Haematology And The Spleen Flashcards
Name the splenic functions:
Erythropoiesis
Culls aged and abnormal RBC
Plays a role in immune surveillance and antibody production.
Removes bacteria, foreign objects and tumor cells.
What are the functions off the white pulp
Immune function
Non-specific
- Clearance of pathogens
- Production of complements
- Clearance of opsonized RBC
- Surveillance of malignant cells
Specific
- Mediated by T and B lymphocytes
What are the functions of red pulp?
Filtration of blood Culling Pitting Removal of intra-cellular inclusions - Heinz bodies (denatured Hb) - Howell-Jolly bodies (Nuclear Remnants) - Pappenheimer bodies (Fe granules)
There are 3 mechanisms of splenomegaly, name and explain them:
- Immune hypertrophy
- RBC destruction work hypertrophy
- Congestion
- Myeloproliferative diseases
- Infiltration
- Neoplasticism
- Miscellaneous
Explain the 6 mechanisms of splenomegaly:
- Immune hypertrophy
- Bacterial endocarditis
- Felty syndrome
- infectious mononucleosis
- RBC destruction work hypertrophy
- Spherocytosis
- Thalasseamia major
- Congestion
- Portal hypertension
- Splenic vein thrombosis
- Myeloproliferative diseases
- CML
- Myelofibrosis
- Polycythemia rubra vera
- Infiltration
- Amyloidosis
- Gaucher’s disease
- Neoplastic
- Hairy cell leukemia
- Metaplastic carcinoma
- Miscellaneous
- Splenic cysts
- Haemangioma
Name 6 causes of massive splenomegaly:
- CML
- Malaria
- Myelofibrosis
- Gaucher’s disease
- Thalassaemia major
- Lymphoma
What is hypersplenism?
Results in one or more cytopenias
May be a result of splenomegaly
Can be reversed following a splenectomy
What is hyposplenism?
Decrease in splenic function due to disease or splenectomy.
May or may not be accompanied by reduction in size.
Impaired filtering and sequestration function leads to thrombocytosis.
Impaired filtering and sequestration leads to an increase in infection risk.
What are some conditions that increase the risk of hyposplenism?
Normal infants Old age Sickle cell Anaemia Amyloidosis Tumors and cysts Radiation Splenectomy Essential thrombocytopenia Adult gluten-induced enteropathy Dermatitis herpetiformis
Rarely: IBD, Splenic arterial thrombosis
What are some laboratory features of hyposplenism?
Howell-Jolly Bodies (Nuclear remnants) Heinz bodies (Denatured Hb) Pappenheimer (Fe) Increased white cell count Acanthocytes Thrombocytosis Target cells Irregularly contracted or cremated cells.
Name 4 causes for a splenectomy:
Hyperactivity
Auto-immune diseases
Extreme enlargement
Diagnostic and therapeutic optons
What are the haemotological indications for a splenectomy?
Autoimmune conditions
- Immune thrombocytopenic purpura
- Autoimmune haemolytic Anaemia
Hereditary disorders
- Thalassaemia
- Rarely pyruvate kinase deficiency
- Some cases of Gaucher’s disease
Myeloproliferative disorders
- Idiopathic Myeloprolifibrosis
Lymphoproliferative disorders
- Hairy leukaemia
Miscellaneous
- Feltys syndrome
What is hereditary spherocytosis?
Most commonly inherited RBC membrane defect
- Due to deficiency in. RBC membrane proteins.
What are the clinical features of hereditary spherocytosis?
Present at any algae Neonatal jaundice Asymptomatic to severe Anaemia Features of haemolysis - Splenomegaly - Gallstones - Mild jaundice Aplastic crisis
What are the diagnositic procedures for the diagnosis in hereditary spherocytosis?
Family history Spherocytic red blood cells Unconjugated bilirubinaemia U-urobilinogen Anaemia Increase in LDH
