Microcytic anaemia: Iron def, alpha and beta thalassemia, sideroblastic anaemia Flashcards
What is anaemia?
Low conc of haemoglobin in the blood.
It is not a disease.
It is a consequence of an underlying disease.
Causes for microcytic anaemia?
Iron deficiency anaemia
Thalasseaemia
Sideroblastic anaemia
Causes for normocytic anaemia?
Acute blood loss
Chronic disease -renal failure, bone marrow failure
Hypothyroid
Pregnancy
Causes for macrocytic anaemia?
Vitamin deficiency (B12, folate)
Excess alcohol
Reticulocytosis
Cytotoxic medications
Myelodysplastic syndrome (MDS)
What is iron deficiency anaemia? Cause?
Shortage of iron in the body, leading to diminished red blood cell production and subsequent oxygen transport.
Dietary insufficiency
Chronic blood loss (e.g. GI bleed, heavy period)
Malabsorption Disorders (e.g. coeliac, IBD, atrophic gastritis)
Increased demand (e.g. pregnancy, rapid growth phases)
Presentation of iron deficiency anaemia?
Tiredness
Lethargy
Weakness
Palpitations
Cognitive Impairment (difficulty concentrating or memory issues)
Cold Intolerance
Headaches and dizziness
Brittle nails
Angular stomatitis
Atrophic glossitis
PICA (children craving and chewing substances that have no nutritional value — such as ice, clay, soil or paper).
Diagnosis/IVx of iron deficiency anaemia?
FBC, CRP
BLOOD FILM
- Hypochromic, microcytic red cells
- Additional pencil cells
- Occasional target cells
Total iron binding capacity (TIBC) -high
Ferritin -low (measured alongside B12 and folate)
Iron def anaemia in age >60:
- suspect colonic malignancy
- do FIT test
- 2ww if inidicated
Management of iron deficiency anaemia?
Iron supplements
Dietary modifications
Tx of underlying conditions
Endoscopic procedures if GI bleeding suspected.
What is thalassaemia?
A group of inherited disorders characterised by abnormal haemoglobin production.
Defects in the four genes for α-globin result in α-thalassaemia.
Defects in the two genes for β-globin result in β-thalassaemia.
Two types
- alpha and beta thalassaemia.
Alpha thalassaemia -presentation, IVx, tx?
Autosomal recessive inheritance.
- 2 defect copies = mild asymptomatic anaemia, α-thalassaemia trait
- 3 defect copies = haemoglobin H disease
- 4 defect copies = hydrops fetalis, may affect the fetus in utero, incompatible with life
Jaundice
Fatigue
Facial bone deformities
IVx:
- FBC (microcytic anaemia)
- Hb electrophoresis (DNA analysis)
Management:
- Blood transfusions
- Stem cell transplantation
- splenectomy (for haemoglobin H disease)
- Regular folic acid
Beta thalassaemia -presentation, IVx, tx?
Autosomal recessive inheritance
One functioning and one dysfunctional copy = β-thalassaemia minor -mild
complete absence of β-globin synthesis = β-thalassaemia major -severe
Presentation:
β-thalassaemia minor -ASYMPTOMATIC
β-thalassaemia major
- SEVERE SYMPTOMATIC AT 3-months OF AGE
- extramedullary haematopoesis
- Frontal bossing
- Maxillary overgrowth and prominent frontal/parietal bones -chipmunk facies
- Hepatosplenomegaly
IVx:
β-thalassaemia minor
- Isolated microcytosis
- ferritin: normal or high
- Increased red cell count
- Hb electrophoresis (diagnostic) shows raised HbA2 (>3.5%)
β-thalassaemia major
- Profound microcytic anaemia
- Increased reticulocytes
- blood film: marked anisopoikilocytosis, target cells and nucleated RBCs.
- TEAR DROP CELLS
- methyl blue stains
- High-performance liquid chromatography (HPLC) or electrophoresis -DIAGNOSTIC
Management:
- regular blood transfusions (prevent iron overload iron chelating agents)
- Hydroxycarbamide (boost HbF levels)
- Allogeneic bone marrow transplantation
- monitoring ferritin every 3 months + annual assessment of endocrine, eyes, ears, cardiac, liver
What is sideroblastic anaemia? Cause?
Impaired ability of the bone marrow to produce normal RBCs.
It results from ineffective erythropoiesis which leads to increased iron absorption in RBCs.
Genetics
Toxins, drugs, chronic alcohol abuse, ISONIAZID (TB)
Presentation of sideroblastic anaemia?
Fatigue
Weakness
Pallor
Tachycardia
high serum ferritin
high iron levels
microcytic anaemia refractory to intensive iron therapy.
Diagnosis/IVx of sideroblastic anaemia?
FBC
Serum ferritin and iron levels: ELEVATED
Blood film: sideroblastic inclusions within the red blood cell cytoplasm.
Bone marrow biopsy: increased iron deposition and ringed sideroblasts.
Management of sideroblastic anaemia?
Avoid triggers -alcohol, toxins
Chelation therapy: To reduce iron overload.
Vitamin B6 (pyridoxine) supplementation
Blood transfusions
Stem cell transplant
