Acute phase proteins, humoral and cell mediated immunity in environmentally-induced hyperthermia in man.

The effects of repeated hyperthermia, caused by a Finnish sauna bath over 1 week, on the serum levels of some acute phase reactant proteins and on both humoral and cell-mediated immunity on twelve healthy young volunteers are presented. The mean rise in rectal temperature during each 30-min period in the bath was about 1.3 degrees C. Heat exposure caused significant increases in the serum concentrations of two of the acute phase reactant proteins, alpha1-antitrypsin (from a mean value of 1.8 (0.1) to 1.9 (0.2) g X l-1, p less than 0.01) and transferrin (from a mean value of 36.9 (3.4) to 38.3 (4.4) mumol X l-1, p less than 0.05), but no changes occurred in immunoglobulins or cell-mediated immunity. These findings suggest that environmentally induced hyperthermia can initiate the acute phase reaction associated with fever.