Protein SAP (serum amyloid P-component) in Waldenström's macroglobulinaemia, multiple myeloma and rheumatic diseases.

Serum amyloid P-component (protein SAP) levels in patients with Waldenström's macroglobulinaemia have been determined to be markedly elevated (83 +/- 34 micrograms/ml) compared with healthy adult controls (35 +/- 11 micrograms/ml) and patients with multiple myeloma (39 +/- 17 micrograms/ml). Seropositive rheumatoid arthritis and ankylosing spondylitis patients demonstrated slightly elevated protein SAP levels compared with normals and systemic lupus erythematosus patients, but these values were indistinguishable from those for patients with amyloidosis associated with a rheumatic disease.