1. Department of internal medicine and hematology, faculty of medicine, Menoufia University, Shebin El-Kom, Egypt
2. Department of internal medicine and hematology, faculty of medicine, Zagazig University, Zagazig, Egypt
3. Department of medical biochemistry, faculty of medicine, Menoufia University, Shebin El-Kom, Egypt
4. Department of hematology and bone marrow transplantation, at el Maadi military forces medical compound, Cairo, Egypt
5. Department of Community medicine, faculty of medicine, Menoufia University, Shebin El-Kom, Egypt