
Thalassemia major (TM( patients present with severe hemolytic anemia and multiple organs impairment. TM have an increased risk for serious infections, due to that a basic defect in the host defense and this may be related to the iron overload, chronic immune-stimulation by repeated blood transfusions, splenectomy and immune deficiency. changing in lymphocyte subsets include a greater number and activity of suppressor T cells (CD-8),reduced proliferative capacity and a number and level of activity of helper T- Cells (CD-4) leading to decreased CD4/CD8 ratio, as well as defective activity of natural killer (NK) cells. High immune globulins were reported and B- lymphocytes were found to be increased, activated with impaired differentiation, impairment of immunoglobulin secretion accompanied by increased levels of IgG, IgM and IgA. Neutrophils and macrophages are associated with defective chemo taxis and phagocytosis.