MEH 11 - Haematology in Systemic Disease Flashcards
Why do changes occur in the blood in systemic disease?
- This is often multifactorial, e.g.:
1) Underlying physiological or external cause - e.g.: those that cause changes in cytokines such as IL-6 or TNF-a
2) Complications of the disease
3) Adverse effects of treatment - e.g. methotrexate affects bone marrow.
What are the 3 contributors to anaemia (caused by inflammatory cytokines) in anaemia of chronic disease?
Give some examples of inflammatory chronic conditions that can result in anaemia.
1) Iron dysregulation - available iron not released for use in bone marrow
2) Marrow shows a lack of response to EPO
3) Reduced lifespan of red cells
- RA, inflammatory bowel disease etc.
How do inflammatory conditions that cause iron dysregulation result in anaemia? (‘functional’ iron deficiency).
1) Inflammatory conditions (e.g.: RA) release cytokines (e.g.: IL-6) which increase the production of hepcidin.
2) Hepcidin inhibits ferroportin, which reduced iron release from RES and iron absorption in the gut.
3) Reduced plasma iron available for erythropoiesis in bone marrow, leads to anaemia.
Anaemia of chronic kidney disease (CKD) is multi-factorial - what are they factors? (5 factors)
How should anaemia of CDK be treated?
1) Underlying cause associated w/raised cytokines (results in reduced iron)
2) Reduced EPO production due to kidney damage
3) Reduce clearance of hepcidin + increased hepcidin production due to cytokines
4) Dialysis - leads to damage to RBC’s
5) Reduced RBC lifespan as a result of uraemia
- Treat underlying condition - give recombinant EPO + ensure B12/folate/iron stores are adequate.
What are the haematological effects of RA?
- Anaemia - GI blood loss due to NSAID treatment
- High platelets + neutrophils when disease is active
- Low platelets + neutrophils may occur due to treatment
- Felty’s syndrome
What is Felty’s syndrome?
- A triad consisting of 1) RA 2) Splenomegaly 3) Neutropenia.
- Neutropenia occurs due to splenomegaly contributing to destruction of neutrophils + failure of bone marrow to produce neutrophils as there is insensitivity to myeloid cells to GCSF.
How does chronic liver disease result in low blood counts (particularly RBC’s)?
What are the other haematological features of liver disease?
- Causes portal hypertension, leading to splenomegaly - leads to splenic sequestration of cells + overactive removal of cells.
- Portal hypertension also leads to gastric/oesophageal varices (dilated veins very prone to bleeding)
- Thrombocytopenia in 75% of patients, impaired production of thrombopoietin in the liver + increased pooling + destruction in the spleen.
What are the possible haematological changes that can occur after a surgery?
1) Anaemia - due to blood loss during or post-op
2) Neutropenia - due to severe sepsis
3) Neutrophilia - due to infection or severe bleeding post-op
4) Thrombocytopenia - due to drugs or sepsis
5) Thrombocytosis - reaction post-op, or due to infection/bleeding
What are the haematological changes associated with infection?
- Chronic infection can cause anaemia of chronic disease
- Bacterial infections often associated with neutrophilia or severe bacterial infections/sepsis can cause neutropenia.
- Parasitic infections associated w/eosionophilia
- Viral infections associated w/lymphocytosis + neutropenia
What kind of clotting abnormality can sepsis lead to?
- Disseminated Intravascular Coagulation (DIC) - pathological activation of coagulation, multiple microthrombi formed in the circulation. Leads to consumption of clotting factors + platelets + microangiopathic haemolytic anaemia (MAHA). Risk of both bleeding + thrombosis.
What are the haematological changes associated with cancer?
- Anaemia - due to bleeding, iron deficiency or chemotherapy.
- Neutropenia - due to chemotherapy or in marrow cancer
- Neutrophilia - inflammation and infection
- Thrombocytopenia - due to chemotherapy, sepsis, DIC etc
- Thrombocytosis - infection, bleeding, iron deficiency etc
