Seroprevalence of anti-Helicobacter pylori and anti-CagA antibodies among healthy children according to age, sex, ABO blood groups and Rh status in south-east of Iran.
OBJECTIVE
The aim of this study was to evaluate the seroprevalence of anti-H. pylori and anti-CagA antibodies in healthy children and to investigate those relation with age, sex, ABO blood groups and Rh status.


METHODS
Serum samples from 386 children (187 males; 199 females), aged 1-15 years were tested for the presence of antibody to H. pylori and its virulence factor (CagA) by use of ELISA. ABO blood grouping were also done by hemagglutination test .


RESULTS
The overall seroprevalence of H. pylori infection was 46.6%. The prevalence of anti-H. pylori antibody was significantly (p<0.05) higher in males (51.9%) compare to females (41.7%). The prevalence of anti-CagA antibody in infected children was 72.8%. Although, the prevalence of anti-CagA antibody was higher in males (78.4%) compared to females (66.3%), but the difference was not statistically significant (p=0.07). In age subgroups of 1-5 years, 6-10 years and 11-15 years, the prevalence of anti-H. pylori was 37.6%, 46.9% and 54.9% and regarding infected-children the prevalence and the mean titer of anti-CagA antibody were 63.8%, 75.94 Uarb/ml; 75%, 63.32 Uarb/ml and 79.45%, 57.11 Uarb/ml; respectively. The seroprevalence of anti-H. pylori and anti-CagA (in infected children) were 53% and 77.3% in blood group A, 50.5% and 64.7% in blood group B, 44.4% and 62.5% in blood group AB, 41.6 % and 76.8% in blood group O, 45.9% and 73% in Rh(+) phenotype and 54.84% and 70.6% in Rh(-) phenotype, respectively. The prevalence of both antibodies did not significantly differ between ABO blood groups or Rh status. However, within blood group A, the prevalence of anti-H. pylori and anti-CagA was significantly higher in males compare to females (p<0.05).


CONCLUSIONS
These results showed that almost half of the children acquire H. pylori infection. Anti-CagA antibody are also common in the children. The seroprevalence of anti-H. pylori and anti-CagA antibodies were higher in males and increased with age. However, the mean titer of anti-CagA antibodies decreased with age, inversely. ABO blood groups may partly influence the prevalence of H. pylori infection, especially in male gender.
Jafarzadeh
Abdollah
A
Rafsanjan University of Medical Sciences, School of Medicine, Department of Immunology, Rafsanjan, Iran. Jafarzadeh14@yahoo.com
Ahmedi-Kahanali
Jafar
J
Bahrami
Mehdi
M
Taghipour
Zahra
Z
D000017:ABO Blood-Group System; D000293:Adolescent; D017677:Age Distribution; D000906:Antibodies / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007223:Infant; D007492:Iran / Q000453:epidemiology; D008297:Male; D010641:Phenotype; D012204:Rh-Hr Blood-Group System; D016036:Seroepidemiologic Studies; D017678:Sex Distribution
D000017:ABO Blood-Group System; D000906:Antibodies; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D012204:Rh-Hr Blood-Group System; C080866:cagA protein, Helicobacter pylori