Haematology Flashcards
Define anaemia
- Decrease of Hb in blood
- Below reference level for age and sex of individual
- Can be caused by low red cell mass (RCM) or increased plasma volume
Diagnosis to determine cause of anaemia
- Cause = reduced production from bone marrow
- Reticulocyte (immature RBC’s in bone marrow) count LOW
- Cause = increased removal
- Reticulocyte count HIGH
How are the types of anaemia classified?
Mean Corpuscular Volume (MCV) = avg volume of RBC’s
What are the 3 major types of anaemia?
- Hypochromic microcytic - LOW MCV
- Normochromic microcytic - NORMAL MCV
- Macrocytic - HIGH MCV
Consequences of anaemia
- Reduced O2 transport
- Tissue hypoxia
- Compensatory changes
- Increased tissue perfusion
- Increased O2 transfer to tissues
- Increased RBC production
Pathological consequences of anaemia
- Myocardial fatty change
- Fatty change in liver
- Aggravates angina and claudication
- CNS cell death
Generic clinical features of anaemia
- Fatigue
- Dyspnoea
- Angina (if pre existing coronary disease)
- Anorexia
- Palpitations
Generic signs of anaemia
- Pallor
- Tachycardia
- Systolic flow murmur
- Cardiac failure
Aetiology of microcytic anaemia
- Low MCV
- Iron deficiency (most common cause)
- Anaemia of chronic disease (anaemia caused by chronic disease)
- Thalassaemia (decreased Hb production)
Aetiology of iron deficiency anaemia
- Blood loss
- Menorrhagia (menstruation)
- GI bleed
- Hookworm
- Poor diet
- Increased demand during growth and pregnancy
- Malabsorption
- Poor intake
- Coeliac disease
Pathophysiology of iron deficient anaemia
- Less Fe available for haem synthesis
- Leads to reduction in Hb
- .˙. Smaller RBC’s -> microcytic anaemia
Clinical presentations for iron deficient anaemia
- Brittle nails + hair
- Spoon shaped nails
- Atrophy of the papillae of tongue
- Angular stomatitis (ulceration of corners of mouth)
Differential diagnosis of iron deficient anaemia
- Thalassaemia
- Sideroblastic anaemia
- Anaemia of chronic disease
Diagnosis of iron deficient anaemia
- Hb M < 130g/L
- Hb F < 120g/L
- Hb Fp < 110g/L
- MCV < 80fL
- Serum ferrite = decreased
- Blood film
- Micro + hypochrom (pale)
Treatment of iron deficient anaemia
- Oral iron - Ferrous sulphate
- Side effects: nausea, diarrhoea/constipation, black stool
- Ferrous gluconate if side effects bad
- IV/ deep IM iron
Define anaemia of chronic disease
- Secondary to chronic disease
- Essentially, body is sick .˙. bone marrow sick -> anaemia
- RBC’s often normocytic
- Microcytic in rheumatoid arthritis and Chron’s
Aetiology of anaemia of chronic disease
Chronic infections such as
- TB
- Crohn’s
- Rheumatoid arthritis
- Systemic Lupus Erythematosus (SLE)
- Malignant disease
Pathophysiology of anaemia of chronic disease
- Decreased release of Fe from bone marrow to developing erythroblasts
- Inadequate erythropoietin (cytokine which increase RBC production) response to anaemia
- Decreased RBC survival
Diagnosis of anaemia of chronic disease
- Serum iron and TIBC = low
- Serum ferritin = normal/raised
- Serum soluble transferrin receptor level = normal
- Blood count & film
- Normocytic or microcytic
- Hypochromic
Treatment of anaemia of chronic disease
Erythropoietin injection = effective in raising Hb level
Aetiology of normocytic anaemia
- Acute blood loss
- Anaemia of chronic disease
- Endocrine disorders
- Renal failure
- Pregnancy
Diagnosis of normocytic anaemia
- Normal B12 and folate
- Raised reticulocytes
- Low Hb
- Blood count & film - RBCs = normocytic
Treatment of normocytic anaemia
- Improve diet + vitamins
- Erythropoietin injection
Define macrocytic anaemia
- High MCV
- Megaloblastic
- Non-megaloblastic
Define megaloblastic macrocytic anaemia
- Erythroblasts with delayed nuclear maturation because of delayed DNA synthesis
- Megaloblasts: high MCV and no nuclei
Define non-megaloblastic macrocytic anaemia
Erythroblasts = normal
Aetiology of macrocytic anaemia
- Megaloblastic
- B12 deficiency
- Folate deficiency
- Non-megaloblastic
- Alcohol
- Liver disease
- Hypothyroidism
Pathophysiology of pernicious anaemia
- Autoimmune disorder + megaloblastic
- Parietal cells of stomach attacked ->atrophic gastritis + loss of intrinsic factor production .˙. B12 malabsorption
- Intrinsic factor antibodies = specific for diagnosis
- Autoimmune gastritis -> parietal and chief cells replaced by mucin-secreting cells
- Leads to achlorhydria (reduced HCl)
Clinical presentation of pernicious anaemia
- Progressively increasing symptoms of anaemia
- Lemon-yellow skin colour (pallor + mild jaundice)
- Glossitis (red sore tongue)
- Neurological features
- Symmetrical paresthesia (tingling fingers and toes)
- Progressive weakness
- Paraplegia
Differential diagnosis of pernicious anaemia
- Folate deficiency
- Disease of terminal ileum
- Bacterial overgrowth in small bowel
- Gastrectomy
Diagnosis of pernicious anaemia
- Blood count & film
- Megaloblastic anaemia characteristics
- Macrocytic RBCs
- Peripheral film = oval macrocytes + hypersegmented neutrophil polymorphs
- Serum bilirubin = raised
- Serum B12 = low
- Hb = low
- Reticulocyte = low
Treatment of pernicious anaemia
- If cause malabsorption -> B12 injection
- Dietary = oral B12
- Replenish B12 stores with IM hydroxocobalamin
Pathophysiology of folate deficiency
- Megaloblastic anaemia
- Absorbed by duodenum/proximal jejunum
- Essential for DNA synthesis .˙. impairment of DNA synthesis + delayed nuclear maturation -> large RBCs + decreased RBC production in bone marrow
- Deficiency can lead to fetal neural tube defects
Aetiology of folate deficiency
- Poor intake
- Increased demand
- Malabsorption - Crohn’s , Coeliac
- Antifolate drugs - Methotrexate, Trimethoprim
Clinical presentation of folate deficiency
- Symptoms of anaemia
- Glossitis
- No neuropathy like B12 deficiency (way to differentiate)
Diagnosis of folate deficiency
- Blood count & film
- Megaloblastic anaemia characteristics
- Macrocytic RBCs
- Oval macrocytes, hypersegmented neutrophil polymorphs
- Serum red cell folate = low
- GI investigation = small bowel biopsy to exclude occult GI disease
- Serum bilirubin = raised
Treatment of folate deficiency
Folic acid tablets daily for 4 months WITH B12 ALWAYS unless confirmed normal B12
Define haemolytic anaemia
- Destruction of RBCs»_space; Production of RBCs
- RBCs = normocytic or macrocytic if many young RBCs
Consequences of haemolytic anaemia
- Shortening red cell survival -> compensatory RBC production by bone marrow
- If loss close enough to compensatory production -> compensated haemolytic disease
- Compensatory production -> reticulocytes released prematurely .˙. cells larger than mature cells -> macrocytic
Aetiology of haemolytic anaemia
- RBC membrane defect
- Hereditary spherocytosis
- Enzyme defects
- G6PD deficiency
- Haemoglobinopathies
- B Thalassaemia
- A Thalassaemia
- Sickle cell disease
- Autoimmune haemolytic anaemia
Clinical presentation + diagnosis of haemolytic anaemia
- Pallor
- Jaundice
- Serum unconjugated bilirubin - HIGH
- Urinary urobilinogen - HIGH
- Faecal stercobilinogen - HIGH
DIAGNOSIS - Hb = LOW
- Reticulocytosis (increased reticulocytes)
- MCHC = INCREASED
Define sickle cell anaemia
Disorder of quality of RBCs
Pathophysiology of sickle cell anaemia
- Sickle cell haemoglobin (HbS) = insoluble and polymerise when deoxygenated
- Flexibility of cells decreased -> rigid and sickle appearance
- Initially reversible but repeated sickling -> membrane flexibility lost .˙. irreversibly sickled
- Sickling -> shortened RBC survival
- Impaired passage through microcirculation -> tissue infarct
Clinical presentation of heterozygous sickle cell trait
- Symptom free except in hypoxia
- Carriage offer protection against Falciparum malaria
Clinical presentation of homozygous sickle cell anaemia
- Vaso-occlusive crises
- acute pain in hand and feet
- Acute chest syndrome
- Vaso-occlusive crisis of pulmonary vasculature
- Pulmonary hypertension
- Mean pulmonary artery pressure > 25mmHg
- Long term presentations
- Delayed sexual maturation
- osteomyelitis
- Infection in bones, lungs and kidneys
- MI
- Retinopathy
Diagnosis of sickle cell anaemia
- Blood count
- Hb = 60-80 g/L
- Reticulocyte = raised
- Blood films
- Sickled erythrocytes
- Sickle solubility test = positive
- Hb electrophoresis - 80-95% HbS and absent HbA
Treatment of sickle cell anaemia
- Treat precipitating factors (infection, dehydration) first
- Folic acid
- Acute painful attacks
- IV fluids
- Analgesia
- Oxygen
- Anaemia
- Blood transfusion (increased risk of iron overload)
- Oral hydroxycarbamide
- Stem cell transplant
Define Thalassaemia
- Disorder of quantity (reduced production)
- Genetic disease -> unbalanced Hb synthesis with under production of one globin chain
- Precipitation of imbalance globin chains in matured red cells -> haemolysis
- Alpha thalassaemia = reduced alpha chain synthesis
- Beta thalassaemia = reduced beta chain synthesis
Define beta thalassaemia
- Little/no B chain production -> excess A chains
- Excess A combines with D and G chains
- Results in increased HbA2 and HbF
What are the different types of Haemoglobin?
- Normal Hb (HbA) = Haem + 2 alpha chains + 2 beta chains (97% of Hb in adults)
- Foetal Hb (HbF) = Haem + 2 alpha chains + 2 gamma chains (1% of Hb in adults)
- Hb delata (HbA2) = Haem + 2 alpha chains + 2 delta chains (2% of Hb in adults)
Pathophysiology of B thalassaemia
- Defect caused by point mutation
- Mutation -> highly unstable B-globin which cannot be utilised
- Heterozygous B-thalassaemia = asymptomatic microcytosis with or without mild anaemia
Clinical presentation of B thalassaemia minor
- Trait carrier
- Heterozygous B-thalassaemia
- Asymptomatic
- Anaemia = mild/absent
- RBCs = hypochromic, microcytic, low MCV
- Differential diagnosis confusion of Fe deficiency; checked by serum ferritin = normal
- Hb electrophoresis = raised HbA2
Clinical presentation of B Thalassaemia intermedia
- Symptomatic with moderate anaemia and do not require regular transfusion
- Splenomegaly
- Bone deformities
- Recurrent leg ulcers
- Gallstones
- Infections
Clinical presentation of B thalassaemia major
- Homozygous B-thalassaemia in first year of life
- Recurrent bacterial infections
- Severe anaemia from 3-6 months
- Extramedullary haematopoiesis (infective RBC prod. outside marrow) -> hepatosplenomegaly + bone expansion
- Life long transfusion dependency
Diagnosis of B-thalassaemia
- Homozygous = blood count + film
- Hypochromic. microcytic anaemia
- Raised reticulocyte count
- Nucleated RBC in peripheral circulation
- Hb electrophoresis: Increased HbF, absent/normal HbA
Treatment of B Thalassaemia
- Regular (every 2-4w) lifelong transfusion too keep Hb > 90g/L
- Iron chelating agents to prevent iron overload
- Oral DEFERIPRONE and sc DESDERRIOXAMINE
- Side effects: deafness, cataracts, retinal damage
- Ascorbic acid -> increase urinary excretion of iron
- Splenectomy if hypersplenism persists
- Bone marrow transplant
State side effects of regular blood transfusions
- Increase in body iron load
- Deposits in liver and spleen -> liver fibrosis + cirrhosis
- Deposits in endocrine glands and heart -> hormonal conditions
Pathophysiology of A-thalassaemia
- Gene deletions
- No A chain synthesis
- Only Hb Barts (4 gamma chains) present
- Hb Barts = unable to carry O2 -> incompatible with life
Clinical presentation of alpha thalassaemia
Infants = stillborn or die soon after birth
What are the 4 main subtypes of leukaemia?
- Acute Lymphoblastic Leukaemia (ALL)
- Acute myeloid leukaemia (AML)
- Chronic myeloid leukaemia (CML)
- Chronic lymphocytic leukaemia (CLL)
Define leukaemia
Presence of rapidly proliferating immature blast blood cells in the bone marrow that are non functional
- Rapidly dividing cells with no function = wasted energy
- Rapid replication = excess space occupied by non functional cells
- COMBINED = limited resources for healthy cells -> limited production of healthy cells
Aetiology of ALL
- Most common age 2-4
- Malignancy of immature lymphoid cells -> rise to T and B cells
- Ionisation radiation during pregnancy
- Down’s syndrome
clinical presentation of ALL
- Marrow failure
- Anaemia - low Hb
- Infection - low WCC
- Bleeding - low platelets
- Bone infiltration -> bone pain
- Liver/spleen infiltration ->hepatosplenomegaly
- Node infiltration -> lymphadenopathy
- CNS infiltration -> cranial nerve palsies
Diagnosis of ALL
- FBC & blood film
- WCC high
- Blast cells on film and in bone marrow
- Normocytic
- Normochromic
- Reticulocyte decreased
Treatment of ALL
- Blood & platelet transfusion
- Neutropenia -> deadly infections; antivirals etc
- ALLOPURINOL -> prevent tumor lysis syndrome
- IV fluids - Hickman line (permanent cannula into main vessel under sub-cut fat to prevent infection)
- Chemo
- Marrow transplantation
Aetiology of AML
- Neoplastic proliferation of blast cells from marrow myeloid elements
- Rapid progression with death in 2 months
- Radiation
- Down’s
Clinical presentation of AML
- Marrow failure
- Anaemia - low Hb
- Infection - low WCC
- Bleeding - low platelets
- Hepatomegaly and splenomegaly
- Gum hypertrophy
Diagnosis of AML
- WCC often raised but can be normal or low
- Few blast cells in peripheral blood so need bone marrow biopsy
- Differential from ALL based on microscopy, immunophenotyping and molecular methods
Treatment of AML
- Blood and platelet transfusions
- Neutropenia
- ALLOPURINOL
- IV fluids + hickman line
- Chemo
- Marrow transplant
Aetiology of CML
- Exclusively adult
- Uncontrolled clonal proliferation of myeloid cells
- 49-60 yrs
Clinical presentation of CML
- Symptomatic anaemia
- Splenomegaly -> Abdominal discomfort
- Weight loss
- Fatigue
- Pallor
Diagnosis of CML
- Blood count
- V. high WCC
- Low Hb (normochromic & normocytic)
- Low or normal or raised platelets
- Bone marrow aspirate -> hypercellular
Treatment of CML
- Oral Imatinib
- Stem cell transplant
Aetiology of CLL
- Most common leukaemia
- Accumulation of mature B cells that. escape apoptosis and undergo cell cycle arrest
- Mutations & deletions
- Trisomies
- Pneumonia may be a trigger event
Clinical presentation of CLL
- Often no symptoms; surprise diagnosis through routine FBC
- Anaemic
- Weight loss
- Hepatosplenomegaly
- Enlarged rubbery non tender nodes
Diagnosis of CLL
Blood count
- Normal/low Hb
- Raised WCC with v high lymphocytes
- Blood film - smudge cells in vitro
Treatment of CLL
- Blood transfusions
- Human IV immunoglobulins
- Chemo or radiotherapy
- Stem cell transplant
- PROGNOSIS (Rule of 3’s)
- 1/3 = never progress
- 1/3 = progress slowly
- 1/3 = progress actively
What are the 2 types of lymphomas
- Hodgkin
- Non-hodgkin
Define lymphoma
- Malignant proliferations of lymphocytes
- Accumulate in lymph nodes -> lymphadenopathy
How are the lymphomas be distinguished histologically?
- Hodgkins
- Characteristic cells with mirror-image nuclei: Reed-Sternberg cells
- Non-hodgkins
- No characteristic cells
- Low grade: follicular lymphoma
- high grade: diffuse large B cell lymphoma
- V high grade: Burkitt’s lymphoma
Aetiology of lymphoma
- Primary immunodeficiency
- Secondary immunodeficiency
- HIV
- Transplant recipients
- Infection
- Epstein-Barr Virus (EBV)
- Human T-lymphotropic virus
- Helicobacter pylori
- Autoimmune disorders
Risk factors of Hodgkin’s
- Affected sibling
- EBV
- SLE
- Obese
- Post-transplantation
Clinical presentation of Hodgkin’s
- Painless cervical lymphadenopathy
- Hepatosplenomegaly
- Infection
- Superior vena cava obstruction with increased jugular venous pressure (JVP)
- Sensation of fullness in head
Diagnosis of Hodgkin’s
- CT/MRI - chest, abdomen and pelvis for STAGING
- Lymph node excision or bone marrow biopsy
- Bloods
- High ESR or low Hb
- High serum lactate dehydrogenase
- Immunophenotyping
- Cytogenetics
- PET scan
What is Staging in Hodgkin’s lymphoma diagnosis?
- 4 stages of classification
- STAGE I
- confined to single lymph node region
- STAGE II
- 2 or more nodal areas on SAME SIDE of diaphragm
- STAGE III
- Nodes on both sides of diaphragm
- STAGE IV
- Spread beyond lymph nodes
- ALL STAGES HAVE ATTACHMENT OF A OR B
- A = no systemic symptoms other than pruritus (itchy skin)
- B = presence of B symptoms such as fever, weight loss and night sweats
Treatment of Hodgkin’s syndrome
- Combination chemotherapy ABVD
- A = Adriamycin
- B = Bleomycin
- V = Vinblastine
- D = Dacarbazine
Aetiology of Non-Hodgkin’s lymphoma
- All lymphomas without Reed-Sternberg cells
- More varied in presentation, treatment, etc
- Strong link with EBV and Burkitt’s
Clinical presentation of Non-Hodgkin’s lymphoma
- Nodal disease - superficial lymphadenopathy
- Extranodal disease
- Skin
- Oropharynx, gut, small bowel, bone, CNS, lungs
- B SYMPTOMS
- Fever
- Night sweats
- Weight loss
How are the clinical presentations of Non-Hodgkin’s lymphoma classified?
- Low/indolent grade
- E.g - Follicular lymphoma
- Slow growing
- Advanced in presentation
- Incurable
- High grade
- E.g. - Diffuse Large B-cell lymphoma
- Nodal presentation
Diagnosis of Non-Hodgkin’s lymphoma
- Raised lactose dehydrogenase = worse prognosis
- Lymph node excision or bone marrow biopsy = NON REED STERNBERG OR PPCORN CELLS PRESENT
- CT/MRI of chest abdomen and pelvis for staging
- Immunophenotyping
- Cytogenetics
Treatment of Non-Hodgkin’s lymphoma
R-CHOP
1. R = RITUXIMAB
2. C = CYCLOPHOSPHAMIDE
3. H = HYDROXY-DAUNORUBICIN
4. O = VINCRISTINE (Oncovin = brand name)
5. P = PREDNISOLONE
Define myeloma
Cancer of differentiated B lymphocytes (plasma cells)
Aetiology of myeloma
- Accumulation of malignant plasma cells in bone marrow -> progressive bone marrow failure
- Malignant plasma cells produce excess of one type of immunoglobulin (monoclonal paraprotein)
- IgG (55%)
- IgA (20%)
- Other are suppressed -> immunoparesis
Clinical presentation of myeloma
OLD CRAB
1. OLD age
2. C - Calcium elevated
3. R - Renal failure - nephrotic syndrome due to high immunoglobulin (protein) deposit in kidneys
4. A - Anaemia
5. B - Bone lytic lesions -> back pain
Diagnosis oof myeloma
- Blood
- Normocytic normochromic anaemia
- Raised ESR
- Rouoleaux formation on blood film
- U&E’s
- High Ca
- High alkaline phosphatase
- Bence-jones protein in urine
- X-Ray
- Lytic ‘punched out’ lesions
- Pepper pot skull
- Vertebral collapse
ESSENTIALS FOR DIAGNOSIS
- MONOCLONAL PROTEIN BAND IN SERUM + URINE
- INCREASED PLASMA CELLS ON BONE MARROW BIOPSY
- HYPERCALCAEMIA/RENAL FAILURE/ANAEMIA
- BONE LESIONS ON SKELETAL SURVEY
Treatment of myeloma
- Bone pain -> analgesia AVOID NSAIDS RENAL IMPAIRMENT
- Fracture risk -> BISPHOSPHONATE (ZOLENDRONATE)
- Anaemia -> RBCs transfusion; eryhtropoietin
- Renal failure -> rehydrate, renal dialysis
- Infection -> broad spectrum antibiotics
- Chemotherapy LESS FIT
Treatment of HIV/AIDS
- Highly Active Antiretroviral Therapy (HAART)
- Start before CD4<200
- More than 3 drugs to minimise replication and cross-resistance
- 2 NRTI + 1 NNRTI
- 2 NRTI + 1 PI
- Requires strict adherence
What is NRTI (HIV/AIDS)
- Nuceloside Reverse Transcriptase Therapy
- Inhibit synthesis of DNA by reverse transcription
- Abacavir
- Didanosine
- Emtricitabine
What is NNRTI (HIV/AIDS)
- Non-Nuceloside Reverse Transcriptase Inhibitors
- Binds directly to inhibit reverse transcriptase
- Efavirenz
- Etravirine
- Nevirapine
What is PI
- Protease Inhibitors
- Acts competitively on HIV enzymes that make viral proteins
- Atazanavir
- Darunavir
- Indinavir