Objective: Our aim was to investigate the hypothesis that the sera interleukin-10 (IL-10) level and polymorphic nucleotides within the IL-10 gene promoters would link to specific IgE and IgG production and the expression of penicillin allergy.
Methods: One hundred and two patients and 86 healthy subjects were chosen for assay of serum IL-10 level by enzyme-linked immunosorbent assay (ELISA) and type -1082 G/A and -819 C/T alleles by sequence-specific primer polymerase chain reaction (SSP-PCR). Radioallergosorbent test (RAST) and ELISA were used to examine eight types of specific immunoglobulin-E (IgE) and IgG antibodies, respectively, which included four types of antibodies to major and minor antigenic determinants.
Results: Compared with control subjects and patients with negative-specific IgE, there were significantly lower levels of IL-10 in patients with positive-specific IgE (P < 0.05). Similarly, there were significantly lower levels of IL-10 in patients with positive-specific IgG compared with normal controls and allergic patients with negative-specific IgG (P < 0.05). The visible negative correlations existed between IL-10 and four types of specific IgE [benzylpenicilloyl (BPO), phenoxomethylpenicilloyl (PVO), benzylpenicillanyl (BPA), amoxicillanyl (AXA)], and patients with three or more positive-specific IgE had significantly lower IL-10 levels than normal controls (P < 0.01). There was a declining trend for IL-10 level in serum with the increase in types of positive-specific IgE. But there was no significant difference in serum IL-10 level between the positive skin-test group and the allergic-history group. Compared with controls and patients with negative antibodies, a significantly decreased frequency of the -1082 G allele was present in patients with positive antibodies (P < 0.01). The allele T and TT genotype at -819 C/T position had lower frequency in the negative-specific IgG group than that in the positive group and controls (P < 0.01).
Conclusions: Positive specific IgE and IgG are associated with decreased IL-10 level in allergic reaction to penicillins. The distributions of genotype and frequency of allele at the -1082 G/A position may be associated with the production of both specific IgE and IgG antibodies.