DR Medhat MRCP

Diseases of platelets
1. Thrombocytosis
- Thrombocytosis is an abnormally high platelet count, usually > 400 * 10 9 /l.
• Causes of thrombocytosis :
Reactive (most common cause): platelets are an acute phase reactant - platelet
count can ↑ in response to stress e.g severe infection , surgery,excercise.
Malignancy
Essential thrombocytosis (see below), or as part of another myeloproliferative
disorder such as chronic myeloid leukaemia or polycythaemia rubra vera
‏)لو حالة زيادة صفائح اسأل المريض عن حادثة شال فيها الطحال(‏ Hyposplenism e.g post splenectomy
Essential thrombocytosis :
- Essential thrombocytosis is one of the myeloproliferative disorders which overlaps
with chronic myeloid leukaemia, polycythaemia rubra vera and myelofibrosis.
- Megakaryocyte proliferation results in an overproduction of platelets.
• Features
Platelet count > 600 * 10 9 /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.
• Management (in high risk patient only ,otherwise→observation)
Age > 60 years
Hydroxyurea (hydroxycarbamide) in high risk patient only→ platelets > 1500
Interferon-α is also used in younger patients
Low-dose aspirin may be used to reduce the thrombotic risk.
Hyposplenism
• Causes
Splenectomy
Sickle-cell
Coeliac disease, dermatitis herpetiformis
Graves' disease
SLE
Amyloid
سؤال
Howell-Jolly body
• Features
Howell-Jolly bodies
Siderocytes
سؤال مهم Persistent either leucocytosis or thrombocytosis
symptom (thromb)
سؤال infection) • TTT ; lifelong penicillin prophylaxis (due to lifelong risk of
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