Haematology In Systemic Disease Flashcards
What are examples of changes to the blood in systemic disease ?
1) an increased expression in IL-6 or other cytokines.
2) complications of the disease which may causes bleeding
3) treatment may have adverse effects - methotrexate which is an immunosuppressant
Why might anaemia may develop - in terms of reduced or dysfunctional erythopoiesis?
1) Anaemia can result from the lack of response in haemostasis loop eg chronic kidney disease where the kidney stops making EPO.
2) Anaemia can result from bone marrow being unable to recons to EPO.
3) Anaemia in chronic disease eg in rheumatoid arthritis where iron is not made available to marrow for RBC production
Why. Is anaemiaof chronic disease a ‘ functional’iron deficiency?
Because there is suffieicient iron inn the body but not available to the developing erythroid cells.
What is the role of hepcidin?
- inhibits ferroportin which is the main exporter of iron out of the macrophage and out of the gut cell. So you need ferroportin to recycle the iron.
- this prevents iron absorption from the gut. And prevents iron release from macrophages.
How do inflammatory conditions regulate hepcidin production?
1) inflammatory condition which causes a release of cytokines for example IL6 from immune cells.
2. This increases production of hepcidin by the liver.
3. This results in inhibition of ferroportin.
4. This results in decreased iron release from RES. And decreased iron absorption in the gut. This leads to plasma iron reduced. Which leads to inhibition of erythropoiesis in bone marrow which leads to ANAEMIA.
Would you prescribe iron supplements to someone with anaemia of chronic disease ?
No , because their issue is it that they don’t have enough iron. Their issue is that their iron is not released from cells. So giving iron would not help.
How does chronic kidney disease lead to anaemia ? 5 causes
- Increased hepcidin due to inflammatory cytokines. And reduced clearance of hepcidin. So hepcidin concentration in blood is very high.
- Patients undergoing dialysis can damage red blood cells.
- Reduced EPO production due to damaged kidney cells.
- Reduced life span of RBC as a direct effect of uraemia, ( uraemia also inhibits megakaryocytes leading to low platelet count )
- Underlying cause of chronic kidney disease is associated with cytokines
.
How do you treat anemia of chronic disease ?
MAIN - treat the underlying condition
- If associated renal failure - recombinant human EPO. If you give this , you need to ensure there are all the correct building blocks eg ensure vit B12 , folate and iron stores are adequate.
- Transfuse cells only if all else fails
What are symptoms of Rheumatoid Arthritis
- swan neck deformity of fingers
2. Boutonnière deformity of thumb
How is RA treated ?
- Pain is treated using pain reliefs. For example NSAIDS. ( which are non-steroidal anti inflammatory drugs eg Iburprofen).
- Disease modifying agents are often : DMARDS. For example corticosteroids , chemotherapy eg methotrexate , monoclonal antibodies against the cytokines.
Why does anaemia develop from RA ? 3 causes
- Could be due to anaemia of chronic disease ( increase in cytokines , increased production of hepcidin etc )
- GI blood loss due to NSAIDS and steroids
- risk of autoimmune haemolytic anaemia
Platelet count and neutrophils in RA ?
High platelets and neutrophils when disease is active
And high CRP
However low platelets and neutrophils may occurs due to treatment , autoimmune reactions or hypersplenism ( splenomegaly can also occur )
What is felty’s syndrome
Rare , potentially serious disorder that is defined by the presence of three conditions. RA , splenomegaly , neutropenia. Which causes repeated infections.
Why neutropenia occur in feltys syndrome ?
Thought to be due to splenomegaly which contributes to destruction of neutrophils and failure of bone marrow to produce neutrophils. And there is insensitivity to GCSF.
How does chronic liver disease lead to splenomegaly?
Chronic liver disease causes portal hypertension which causes splenomegaly which leads to splenic sequenstration of cells and overactive removal of cells.
LOW BLOOD COUTN