Haematology Flashcards
features of acute intermittent porphyria
rare AD condition due to defective biosynthesis of haem - causes toxic accumulation of porphobilinogen and delta aminolaevulinic acid
presents with abdo pain and neuropsychiatric sx
abdominal: abdominal pain, vomiting
neurological: motor neuropathy
psychiatric: e.g. depression
hypertension and tachycardia common
investigation findings in acute intermittent porphyria
urine turns deep red on standing
raised urinary porphobilinogen
management of acute intermittent porphyria
avoiding triggers
acute attacks
IV haematin/haem arginate
IV glucose should be used if haematin/haem arginate is not immediately available
features of acute myeloid leukaemia
most common acute leukaemia in adults
may arise secondary to myeloproliferative disorder
sx related to bone marrow failure
anaemia: pallor, lethargy, weakness
neutropenia: whilst white cell counts may be very high, functioning neutrophil levels may be low leading to frequent infections etc
thrombocytopenia: bleeding
splenomegaly
bone pain
managing antiphospholipid syndrome in pregnancy
low dose aspirin once pregnancy is confirmed
low molecular weight heparin once a fetal heart is seen on ultrasound. This is usually discontinued at 34 weeks
without management:
recurrent miscarriage
IUGR
pre-eclampsia
placental abruption
pre-term delivery
venous thromboembolism
features of aplastic anaemia
hypoplastic bone marrow due to drugs, toxins, infections, radiation, or idiopathic causes
normochromic, normocytic anaemia
leukopenia, with lymphocytes relatively spared
thrombocytopenia
overview of warm autoimmune haemolytic anaemia
the antibody (usually IgG) causes haemolysis at body temperature
haemolysis tends to occur in extravascular sites e.g., spleen
caused by: idiopathic, AI disease, lymphoma, CLL, drugs
treat with steroids
overview of cold autoimmune haemolytic anaemia
IgM causes haemolysis best at 4C, mediated by complement, usually intravascular haemolysis
Features may include symptoms of Raynaud’s and acrocynaosis
caused by neoplasia and infections, poor response to steroids
definition of beta thalassemia major
absence of b globulin chains, presents in the first year of life with failure to thrive and hepatosplenomegaly- HbA2 and HbF raised, HbA absent
managed with repeated transfusions -> iron overload, organ failure
features of beta thalassemia trait
autosomal recessive condition characterised by a mild hypochromic, microcytic anaemia - microcytosis usually disproportionate to anaemia
HbA2 may be raised
blood film of hyposplenic patient
target cells
Howell-Jolly bodies
Pappenheimer bodies
siderotic granules
acanthocytes
blood film in iron deficiency anaemia
target cells
‘pencil’ poikilocytes
if combined with B12/folate deficiency a ‘dimorphic’ film occurs with mixed microcytic and macrocytic cells
blood films in myelofibrosis
‘Tear-drop’ poikilocytes
features and management of post-transfusion non-haemolytic febrile reaction
due to antibodies reacting with white cell fragments in the blood product and cytokines that have leaked from the blood cell during storage
causes fever and chills
mx - slow/stop transfusion and give paracetamol
features and management of post-transfusion minor allergic reaction
due to foreign plasma proteins
causes pruritis, urticaria
stop transfusion and give antihistamine
features and management of post-transfusion anaphylaxis
due to patients with IgA deficiency with anti-IgA antibodies
causes hypotension, dyspnoea, wheezing, angioedema
stop transfusion, IM adrenaline ABC support
features and management of post-transfusion acute haemolytic reaction
due to ABO-incompatible blood
causes fever, abdominal pain, hypotension
stop transfusion, confirm dx, confirm pt, send blood for coombs and repeat typing and X matching, supportive care
features and management of post-transfusion transfusion-associated circulatory overload (TACO)
due to excessive rate of transfusion with pre-existing heart failure
causes pulmonary oedema, hypertension
slow/stop transfusion, consider IV loop diuretic e.g., furosemide with oxygen
features and management of post-transfusion transfusion related acute lung injury (TRALI)
non cardiogenic pulmonary oedema secondary to increased vascular permeability due to activated neutrophils
Hypoxia, pulmonary infiltrates on chest x-ray, fever, hypotension
stop transfusion, give oxygen and supportive care
indications for fresh frozen plasma
for ‘clinically significant’ but without ‘major haemorrhage’ in patients with a prothrombin time (PT) ratio or activated partial thromboplastin time (APTT) ratio > 1.5
prophylaxis for invasive surgery with significant bleeding risk
indications for using cryoprecipitate
small volume 15-20ml
contains concentrated Factor VIII:C, von Willebrand factor, fibrinogen, Factor XIII and fibronectin
treats ‘clinically significant’ but without ‘major haemorrhage’ who have a fibrinogen concentration < 1.5 g/L
disseminated intravascular coagulation, liver failure
indications for using prothrombin complex concentrate
emergency reversal of anticoagulation in patients with either severe bleeding or a head injury with suspected intracerebral haemorrhage
prophylaxis in patients with emergency surgery
red cell transfusions and indications
red blood cells should be stored at 4°C prior to infusion
in a non-urgent scenario, a unit of RBC is usually transfused over 90-120 minutes
threshold for ACS patients - 80g/L, without ACS 70g/L
aim to +20g/L
features of burkitt’s lymphoma
high-grade B-cell neoplasm affecting maxilla/mandible (endemic african form) or abdominal (sporadic, common form) - assx HIV
microscopy - ‘starry sky’ appearance: lymphocyte sheets interspersed with macrophages containing dead apoptotic tumour cells
treating burkitt’s lymphoma
chemotherapy, may cause tumour lysis syndrome (reduce chance with rasburicase)
complications of chronic lymphocytic leukaemia
anaemia
hypogammaglobulinaemia leading to recurrent infections
warm autoimmune haemolytic anaemia in 10-15% of patients
transformation to high-grade lymphoma (Richter’s transformation)
features of chronic lymphocytic leukaemia
often none: may be picked up by an incidental finding of lymphocytosis
constitutional: anorexia, weight loss
bleeding, infections
lymphadenopathy more marked than chronic myeloid leukaemia
FBC - lymphocytosis, anaemia, thrombocyopaenia
smudge cells / smear cells on blood film
treatment- imatinib
definitions of cryoglobulinaemias
Immunoglobulins which undergo reversible precipitation at 4 deg C, dissolve when warmed to 37 deg C. One-third of cases are idiopathic
features of cryoglobulinaemias
Raynaud’s only seen in type I
cutaneous
vascular purpura
distal ulceration
ulceration
arthralgia
renal involvement
diffuse glomerulonephritis
investigastions and management of cryoglobinaemia
low complement (esp. C4)
high ESR
treatment of underlying condition e.g. hepatitis C
immunosuppression
plasmapheresis
indications for using DOACs
prevention of stroke in non-valvular AF if:
prior stroke or transient ischaemic attack
age 75 years or older
hypertension
diabetes mellitus
heart failure
prevention of VTE following hip/knee surgery
treatment of DVT and PE
definition and causes of disseminated intravascular coagulation
coagulation and fibrinolysis are dysregulated causing widespread clotting with resultant bleeding
causes
sepsis
trauma
obstetric complications e.g. aminiotic fluid embolism or hemolysis, elevated liver function tests, and low platelets (HELLP syndrome)
malignancy
blood picture in disseminated intravascular coagulation
↓ platelets
↓ fibrinogen
↑ PT & APTT
↑ fibrinogen degradation products
schistocytes due to microangiopathic haemolytic anaemia
definition of factor v leiden
Factor V Leiden (activated protein C resistance) - most common inherited thrombophilia
definition and features of fanconi anaemia
rare autosomal recessive bone marrow syndrome
features
haematological:
aplastic anaemia
increased risk of acute myeloid leukaemia
neurological
skeletal abnormalities:
short stature
thumb/radius abnormalities
cafe au lait spots
features of G6PD deficiency
commonest red blood cell enzyme defect
X linked recessive inheritance
neonatal jaundice is often seen
intravascular haemolysis
gallstones are common
splenomegaly may be present
Heinz bodies on blood films. Bite and blister cells may also be seen
triggers of haemolysis in G6PD deficiency
anti-malarials: primaquine
ciprofloxacin
sulph- group drugs: sulphonamides, sulphasalazine, sulfonylureas
definition of acute graft vs host disease
Is classically defined as onset is classically within 100 days of transplantation*
Usually affects the skin (>80%), liver (50%), and gastrointestinal tract (50%)
Multi-organ involvement carries a worse prognosis**
definition of chronic graft vs host disease
May occur following acute disease, or can arise de novo
Classically occurs after 100 days following transplantation
Has a more varied clinical picture: often lung and eye involvement in addition to skin and GI, although any organ system may be involved
pathophysiology of graft vs host disease
multi-system complication of allogeneic bone marrow transplantation
due to T cells in the donor tissue (the graft) mount an immune response toward recipient (host) cells
hereditary causes of haemolytic anaemia
membrane: hereditary spherocytosis/elliptocytosis
metabolism: G6PD deficiency
haemoglobinopathies: sickle cell, thalassaemia
acquired causes of haemolytic anaemia
Acquired: immune causes (Coombs-positive)
autoimmune: warm/cold antibody type
alloimmune: transfusion reaction, haemolytic disease newborn
drug: methyldopa, penicillin
Acquired: non-immune causes (Coombs-negative)
microangiopathic haemolytic anaemia (MAHA): TTP/HUS, DIC, malignancy, pre-eclampsia
prosthetic heart valves
paroxysmal nocturnal haemoglobinuria
infections: malaria
drug: dapsone
features of haemophilia
Haemophilia A - deficient factor VIII
haemophilia B - deficient factor IX
Features
haemoarthroses
haematomas
prolonged bleeding after surgery or trauma
Blood tests
prolonged APTT
bleeding time, thrombin time, prothrombin time normal
features of hereditary angioedema
autosomal dominant condition
Symptoms
attacks may be proceeded by painful macular rash
painless, non-pruritic swelling of subcutaneous/submucosal tissues
may affect upper airways, skin or abdominal organs (can occasionally present as abdominal pain due to visceral oedema)
urticaria is not usually a features
features of hereditary spherocytosis
normal biconcave disc shape is replaced by a sphere-shaped red blood cell and destroyed by the spleen
causes failure to thrive
jaundice, gallstones
splenomegaly
aplastic crisis precipitated by parvovirus infection
degree of haemolysis variable
MCHC elevated
management of hereditary spherocytosis
acute haemolytic crisis:
treatment is generally supportive
transfusion if necessary
longer term treatment:
folate replacement
splenectomy
features of hodgkins lymphoma
malignant proliferation of lymphocytes with reed-sternberg cell
painless, nontender, asymmetrical lymphadenopathy - neck, axillary, inguinal
alcohol induced lymph node pain
B symptoms - poor prognosis
weight loss > 10% in last 6 months
fever > 38ºC
night sweats
staging of hodgkins lymphoma
I: single lymph node
II: 2 or more lymph nodes/regions on the same side of the diaphragm
III: nodes on both sides of the diaphragm
IV: spread beyond lymph nodes
Each stage may be subdivided into A or B
A = no systemic symptoms other than pruritus
B = weight loss > 10% in last 6 months, fever > 38c, night sweats (poor prognosis)
management of hodgkin’s lymphoma
chemotherapy combinations
ABVD - (doxorubicin, bleomycin, vinblastine, and dacarbazine)
radiotherapy
chemo then radio
hematopoietic cell transplantation for relapsed or refractory classic Hodgkin lymphoma
causes of hyposplenism
splenectomy
sickle-cell
coeliac disease, dermatitis herpetiformis
Graves’ disease
systemic lupus erythematosus
amyloid
definition and features of immune thrombocytopenia
immune-mediated reduction in the platelet count with antibodies directed against the glycoprotein IIb/IIIa or Ib-V-IX complex
may be detected incidentally on bloods - isolated thrombocytopaenia
symptomatic patients may present with
petechiae, purpura
bleeding (e.g. epistaxis)
catastrophic bleeding (e.g. intracranial) is not a common presentation
treatment of immune thrombocytopenia
first-line treatment for ITP is oral prednisolone
pooled normal human immunoglobulin (IVIG) may also be used - raises platelet count quicker than steroids
splenectomy if platelets < 30 after 3 months of steroid therapy
causes of iron deficiency anaemia
Excessive blood loss
Inadequate dietary intake
Poor intestinal absorption
Increased requirements
investigation findings in iron deficiency anaemia
FBC - hypochromic microcytic anaemia
low serum ferritin (low iron stores)
high TIBC and high transferrin
Blood film anisopoikilocytosis (red blood cells of different sizes and shapes) , target cells, ‘pencil’ poikilocytes
Endoscopy to rule out malignancy - especially in older, new unexplained IDA
blood results in anaemia of chronic disease
low serum iron
low TIBC
low transferrin saturation
high ferritin
features of lead poisoning
consider in questions giving a combination of abdominal pain and neurological signs
Features
abdominal pain
peripheral neuropathy (mainly motor)
neuropsychiatric features
fatigue
constipation
blue lines on gum margin (only 20% of adult patients, very rare in children)
investigation findings for lead poisoning
blood lead level >10mcg/dL
FBC - microcytic anaemia, basophilic stippling and clover-leaf morphology
raised serum and urine levels of delta aminolaevulinic acid
managing lead poisoning
dimercaptosuccinic acid (DMSA)
D-penicillamine
EDTA
dimercaprol
causes of generalised lymphadenopathy
Infective
infectious mononucleosis
HIV, including seroconversion illness
eczema with secondary infection
rubella
toxoplasmosis
CMV
tuberculosis
roseola infantum
Neoplastic
leukaemia
lymphoma
Others
autoimmune conditions: SLE, rheumatoid arthritis
graft versus host disease
sarcoidosis
drugs: phenytoin and to a lesser extent allopurinol, isoniazid
lymphatic drainage of ovaries, uterus and cervix
The ovaries drain to the para-aortic lymphatics via the gonadal vessels
The body of the uterus drains through lymphatics contained within the broad ligament to the iliac lymph nodes.
The cervix drains into external iliac nodes, presacral nodes, and internal iliac nodes
causes of macrocytic anaemia
Megaloblastic causes of macrocytic anaemia
vitamin B12 deficiency
folate deficiency
e.g. secondary to methotrexate
Normoblastic causes of macrocytic anaemia
alcohol
liver disease
hypothyroidism
pregnancy
reticulocytosis
myelodysplasia
drugs: cytotoxics
indications for urgent FBC
Pallor
Persistent fatigue
Unexplained fever
Unexplained persistent infections
Generalised lymphadenopathy
Persistent or unexplained bone pain
Unexplained bruising
Unexplained bleeding
features of methaemoglobinaemia
describes haemoglobin which has been oxidised from Fe2+ to Fe3+ - causes tissue hypoxia due to inability to bind oxygen, moves oxygen dissociation curve to left
Features
‘chocolate’ cyanosis
dyspnoea, anxiety, headache
severe: acidosis, arrhythmias, seizures, coma
normal pO2 but decreased oxygen saturation
management of methaemoglobinaemia
NADH methaemoglobinaemia reductase deficiency: ascorbic acid
IV methylthioninium chloride (methylene blue) if acquired
features of monoclonal gammopathy of undetermined significance
usually asymptomatic
no bone pain or increased risk of infections
around 10-30% of patients have a demyelinating neuropathy
normal immune function
lower and stable level of paraproteinaemia than myeloma
no clinical features of myeloma
features of myelodysplastic syndrome
ineffective hematopoiesis leading to peripheral cytopenias despite a typically hypercellular bone marrow
fatigue, weakness, and pallor due to anaemia; recurrent infections due to neutropenia; and easy bruising or bleeding due to thrombocytopenia
features of myelofibrosis
a myeloproliferative disorder caused by hyperplasia of abnormal megakaryocytes - resultant release of platelet derived growth factor is thought to stimulate fibroblasts
haematopoiesis develops in the liver and spleen
Features
e.g. elderly person with symptoms of anaemia e.g. fatigue (the most common presenting symptom)
massive splenomegaly
hypermetabolic symptoms: weight loss, night sweats etc
features of myeloma
haematological malignancy characterised by plasma cell proliferation
CRABBI
hypercalcaemia - constipation, nausea, anorexia and confusion
renal - monoclonal production of Ig causes light chain deposition within the renal tubules - renal damage - dehydration, thirst
anaemia - bone marrow crowding suppresses erythropoiesis leading to anaemia
bones - bone marrow infiltration by plasma cells causes lytic bone lesions causing pain
bleeding - bone marrow crowding results in thrombocytopenia, increasing risk of bleeding and bruising
infection - a reduction in the production of normal immunoglobulins results in increased susceptibility to infection
causes of neutropenia
viral
HIV
Epstein-Barr virus
hepatitis
drugs
cytotoxics
carbimazole
clozapine
myelodysplastic malignancies
aplastic anemia
rheumatological conditions
systemic lupus erythematosus
definition of neutropenia
low neutrophil counts, < 1.5 * 109. A normal neutophil count is 2.0 - 7.5 * 109.
Mild 1.0 - 1.5 * 109
Moderate 0.5 - 1.0 * 109
Severe < 0.5 * 109
predisposes to severe infection
features of non-hodgkin lymphoma
Painless lymphadenopathy (non-tender, rubbery, asymmetrical)
Constitutional/B symptoms occur later (fever, weight loss, night sweats, lethargy)
Extranodal Disease more common - gastric (dyspepsia, dysphagia, weight loss, abdominal pain), bone marrow (pancytopenia, bone pain), lungs, skin, central nervous system (nerve palsies)
differentiated from hodgkin lymphoma via biopsy
investigating non-hodgkin lymphoma
Excisional node biopsy
CT chest, abdomen and pelvis (to assess staging)
HIV test - risk for NHL
FBC and blood film - normocytic anaemia, rule out other haem malignancies
ESR - prognostic indicator
LDH - marker of cell turnover
management of non hodgkin lymphoma
watchful waiting, chemotherapy or radiotherapy - depends on sub type
Rituximab often used
flu/pneumococcal vaccine
causes of normocytic anaemia
anaemia of chronic disease
chronic kidney disease
aplastic anaemia
haemolytic anaemia
acute blood loss
features of paroxysmal nocturnal haemoglobinuria
acquired disorder leading to haemolysis due to increased sensitivity of cell membranes to complement - increased risk of VTE
Features
haemolytic anaemia
red blood cells, white blood cells, platelets or stem cells may be affected therefore pancytopaenia may be present
haemoglobinuria: classically dark-coloured urine in the morning (although has been shown to occur throughout the day)
thrombosis e.g. Budd-Chiari syndrome
aplastic anaemia may develop in some patients
management of paroxysmal nocturnal haemoglobinuria
blood product replacement
anticoagulation
eculizumab, a monoclonal antibody directed against terminal protein C5, is currently being trialled and is showing promise in reducing intravascular haemolysis
stem cell transplantation
platelet thresholds for platelet transfusion before invasive procedure
> 50×109/L for most patients
50-75×109/L if high risk of bleeding
100×109/L if surgery at critical site
platelet thresholds for platelet transfusion in active bleeding
platelet count of <30 x 10 9 with clinically significant bleeding grade 2 e.g. haematemesis, melaena, prolonged epistaxis)
thresholds for transfusion are higher (maximum < 100 x 10 9) for patients with severe bleeding (WHO grades 3&4), or bleeding at critical sites, such as the CNS.
contraindications for platelet transfusion
Chronic bone marrow failure
Autoimmune thrombocytopenia
Heparin-induced thrombocytopenia, or
Thrombotic thrombocytopenic purpura.
types of polycythaemia
Relative causes
dehydration
stress: Gaisbock syndrome
Primary
polycythaemia rubra vera
Secondary causes
COPD
altitude
obstructive sleep apnoea
excessive erythropoietin: cerebellar haemangioma, hypernephroma, hepatoma, uterine fibroids*
features of polycythaemia vera
myeloproliferative disorder caused by clonal proliferation of a marrow stem cell leading to an increase in red cell volume, and increased neutrophils and platelets
JAK2 mutation
pruritus, typically after a hot bath
splenomegaly
hypertension
hyperviscosity - arterial and venous thrombosis
haemorrhage (secondary to abnormal platelet function)
low ESR
management of polycythaemia vera
aspirin
reduces the risk of thrombotic events
venesection
first-line treatment to keep the haemoglobin in the normal range
chemotherapy
hydroxyurea - slight increased risk of secondary leukaemia
phosphorus-32 therapy
managing DVT and PE in pregnancy
S/C low-molecular weight heparin preferred to IV heparin (less bleeding and thrombocytopenia)
warfarin C/I
increased clotting due to increase in factors VII, VIII, X and fibrinogen, decrease in protein S, uterus presses on IVC causing venous stasis in legs
features of primary immunodeficiency
definition of sickle cell disease
autosomal recessive condition that results for synthesis of an abnormal haemoglobin chain termed HbS
sx arise at 4-6months
normal haemoglobin: HbAA
sickle cell trait: HbAS
homozygous sickle cell disease: HbSS
management of sickle cell anaemia
Crisis management
analgesia e.g. opiates
rehydrate
oxygen
consider antibiotics if evidence of infection
blood transfusion
exchange transfusion: e.g. if neurological complications
Longer-term management
hydroxyurea - increases HbF
types of sickle cell crisis
thrombotic, ‘vaso-occlusive’, ‘painful crises’
acute chest syndrome
anaemic - aplastic, sequestration
infection
definition of sequestration crises
sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
associated with an increased reticulocyte count
definition of aplastic crises
caused by infection with parvovirus
sudden fall in haemoglobin
bone marrow suppression causes a reduced reticulocyte count
definition of acute chest syndrome
vaso-occlusion within the pulmonary microvasculature → infarction in the lung parenchyma
dyspnoea, chest pain, pulmonary infiltrates on chest x-ray, low pO2
management
pain relief
respiratory support e.g. oxygen therapy
antibiotics: infection may precipitate acute chest syndrome and the clinical findings (respiratory symptoms with pulmonary infiltrates) can be difficult to distinguish from pneumonia
transfusion: improves oxygenation
causes and definition of sideroblastic anaemia
red cells fail to completely form haem - leads to red cells fail to completely form haem
Acquired causes
myelodysplasia
alcohol
lead
anti-TB medications
investigation results for sideroblastic anaemia
full blood count
hypochromic microcytic anaemia (more so in congenital)
iron studies
high ferritin
high iron
high transferrin saturation
blood film
basophilic stippling of red blood cells
bone marrow
Prussian blue staining will show ringed sideroblasts
causes of splenomegaly
myelofibrosis
chronic myeloid leukaemia
visceral leishmaniasis (kala-azar)
malaria
Gaucher’s syndrome
portal hypertension e.g. secondary to cirrhosis
lymphoproliferative disease e.g. CLL, Hodgkin’s
haemolytic anaemia
infection: hepatitis, glandular fever
causes of thrombocytopenia
heparin induced thrombocytopenia (HIT)
drug-induced (e.g. quinine, diuretics, sulphonamides, aspirin, thiazides)
alcohol
liver disease
hypersplenism
viral infection (EBV, HIV, hepatitis)
pregnancy
SLE/antiphospholipid syndrome
vitamin B12 deficiency
causes of thrombocytosis
reactive: platelets are an acute phase reactant - platelet count can increase in response to stress such as a severe infection, surgery. Iron deficiency anaemia can also cause a reactive thrombocytosis
malignancy
essential thrombocytosis (see below), or as part of another myeloproliferative disorder such as chronic myeloid leukaemia or polycythaemia rubra vera
hyposplenism
features of essential thrombocytosis
myeloproliferative disorders which overlaps with chronic myeloid leukaemia, polycythaemia rubra vera and myelofibrosis. Megakaryocyte proliferation results in an overproduction of platelets.
platelet count > 600 * 109/l
both thrombosis (venous or arterial) and haemorrhage can be seen
a characteristic symptom is a burning sensation in the hands
a JAK2 mutation is found in around 50% of patients
treating essential thrombocytosis
hydroxyurea (hydroxycarbamide) is widely used to reduce the platelet count
interferon-α is also used in younger patients
low-dose aspirin may be used to reduce the thrombotic risk
features of thrombotic thrombocytopenic purpura
abnormally large and sticky multimers of von Willebrand’s factor cause platelets to clump within vessels
rare, typically adult females
fever
fluctuating neuro signs (microemboli)
microangiopathic haemolytic anaemia
thrombocytopenia
renal failure
features in thymoma
Associated with
myasthenia gravis (30-40% of patients with thymoma)
red cell aplasia
dermatomyositis
also : SLE, SIADH
multimers of von Willebrand’s factor cause platelets to clump within vessels
cause of tumour lysis syndrome
occurs from the breakdown of the tumour cells and the subsequent release of chemicals from the cell. It leads to a high potassium and high phosphate level in the presence of a low calcium
suspect in any patient presenting with an acute kidney injury in the presence of a high phosphate and high uric acid level
causes of vitamin b12 deficiency
pernicious anaemia: most common cause
post gastrectomy
vegan diet or a poor diet
disorders/surgery of terminal ileum (site of absorption)
Crohn’s: either diease activity or following ileocaecal resection
metformin (rare)
prophylaxis of of tumour lysis syndrome
IV fluids
patients are higher risk should receive either allopurinol or rasburicase
increased serum creatinine (1.5 times upper limit of normal)
features of vitamin b12 deficiency
macrocytic anaemia
sore tongue and mouth
neurological symptoms
the dorsal column is usually affected first (joint position, vibration) prior to distal paraesthesia
neuropsychiatric symptoms: e.g. mood disturbances
1 mg of IM hydroxocobalamin 3 times each week for 2 weeks, then once every 3 months
features of von willebrand disease
most common inherited bleeding disorder, autosomal dominant
behaves like platelet disorder - epistaxis and menorrhagia
features
prolonged bleeding time
APTT may be prolonged
factor VIII levels may be moderately reduced
defective platelet aggregation with ristocetin
types of von willebrand disease
type 1: partial reduction in vWF (80% of patients)
type 2*: abnormal form of vWF
type 3**: total lack of vWF (autosomal recessive)
management of von willebrand disease
tranexamic acid for mild bleeding
desmopressin (DDAVP): raises levels of vWF by inducing release of vWF from Weibel-Palade bodies in endothelial cells
factor VIII concentrate
features of waldenstrom’s macroglobulinaemia
uncommon condition seen in older men - lymphoplasmacytoid malignancy characterised by the secretion of a monoclonal IgM paraprotein
Features
systemic upset: weight loss, lethargy
hyperviscosity syndrome e.g. visual disturbance
hepatosplenomegaly
lymphadenopathy
cryoglobulinaemia e.g. Raynaud’s
diagnosis and management of waldenstrom’s macroglobulinaemia
bone marrow biopsy - infiltration of the bone marrow with lymphoplasmacytoid lymphoma cells
rituximab
features of wiskott aldrich syndrome
X linked recessive cause of primary immunodeficiency due to a combined B- and T-cell dysfunction
Features
recurrent bacterial infections (e.g. Chest)
eczema
thrombocytopaenia
low IgM levels
