University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

494

Pages:

3
Author:

Mariam A. A.

Types of Anaemia Pernicious anaemia Pathogenesis Patient has an auto-immune disease where antibodies are produced and bind to the intrinsic factor that is produced by parietal cell. B12 is meant to bind to that intrinsic factor, however, it has already been occupied by the antibodies. As a result, B12 cannot be absorbed by the body. This will lead to decreased DNA condensation and maturation during erythropoiesis. As a result, there will be a decreased production of functional Hb -> macrocytosis -> too large -> gets stuck in capillaries -> haemolysis Another cause is in the elderly the size of the stomach decreases and it becomes less functional, which leads to less intrinsic factor production. Histology • • Hyper segmented neutrophil due to impaired DNA synthesis Enlarged RBCs because DNA cannot get condensed Treatment • B12 administration in a different route - e.g., intermuscular injection Hereditary spherocytosis Pathogenesis This is when there is a mutation in ankyrin and/or spectrin. This weakens them and thus causes them to increase in rigidity and decrease in flexibility and affects the disc shape of the RBC, instead they take a sphere shape. This causes them to get stuck within capillaries, especially sinusoids, where they end up getting destroyed by macrophages. This may also leads to splenomegaly Histology RBCs in spherical form, there is no light shade in the middle and thus this indicates that there is no disc shape. Treatment • severity dependent: - splenectomy - RBC transfusions - Folic acid supplementation Sickle cell anaemia Pathogenesis This occurs when there is a missense mutation in one of the amino acids of the beta chain of Hb. Instead of getting valine produced, its’ structure changes cause the Hb to polymerase. As a result Hb molecules will get attached to on another, taking the shape of a sickle, It takes this shape because they are not bound to oxygen. However, when they are bound to oxygen, they get the normal shape back, but when there is no oxygen they get back to sickle cell shape, Histology Sickle shaped cells Consequences Vaso-occlusion crisis -> RBCs get stuck in various areas of the body Treatment • Oxygen • Pain relievers • Blood transfusions Haemorrhage anaemia Pathogenesis Injury, surgery, ulcer or heavy menses -> excessive blood loss > low RBC count -> low O2 delivery -> anaemia Histology Low RBC count Treatment • severity dependent Aplastic anaemia Pathogenesis Affects RBCs, WBCs and platelets. This type occurs when there is a bone marrow disease, where the hemocytoblast cannot differentiate into a myeloid, which means that the patient will have a very low number of RBCs, WBSs and platelets, which is collectively known as pancytopenia Histology Bone marrow marked as hypocellular for the patient’s age. This is how it is distinguished from other types of anaemia Treatment • • • blood transfusions bone marrow transplant severity dependent Haemolytic anaemia Pathogenesis Abnormalities in RBCs, G6PD, immune mediated or mechanical damage -> excessive breakdown of RBCs Histology • • appear dense than normal RBCs presence of reticulocytes, appear basophilic due to the presence of ribosomes Treatment • • cause and severity dependent blood transfusions