Type of anaemia caused by pulmonary TB

Microcytie hypochromic anaemia Tuberculosis is a chronic inflammatory disorder. It is associated with anemia of chronic disease Anemia that is often observed in patients with infectious inflammatory or neoplastic disease that persists for more than 1 or 2 months is called anemia of chronic disease. - The characteristic feature of this group is occurrence of anemia in the presence of ample storage iron. The erythrocytes in anemia of chronic disease are usually normocytic and nonnochronic, however hypochromia and microcytosis may also be observed. The morphological features are determined by the primary disease. - "For instance many patients with cancer have anemia that is typically normocytic and normochromic. In contrast patients with long standing active rheumatoid ahritis or chronic infections such as tuberculosis will have a microc tic hypochromic anemia". The key pathological feature in anemia of chronic disease is failure to mobilize stored irony (ferritin). Ferritin is present in the macrophages of bone marrow and reticuloendothelial system. Under normal circumstances, iron can be mobilized back from the ferritin into the circulation. When developing erythrocytes require iron, the iron stored as ferritin is presented to the plasma from where it is carried to the developing erythrocytes. Why there is failure of iron mobilization in anemia of chronic disease? Anemia of chronic disease occurs in ceain inflammatory conditions or chronic disease. In these conditions macrophages are activated and they release ceain cytokines e.g. IF, IL-1, TNF. These cytokines stimulate synthesis of hepcidin in the liver. Increased hepcidin synthesis inhibits release of iron from the storage pool. Thus in anemia of chronic diseases, the macrophages, despite being rich in stored iron cannot provide iron to developing erythrocyte. The other impoant effect of cytokines released by rnacrophages in chronic inflammatory disorders is inhibition of CFUE (colony forming units erythroid). The inhibition leads to decreased synthesis of erythropoletin which in turn decreases erythropoiesis and produces anemia. The Hematological Parameters in Anemia of Chronic disease Serum iron --> Normal to decreased Serum ferritin --> Normal to increased TIBC --> Decreased % saturation Normal to increase Bone marrow iron stores --> Normal to increase MCV (MCH) --> Decreased