[1] Atlas Clin, Batna, Algeria
[2] Univ Tunis El Manar, Fac Med Tunis UR17SP04, Inst T Kassab, Serv Rhumatol, Tunis, Tunisia
[3] Univ Hassan 2, Fac Med & Pharm, Ctr Hosp Univ Ibn Rochd, Serv Rhumatol, Casablanca, Morocco
[4] Univ Cape Town, Dept Med, Cape Town, South Africa