Haem Physio and anaemia Flashcards
What is Haemotopiesis?
production of mature blood cells from precursor stem cells.
Primary site of haematoiesis?
is red bone marrow
What are red bone marrow replaced with as we age?
replaced with yellow marrow
What are common 2 types of precursors from stem cells?
Common myeloid precursor.
Common lymphoid precursor
what is the main stimulant of erythropoiesis ?
hypoxia
Why is iron essential?
contributes to oxygen and electron transport
Why is Fe2+ needed rather Fe3+ ?
Fe2+ will be able to carry out the needed function rather than Fe3+ (commonly converted from 2+ –> 3+ during inflammation / oxidative stress).
Where is Iron commonly absorbed?
Jejunum / duodenum
What is Hepcidin?
Liver produced protein that controls iron absorption via down regulating ferroportin in response to iron load + inflammation.
What transport iron?
transferrin
what is iron stored in the body?
Macrophages
bone marrow
liver - > largest parenchymal store
Hb –> largest total store
what is used to assess the level of iron present in body?
ferritin
What are the causes of iron overload?
Haemochromatosis
Thalassemia
long-term transfusions
sideroblastic anaemia
Define Anaemia?
insurfficiencent amount of RBC / Hb
What are the causes of microcytic hyochromatic anaemia?
reduced Hb production
Causes of LOW level of iron?
Chronic blood loss: Menorriagia, GI bleeds usually lower.
Malabsorption: coeliac disease, post gastrectomy.
Poor dietary intake: vegan or vegetarian.
Infection: hookwork most common cause worldwide.
Iron studies in patient with iron deficiency?
low iron, ferritin, transferrin saturation
What does TIBC during low iron levels?
TIBC tries to compensate for low stores by increasing transferrin + therefore the iron carrying capacity of blood.
Management for iron deficiency ?
screen for coeliac iron supplements (Ferrous Sulphate or fumerate)
if iron therapy not working, consider…
Poor compliance.
Wrong diagnosis.
Continued activity of underlying cause
What is macrocytic anaemia?
Cell become large due to defective nuclear maturation + DNA synthesis during haematopoesis.
Causes of macrocytosis?
Megaloblastic macrocytic anemia.
Non megaloblastic macrocytosis +/- anemia.
Others: reticulocytosis, cold agglutinins.
What are the causes of B12 deficiency ?
Dietary Pernicious anaemia Gastrectomy PPI Bacterial overgrowth Coeliac disease Bowel resection Chronic pancreatitis
What are causes of folate deficiency ?
Low intake (poverty) Coeliac disease Tropical sprue Increased demand (pregnancy, malignancy, haemolytic anaemia) Drugs (immunosuppressants, alcohol).
Investigations for B12 / Folate ?
Serum: low B12 / folate.
FBC: low Hb, high MCV, reticulocytes.
Bone barrow biopsy: megaloblasts.
Immunology: anti gastric parietal cells, anti intrinsic factor.
Film: howel jolly bodies, hypersegmented neutrophils.
