Blood, Pure and Eloquent

A GP’s guide to Haematology

Douglas Wardrop

Background

• Oxford Experience – in the lab, getting GP calls

• Email service – 24h reply – What is the GP’s hunch?

• Three cell lines – logical; too many? Too few?

• Don’t treat cell lines in isolation

• Blood film – part of the examination but requestor needs to supply clinical details

Subspecialties

• General

• Red cell

• Leukaemia

• Lymphoma

• Stem Cell Transplant

• Haemophilia and Thrombosis

• Transfusion

Blood films

Normal FilmX

Y

Z

Acute Leukaemia

The Most Common Questions

1. Neutropenia – 13%

2. Anaemia - 10%

3. Thrombocytosis (9%)

4. Serum Electrophoresis (9%)

5. Anticoagulation/clotting test interpretation (8%)

6. Thrombophilia (7%)

NEUTROPENIA

• 48 yo lady TATT

• PMHx – Epilepsy (well controlled on Epilim)

• Hb – 142 g/L

• WBC – 3.2 x 109/L

• Plts 274 x 109/L

• Neutrophils – 1.2 x 109/L

neutropenia

• 1 (one) is the magic number

• Rarely a problem in isolation (i.e. look at the other cell lines)

• Blood film?

• Leading causes – post viral, drugs (esp. anti-epileptics, anti-psychotics), black race.

• Younger cf. older patients

• If persists, think of B12/folate def., HIV, Hep infections, autoimmune (e.g. SLE)

Reasons for heightened concern

• Severe Neutropenia (<0.5 x 109/L) or rapidly dropping

• Other cell lines affected, especially if a downward trend.

• Abnormal blood film - ?check monocyte count

• Sick/feverish patient – treat first and ask questions later

ANaemia

• 45 yo lady TATT

• Hb – 81g/L

• WBC – 5.2 x 109L (normal differential)

• Plts 322 x 109/L

• MCV 71fl

Microcytic Anaemia

YX

Think about….

• Each cell lines in turn

• Check film – any clues?

• Stepwise approach:• Ferritin• Transferrin sats• HPLC

• Always search for a cause – very rarely dietary

• Iron – poorly tolerated – try at least x2 (before IV)

• Take with orange juice (empty stomach), avoid coffee, tea, milk

Consider haemoglobinopathies

• If Iron replete and still microcytic?

• Thalassaemia?

• β-trait -HPLC

• α-thalassaemia – genetic tests expensive. Presumptive diagnosis if HPLC and ferritin normal

HPLC

Normal (Hb A) Hb βThal. Trait

Thrombocytosis

• 48 y.o. man noted to be hypertensive (confirmed with ABPM)

• Bloods:

• Hb – 140g/L (N MCV)

• WBC 8.2 x 109/L (N diff)

• Plts – 620 x 109/L

Thrombocytosis

• 1. Reactive (Much more likely)• Infection• Cancer• Bleed• Fe2+ deficiency• Trauma

• 2. Consider clonal causes• Check other cell lines (?PRV, ET)• Check after 6-8 weeks• Blood film/ferritin/ESR• JAK2 V617F/MPL mutations

Thrombocytosis

Serum Electrophoresis

• 70 y.o. lady (N - F+W) presents with acute left visual loss

• Hb – 115g/L (N MCV)

• WBC 7.2 x 109/L (N diff)

• Plts –322x 109/L

• SEP – IgG PP 5.1g/L (no immunoparesis)

• Seen by ophthalmologist – CRVO

Questions to ask

• 1. All all Igs present and correct in correct numbers

• 2. Is there a paraprotein? Which type?

• 3. Is there immunoparesis?

• Look for end-organ failure

MGUS

• Very common (and increasingly detected)

• Vast majority will never need treatment

• Be aware of infections

MGUS

• MGUS vs Smouldering Myeloma vs Multiple Myeloma

• 4 x diagnostic criteria (all must be met)

• PP <30g/L

• BM plasma cells <10%

• No evidence of other B cell lymphoproliferatve disorder

• No end-organ damage

Thrombophilia

• 28 y.o. asymptomatic man - Factor V Leiden heterozygosity detected

• Father had unprovoked DVT aged 50 and found to be a carrier

• What do you do differently?

• Avoid the thrombophilia screen!

Hereditary Thrombophilias

• Affect venous system• Factor V Leiden• P20210A mutation• Protein C deficiency• Protein S deficiency• Antithromin III deficiency

• Acquired thrombophilia • Anti-phospholipid syndrome (both arterial and

venous)

Use of Thrombophilia Screens

• Less frequently requested

• Occasional use in obstetrics/very strong FHx

• Presence of positive result does increase lifetime risk of PE/DVT but not enough to treat

• If strong FHx, a negative screen does not rule out increased clotting risk

• Personal/family history much more important

Clotting Assays

• 25 yo lady – easy bruising

• Hb – 142 g/L

• WBC – 5.2 x 109/L

• Plts 274 x 109/L

• PT – 12.2s (11-16s)

• APTT – 45s (26-36s)

Bleeding risk

• Bleeding is most important risk (cf. clotting)

• History and pattern of bleeding? FHx? Drugs?

• Haemostatic challenges• Tooth extraction• Trauma• Surgery• Menses

• Much more valuable to the physician that clotting screen

History of bleeding disorder?

• Prothrombin time (PT)

• Activated partial thromboplastin time (aPTT)

• Platelet count

• Fibrinogen

Only meaningful when combined with a clotting history.

Pronlonged aPTT

• In this case, is this significant?

• Raised aPTT• Benign causes – e.g. Factor XII deficiency• Lupus anticoagulant• Bleeding diatheses (congenital or acquired)

• Correlate with history and consider repeating

• Haematology will do a 50:50 mix and go from there.

Thank you for listening