EFFECT OF HEAT INACTIVATION OF SERUM ON BORDETELLA-PERTUSSIS ANTIBODYDETERMINATION BY ENZYME-LINKED-IMMUNOSORBENT-ASSAY

The effect of heat inactivation on Bordetella pertussis antibodies det ermined by enzyme-linked immunosorbent assay (ELISA) was studied. Sera were heated at increasing temperatures (from 30 to 50 degrees C at 5 degrees C increments and from 52 to 70 degrees C at 2 degrees C increm ents). Between 30 and 50 degrees C, no significant differents were obs erved in immunoglobulin G (IgG) antibodies to pertussis toxin (PT). Fr om 50 to 56 degrees C the antibody values were twofold higher than tho se of uninactivated sera; at 64 degrees C the values were 3.6- to 9.1- fold higher. The increase in PT IgG antibody values was more pronounce d in sera with low antibody values. ELISA antibody values of sera form a vaccine trail were determined in unheated and heat inactivated sera . The geometric mean value (GMV) of the heat inactivated samples was 3 .2 times the geometric mean value of the uninactivated sera. ELISA IgG antibodies to filamentous hemagglutinin, fimbriae-2, and pertactin we re studied, and the values of heat inactivated sera did not differ sig nificantly from the values of the uninactivated sera. Our findings ind icate that heat inactivation of sera leads to higher, variable, and fa lse-positive PT IgG values. (C) 1998 Elsevier Science Inc.