Serum protein concentrations during Schistosoma mansoni infection in intact and T-cell deprived mice. I. The acute phase proteins, C3 and serum amyloid P-component (SAP).

Normal mice developed marked elevation of two acute phase plasma proteins, C3 and serum amyloid P-component (SAP), between 40 and 50 days after percutaneous infection with cercariae of Schistosoma mansoni. The high levels persisted until the end of the experiment (day 106). The onset of this acute phase response corresponds with the reported time at which granulomata develop in the liver. In mice deprived of T cells by thymectomy and anti-thymocyte serum, the granulomata were significantly smaller and all the animals died between days 70 and 80. These mice had normal C3 levels throughout although there was a rise in SAP concentration. C3 and SAP levels in infected control mice, which had been thymectomized but not deprived of T cells with anti-thymocyte serum, were the same as in intact infected animals. The different behaviour of C3 and SAP in infected T-cell deprived mice may reflect the alteration in specific schistosomal pathology and/or a role for T cells in mediation of the acute phase production of some proteins.