Sickle Cell Anaemia

Epidemiology

1 in 4 chance of disease

50% chance of being a carrier

AUTOSOMAL RECESSIVE disorder causing the production of abnormal Beta globing chains

1 in 4 chance of being disease free

Commonest in Africans but also in India, Middle East and southern Europe

Risk Factors

African

Family history

Pathophysiology

The flexibility of the cells is decreased and they become rigid and take up their characteristic sickle appearance

Don't return to normal when oxygenated

An alteration in the beta-globin chain

Clinical Presentation

Pulmonary hypertension - mean pulmonary artery pressure greater than 25mmHg by right heart catheterisation

Anaemia - chronic haemolysis produces a stable haemoglobin level

Acute chest syndrome - a vaso-occlusive crisis of the pulmonary vasculature

Many problems occur in growth & development, bones, cardiac, neurological, liver, renal, eye and pregnancy

Vaso-occlusive crises - acute pain in the hands and feet owing to vast-occlusion of the small vessels and avascular necrosis of the bone marrow in children

Diagnosis

Blood films

Blood count

Sickle solubility test will be POSITIVE

Hb electrophoresis

Level of Hb is in the range of 60-80 g/L

RAISED RETICULOCYTE COUNT

Sickled erythrocytes shown

Shows 80-95% HbS and absent HbA

Aim for diagnosis at birth (cord blood) to aid prompt pneumococcal prophylaxis

Confirms diagnosis

Treatment

FOLIC ACID to all haemolysis patients

Acute painful attacks

Precipitating factors such as infection, cold and dehydration should be avoided or treated quickly

Anaemia

Analgesia

Oxygen and antibiotics if required

IV fluids

Oral Hydroxycarbamide - increases HbF concentrations

Stem cell transplant

Blood transfusion given for certain cardiac conditions e.g. stroke and heart failure