Categories: Hematology/Oncology

Sickle Cell Anemia Occlusion: Mechanism

  • MECHANISM: The loss of the hydrophilic AA for a hydrophobic AA will allow it to interact with hydrophobic AA helices on another B chain and form aggregates
  • These sickled cells form polymers with themselves; they lose flexibility and a collection of rigid sickle cells will cause occlusion in the micro circulation
  • Upon returning to oxygenated tissue, the cells will be able to return to their discoid cell shapes
  • Repeated sickling will cause ion channel dysfunction (loss of Ca2+/K+), cellular dehydration (will be permanently sickled and destroyed in the spleen)
  • Normally, RBCs remain soluble and flexible in the blood when passing through the circulation at varying degrees of oxygen saturation
  • In Sickle cell anemia: substitution of VALINE for GLUTAMIC ACID in position 6 of the Beta-chain => This substitution results in an alteration of the quaternary structure of the hemoglobin molecule
  • When de-oxygenated, the mutated RBCs will form long polymers & cross linking; thus becoming rigid and insoluble


  1. Deepa Manwani and Paul S. Frenette. Vaso-occlusion in sickle cell disease: pathophysiology and novel targeted therapies. ASH Education Book December 6, 2013 vol. 2013 no. 1 362-369
  2. Chapter 49: Disorders of Hemoglobin Structure: Sickle Cell Anemia and Related Abnormalities. Kavita Natrajan; Abdullah Kutlar. Williams Hematology, 9e
  3. Odièvre M-H, Verger E, Silva-Pinto AC, Elion J. Pathophysiological insights in sickle cell disease. The Indian Journal of Medical Research. 2011;134(4):532-537.
Get Medical Pearls directly to your inbox every week!
Weekly posts with high yield medical knowledge, directly to your mailbox!
Dr. C Humphreys

Internal Medicine

Recent Posts

Mechanism of a Mixed Apnea

Mixed apneas are characterized by absent respiratory effort and airflow in the first section of…

6 months ago

How Does Hypothyroidism Cause Hypoventilation?

Although rare, the differential diagnosis of hypoventilation and hypercapnia respiratory failure includes hypothyroidism. It is…

6 months ago

Why is Pro-BNP/ BNP lower in Obesity?

B-type natriuretic peptide (BNP) is a hormone created in response to cardiac wall stretch due…

1 year ago

What is Peribronchovascular Distribution on CT imaging?

A common finding described on computed tomography (CT) imaging. A disease with a peribronchovascular distribution…

2 years ago

Trapped Lung vs. Lung Entrapment

Though often used synonymously; Trapped Lung and Lung Entrapment technically describe separate entities along the…

2 years ago

Cause of Pericardial Effusion in Pulmonary Hypertension: Pathogenesis

It is not clearly understood why patients with pulmonary hypertension (PH) develop pericardial effusions. However,…

2 years ago

This website uses cookies.