The Significance of Serum Amyloid ProteinA and Selected Cytokines in Diagnosis of Secondary Renal Amyloids

Overview

The authors present the results of a prospective study focused on evaluation of the influence ofserum amyloid A (SAA) and some cytokines on the development and progression of secondary renalamyloidosis. In addition to SAA the authors examined plasma levels of the factor stimulatingmacrophage colonies (M-CSF), interleukin 1 (IL-1), interleukin 6 (IL-6), the tumor necrosis factoralpha (TNF alpha), soluble receptor for interleukin 6 (sIL-6R), soluble receptor II for the tumournecrosis factor (sTNF-RII), soluble interleukin 2 receptor (sIL-2R), as well as some adhesionmolecules (ICAM, VCAM), and as a representative of chemokines they assessed interleukin 8 (IL-8).A total of 22 patients were examined with a histologically confirmed secondary amyloidosis, and 23healthy volunteers. Plasma elevation of the SAA concentrations was recorded which is probablyassociated with the activity of the basic disease, but also with the presence of amyloid deposits intissues. Raised TNF-alpha, sTNF-RII and IL-6 levels reflect probably the activity of the basic disease.Marked elevation of M-CSF levels supports the hypothesis on the dominant role of macrophages inthe formation of amyloid deposits. Raised M-CSF concentrations were recorded in urine as well asits fractional excretion (FE). Furthermore, increased concentrations of TNF-alpha, sIL-6R and itsFE and ICAM and VCAM along with their fractional excretions were found. The increase of thesesubstances and their FE might suggest local production of these substances in the kidneys.

Key words:
secondary amyloidosis, serum amyloid A, cytokines, adhesion molecules, M-CSF