Haematology Flashcards
What is polycythaemia?
Erythrocytosis of any cause (high red blood cell count) and increased haemoglobin and packed cell volume (PCV)
Describe the epidemiology of polycythaemia
95% of patients have the JAK2 mutation
What is the difference between absolute and relative polycythaemia?
Absolute = increased number of RBCs
Relative = normal number of RBCs but reduction in plasma
What is the difference between primary and secondary absolute polycythaemia?
Primary = increased sensitivity of BM cells to EPO
Secondary = more circulating EPO
What are 2 causes of primary absolute polycythaemia?
- Polycythaemia rubra vera = genetic mutation in JAK2 gene
- Primary familial and congenital polycythaemia = genetic mutation in EPO receptor gene
What are 8 causes of secondary absolute polycythaemia?
- Chronic hypoxia
- Erythropoietin producing tumour (e.g. renal carcinoma)
- High altitude
- COPD
- Sleep apnoea
- PKD
- Renal artery stenosis
- Kidney cancer
What are 3 causes of relative polycythaemia?
- Obesity
- Dehydration
- Excessive alcohol consumption
What are 2 signs of polycythaemia?
- Hypertension
- Angina
What is a sign of polycythaemia rubra vera that is not seen in secondary polycythaemia?
Hepatosplenomegaly
What are 9 symptoms of polycythaemia?
- Easy bleeding/bruising
- Fatigue
- Dizziness
- Headaches
- Blurred vision
- Plethoric complexion
- Itching especially after contact with water
- Tinnitus
- Erythromelalgia (burning sensation in fingers/toes)
What are 3 investigations for patients with polycythaemia?
- FBC
- BM biopsy
- Genetic testing for JAK2 gene
What is the difference between FBC for polycythaemia rubra vera and secondary polycythaemia?
Both = low serum EPO
Rubra vera = raised WBC and platelets
Secondary = normal WBC and platelets
What is the treatment for polycythaemia?
- Blood letting (venesection - removal of 400-500ml of blood)
- Low dose aspirin daily
- Hydroxycarbamide (for those at risk of thrombus)
- Treat the cause
What is thrombocytopenia?
Deficiency of platelets in the blood
Describe the epidemiology of immune thrombocytopenia (ITP)
- Mainly seen in children aged 2-6
- Primary = often post-viral infections (self-limiting)
- Secondary = more common in young women, malignancies and HIV
What are 3 causes of ITP?
- Reduced platelet production in BM
- Autoimmune destruction of platelets
- Problems of enlarged spleen
Describe the pathophysiology of ITP
- Autoimmune destruction of platelets due to IgG antibodies
- IgG antibodies coat the platelets which are then removed by binding to Fc receptors on macrophages
What are 6 symptoms of both ITP and TTP?
- Purpura (red/purple spots on skin caused by bleeding underneath)
- Epistaxis
- Easy bruising
- Menorrhagia
- Headache
- Fatigue
What are 2 symptoms of ITP?
- Gum bleeding
- Vomiting
What are 3 investigations for ITP?
- FBC
- BM biopsy
- Platelet autoantibodies present in 70% of cases
What is the treatment for ITP?
- 1st line = corticosteroids e.g. prednisolone
- IV IgG (temporarily increases no. of platelets)
- Splenectomy
- Immunosuppression = oral azathioprine
Describe the epidemiology of thrombotic thrombocytopenia (TTP)
- Rare
- More common in adults
- More common in females (3:2)
- Associated with HIV, cancer and systemic lupus erythematosus
What is the cause of TTP?
Deficiency of von Willebrand Factor cleaving protein (vWF-cp) a.k.a ADAMTS 13 (responsible for the degradation of vWF)
Describe the pathophysiology of TTP
- Lack of vWF-cp results in extensive microvascular clot formation in small vessels in the body
- Results in low platelet count and organ damage
What are 4 symptoms of TTP?
- Flu-like symptoms (fever, aches)
- Haemoptysis (coughing up blood)
- Abdominal pain
- Chest pain
What is a sign of TTP?
GI bleeding
What are 6 investigations for patients with thrombocytopenia?
- Normal coagulation screen
- Blood smear = fragmented erythrocytes
- U&E = raised creatinine
- Raised bilirubin
- Raised reticulocyte count
- Urinalysis = proteinuria and haematuria
What is the treatment for TTP?
- IV plasma exchange
- Steroids = IV methylprednisolone
- Rituximab (monoclonal antibody)
- Folic acid
What should you absolutely not do for patients with TTP?
Platelet transfusions
What is Von Willebrand Disease?
A deficiency in vWF a.k.a pseudohaemophilia
Describe the epidemiology of VWD
- Most common hereditary coagulopathy
- More common in females
- Poorer prognosis in blood type O
What is the cause of VWD?
- vWF deficiency
- Can be congenital or acquired
What is the function of vWF?
- Assists platelet plug formation
- vWF binds to factor VIII to protect it from liver protein C destruction (prevents clearance of factor VIII from plasma)
What are the types of VWD?
- Type 1: most common (60-80%); autosomal dominance; defect in QUANTITY of vWF
- Type 2
- Type 3
- Platelet type: most rare
What are 3 symptoms of VWD?
- Epistaxis
- Menorrhagia
- Spontaneous bleeding
What are 6 investigations for patients with VWD?
- FBC
- Fibrinogen level
- Platelet count = normal
- Clotting screen
- Plasma vWF = decreased
- Factor VIII levels = decreases
What is the treatment for VWD?
- Stop any antiplatelet drugs and NSAIDs
- Tranexamic acid (for minor bleeds)
- COC (for menorrhagia)
- Desmopressin (increase vWF levels)
- Platelet transfusions
What is haemophilia A?
Factor VIII deficiency
Describe the epidemiology of haemophilia A
- 5 times more common than haemophilia B
- Mainly affects men (X linked recessive disorder)
What are the types of haemophilia A?
- Mild = >5% FVIII activity
- Moderate = 1-5% FVIII activity
- Severe = <1% FVIII activity
What are 2 signs of haemophilia A and B?
- Haematoma (collection of blood outside blood vessels)
- Hemarthrosis (bleeding into joint spaces - happens in severe)
What are 4 symptoms of haemophilia A and B?
- Severe bleeding following injury (happens in moderate)
- Easy bruising
- Haematuria
- Severe epistaxis
What are 3 investigations for patients with haemophilia A and B?
- Prothrombin time (PTT) = normal
- Activated partial thromboplastin time (APTT) = prolonged
- Plasma factor VIII/IX = reduced
Why is PTT normal and APTT is prolonged in patients with haemophilia A and B?
Factors VIII and IX are not in the extrinsic pathway so PTT is not affected whereas APTT is
What is the treatment for haemophilia A and B?
- IV factor VIII and IX
- Fresh frozen plasma containing factor VIII/IX
- Desmopressin (boosts FVIII/IX activity)
- Hep A vaccinations
What is a complication of haemophilia A and B?
Joint deformities and arthritis from recurrent bleeding into joints
What is haemophilia B?
Factor IX deficiency
What are the types of haemophilia B?
- Mild = 6-30% FIX levels
- Moderate = 1-5% FIX levels
- Severe = <1% FIX levels (50% of cases)
What is disseminated intravascular coagulopathy?
Widespread activation of coagulation cascade and platelet activation
What are 8 causes of DIC?
- Sepsis
- Crush syndrome
- Malignancy e.g. leukaemia
- Amniotic fluid embolism
- Abruptio placentae
- Infection e.g. meningitis
- Haemolytic transfusion reactions
- Liver disease
Describe the pathophysiology of DIC
- Initial thrombosis following bleeding
- Occurs when the balance between forming new clots and breaking down clots is tipped in favour of forming clots = widespread clotting = organ ischaemia
- Depletion of clotting factors leads to bleeding
What are 2 signs of DIC?
- GI bleed
- ARDS (adult respiratory distress syndrome)
What are 8 symptoms of DIC?
- Spontaneous bleeding at venepuncture/IV sites
- Epistaxis
- Bruising
- Rash
- Purpura (red/purple spots on skin caused by bleeding underneath)
- Confusion and Shock
- Shortness of breath
- Haemoptysis (coughing up blood)
What are 2 investigations for DIC?
- FBC
- Blood smear/film = schistocytes (fragmented RBCs)
What do bloods show in patients with DIC?
- Low platelets
- Low fibrinogen
- High d-dimer
- Long PT
- Long APTT
What is the treatment for DIC?
- Treat underlying cause
- Cryoprecipitate (for low fibrinogen)
- Platelet transfusion
- Red cell transfusion
- Fresh frozen plasma
What are 2 complications of DIC?
- Organ failure by infarction
- Death
What is the cause of glandular fever (infectious mononucleosis)?
Epstein Barr Virus
What are 3 signs of glandular fever?
- Lymphadenopathy (swollen lymph nodes)
- Tonsillar enlargement
- Splenomegaly
What are 3 symptoms of glandular fever?
- Fever
- Sore throat
- Fatigue
What are 2 investigations for patients with glandular fever?
- Test for heterophile antibodies (Monospot test or Paul-Bunnel test)
- Test for EBV antibodies
What is the treatment for glandular fever?
- Usually self-limiting (2-3 weeks)
- Advised to avoid alcohol and contact sports
- Emergency surgery (if splenic rupture)
What is multiple myeloma?
Cancer of plasma cells resulting in excess production of certain immunoglobulins (most often IgG and IgA)
Describe the epidemiology of multiple myeloma
- 75+
- Afro-Caribbean’s
- Males
- IgG = 55%
- IgA = 20%
- Close link to monoclonal gammopathy of undetermined significance (MGUS)
What is monoclonal gammopathy of undetermined significance (MGUS)?
- Too much of an immunoglobulin is released by abnormal plasma cells
- 1% of cases develop into myeloma
What are the signs of multiple myeloma?
OLD CRAB:
- Old >75
- Calcium (high) >2.75mmol/L
- Renal impairment
- Anaemia
- Bone lesions (pepper pot skull)
What are 6 symptoms of multiple myeloma?
- Fatigue
- Dizziness
- Polyuria/polydipsia
- Constipation
- Abdominal pain
- Back pain
What are 5 investigations for patients with multiple myeloma?
- FBC = anaemia and raised ESR
- Blood film = rouleaux
- Serum and urine electrophoresis = Bence Jones protein in urine
- Xray = pepper pot skull and fractures
- CT = bone lesions and cord compression
What is the treatment for multiple myeloma?
Palliative disease
- Bisphosphonates
- Analgesia (avoid NSAIDs)
- Chemotherapy/radiotherapy
- Blood transfusions
- Infection control
What are 5 complications of multiple myeloma?
End organ damage:
1. Lytic bone lesions
2. Infections
3. Fractures
4. Renal failure
5. Proteinuria
What is anaemia?
Lower than normal concentration of haemoglobin (Hb <130 in men, <120 in women)
What are 4 signs of anaemia?
- Tachycardia
- Skin pallor
- Conjunctive pallor
- Raised respiratory rate
What are 5 symptoms of anaemia?
- Fatigue
- Headache
- Dizziness
- Dyspnoea (especially on exertion)
- Palpitations
What are 4 distinguishing symptoms of anaemia?
- Jaundice/dark urine (haemolytic anaemia)
- Lemon/yellow skin (B12 deficiency)
- Koilonychia (spoon shaped nails) (iron deficiency)
- Angular stomatitis (irritated cracked sores/inflammation around corners of mouth) (iron/B12 deficiency)
What is microcytic anaemia?
Anaemia with a MCV (mean corpuscular volume) of <80fl
Describe the epidemiology of microcytic anaemia
- 2-5% of men and post menopausal women
- Premenopausal women are at a higher risk due to menses
- Iron deficiency anaemia is the most common type of anaemia
What are 5 causes of microcytic anaemia?
- Iron deficiency
- Anaemia of chronic disease
- Thalassaemia
- Sickle cell
- Sideroblastic anaemia
What are 6 causes of iron deficiency?
- Blood loss (e.g. menorrhagia)
- Poor diet
- Malabsorption (e.g. coeliac disease)
- Hookworm
- Pregnancy
- Breastfeeding
What are 4 causes of anaemic of chronic disease?
- Cancer
- HF
- CKD
- Chronic inflammation (e.g. connective tissue disorders)
What is thalassaemia?
When the body makes an abnormal form/inadequate amount of Hb resulting in defective subunits
What is sideroblastic anaemia?
Normal iron levels but body cannot insert iron into Hb