6.1 - Haematology In Systemic Disease Flashcards
How can reduced erythropoiesis occur and by what Mechanism?
Lack of response to the haemostasis loop e.g in chronic kidney disease the kidney stops making EPO
1) empty bone marrow unable to respond to stimulus from EPO e.g after chemotherapy or toxic insult such as parvovirus infection or in aplastic anaemia
2) marrow infiltrated by cancer cells or fibrous tissue (myelofibrosis) = normal haemopoietic cells are reduced.
How can you get dyserythropoesis?
Dyserythropoesis = lack of RBC
1) iron disregulation: iron not released for use in bone marrow
2) marrow shows lack of response to EPO
3) reduced lifespan of RBC
All as a result of inflammatory cytokines
What diseases can you get dyserythropoesis with?
- Renal disease
- Inflammatory conditions e.g rheumatoid arthritis, SLE, inflammatory bowel disease, chronic infections, etc.
What is a functional iron deficiency?
Sufficient iron in body but not available to developing erythroid cells
- macrophages eat old senescent RBC and recycle iron
- recycled iron is the main source of iron for new RBC
- small amount of iron absorbed from the gut
What does hepcidin do?
A negative regulator of iron absorption
Decreases ferroportin, a protein involved in moving iron out of cells
So
- prevents iron absorption from gut
- prevents iron release from macrophages
What is hepcidin regulated by?
HFE
Transferrin receptor
Inflammatory cytokines
NB: its made in the liver
What would you look for to detect anaemia of chronic renal failure?
- normocytic monochromic or microcytic anaemia
- Normal/high ferritin
- normal/high reticulocyte haemoglobin content
- CRP often elevated
What are the consequences of anaemia of chronic renal failure?
Reduced EPO due to damaged kidneys
Raised cytokines
Reduced lifespan of RBC
Reduced clearance of hepcidin = increased hepcidin production due to inflammatory cytokines.
What’s the treatment for anaemia of chronic disease/inflammation?
Treat underlying condition
If associated renal failure, recombinant human EPO
Ensure b12, iron and folate stores and adequate
Transfuse if all else fails and patient is symptomatic
What is the management of anaemia of chronic renal failure?
iron given as IV as absorption is impaired
What is the treatment of rheumatoid arthritis?
Analgesis, often NSAIDs
Corticosteroids
Chemotherapy e.g methotrexate
Biological agents
Why would blood be hypochromic in rheumatoid arthritis?
Low
- ACD
- blood loss e.g due to NSAIDs/corticosteroids
- haematinic
- immune
Why would a blood film for someone with RA show neutrophils?
High
- associated inflammatory infection
- drug reactions
What’s feltys syndrome?
Rheumatoid arthritis + splenomegaly + neutropenia
Neutropenia is secondary to splenomegaly, peripheral destruction of neutrophils and failure of bone marrow to produce neutrophils
What does portal hypertension cause and What does this lead to?
Oesophageal and gastric varices, but mainly causes splenomegaly
This leads to
- splenic sequestration of cells
- overactive removal of cells
