uDefined as a disorder of unknown aetiology, characterized by anaemia, leucopenia, and thrombocytopenia resulting from insuffient or non-production of blood cells in the bone marrow.
Classifications:
Generally classified as follows-
1) Idiopathic-when no cause is known
2) Secondary- when the disorder is the result of exposure
to certain drugs or chemicals
A sequel to certain viral infections or
Related to certain other specific condition.
3) Constitutional-When associated with inherited defects in DNA repair as seen in Fanconi’s syndrome.
Etiology:
Acquired:
Idiopathic- No cause is found (abt 50% of cases)
Secondary to –
Administration of drugs (Idiosyncrasy/cytotoxic effects): chloramfenical, Butazolidine, INH.
Idiosyncratic reactions are qualitatively abnormal reactions to a drug which cause hypoplasia of the bone marrow.
Exposure to chemicals: Benzine, insecticides
Viral infection : Infective hepatitis
Exposure to radiation.
Associated with thymoma.
Congenital:
Fanconi’s syndrome.
Fanconi’s syndrome:
Familial aplastic anaemia occur in which the onset is usually in the first decade of life.
There may be associated abnormalities, such as:
Patchy brown cutenious pigmentation and
Neurological, Renal or skeletal malformations.
Associated biological abnormalities are a diminished capacity for DNA repair and increased random chrosome breakage during mitosis resulting in an initiating event in the development of aplastic anaaemia or leukaemia.
Clinical presentation:
Anaemia: Due to decrease RBC
Fatigueness
Weakness
Tiredness
Effort dyspnea
Palpitation
Infection: Due to decrease WBC
Malaise
Sore throat
Ulceration of mouth and pharynx
Fever
Chills
Sweating
Chronic skin infection.
Bleeding manifestation: due to decrease platelets.
Echymosis
Petechae
Epistaxis
Bleeding from gum
Secondary invasions may occur by-
Candida albicans
Cytomegalo viruses
Yeasts,
Fungi,
Pneumocystitis carini
AIDS etc.
Lab diagnosis of Aplastic anaemia:
In blood:
Hb% - marked reduced( 5-7g/dl)
RBC – Reduced
WBC –May be normal or reduced.
MCV- Normal or sometimes elevated.
MCH- Normal
MCHC- Normal
ESR – Normal or may be raised when associated with infection.
In peripheral blood film:
RBC: Normocytic normochromic
sometimes shows anisopoikilocytosis
Reticulocytes fer or absent.
WBC: Marked neutropenia
Relative lymphocytosis with leukopenia
Platelates:
Thrombocytopenia.
In the bone marrow:
Total marrow-
Hypoplasia or aplasia.
Haemopoetic cell reduced or absent.
Fat cells fatty spaces increased-marrow appear white instead of red.
Isolated areas are normocellular or hypercellular.
Sideroblastic anaemia:
It’s an rare form of anaemias in which the cause is not evident. Peripheral blood picture simulate iron deficiency; but there is no deficiency of iron. On the contrary iron may be in excess in the body. In these anaemias iron accumulate within the cells (siderocytes)
and they appear as basophilic granules (Pappenheimer bodies) with Romanowsky stain (Leishman’s stain).
Causes of sideroblastic anaemias:
1) Hereditary-
Sex linked,
partially recessive inheritance
Male affected
Females may show no abnormality.
2) Acquired:
Primary-Acquired idiopathic sideroblastic Anaemia
Secondary- due to
Drugs- Antitubercular ( INH, Cycloserine)
Lead,Ethanol.
Nutritional deficiency-
Nutritional megaloblastic anaemia,
Malabsorption syndrome & other malnutrition.
Marrow proliferative disorders-
Myloproliferative syndrom
Acute leukaemias
Erythroleukaemias
Haemolytic anaemias
Clinical features:
Onset is usually insidous and characterised by mild to moderate anaemia.
Skin may become larger and liver and spleen may be enlarged (due to deposition of iron)
Diagnosis:
Hb: low usually 6-8g/dl
PCV: Reduced
MCH: Often low
MCHC: Normal or slightly decreased.
Reticulocyte normal or slightly increased.
Bone marrow findings:
Marrow is hyperplastic due to erythroid hyperplasia.
Erythropoesis is usually normoblastic.
Late normoblasts will often show vacuolated appearance on iron staining.
Almost all nucleated red cells will show an increase of siderotic granules, many in ring forms. This is the most diagnostic features of iron deficiency anaemia.
Anaemia due to chronoc infection:
These type of anaemia commonly seen in patient with chronic diseases.
Example:
Chronic inflammation like Rh arthrities, SLE.
Chronic infection like TB and
Malignancy.
The anaemia is usually mild
The mechanism is not well known but there is some postulated mechanism.
Haemolytic anaemia:http://inhumanbeing.blogspot.com/
Haemolytic anaemia:http://inhumanbeing.blogspot.com/
