Serum amyloid P component scintigraphy and turnover studies for diagnosis and quantitative monitoring of AA amyloidosis in juvenile rheumatoid arthritis.

Abstract

OBJECTIVE:

To evaluate aspects of the natural history of AA amyloidosis complicating juvenile rheumatoid arthritis (JRA), and its response to therapy with chlorambucil.

METHODS:

Scintigraphy and 7-day turnover studies were performed in JRA patients with histologically proven (n = 35) or clinically suspected (n = 30) AA amyloidosis, following intravenous injection of 123I and 125I-labeled serum amyloid P component (SAP). Prospective monitoring studies were performed over 2-3 years in 20 patients with amyloidosis. All but 2 amyloidosis patients were treated with chlorambucil.

RESULTS:

Positive scanning results were obtained in all patients in whom imaging was performed within 12 years of positive biopsy findings of amyloid and in 5 patients with clinically suspected amyloidosis. Negative scanning results with normal SAP metabolism, indicating regression of amyloid, were obtained in 4 patients whose amyloidosis had been in full clinical remission for more than 12 years. Prospective monitoring studies in patients whose JRA-associated inflammatory activity was in remission demonstrated regression of amyloid in 8 patients and no substantial changes in 8 others; however, in 4 further patients with active inflammation, there was accumulation of amyloid. There was a very poor correlation between the amount of amyloid present at a particular site and the resultant organ dysfunction.

CONCLUSION:

Radiolabeled SAP scintigraphy and turnover studies are useful complementary tools in the diagnosis, screening, and quantitative monitoring of type AA amyloidosis in JRA. The amyloid deposits may progress and/or regress at different rates in different anatomic sites over short periods.

• Authors: P N Hawkins, S Richardson, D M Vigushin, J David, C R Kelsey, R E Gray, M A Hall, P Woo, J P Lavender, M B Pepys
• Journal: Arthritis and rheumatism (Arthritis Rheum) Vol. 36 Issue 6 Pg. 842-51 (Jun 1993) ISSN: 0004-3591 [Print] United States
• PMID: 8507227 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Iodine Radioisotopes
• Serum Amyloid P-Component

Topics

• Adolescent
• Adult
• Amyloidosis (complications, diagnostic imaging, epidemiology)
• Arthritis, Juvenile (complications, epidemiology)
• Child
• Female
• Follow-Up Studies
• Humans
• Iodine Radioisotopes
• Male
• Prospective Studies
• Radionuclide Imaging
• Serum Amyloid P-Component (analysis, metabolism)