Affiliation: | 1. Department of Rheumatology, Sudan Medical Specialization Board, Khartoum Sudan ; 2. Department of Internal Medicine, Wayne State University, Detroit Michigan, USA ; 3. Department of Internal Medicine and Rheumatology, Omdurman Military Hospital, Khartoum Sudan ; 4. Department of Internal Medicine, Detroit Medical Centre, Detroit Michigan, USA ; 5. Department of Clinical Medicine, Medical and Cancer Research Institute, Nyala Sudan ; 6. Faculty of Medicine, Alfashir University, Alfashir Sudan |