Detection of specific IgE antibodies to major and minor antigenic determinants in sera of penicillin allergic patients.
OBJECTIVE
To investigate the mechanism(s) of penicillins allergic reaction.


METHODS
The radioallergosorbent test (RAST) was used to detect 9 specific IgE antibodies, including major antigenic determinants: benzylpenicilloyl (BPO), ampicilloyl (APO), amoxicilloyl (AXO), phenoxomethylpenicilloyl (PVO) and flucloxacilloyl (FLUO), and minor antigenic determinants: benzylpenicillanyl (BPA), amoxicillanyl (AXA), 6-aminopenicillanic (APA) and phenoxomethylpenicillany (PVA), in the sera of 32 penicillin allergic patients. The relationship between specific IgE antibodies and penicillins chemical structures was studied by radioallergosorbent inhibition test.


RESULTS
Nineteen of 32 patients (59.4%) were RAST positive, among whom, five cases were positive only to one or two antigenic minor determinants, and three cases were positive only to one or three major antigenic determinants. The remaining 11 patients were positive not only to major antigenic determinants but also minor antigenic determinants. In 9 specific IgE antibodies, the positive rate of PVA-IgE was the highest (34.38%), followed by BPO-IgE (31.25%). The positive rate of FLUO-IgE was the lowest (15.63%). Of the total patient group, 53.13% were positive to one or more minor antigenic determinants, while 37.5% (12/32) were positive to one or more major antigenic determinants. The percentage of patients with urticarial reactions who were positive to minor antigenic determinants (63.16%) was significantly higher than observed in the anaphylactic shock group (38.5%, P < 0.05).


CONCLUSIONS
The minor antigenic determinant was important in allergic reaction. The combining sites of the specific IgE antibodies were likely to be the side-chain of drug or the overwhelming drug molecule.
Zhao
Yongxing
Y
Department of Clinical Pharmacology, Medical School of Zhengzhao University, Zhengzhou 450052, China.
Qiao
Hailing
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D004342:Drug Hypersensitivity / Q000276:immunology*; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010406:Penicillins / Q000276:immunology*; D011852:Radioallergosorbent Test
D000906:Antibodies; D000939:Epitopes; D010406:Penicillins; D007073:Immunoglobulin E