Post on 18-Dec-2015
transcript
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Topics for discussion
Polycythaemic indices Neutropaenia Lymphocytosis Platelet clumping Immunoglobulins Thrombophilia
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Normal indices
Female Hb 12-
15g/dl Hct 0.36-
0.44 Rbc 3.86-4.9 x
Male Hb 13-
16g/dl Hct 0.38-
0.49 Rbc 4.15-5.15 x
Polycythaemic indices
HCT > 0.48 HCT > 0.52
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Polycythaemic indices
When does it matter? What are the consequences? When to investigate and how far? When to refer?
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1) When does it matter?Clinical Context
Age Persistence or
progression of abnormality
VTE Arterial disease Abdominal mass Family history
Drugs Smoker Alcohol Cyanotic heart
disease Chronic respiratory
disease Hypertension
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Definition and Classification of Polycythaemia
Hct > 0.52 men and > 0.48 women
True Polycythaemia
Primary (MPD)SecondaryCongenital eg high o2 affinity Hb Erythropoetin- driven Drugs eg androgens Post renal transplant
Relative PolycythaemiaRelative Polycythaemia
Reduction in plasmaReduction in plasmavolume but no increase in volume but no increase in red cell massred cell mass
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2) What are the consequences?A Primary High risk VTE and
stroke
Pseudo/Apparent Unknown risk of VTE
Secondary Less risk VTE
B Underlying pathology
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3) When to investigate and how far? History and Examination If no obvious cause repeat (uncuffed) Age if young (?) do renal / abdominal
ultrasound Urate levels (a) well hydrated 87 year old man, non smoker (b) 37 year old female, non smoker, asthmatic
on ventolin, normal renal USS
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4) When to refer?
No obvious cause (pseudo) and persistence of abnormality
If white cells and platelets elevated as well
If obvious cause AND VTE/ Arterial history
If there is obvious cause but concern re necessity for venesection
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Case 1
82 year old lady 3 episodes VTE and stroke/ now on
indefinite warfarin GP referral with Hb 17.8 g/dl HCT 0.549
WCC 7.1 x109/L Platelets 268 x 109/L
JAK 2 V617 mutation positivePrimary proliferative polycythaemia
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Case 2 59 year old male/ heavy smoker Went to GP as tired Progressively abnormal Hb and HCT 2007Hb 16.2 g/dl HCT 0.47 2009Hb 18.3 g/dl HCT 0.53 Haematology referral Epo levels 40iu/l (5-25)
Renal cancer
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Mild NeutropaeniaFacts
Normal Neutrophil count 1.9 – 7.0 x109/L Ethnic variant 0.8 x 109/L
When does it matter? Clinical context ? Recent acute/ severe viral infection Drugs Other abnormal haematological indices History of recurrent bacterial infections Disease associations eg SLE Degree of neutropaenia Blood film appearance
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Case provided
68 year old man of Asian origin, negative viral screen, on no medication, well.
Neutrophils 1.16 x 109/L How often should this be
monitored? Request blood film and if normal
recheck in 3-4 months
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Causes isolated lymphocytosis in elderly
CLL Low grade lymphoma Monoclonal B-cell Lymphocytosis
(MBL) Splenectomised Smoking Endocrine
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CLL Diagnosis of lymphocytes > 5 x109/L Median age 72 Stage A accounts for 80% cases Outcome for stage A
50% stable and never require treatment50% progress and require treatment
Median survival 9 years 20% Stage B and C require treatment
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Case provided (CLL)
76 year old lady, IHD on various medications
Lymphocytes 6 x 109/L How often to monitor? When to refer?
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How often to monitor?
First must request blood film.
If no lymphadenopathy, organomegaly, B symptoms and otherwise normal blood count 6 monthly and there is an ‘assumption’of CLL
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When to refer If rapid rise in lymphocytes (LDT < 6 months)
If at diagnosis presence of ‘B’ symptoms, hepatosplenomegaly or additional abnormality in blood count
Patient choice ie would like a substantive diagnosis
Blood film suggestive of other low grade lymphoproliferative disorder.
Initial Lymphocytes > 30 x 109/L
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Importance of Red blood cell countRaised RBC with Microcytosis
Thalassaemia traitHb 9 g/dl MCV 62 RBC
6.0 x 109/L
Iron deficient primary polycythaemia
Hb 16 g/dl MCV 77 RBC 5 x 109/L
Compare Primary
polycythaemiaHb 20 g/dl MCV 90 x
109/l RBC 6 x 109/L
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Platelet clumping
In vitro phenomenon Of no clinical consequence Lab should delete platelet count Citrated sample sometimes helps
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Polyclonal increase immunoglobulins
Connective tissue disease Chronic infections (HIV TB) Non haematological malignancies
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Why do thrombophilia tests?
Predict the rate of recurrence in a patient with VTE
Predict the risk of 1st VTE in family member
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1) Predicting rate of recurrence VTE
Recurrence rate 15-20% First 2 years
Post op Other provoked SpontaneousMinimal 10% 20%
No additional risk factor for recurrence if thrombophilia
Single biggest risk factor for recurrence VTE is VTE
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2) Prediction VTE in unselected cases
Background incidence VTE women childbearing age 1 per 10,000 per year
COCP 3x risk COCP + Factor V Leiden 30x risk Screening all women not
economically viable
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3) Selective screening of asymptomatic relatives
Thrombotic family Defect identified Risk VTE
asymptomatic family member is UNCERTAIN unless
HIGH RISK antithrombin deficiencyProtein C /S deficiency
Thrombotic family Defect not identified Risk VTE
asymptomatic family member is UNCERTAIN
False reassurance
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Testing females prior COCP with family history
BSCH guidelines 2010First degree relative VTE
Tested positive Tested negative Not tested
Consider an alternative contraception or transdermal HRT
Thrombophilia testing not recommended