H.pylori Infection And HLA-DR Antigen Expression On Peripheral Blood Lymphocytes And Monocytes Among Family Members Of Children With Recurrent Abdominal Pain

Objective:To investigate the prevalence and the phenotype of Helicobacter pylori (Hp) infection in family members of children with recurrent abdominal pain. To study the human leukocyte antigen (HLA)-DR expression on the peripheral blood lymphocytes and monocytes in family members. To explore the association between HLA-DR expression and Hp-associated recurrent abdominal pain.Methods:Hp immunophenotyping method was used to check the Hp type of 62 family members and 37 normal controls. Individuals were divided into three groups:children with recurrent abdominal pain, family members with recurrent abdominal pain and adults without recurrent abdominal pain. Venous EDTA blood specimen was obtained for lymphocytes and monocytes HLA-DR analysis by flow cytometry.Results:The positive rate of Hp immunophenotyping antibody test in 99 volunteers was 67.6%, and the prevalence of Hp I type was 53.5% while Hpâ…¡type was 14.1%, the positive rate of Hp was 93.5%. Hpâ…¡type caused recurrent abdominal pain easier than Hpâ… type (x2=5.105, p=0.024). The expression of HLA-DR on peripheral blood lymphocytes among three groups has no difference (H=0.966, p=0.617), but the result was different on monocytes (H=10.624,p=0.005), children and family members with recurrent abdominal pain expressed higher than those without recurrent abdominal pain.Conclusion:The seropositive rate of Hp antibodies is high in the family members with recurrent abdominal pain. There is familial cluster phenomenon in family members suffering from recurrent abdominal pain. The expression of HLA-DR on peripheral blood monocytes in family members with recurrent abdominal pain is higher than those without. There is no difference in the expression on lymphocytes. The expression of HLA-DR on monocytes may be associated with immunocompetence stimulated by chronic infection.