Reel Patient Video By:James Lace MD, Mt. Meru Hospital, Tanzania; Kausay Wasi Clinic, Peru Image Source - wikipedia.org and howshealth.com