WHAT IS ANAEMIA?
Anaemia is defined as a haemoglobin concentration in blood below the lower limit of the normal range for the age and sex of the individual. In adults the lower extreme of the normal haemoglobin is taken as 13.0gm/dl for males and 11.5gm/dl for females. Newborn infants have higher haemoglobin level and therefore 15gm/dl is taken as the lower limit at birth whereas at 3 months the normal lower level is 9.5gm/dl. Although haemoglobin value is employed as the major parameter for determining whether or not anaemia is present the red cells counts haematocrit and absolute values provide alternate means of assessing anaemia.
WHAT ARE PATHOPHYSIOLOGY CAUSE OF ANANEMIA?
Subnormal level of haemoglobin causes lowered oxygen carrying capacity of the blood. This in turn initiates compensatory physiologic adaptations such as follow:
i. Increased release of oxygen from haemoglobin
ii. Increased blood flow to the tissues
iii. Maintenance of the blood volume
iv. Redistribution of blood flow to maintain the cerebral blood supply
Eventually however tissue hyoxia develops causing impaired functions of the affected tissues. The degree of functional impairment of individual tissues is variable depending upon their oxygen requirements. Tissues with high oxygen requirement such as the heart CNS and the skeletal muscle during exercise bear the brunt of clinical effects of anaemia.
WHAT ARE THE CLINICAL FEATURES OF ANAEMIA?
The haemoglobin level at which develops upon 4 main factors:
- The speed of onset of anaemia: rapidly progressive t symptom than anaemia of slow onset as there is less time for physiologic adaptation
- The severity of anaemia: mild anaemia produces no symptom or signs but rapidly developing severe anaemia may produce significant clinical features.
- The age of the patient: the young patient due to good cardiovascular compensation tolerate anaemia quite well as compared to the elderly. The elderly patient develop cardiac and cerebral symptom more prominently due to the associated cardiovascular disease.
WHAT IS SIDEROBLASTIC ANAEMIA?
The sideroblastic anaemia comprise a group of disorders of diverse etiology in which the nucleated erythroid precursors in the bone marrow show characterstics ‘ringed sideroblastic,.
WHAT ARE SIDEROCYTES AND SIDEROBLATS?
Siderocyctes and sideroblasts are erythrocytes and normoblasts respectively which contain cytoplasmic granules of iron.
WHAT IS MEANT BY SIDEROCYCTES?
these are red cells containing granules of non-haem iron. These granules stain positively with Prussian blue reaction as well as stain with Romanowsky dyes when they are referred to as pappenheimer bodies. Siderocytes are normally not present in the human appear following spelenectomy. This is because the reticulocytes on release from the marrow are finally sequestered in the spleen to become matured red cells. In the absence of spleen the final maturation step takes place in the peripheral blood and hence siderocytes make their appearance in the blood after splenectomy.
WHAT IS MEANT BY SIDEROBLASTS?
these are nucleated red cells containing sideroblastic granules which stain positively with Prussian blue reaction. Depending upon the number size and distribution of sideroblastic granules, sideroblasts may be normal or abnormal.
Normal sideroblats contain a few fine scattered cytoplasmic granules representing iron which has not been utilised for haemoglobin synthesis. These cells comprise 30-50% of normoblasts in the normal marrow but are reduced or absent in iron deficiency.
Abnormal sideroblasts are further of 2 types:
One type is a sideroblast containing numerous diffusely scattered a coarse cytoplasmic granules and are seen in conditions such as dyserythropoiesis and haemolysis. In this type, there is no defect of haem or globin synthesis but the percentage saturation of transferrin is increased.
The other is ringed sideroblast in which haem synthesis is disturbed as occurs in sideroblasts anaemia. Ringed sideroblasts in which haem synthesis. The ringed arrangement of these granules is due to the presence of iron-laden mitochondria around the nucleus.
WHAT ARE THE TYPES SIDEROBASTIC ANAEMIA?
Hereditary sideroblastic anaemia
Acquired siceroblastic anaemia
THATS ALL ABOUT” WHAT IS ANAEMIA?” .