Patients and methods: Descriptive, comparative, retrospective and prospective study, combination with treatment intervention in patients diagnosis with AS, following to modified ACR-1984 criteria (New York criteria) who are inpatient or outpatient in the Department of General Internal Medicine - Endocrinology of Hue University of Medicine and Pharmacy and in the Department of Nephrology and Rheumatology of Hue Central Hospital from May 2018 to August 2019.