Flashcards in Haematology Deck (49)
How are haemophilia A and B inherited?
Sex linked recessive
What are the hallmarks of haemophilia?
Haemorrhage into joints
Bleeding with tooth extraction
What are the blood laboratory findings in haemophilia?
Normal prothrombin time
Normal bleeding time
Normal fibrinogen level
Prolongation of the partial thromboplastin time
What factors are deficient in haemophilia A and B?
Haemophilia A - Factor VIII
Haemophilia B - factor IX - Christmas disease
What is multiple myeloma?
Bone marrow cancer affecting plasma cells, collections of abnormal plasma cells accumulate and interfere with production of other blood cells
Increased amounts of amyloid light chain can get deposited in multiple organs including the carpal tunnel
CRAB: elevated calcium, renal failure, anaemia, bone lesions
What are symptoms of anaemia?
Shortness of breath on exertion
Syncope or pre-syncope
Failure to thrive in children
What are signs of anaemia?
What are the main causes for anaemia?
Increased usage: Bleeding, Haemolysis
Decreased production: Iron/B12/folate deficiency, Renal failure (EPO), Haematological malignancies, Bone marrow failure syndromes
Anaemia of Chronic Disease: decreased iron utilisation
What questions are important in a history for a presentation of anaemia?
Diet: veganism, phytates, alcohol
Bowels: Malabsorption, changing habit, blood, pain
Menses and multiparity: menorrhagia
Family history: bowel Ca, ethnicity (sickle/thal)
Drugs: Antiplatelets/anticoagulants, PPI
Past medical history: Renal disease, chronic diseases
Systematic review: Features of malignancy (weight loss), Inflammatory disease processes (fevers, joint pains, rashes), Haemolytic features (dark urine, jaundice)
What clinical signs would you look for on examination of a patient presenting with anaemia?
Signs of malignancy: Cachexia, lymphadenopathy, masses
Signs of inflammatory diseases: Fevers, joint swelling, rashes
Signs of chronic infection: Such as ulcers, bronchiectasis, deep infections
Signs of heart failure: oedema, SOB, PND, arrhythmia, reduced exercise tolerance, pink sputum
Signs of liver disease: caput medusa, spider naevi, ascites, jaundice
Haemtological features: Hepatosplenomegaly
What are some causes of iron deficiency?
Blood loss: Menstrual, Multiparity, GI
Malabsorption: Diarrhoea, Gastrointestinal symptoms
What investigations would you do for iron deficiency anaemia?
FBC, MCV, MCH: microcytic, hypochromic
Coeliac serology (anti-TTG antibodies and IgA)
Upper and Lower GI endoscopy
In which patients might you find folic acid deficiency anaemia?
Malabsorption, especially if combined deficiencies
What is b12 deficiency associated with?
Peripheral neuropathy and subacute combined degeneration of spinal cord
How is b12 absorbed? What clinical relevance does this have?
Bound to intrinsic factor in the terminal ileum
Malabsorptive states lead to deficiency
Intrinsic factor from stomach so gastrectomy can affect this
What investigations would you do to check a patient who has suspected b12 or folate deficiency?
Check serum B12 and serum folate
Intrinsic factor antibodies
What are causes of microcytic anaemia?
Late Anaemia of Chronic Disease
What are causes of normocytic anaemia?
What are causes of a macrocytic anaemia?
Paraprotein (multiple myeloma)
What additional tests might need to be performed to determine a cause for a patients anaemia?
Reticulocyte count: if raised, haemolysis or haemorrhage
Blood film: can be diagnostic of specific causes
Haemolysis screen: lactate dehydrogenase, haptoglobin, bilirubin and Direct antiglobulin test (autoimmune screen)
Renal function: eGFR is proportional to EPO
CRP/ESR: useful for chronic disease
LFTs: includes bilirubin
Myeloma screen: Ca, Igs, protein electrophoresis, serum free light chains, Bone marrow biopsy
How might haemochromatosis present?
Joint and bone pain
What is haemophilia A? What is its heritability?
X linked recessive disorder resulting in lack of factor VIII
A man can only get the faulty X chromosome from his mother
Female can only get it if both parents carry a faulty X chromosome
A 59 year old woman is brought to a&e by her concerned son who thinks she is having a heart attack. She mentions no pain but rather that her heart is skipping. On examination she has an irregularly irregular pulse. She has a history of dvt so is referred to the anticoagulation clinic where she is commenced on warfarin. What range of inr is deemed therapeutic in this individual?
A 68 year old man presents to his gp with his wife complaining of increasing lower back pain. He gets constipated but has noticed no bleeding or weight loss. He experiences bouts of confusion. Investigations show elevated calcium, normocytic anaemia and raised creatinine. Paraproteins are detected in the urine. What is the most likely diagnosis?
What are major features of multiple myeloma?
Bence Jones protein
A 19 year old student presents with a supraclavicular lump. On examination it is rubbery and non tender. On further questioning she has been feeling lethargic, having night sweats and has lost weight. A biopsy is done which shows characteristic cells with mirror image nuclei. What is the most likely diagnosis?
Mirror image nuclei = reed sternberg cells
Incidence high in young adults and elderly
A 9 year old boy is brought by his worried parents to the ED as he developed a number of bruises last night. On questioning the parents state that he presented 5 days ago with fever, abdo pain and vomiting for which the GP diagnosed gastroenteritis. Since then he has become increasingly unwell. He has no medical history and there are no social concerns. On examination there are bruises of varying sizes and petechiae over his trunk. He looks pale and his consciousness seems depressed. Investigation reveals increased unconjugated plasma bilirubin, low haptoglobin, renal impairment and thrombocytopenia. What is the likely diagnosis?
Haemolytic uraemic syndrome
Initial gastroenteritis and subsequent haemolysis
Can resolve of own accord but may need plasmapheresis in severe cases
Give examples of antioxidants
Prevent radical formation: transferrin and lactoferrin
Remove/inactivate ROS: SOD, vit C and E, glutathione
What can the uncontrolled production reactive oxygen species in inflammation cause?
Lipid and protein peroxidation
Damage to cell membranes
Increased capillary permeability
Impaired mitochrondrial respiration
DNA strand breaks
What is a bence Jones protein?
Immunoglobulin light chain found in urine
Suggestive of multiple myeloma
Where are iron, folate and b12 absorbed?
Iron - duodenum
Folate - jejunum
B12 - terminal ileum
What are general causes of thrombocytopenia?
Impaired production: myelodysplastic syndromes, myeloma, tumour infiltration, aplastic anaemia, HIV
Excessive destruction/increased consumption: ITP, DIC, TTP
Sequestration: splenomegaly, hypersplenism
Dilutional: massive transfusion
What are some acquired causes of platelet dysfunction?
Drug induced: NSAIDs
Why does renal disease lead to platelet dysfunction?
Platelet function impaired by urea and other metabolites which accumulate in renal disease
What are potential complications of haemophilia A?
Develop antibodies to factor VIII
Deep internal bleeding
Infection secondary to transfusion
How can liver disease lead to bleeding tendency?
Vit K deficiency: cholestasis
Reduced synthesis of coag factors
Thrombocytopenia: hypersplenism secondary to portal hypertension or folic acid deficiency
Functional abnormalities of platelets and fibrinogen
DIC in acute liver failure
Give some causes of DIC
Septicaemia - gram neg
Haemolytic transfusion reaction
Obstetric: placental abruption, amniotic fluid embolism, pre eclampsia
Infections: falciparum malaria
What are some risk factors for hypercoagulable states?
Hx of unprovoked VTE
Acute inflammatory state
Paroxysmal nocturnal haemoglobinuria
Heparin induced thrombocytopenia
COCP, HRT, SERM
Protein c/s deficiency
Long haul flight
Factor V Leiden mutation
What investigations would you do in a patient with suspected thrombophilia?
Peripheral blood smear: red cell fragmentation, spherocytes, thrombocytopenia, sickle shaped cells
APTT: reduced or prolonged
Fibrinogen: elevated if prothrombotic, reduced if DIC
Serum albumin: low in nephrotic syndrome
Serum creatinine: high in nephrotic syndrome
Serum triglycerides: high in nephrotic syndrome
What patient related factors are checked for on a VTE risk assessment form?
Active cancer or treatment
Age over 60
Obesity BMI over 30
One or more significant medical comorbidities
Personal Hx first degree relative with VTE Hx
Use of HRT
Used of COCP
Varicose veins with phlebitis
What admission related factors are checked for on a VTE risk assessment form?
Significantly reduced mobility for 3 days or more
Hip or knee replacement
Total anaesthetic and surgery time over 90 mins
Surgery involving pelvis or lower limb with total time over 60 mins
Acute surgical admission with inflam or intra abdo condition
Critical care admission
Surgery with significant reduction in mobility
In whom might you consider doing a thrombophilia screen?
Patients presenting with first VTE age under 50
Unprovoked or recurrent VTE
Thrombosis in unusual site
Neonatal purpura fulminans
Warfarin induced skin necrosis
Family Hx in first degree relative at young age
What is included in a thrombophilia screen?
Protein c level
Free protein s level
Activated protein c resistance
Prothrombin gene mutation
What are management options for thrombophilia?
Low molecular weight heparin, unfractioned heparin or fondaparinux
Mechanical thromboprophylaxis: graduated compression stockings, intermittent pneumatic compression device
What are Howell Jolly bodies?
Blue black inclusions of red blood cells which represent nuclear fragments commonly seen in asplenic patients
What are schistocytes?
Fragmented red blood cells seen in intravascular haemolysis
What can cause a microcytic anaemia?
Anaemia of chronic disease
What can cause a normoblastic macrocytic anaemia?