| Background Helicobacter pylori (H. pylori) is a spiral gram-negative bacteria, discovered by Marshall and Warren in 1982. The discovery of this worm is one of the important landmarks in modern gastroenterology. More than half of the worldwide population is infected with H. pylori. H.pylori is considered as a main contributor to the pathogensis of gastric diseases, including chronic gastritis and digestive ulcer, and is relevant to the incidence of gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. The toxicng factors vary with different H.pylori strains, and different response to the same strain also exists in different populations even under the same environment. Obviously, the host immune response plays an important role in the outcomes of H.pylori infection. Studies found that infection with H.pylori can trigger strong humoral and celluar immune responses. IgM presents in the acute phase, IgA appears in gastric mucosa and IgG exists stably in peripheral blood for a long time. Despite the strong response against H. pylori, it seems that this worm can manage to survive safely. In some volunteer and animal experiments, vaccine induced responses are effective to eradicate H. pylori. It was reported that the main protecting antibody type is secretary IgA, and IgG in some time. Concerning the cellular-6-response, it is widely accepted that the pathological injury is mainly induced by Thl response, while Th2 response is helpful to eradicate H. pylori. It is suggested in some experiments, however, vaccines, which could induce balanced Thl, and Th2 responses, are better than those only induced Th2 response. Many problems have not been revealed in the field of H. pylori immunity. H.pylori reside in gastric mucosa, and it is previously accepted that there are no H. pylori antigens in peripheral blood. However, the contrary result was reported recently. It is not exactly known whether the soluble antigens or just anti-idiotype mimicry exist in peripheral blood. In some experiments, the proliferation response of peripheral blood monocytes (PBMC) against H. pylori occurred not only in H.pylori -positive populations, but also, even higher, in H.pylori -negative populations. The followed experiments were designed to seek the possible answer.METHODS 1 > Detection of rheumatoid factors (RF) in serum by gel agglomeration test. 2 x Clearance of antigen-antibody complex in serum samples by PEG-6000 precipitation. 3, Detection of H.pylori infection and anti-idiotype mimicry of H. pylori antigen by three different ELISA system and competitive ELISA test. 4> Further verification of anti-idiotype mimicry of serai H.pylori antigen by dot blot, SDS-PAGE and Western blot. 5, Observation of proliferation response of PBMC (from H.pylori -positive, H.pylori -negative populations and fetal umbilical blood , respectively) against H.pylori, Campylobacler jejun antigens, PHA or PHA+ H.pylori antigens by 3H -thymidine incorporation. 6, Detection of Thl > Th2 level in PBL from H.pylori -positive, H.pylori -negative populations or from fetal umbilical blood by flow cytometry. 7, Detection of IL-10, TGF-B 1 secreted by PBMC derived from H.pylori -positive, H.pylori -negative populations andfetal umbilical blood as well.RESULTS 1 Seven RF-positive samples were found among two hundred undetermined sera samples, and the positive rate is 3.5%. 2. Detection on 160 determined sera samples by three ELISA system, the positive rates of anti-idiotype mimicry were 95.00%, 93.75% or 96.25% respectively in H.pylori -positive samples, and 2.50%, 1.25% or 5.00% respectively in H.pylori -negative samples; the difference is significant between Hp-positive and Hp-negative samples(P7 , P2 > P3 < 0.01 , respectively), while the difference among the three ELISA systems is not significant (P>0.05) . 3-, The positive rates of anti H.pylori antibody and anti-idiotype were 56.5% and 51.0%,respectively in 200 undetermined sera samples; the difference is not significant (P>0.05) . 4^ Detection on 200 undetermined sera s...
|
PDF Full Text Request