Haematology In Systemic Disease Flashcards
physiological level cycle of blood cells
RBC that are made in the bone marrow, mature and stay in the blood vessels
When they are old or damaged then they are removed by the spleen (the RES)
Changes to the blood in systemic disease
Often multi-factorial
In individual conditions usually represent an underlying disease but not actually representing the disease itself (i.e. secondary affects/complications)
It could also be due to the effects of treatments that have been given e.g. methotrexate used for RA which will have an impact of the bone marrow
Why might anaemia develop
Reduced or dysfunctional erthropoiesis?
Anaemia can result from lack of response in the haemostatic loop e.g. in chronic kidney disease the kidney stops making erythropoietin
Anaemia can result from marrow being unable to respond to EPO e.g. after chemotherapy, toxic insult or infections such as parvovirus
In Anaemia of chronic disease e.g. rheumatoid arthritis, iron is not made available to marrow for RBC production
In anaemia of chronic disease there are at least 3 contributors all caused by inflammatory cytokines
Iron dysregulation: available iron is not released for use in bone marrow
The marrow shows a lack of response to erythropoietin
There is reduced lifespan of red cells
Examples of diseases - Rheumatoid arthritis
Inflammatory bowel disease (Ulcerative Colitis or Crohns disease)
Chronic infections eg bronchiectasis, TB
Anaemia of chronic disease - functional iron deficiency
Sufficient iron in the body but its not a viable to the developing erythroid cells
E.g. ferroportin is the main exporter of iron out of the marcrophage (where it has been recycled) so if ferroportin is absent or deficient (could be inhibited by Hepcidin (which is increased by cytokines stimulating the liver (when inflammation is present))) then will look like an iron deficiency - therefore presenting with anaemia
Anaemia of chronic kidney disease is even more multifactoral
Underlying cause of CKD often associated with raised cytokines
Reduced clearance of Hepcidin and increased hepcidin production due to inflammatory cytokines
Dialysis damaged to RBC
Leads to reduced lifespan of RBC as a direct effect of uraemia
(Uraemia also inhibits magakaroycytes leading to low platelet counts)
Treatment of anaemia of chronic disease
Need to treat the underlying condition
If there is associated renal failure, then people may receive recombinant human EPO
Ensure Vit B12 folate and iron stores are adequate as the patient must have all the building blocks for EPO therapy to work (Iron, Vit12 and Folate)
Transfuse RBC abut only if all else fails
Management of anaemia of chronic renal failure
Use Reticulocyte Haemoglobin Content (CHr) (or % hypochromic cells) to assess for functional iron deficiency
Give iron if ferritin <200
Possible haematological abnormalities in kidney disease
That would be seen it RBC:
Anaemia: caused by CKD, or Blood loss due to kidney stones being present, or cancer or something in the Diet causesing the filtration system to not function properly
Polycythaemia (increased RBC mass by increased RBC production) could be due to a renal transplant, a renal tumour or polycystic kidneys
That would be seen in neutrophils:
Neutropenia (lack of): Immunosuppression - post renal transplant drugs or autoimmune kidney disease
Neutrophilia (large amounts of): Inflammation, Infection, Drugs: such as steroids can cause neutrophilia
That would be seen in Platelets
Thrombocytopenia (low platelet count): Uraemia inhibits platelet production, Many drugs or haemolytic uraemic syndrome (children, E coli)
High platelet count - Inflammation, Bleeding, or Iron deficiency
Rheumatoid arthritis
A chronic immune mediated inflammatory condition
Treated with
Felty’s syndrome
Neutropenia
Haematological features of liver disease
Liver cirrhosis - Chronic liver disease will cause Portal Hypertension which causes splenomegaly which leads to:
Splenic sequestration of cells
Overactive removal of cells
LOW blood counts
Blood loss - which is contributed to by:
deficiencies of coagulation factors
Endothelial dysfunction - could be hastened by drugs (NSAIDS)
thrombocytopenia
defective platelet function
Portal hypertension - also leads to oesophageal and gastric varices (dilated veins prone to bleeding due to higher than normal pressure)
Most clotting factors are made by the liver; synthesis of some is dependent on Vitamin K – patients with liver disease quickly become deficient in clotting factors leading to haematological problems - clots dont form properly so we bleed more - less RBCs
Thrombocytopenia in 75% patients with liver disease - Impaired production as thrombopoietin is made in the liver
leading to splenic pooling and increased destruction of RBC
Those platelets made often have reduced function which contributes to the bleeding
Target cells often seen in liver disease – due to increased cholesterol: phospholipid ratio
Other haematological features of liver disease are dependent on the underlying causes
Alcohol excess
Directly toxic to bone marrow cells – can contribute to (pan)cytopenia
Post Op reach time changes that could lead to haematological issues
Anaemia could occur due to - Blood loss pre-op or Blood loss during op
Temporary relative polycythaemia due to - Dehydration
Neutropenia due to - Severe sepsis
Neutrophilia due to Post-op reaction or Infection or Severe bleeding
Thrombocytopenia due to - Drugs or Sepsis or Disseminated intravascular coagulation (DIC)
Thrombocytosis due to - Post-op reaction or Infection or Bleeding
Haematological changes with infection
Chronic infection can cause anaemia of chronic disease
Infection with malaria can cause haemolytic anaemia
Bacterial infection is often associated with neutrophilia
Severe bacterial infection/sepsis can cause neutropenia
Parasitic infections are associated with eosinophilia
Viral infections can cause a lymphocytosis and neutropenia
Infection can cause a reactive thrombocytosis
Severe infection can cause thrombocytopenia
Thrombocytopenia may be associated with DIC in severe sepsis
Sepsis can lead to clotting abnormalities e.g.
Disseminated intravascular coagulation (DIC)
Pathological activation of coagulation (coagulation goes on and on)
Numerous microthrombi are formed in the circulation
This leads to consumption of clotting factors and platelets, and a consequent microangiopathic haemolytic anaemia (MAHA)
Clotting tests are affected - usually long clotting times, low fibrinogen and raised D-dimers or fibrin degradation products
Risk of both bleeding and thrombosis
Risk of anaemia due to RBC “catching” on the microthrombi and causing tears in the RBC, therefore being removed and broken down by the spleen
Haematological changes in cancer
Anaemia due to - Bleeding eg bowel, stomach, bladder, endometrium or Iron deficiency or ACD or other Treatments e.g. chemotherapy
Polycythaemia due to - an EPO producing tumour
Neutropenia due to - Chemotherapy or the Marrow being infiltrated by cancer cells
Neutrophilia due to - Inflammation or Infection
Thrombocytopenia due to - Chemotherapy, Sepsis, D.I.C or Marrow infiltrated by cancer
Thrombocytosis due to - Inflammation, Infection, Bleeding or Iron deficiency
Leucoerythroblastic film
Granulocyte precursors and nucleated (immature) RBC seen on blood film (spill out from the marrow into the blood when the marrow is under stress)
This can come about from -
Sepsis/shock
Bone marrow infiltration by carcinoma or haematological malignancy
Severe megaloblastic anaemia - thalassaemia
Primary Myelofibrosis (with tear drop RBCs)
Leukaemia
Storage disorders
