Correlation of persistently high serum amyloid A protein and C-reactive protein concentrations with rapid progression of secondary amyloidosis

Abstract

The importance of serum amyloid A protein in the progression of renal failure was studied over three years in 28 patients with secondary (amyloid A type) amyloidosis predominantly due to rheumatoid arthritis. Creatinine clearance, the amount of protein in the urine, and serum amyloid A and C-reactive protein concentrations were determined regularly. Linear regression analysis showed a close correlation between the change in creatinine clearance each year and both serum amyloid A concentrations (20 patients: r = - 0.83, p < 0.001) and C-reative protein concentrations (28 patients: r= - 0.80, p < 0.001). The correlation between serum amyloid A and C-reactive protein concentrations was also significant (317 parallel measurements: r = 0.81, p < 0.001). These findings suggest that monitoring serum amyloid A or C-reactive protein concentrations is valuable in assessing the prognosis in secondary amyloidosis and that therapeutic measures that lower amyloid A concentrations may reduce the formation of amyloid.