Suggested Haematology Referral Guidelines Last update 08/02/2000.

These suggestions resulted from a talk given by Dr Grant Robinson, Consultant Haematologist (Nevill Hall, Abergavenny & UHW, Cardiff) to Gwent GPs.  They represent his own views and do not constitute an official referral policy.  As always, the best course if in doubt is to discuss the case with a friendly haematologist.

 In Gwent these are:

Topics covered

Erythrocytosis

Differential diagnosis

Primary  (True increase in red cell mass)
Polycythaemia Vera
Idiopathic erythrocytosis

Secondary (True increase in RCM)
Lung disease
CCHD
CarboxyHb
High affinity Hb
Tumours
Renal
Fibroids
Renal disease

Apparent (No increase in RCM)
Stress
Smoking
Diuretics (EtOH)
Hypertension

Normal range
Hct 0.39 - 0.50 (m) 0.34 - 0.45 (f)
Risk of thrombosis rises with Hct

First line tests
FBC, retics
U&E, LFT, urate

Management before referral
Repeat measurements
Lifestyle measures (cigs, drink, exercise)

Triggers for referral
Features of polycythaemia vera
Thromboembolism
Haematocrit > 55%
Persistant unexplained erythrocytosis
M > 51% F > 48%

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Thrombopenia

Differential diagnosis
Reduced production
Any cause of bone marrow failure
Megaloblastic anaemia
EtOH
Inherited disorders (rare)
Amegakaryocytosis (rare)

Increased consumption
Immune
ITP
Drugs
Quinine
Heparin
Sulphonamides
Gold
APL
HIV

Non-immune
Sepsis/DIC
TTP/HUS
Hypersplenism

Normal range
150 - 400 x 109/l
Spontaneous bleeding rare > 20 x 109/l

Differential diagnosis
Clumping artefact

First line tests
FBC and blood film exam
Folate & B12 levels

Management before referral
Repeat measurements
?drugs, alcohol

Triggers for referral
History of bleeding/bruising
Lymphadenopathy/splenomegaly
Other FBC abnormalities
Persistant unexplained thrombopenia < 100

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Neutropenia

Differential diagnosis
Reduced production
Infection
Any cause of bone marrow failure
Megaloblastic anaemia
Drugs
NSAIDS
Antibiotics
Antipsychotics
Antithyroids
Chemo
Congenital (rare)
Cyclical
T-cell associated

Increased consumption
Hypersplenism
Felty's
Immune
SLE

Normal range
1.8 - 8.5 x 109/l

First line tests
FBC and film
Folate & B12 levels
RhF, ANA

Management before referral
Repeat measurements
?drugs

Triggers for referral
History of unexplained infection
Neuts < 1.0 x 109/l
Lymphadenopathy/splenomegaly
Other FBC abnormalities
Persistant unexplained neutropenia

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Macrocytosis

Differential diagnosis
B12 deficiency
Poor intake (rare - pure vegans)
Pernicious anaemia
Generalised malabsorption
Blind loop, Diphyllobothrium latum (please refer if you ever see!)
Localised lesion/excision stomach/terminal ileum

Folate deficiency
Poor intake
EtOH
Malabsorption
Increased requirement
DHFR inhibitors
Methotrexate
Trimethoprim

Other causes
Reticulocytosis
Myelodysplasia
EtOH
Hypothyroidism

Normal range
MCV 82 - 97

First line tests
FBC and film, Retics
B12, folate
TFTs, LFTs

Management before referral
Alcohol

Management of B12 deficiency
Repeat serum B12 level
Measure IF antibodies before treatment
Trial of B12
Assess need for further investigation

Triggers for referral
Other FBC abnormalities
Neurological abnormailities
Persistant unexplained macrocytosis
Haematinic deficiency requiring further investigation

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Thrombocytosis

Normal range
150 - 400 x 109/l

Differential diagnosis
Primary vs. Secondary (inflammation, iron deficiency)

First line tests
FBC and blood film
ESR, CRP
Ferritin
Urate

Management before referral
Correct and investigate iron deficiency
Beware masked PV

Triggers for referral
Splenomegaly
Thromboembolism
Platelet count > 600 x 109/l
Persistant unexplained thrombocytosis

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Iron deficiency

Differential diagnosis
Blood loss
Intake failure

First line tests
FBC
Ferritin
FOBs (insensitive)
Consider endomysial and gliadin antibodies

Triggers for referral
Age dependant - low threshold to investigate > 60 y
?Gynae/Gastro/Surgical/Haem referral

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