Serum amyloid A as a marker of ankylosing spondylitis activity

Serum amyloid A protein A (SAA) is a normal serum protein (serving as a precursor of fibrillar tissue protein AA), synthesized in the liver and a rapidly responding marker of the acute phase of inflammation. A constant high concentration of SAA is one of the factors in the development of AA-amyloidosis. As a rule, secondary amyloidosis develops in patients with long-term and poorly controlled inflammatory diseases, including rheumatic diseases, one of which is ankylosing spondylitis (AS).Objective: to assess the level of SAA in AS patients and its relationship with indicators of disease activity.Patients and methods. The study included 124 patients with AS who met the modified New York 1984 criteria. The disease activity and functional status of patients were assessed according to the recommendations of Russian experts. SAA and CRP, ESR in blood serum were measured in all patients.Results and discussion. The median SAA concentration was 12.5 mg/L [4; 71.6]. Of 124 patients, 31% had SAA levels <5 mg/L and 69% had >5 mg/L. A strong correlation was found between the levels of SAA and CRP (r=0.80, p<0.000001), no significant relationship was found between SAA and ESR (r=0.31, p=0.92). The correlation between the AS activity according to the BASDAI index and SAA was weak (r=0.3, p<0.002), the correlation with ASDAS-CRP was moderate (r=0.54, p<0.00001).Conclusion. A statistically significant relationship was found between SAA and CRP levels, as well as the AS activity indices. Research has shown that SAA can be used as one of the markers of inflammation in AS.

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AB0072 SERUM AMYLOID A PROTEIN (SAA) IN ANKYLOSING SPONDYLITIS AND THE RELATIONSHIP WITH SYSTEMIC INFLAMMATION

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.1782 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 1066.2-1066

Author(s):

K. Sakharova ◽

M. Cherkasova ◽

S. Erdes

Keyword(s):

Ankylosing Spondylitis ◽

Disease Activity ◽

Serum Amyloid A ◽

Inflammatory Diseases ◽

Strong Association ◽

Critical Role ◽

Serum Amyloid ◽

Aa Amyloidosis ◽

Amyloid A ◽

Serum Amyloid A Protein

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

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Amyloid deposition in granuloma of tuberculosis patients: A pilot study

10.1101/2021.02.08.21250526 ◽

2021 ◽

Author(s):

Shreya Ghosh ◽

Akansha Garg ◽

Chayanika Kala ◽

Ashwani Kumar Thakur

Keyword(s):

Serum Amyloid A ◽

Amyloid Deposition ◽

Serum Amyloid ◽

Secondary Amyloidosis ◽

Amyloid Formation ◽

Tuberculosis Patients ◽

Amyloid A ◽

Inflammatory Conditions ◽

Amyloid Deposits ◽

Serum Amyloid A Protein

AbstractThe formation of granuloma is one of the characteristic feature of tuberculosis. Besides, rise in the concentration of acute phase response proteins mainly serum amyloid A is the indicator for chronic inflammation associated with tuberculosis. Serum amyloid A drives secondary amyloidosis in tuberculosis and other chronic inflammatory conditions. The linkage between serum amyloid A (SAA) protein and amyloid deposition site is not well understood in tuberculosis and other chronic inflammatory conditions. We hypothesized that granuloma could be a potential site for amyloid deposition because of the presence of serum amyloid A protein and proteases that cleave SAA and trigger amyloid formation. Based on this hypothesis, for the first time we have shown the presence of amyloid deposits in the granuloma of tuberculosis patients using the gold standard, Congo red dye staining.

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