Hypochromic microcytic anaemia Flashcards
What is hypochromic microcytic anaemia?
Microcytosis is a term used to describe red blood cells that are smaller than normal.
Hypochromic means that the red blood cells have less haemoglobin than normal. Low levels of haemoglobin in your red blood cells leads to appear paler in colour.
In microcytic hypochromic anaemia, your body has low levels of red blood cells that are both smaller and paler than normal
Causes of hypochromic microcytic anaemia?
Iron deficiency anaemia.
Sideroblastic anaemia
Thalassaemias
What are the signs & symptoms of Iron deficiency anaemia (IDA)?
Fatigue Pica Nail changes Hair loss Dysphagia Glossitis and angular stomatitis Impaired muscular performance Gastric difficulties Growth impairment Recurrent infections Restless leg syndrome Dyspnoea Lesion on rectal examination
What are the risk factors for IDA?
Black women Pregnancy Vegan Menorrhagia Hookworm infection Haemodialysis Coeliac disease Gastrectomy NSAID use Obesity H.pylori
What are the tests and investigations for IDA?
FBC- MCV (less than 80 fL), MCH (low) ,MCHC (low)
Peripheral blood smear
Reticulocye count- low
Iron studies-serum iron (low), serum ferritin (low), TIBC (increased)
Endoscopy to rule out malignancy
What is included in the management of IDA?
Oral ferrous sulphate, IV if not tolerated
SE: GI discomfort and black stools
What causes IDA?
This occurs when iron absorption from the diet is not sufficient to cover iron losses.
Causes of iron deficiency?
4 major categories in the causes of iron deficiency leading to IDA:
- Decreased iron intake because of inadequate diet or impaired malabsorption.
- Increased iron loss
- Increased iron’s requirement because of infancy, pregnancy or lactation.
- Unknown cause
Causes of iron loss
GI bleeding (usually unknown lesion) Menorrhagia Blood donation Haemoglobinuria Self-induced bleeding Idiopathic pulmonary haemosiderosis Good pasture's syndrome Hereditary haemorrhagic telangiectasia Angiodysplasia Disorders of haemostasis Chronic renal failure Haemodialysis Runner's anaemia
Thalassaemias
This is also a microcytic haemolytic anaemia.
Thalassemia is an inherited blood disorder in which the body makes an abnormal form of haemoglobin.
The disorder results in excessive destruction of red blood cells, which leads to anaemia.
How many types of thalassaemias are there?
Two.
Alpha and beta thalassaemias.
What is Beta thalassaemia?
This is usually caused by point mutations in B-globin genes on chromosome 11, leading to a decrease in the production of B-globin or its absence.
How many types of the presentation can you get with beta thalassaemia?
BT minor
BT intermedia
BT major
What is BT minor?
Heterozygous carrier state, asymptomatic
Mild, well-tolerated anaemia may worsen during pregnancy.
Diagnosed with increased HbAz.
What is BT intermedia?
Mild homozygous mutations.
Moderate anaemia, but not requiring transfusions.
May cause splenomegaly.
What is BT major?
Significant abnormalities in both B-globin genes.
Presenting after 6 months of age with anaemia and failure to thrive.
Extramedullary haematopoiesis occurs, causing skull bossing and hepatosplenomegaly with osteopenia.
Tests for BT?
FBC MCV Blood film (in major disease, marked anisocytosis (different cell sizes) and poikilocytosis (different cell shapes). Hypochromic and microcytic. HbA2 HbF Hb electrophoresis
Management of BT?
Fitness
Healthy diet
Folate supplementation
Regular, life-long blood transfusions to keep Hb>90 g/l
Iron overload can cause cardiac problems, hypothyroidism, hypocalcaemia and hypogonadism- Iron chelators are given such as deferasirox PO and desferrioxamine SC
Splenectomy if hypersplenism persists, best left till after 5 years due to risk of infections.
Hormonal replacement/treatment for endocrine complications.
A bone marrow transplant may be curative- 1 in 8 chance of a suitable donor.
What is alpha thalassaemia?
Genetic deletions in the 2 a-globin genes on each chromosome 16 i.e 4 genes.
Presentation of AT?
If all 4 genes are deleted, death in utero (Bart’s hydrops fetalis)
Haemoglobin H disease (HbH) occurs if 3 genes are deleted, with moderate anaemia and features of haemolysis: hepatosplenomegaly, leg ulcers, jaundice, blood film similar to major BT.
If two genes deleted, there is an asymptomatic carrier state, with decreased MCV
If one gene deleted, normal clinical state
Tests of AT?
FBC MCV Blood film Iron HbA2 HbF HB electrophoresis Howell-jolly bodies in RBCs seen in films
Management of AT?
Fitness
Healthy diet
Folate supplementation
Regular, life-long blood transfusions to keep Hb>90 g/l
Iron overload can cause cardiac problems, hypothyroidism, hypocalcaemia and hypogonadism- Iron chelators are given such as deferasirox PO and desferrioxamine SC
Splenectomy if hypersplenism persists, best left till after 5 years due to risk of infections.
Hormonal replacement/treatment for endocrine complications.
A bone marrow transplant may be curative- 1 in 8 chance of a suitable donor.
What is sideroblastic anaemia?
Sideroblastic anaemia is a group of blood disorders characterized by an impaired ability of the bone marrow to produce normal red blood cells.
There are many potential causes of sideroblastic anaemia.
Depending on the cause, it can be classified as hereditary (sometimes called congenital), acquired, and idiopathic (cause unknown).
Pathophysiology of sideroblastic anaemia?
In this condition, the iron inside red blood cells is inadequately used to make haemoglobin, despite normal amounts of iron.
As a result, iron accumulates in the red blood cells, giving a ringed appearance to the nucleus (ringed sideroblast).
Signs and symptoms of sideroblastic anaemia?
Fatigue
Breathing difficulties
Weakness
Enlargement of the liver or spleen.
What is IRIDA?
A hereditary disorder marked by with iron deficiency anaemia that is typically unresponsive to oral iron supplementation and may be only partially responsive to parenteral iron therapy.
Pathophysiology of IRIDA
IRIDA results from variants in the TMPRSS6 gene that lead to uninhibited production of hepcidin. IRIDA is characterised by microcytic, hypochromic anaemia and serum hepcidin values that are inappropriately high for body iron levels.
