Acute phase reactants and interleukin 6 after total hip replacement. Effects of high dose corticosteroids

A randomised study was performed to evaluate the association between some commonly measured acute phase proteins and interleukin-6 after a standard musculoskeletal operation, and to investigate the effect of high doses of corticosteroids on these proteins. Eight men and four women with osteoarthrosis but who were otherwise healthy and who were each to have an uncemented hip prosthesis inserted by the porous coated anatomical technique, were included. Patients were randomised to receive methylprednisolone 30 mg/kg body weight 1 1/2 hours before, and four and 12 hours after, operation (n = 6) and compared to a control group (n = 6). Plasma concentrations of C reactive protein, haptoglobin, orosomucoid and alpha 1-antitrypsin; serum concentration of albumin; packed cell volume; white cell count; and plasma concentration of interleukin-6 were measured. The increases in concentrations of acute phase proteins in plasma were significantly less in the group given steroids, but this did not have any obvious clinical consequences. Increase in the concentration of interleukin-6 preceded the increases in acute phase proteins in both groups, reflecting the role of interleukin-6 in the regulation of expression of acute phase protein genes in hepatic cells. The increase of interleukin-6 in the group receiving steroids was less pronounced than that in the control group, indicating that corticosteroids inhibit the generation of interleukin-6 in vivo.