Specific serum immunoglobulin G to H pylori and CagA in healthy children and adults (south-east of Iran)

Abstract

To evaluate the serologic IgG response to H pylori and CagA across age groups and in healthy children and adults. Totally, 386 children aged 1-15 years and 200 adults aged 20-60 years, were enrolled to study. The serum samples of participant were tested for presence of anti-H pylori and anti-CagA IgG by using ELISA method. The seroprevalence of H pylori in adults was significantly higher than that observed in children (67.5% vs 46.6%; P < 0.000003). In children, the seropositivity rate in males (51.9%) was significantly (P < 0.05) higher than that observed in females (41.7%). The prevalence of serum anti-CagA antibody was 72.8% and 67.4% in infected children and adults, respectively. The mean titer of serum anti-CagA antibodies was significantly higher among children in comparison to adults (64.1 Uarb/mL vs 30.7; P < 0.03). In infected children and adults the prevalence of serum anti-CagA antibody was higher in males compared to females (78.4% vs 66.3%; P = 0.07 and 75.6% vs 54.71%; P < 0.04, respectively). The age-specific prevalence of anti-H pylori and anti-CagA antibody (in infected subjects) was 37.6% and 59.57% at age 1-5 years, 46.9% and 75% at age 6-10 years, 54.9% and 79.45% at age 11-15, 59.01% and 83.33% at age 20-30 years, 66.6% and 60.52% at age 31-40 years, 73.46% and 63.88% at age 41-50 years and 75.75% and 60% at age 51-60 years with mean titer of anti-CagA antibody of 75.94, 63.32, 57.11, 52.06, 23.62, 21.52 and 21.80 Uarb/mL, respectively. There was significant difference between mean serum anti-CagA antibody in age subgroups (P < 0.001). These results showed that anti-H pylori and anti-CagA antibodies were common in the children and adults. The H pylori-specific antibodies influenced by age and sex of subjects. Moreover, it seems that males are more susceptible to infection with CagA(+) strains compared to females. The seroprevalence of anti-CagA antibody was increased with age, up to 30 years and then decreased. It was also found that the magnitude of the IgG response to CagA decreased with advanced age.