Search

Serum SAA concentration was determined by radioimmunoassay in 21 Polish children with amyloidosis secondary to juvenile rheumatoid arthritis (JRA). The results were compared to controls and children with JRA in Polish populations (where amyloidosis is a frequent complication of JRA) as well as to American children with JRA (where amyloidosis in JRA has been observed only sporadically) and American control children. No significant differences of SAA protein levels were found in the amyloidotic Polish children when compared to JRA Polish and American children. However, significantly higher levels of SAA protein were present in amyloidotic Polish children when compared to the control Polish and American group. High serum SAA protein concentration in JRA children did not necessarily correlate with the presence of secondary amyloidosis. Other mechanisms are probably involved in the development of amyloidosis.

The concentration of serum IgG, IgM, IgA, IgD, IgE and complement C3 as well as Kappa and Lambda free and bound light chains were determined in sera from 21 amyloidotic Polish children with juvenile rheumatoid arthritis (JRA), Polish and American children with JRA, and control children from a Polish population. Comparable concentrations of IgG, IgM, IgA, IgE and C3 were found in amyloidotic children when compared to Polish JRA children with active polyarticular disease. However, the amyloidotic Polish children with JRA had significantly higher levels of IgG, IgM, IgA, IgE and complement C3 fraction when compared to American JRA children. The levels of IgA and IgE were significantly elevated in amyloidotic and Polish JRA populations when compared to American JRA patients. Free immunoglobulin light chains were not found in the sera of any of the children tested in this study. However, in the patients with amyloidosis, significantly diminished levels of bound Kappa and Lambda light chains were found.