AIMSTo investigate whether serum amyloid A protein (SAA) and C-reactive protein (CRP) concentrations could be used in the management of beta thalassaemic patients undergoing bone marrow transplantation (BMT).METHODSSerum SAA and CRP concentrations were determined in paired samples from 66 patients with beta thalassaemia before and after BMT. Serum SAA concentrations were determined by an enzyme linked immunoassay (EIA); serum CRP concentrations were determined by a nephelometric assay.RESULTSSerum SAA concentrations before transplantation were significantly higher in the group that subsequently rejected the transplant than the group without complications. SAA concentrations increased after BMT in acute graft versus host disease (GvHD) and rejection. No significant increase in SAA or CRP was found in chronic GvHD. Increases in serum in SAA and CRP concentrations were not related to concomitant infection episodes.CONCLUSIONSThe different acute phase response in acute GvHD and rejection compared with chronic GvHD suggests that different immunopathogenic mechanisms are responsible.