Noha M Abdel Baki1, Zeinab O Nawito1, Nehal M S Abdelsalam2, Dina Sabry3, Hossam Elashmawy4, Nagy A Seleem5, Azza Ali Abdel-Azeem Taha6, Mohamed El Ghobashy7. 1. Cairo University, Faculty of Medicine, Kasr Al Ainy, Department of Rheumatology and Rehabilitation, Cairo, Egypt. 2. Dar Alsalam hospital, Ministry of Health, Department of Rheumatology and Rehabilitation, Cairo, Egypt. 3. Cairo University, Faculty of Medicine, Kasr Al Ainy, Department of Medical Biochemistry and Molecular Biology, Cairo, Egypt. 4. Al-Azhar University, Faculty of Medicine, Department of Clinical Pathology, Cairo, Egypt. 5. Al-Azhar University, Faculty of Medicine, Department of Orthopedic Surgery, Cairo, Egypt. 6. Menoufia University, Faculty of Medicine, Department of Public Health and Community Medicine, Cairo, Egypt. 7. Cairo University, Faculty of Medicine, Kasr Al Ainy, Department of Radiology, Egypt.