Primary Research On Api2-malt1 Fusion Gene Detection And Clinical Meaning Of Primary Gastric Lymphoma

Background:Primary gastric lymphoma(PGL) is one of gastric maligant tumors which is relatively rare to meet. The incidence ratio in gastric maligant tumors was about 1% to 4%, but it is the most hackneyed lymphadenoma. At present, many studies consider that the detection of t(1;18) (q21; q21) chromosome translocation and its product of inhibitor of apoptosis protein-2 mucosa-associated lymphoid tissue lymphoma translocation gene 1(API2-MALT1) fusion gene possess a certain value for diagnosis, curing and prognosis judgement of gastric lymphoma. There were few researches on the relation between this gene and gastric lymphoma in the domestic, only a few literatures reported that use of RT-PCR method detected API2-MALT1 fusion gene transcription of gastric mucosa-associated lymphoid tissue lymphoma(MALToma) through paraffin imbedding section preparatio, but its positive rate was much lower. Now, there were no studies about use of RT-PCR detecting API2-MALT1 fusion gene transcription through common practice biopsy tissue samples by endoscope in the domesitc.Objective:Though detecting API2-MALT1 fusion gene transcription of endoscopic biopsy tissue from 13 cases of primary gastric lymphoma, judge the feasibility of RT-PCR to detect API2-MALT1 fusion gene transcription of endoscopic biopsy tissue sample, combine together with related clinical data, to explore the clinical value of diagnosis, differential diagnosis, therapeutic regimen formulation and prognosis decision of fusion gene to gastric MALToma.Methods:Collected symptom, physical sign, serologic examination, Helicobacter pylori(Hp), gastroscope, ultrasonic endoscope, treatment methods and therapeutic efficacy datas of 13 cases. Extracted nucleic acid from biopsy tissue through ultrasonic endoscope, reverses transcription as cDNA, then used RT-PCR to amplificate cDNA, with amplification output carrying out agarose gel electrophoresis, at last, undertook sequencing of PCR product.Results:Through detecting pathology tissue from ultrasonic endoscope biopsy, finally diagnosed 13 cases of primary gastric lymphoma. There were five cases of positive API2-MALT1 fusion gene(all MALToma), of the total, one cases existing two positive fusion genes. And carried out sequencing of the two positive cases, then confirmed as fusion gene. There were 8 negative cases,6 cases of MALT lymphadenoma and 2 cases of diffuse large B-cell lymphoma(DLBCL) among the total. The two groups'symptom, physical sign, blood routine, liver and kidney function, electrolyte, sternum, liver, gall and spleen ultrasound showed normal. In the tumor marker of AFP,CEA,CA199,CA125, only CA125 in the two negative cases heightened. There was one case of Hp infected positively in the postive group, but five cases of positive Hp in the negative group. There were two cases soakage mucous layer, one case soakage submucosa, two cases soakage muscularis propria, and one case existing gastric lymphadenectasis in the positive group. There were two cases soakage mucous layer, four cases soakage muscularis propria, two cases soakage placenta percreta, and there cases existing gastric lymphadenectasis in the negative group. Two cases were complete remission and three cases partial remission in the positive group, but four cases were complete remission, three cases partial remission and one case stable in the negative group.Conclusion:API2-MALT1 fusion gene is the abnormality of specificity genetics in MALT gastric lymphoma, having a certain value for diagnosing MALT gastric lymphoma. It is feasible with RT-PCR detecting biopsy specimens obtaining from ultrasonic endoscope in the clinic. However, it was invalid through resisting Hp to treat lymphadenoma of API2-MALT1 fusion gene. The detection of this fusion gene has some certain value on guiding diagnosis and treatment of gastric lymphoma.