VENOM-SPECIFIC IGG ANTIBODIES IN BEE AND WASP ALLERGY - LACK OF CORRELATION WITH PROTECTION FROM STINGS

This paper investigates the relationship between venom IgG levels and protection from stings. Venom-specific IgG antibody levels have been m easured by radioimmunoassay in untreated wasp- (n = 38) and bee-allerg ic (n = 16) patients presenting with systemic reactions to stings and in a sub-group of these (wasp = 15; bee = 9), before and after the ini tial course of venom immunotherapy (VIT). A history was taken of all r eactions, the last systemic reaction being graded on a scale of 1-8 an d of the number and timing of stings. In untreated patients venom IgG levels were much higher in bee-allergic patients (mean +/- s.e. = 68.2 +/- 7-1% positive pool) than in the wasp group (27.1 +/- 4.2%) (P < 0 .05 Mann-Whitney U-test). There was a marked rise in venom IgG after t he initial course of VIT in the wasp group (geometric mean and 95% con fidence intervals = 40.5%, 28.8-54.3) but a much smaller rise in the b ee group (15.3%, 6.6-24.1), with no overlap in the 95% confidence inte rvals. Bee patients, who were mainly beekeepers or their relatives, ha d been more heavily immunized with venom than wasp patients. They had received: (i) more stings (mean number of stings: bee, 26; wasp, 4; P < 0.001) and (ii) more stings per year. Wasp patients received their s maller number of stings over a much longer period, up to 40 yr. There was no correlation between the severity of the last systemic reaction and the venom IgG levels alone or venom IgG and IgE levels in combined analysis in either bee or wasp patients. This study shows that the pa ttern of IgG response differs in bee and wasp-allergic subjects, and t hat most bee-allergic subjects with systemic reactions have high level s of venom IgG. The degree of immunization with venom seems to be an i mportant determinant of the venom IgG level. Our findings suggest that venom-specific IgG levels do not predict systemic reactions to stings and are not useful for monitoring VIT. If protection from stings is I gG-mediated, our observations suggest that the relevant immune respons e is more complex, possibly involving IgG sub-classes, IgG antibodies to individual venom antigens or antibody affinity, and not adequately reflected by measurement of the concentration of venom-specific IgG.