Background:Serum amyloid A protein (SAA) likely has a critical role in control and possibly propagation of the primordial acute phase response and is the precursor of AA amyloid fibrils. Prolonged elevations in SAA are the major inciting factor for AA amyloidosis developing in chronic inflammatory diseases. In Russia 2-4% of patients with ankylosing spondylitis (AS) have secondary (AA) amyloidosis.Objectives:To study the level of SAA in AS its relationship with indicators of disease activity.Methods:124 patients with AS (according to mNYC 1984) 70 men, 54 women, of whom HLA B 27 positive 91.1% mean age 38.1 (± 12.9), age at the onset of the disease 23.5 (± 9.9) consecutively admitted to the clinic of the Research Institute rheumatology from February to November 2020. In addition to the standard examination (the median CRP 6.7 mg/l [1.4; 24.9], ESR 13 mm/h [7; 27], SAA was studied in all patients by the nephelometric method.Results:The median SAA in 124 patients was 12.5 mg/l [4;71.6]. Among them, 31% had normal SAA level (<5 mg/l), and 69 % - more than 5 mg/l. In 21 (17.5 %) cases, the level of SAA was increased at normal CRP levels, and only in 2 cases an increase in the level of CRP at normal SAA levels; 50 patients (40.3 %) with normal ESR had elevated SAA levels, and 7 (5.6%) - ESR exceeded the upper limits of the norm with normal SAA levels. Comparison of the average values of the levels of SAA, CRP, ESR in men and women did not reveal significant differences between them. The SAA level was weakly correlated with ESR (r = 0.2; p=0.002) and BASDAI (r=0.3; p=0.002), moderately with ASDAS-CRP (r=0.5; r<0.0001), but showed a strong association with CRP (r = 0.80; p<0.00001). Patients with elevated SAA levels (>5 mg/l) had a shorter disease duration (10 and 12 year; p<0.0004), higher ASDAS-CRP (2.9 and 2.4; p<0.003), blood CRP level (14.6 and 1.3; p<0.00001), and significantly more peripheral arthritis (60% and 39%; p<0.05) than patients with normal indicators.Conclusion:The level of SAA correlates well with indicators of AS activity, especially with the level of CRP, and can be used as an alternative indicator of disease activity.Disclosure of Interests:None declared
Role of Serum Amyloid A Protein in Various Diseases with Special Reference to Periodontal and Periapical Inflammation- A Review
