Serum amyloid protein (SAP) as a marker of autoimmune disease in mice

Acute phase proteins are good markers of inflammatory processes. To clarify whether Serum Amyloid Protein (SAP) can be a marker for the onset of SLE disease in mice, we measured constitutive and inducible SAP levels in normal mice of different strains, in C57Bl/6 lpr/lpr (B6lpr) and [NZB x NZW]F1 (NZB/W) SLE-prone mice, in mice that develop Lupus-like syndrome during chronic Graft versus Host (GvH) reaction and in mice suffering acute GvH reaction. In comparison to B6lpr, NZB/W mice showed higher blood levels of SAP but those levels did not correlate with autoimmune parameters. In B6lpr, the SAP levels steadily increased with age and correlated with some of the parameters used for monitoring the SLE disease. High levels of SAP were also found in mice suffering acute GvH reaction whereas the lupus-like chronic GvH disease was associated with limited increase of SAP levels.