Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Sickle Cell Anemia:

No description
by

Tiffany Ford

on 4 December 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Sickle Cell Anemia:

HbS then forms polymerized
crystals, which are polymers of the hemoglobin, that distort the cells
Complications
chronic anemia
acute chest syndrome
stroke
infections
crises
pulmonary hypertension
What Happens?
Sickle Cell Anemia results from the substitution of valine for glutamic acid in the hemoglobin molecule
Genetics
The mutant B-allele codes for the production of the variant hemoglobin S.
The heterozygous carrier state is known as sickle cell trait 31.
The sickle cell gene mutation is a point mutation in the sixth codon of exon 1 in the gene, replacing adenine with thymine
Genetics continued
In addition, red blood cells that are homozygous for HbS are prone to premature destruction, with a red blood cell life span of 8–25 days whereas normal red blood cells have a life span of about 100-120 days
Sickle Cell Anemia: So Many Molecules, So Little Time
By :Tiffany Ford

Sickled Cells
Vaso Occlusion
Since these cells have become less pliable, sticky, and are adhering to small veins/arteries, vaso occlusion comes into play
Background Info:
Sickle cell Anemia is.....
Inherited blood disorder formed from mutant version of the B-globin gene on chromosome 11.
Mainly effects people of African American descent or Hispanic descent
A single nucleotide substitution (GTG for GAG) in the sixth codon of the beta-globin gene, results in this amino acid substitution
As a result sickled cells are formed that cannot navigate capillaries
Vaso Occlusion: Painful crises
Imagery
All sickle cell patients do not share the same pleiotropic genes; therefore the severity of sickle cell anemia varies among individuals.
Some carriers have mutated genes that can either improve or worsen the phenotype.
Although sickle cell anemia has negative effects from the genetic mutation,
polymorphism
balances this out with some protective benefits caused by natural selection.
For example, the HbS gene offers some benefit in terms of protection against malaria.

Recent Studies
A recent study was done on vaso-occlusion in sickle cell disease and whether chronic vascular inflammation and endothelial activation initiates this process
A pro-thrombotic and anti-inflammatory tumor necrosis factor recently identified as
TNFSF14
, was tested to see whether it had an effect on the endothelial cells of sickle cell patients
Scientists in this study also wanted to see if TNFSF14 had an effect on platelet levels and if this activation was altered in sickle cell anemia
Methods
Patients were homozygous for HbSS or HbSC
Steady State
controls homozygous for hemoglobin A (HbAA) normal
blood cells were taken, cetrifuged, incubated, washed and stored for analysis
Results
Results found that plasma levels of TNFSF14 were higher in sickle cell anemia patients in comparison to the control.
Also that the protein TNFS14 itself was significantly higher on the platelet surface in comparison to the control
What does this mean?
This study shows how platelets and the activation of the platelets affect the vascular inflammation that triggers vaso-occlusive properties. More studies have to be done to figure out if TNFSF14 is, in fact, contributing to inflammation in sickle cell anemia
TNFSF14 is membrane bound;
facilitate the adhesion of platelets to the endothelium
Other studies
Adhesion molecules VCAM-1, ICAM-1, p-selectin, e-selectin tested
Results
The levels of these molecules were higher in the patients with sickle cell anemia than in controls
Genetic modifiers and adhesion molecules seem to be the main focus on finding a therapeutic protocol that will improve the health of these patients
More experimental evidence on the role inflammation plays on the vaso-occlusion process of sickle cell anemia will provide a strong basis for future trials of therapy in sickle cell patients.
Genotypes of sickle cell
HbSC disease which is a double heterozygote for HbS and HbC
HbS with hereditary persistence of HbF or fetal hemoglobin
HbS/HbE syndrome which is very rare with a phenotype usually related to HbSB thalessemia
References
1. El Gindi, H. D., Mostafa, N. O., Zaki, S. T., & El Wassef, M. (2011). sP-SELECTIN: AN ACTIVATED ENDOTHELIAL PLATELET ADHESION MOLECULES IN SICKLE CELL DISEASE. International Journal Of Academic Research, 3(5), 404-408.
2. Garrido, V. T., Proença-Ferreira, R., Dominical, V. M., Traina, F., Bezerra, M. C., Mello, M. B., & ... Conran, N. (2012). Elevated plasma levels and platelet-associated expression of the pro-thrombotic and pro-inflammatory protein, TNFSF14 (LIGHT), in sickle cell disease. British Journal Of Haematology, 158(6), 788-797. doi:10.1111/j.1365-2141.2012.09218.x
3. Helvaci, M., Aydin, Y., & Ayyildiz, O. (2013). Clinical severity of sickle cell anemia alone and sickle cell diseases with thalassemias. Healthmed, 7(7), 2028-2033.
4. Hyacinth, H. I., Adekeye, O. A., & Yilgwan, C. S. (2013). Malnutrition in Sickle Cell Anemia: Implications for Infection, Growth, and Maturation. Journal of Social, Behavioral & Health Sciences, 7(1), 23-34. doi:10.5590/JSBHS.2013.07.1.02
5. Inati, A., Koussa, S., Taher, A., & Perrine, S. (2008). Sickle cell disease: new insights into pathophysiology and treatment. Pediatric Annals, 37(5), 311-321.
6. Kanavaki, I., Makrythanasis, P., Lazaropoulou, C., Kattamis, A., Tzanetea, R., Kalotychou, V., & ... Papassotiriou, I. (2012). Adhesion molecules and high-sensitivity C-reactive protein levels in patients with sickle cell beta-thalassaemia. European Journal Of Clinical Investigation, 42(1), 27-33. doi:10.1111/j.1365-2362.2011.02551.x
7. Kaur, M. M., Dangi, C. S., & Singh, M. M. (2013). AN OVERVIEW ON SICKLE CELL DISEASE PROFILE. Asian Journal Of Pharmaceutical & Clinical Research, 25-37.
8. Mansilla-Soto, J., Rivière, I., & Sadelain, M. (2011). Genetic strategies for the treatment of sickle cell anaemia. British Journal Of Haematology, 154(6), 715-727. doi:10.1111/j.1365-2141.2011.08773.x.
9. Shah, A., Hussain, R., Fareed, M., & Afzal, M. (2012). Gene frequency of sickle cell trait among Muslim populations in a malarial belt of India, i.e., Manipur. Egyptian Journal Of Medical Human Genetics, 13(3), 323-330. doi:10.1016/j.ejmhg.2012.04.001.
10. Thein, S. (2011). Genetic Modifiers of Sickle Cell Disease. Hemoglobin, 35(5/6), 589-606. doi:10.3109/03630269.2011.615876
Full transcript