ABSTRACT
The ACP1 (acid phosphatase locus 1) gene encodes a highly polymorphic low molecular weight protein tyrosine phosphatase (LMPTP) involved in the modulation of various signal transduction pathways including T-cell receptor. Previous studies suggest an association of this enzyme with allergic disorders. The aim of this study was to review our previous data and to confirm the association by further observations. Two new independent samples of individuals were studied from the population of Rome. ACP1 genotype was determined and history of allergic disorders was recorded. All allergic subjects had at least one positive prick test. Three-way contingency table analyses were performed by a log linear model. In all samples studied from different populations (Italian, English, and Chinese for a total of 958 subjects) we found that the proportion of allergic subjects was higher among genotypes with low enzymic activity than among genotypes with high activity. Concentration of IgE was negatively correlated with ACP1 enzymic activity. Carriers of ACP1 genotypes associated with low enzymic activity may be more susceptible to allergic disorders.
Subject(s)
Hypersensitivity/genetics , Polymorphism, Single Nucleotide , Protein Tyrosine Phosphatases/genetics , Proto-Oncogene Proteins/genetics , Adult , Aged , Aged, 80 and over , Asian People/genetics , Asthma/genetics , Child , Colonic Neoplasms/genetics , Dermatitis, Atopic/genetics , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Hypersensitivity/enzymology , Hypersensitivity/ethnology , Leiomyoma/genetics , Linear Models , Male , Middle Aged , Odds Ratio , Phenotype , Protein Tyrosine Phosphatases/metabolism , Proto-Oncogene Proteins/metabolism , Retrospective Studies , Rome , Skin Tests , Uterine Neoplasms/genetics , White People/geneticsABSTRACT
Recent studies suggest that genetic polymorphism modulates immunoglobulin E (IgE)-mediated atopic reactions. Adenosine is an important local hormone influencing immune function and tissue reactivity; because adenosine concentration is regulated by adenosine deaminase (ADA), we have investigated the possible effect of ADA polymorphism on the relationship between IgE and positive prick test. A random sample of 160 schoolchildren from the population of Viterbo (Italy) were studied. Prick testing was performed with a panel of local allergens. Total IgE assay was performed according to standard clinical procedure. ADA phenotype was determined according to Spencer et al. A highly significant correlation between prick test and IgE was observed. However, the strength of correlation was moderate (eta2 = 0.16), indicating that positive prick testing depends on other variables besides IgE. The relationship between IgE and positive prick testing is stronger in carriers of ADA*2 allele than in ADA*1/*1 subjects. Also, sensitivity and predictive values are higher in ADA*2 carriers than in homozygous ADA*1/*1 children. The data suggest that the effect of IgE level on local reactivity is influenced by ADA polymorphism; at low level of IgE, the presence of the ADA*2 allele seems to protect from positive prick testing.
