血吸虫病和激动的肠炎的诊断和流行病学的tools课件.ppt

The Association of Schistosomiasis and Inflammatory Bowel Disease with Colorectal Cancer:Tools for Diagnosis and EpidemiologyPeter Chun,Ph.D 天马行空官方博客：；QQ:1318241189；QQ群：175569632In Egypt,schistosomiasis(from S.haematobium and mansoni)has been strongly linked to bladder cancer.The evidence includes:n nEpidemiological evidencen nExperimentally induced schistosomiasisn nHistopathology n nAge and gender ratios M.H.Mostafa et al.Relationship between Schistosomiasis and Bladder Cancer.Clin Microbiol Rev 1999.12(1)97-111The evidence linking S.manosini&haematobium infection to cancer of the large intestine is scant,but intestinal infestation with S.japonicum is considered a significant contributory factor to the development of cancer of the colon and rectum.A.Ishii et al.Parasitic infection and cancer:with special emphasis on Schistosoma japonicum infections(Trematoda).A review.Mutat Res.1994 305(2)273-81n nColorectal cancer correlates with prevalence and intensity Colorectal cancer correlates with prevalence and intensity of shistosome infection.of shistosome infection.n nThe age of onset of cancer is lower in areas of shcistosome The age of onset of cancer is lower in areas of shcistosome endemicity and length of survival is shorter.endemicity and length of survival is shorter.n nAffected individuals usually have a long history of Affected individuals usually have a long history of inflammatory large bowel symptoms.inflammatory large bowel symptoms.n nThe cancers correspond in anatomic location to the area The cancers correspond in anatomic location to the area most affected by the parasite.most affected by the parasite.Z.Xu et at.Schsitosoma japonicum and colorectal cancer:an epidemiological study in the Peoples Republic of China.Int J Cancer.1984.34(3):315-8C.Ming-Chai et al.Evolution of colorectal cancer in schistosomiasis:transitional mucosal changes adjacent to large intestinal carconoma in colectomy specimens Cancer 1980.46(7):1661-75Chen et al.Colorectal cancer and schistosomiasis.Lancet 1981 971-3ES.Zhao et al.Carconoma of the large instestine with schistosomiasisanalysis of 279 cases.Zhonghua Zhong Liu Za Zhi.1981 3(1):67-9ES Zhao.Cancer of the colon and schistosomiasis.J R Soc Med.1981 74(9):645K.Shindo.Significance of schistosomiasis japonica in the development of cancer of the large intestine.Dis Colon Rectum 1976;(19)460-9K.Inoguchi et al.The correlation between primary colorectal carcinoma and schistosomiasis japonica.Igakku Kenkyu 1978;(48)93-9K.Matsuda et al.Possible Associations of Rectal Carcinoma with Schistosoma japonicum Infection and Membranous Nephropathy:a Case Report with a Review.Japanese J Clin Oncol(29)576-581 天马行空官方博客：；QQ:1318241189；QQ群：175569632Pathologically,patients with colonic schistosomiasis manifest epithelial dysplasia,and resemble the changes found in long-standing chronic ulcerative colitis.Chen et al.considered these dysplastic changes as premalignant lesions.Chen et al.Colorectal cancer and schistosomiasis.Lancet 1981 971-3The evidence associating colorectal cancer and ulcerative colitis and Crohns disease is strong.Tumors often occur at the site of chronic inflammation.The absolute risk of developing colorectal hanker is high when extensive disease begins at a young age.40%of patients diagnosed with pancolitis from ulcerative colitis before age 15 years developed colon cancer during 20 years of follow up in a population-based linkage study in Sweden.DK Podolsky.Inflammatory bowel disease.N Engl J Med.2002.347:417-429We describe here two membrane based colloidal gold tests which can aid in the detection of inflammatory bowel disease and schistosomiasis.Both are easy to perform and can be done at the clinic level at the same time that other screening tests for colorectal cancer are done.We propose the use of these new tests to secure large scale epidemiological evidence linking these two diseases to colorectal cancer in ChinaTests for Fecal Occult BloodChemical TestsChemical Testsn nPrinciple:Based on Principle:Based on peroxidase activity of peroxidase activity of heme.heme.n nAdvantages:Sensitive,Advantages:Sensitive,Inexpensive.Will detect Inexpensive.Will detect digested blood.digested blood.Quantitation possible.Quantitation possible.n nDisadvantages:Not Disadvantages:Not specific.Dietary specific.Dietary restriction required.restriction required.Immunological TestsImmunological Testsn nPrinciple:Based on Principle:Based on detection of human detection of human hemoglobin.hemoglobin.n nAdvantages:Very specific.Advantages:Very specific.No dietary restrictions.No dietary restrictions.n nDisadvantages:Disadvantages:Expensive.More complex Expensive.More complex to perfom.to perfom.Examples of Chemical Testsn nChromogens:O-tolidine/Benzidine,Guaic,Chromogens:O-tolidine/Benzidine,Guaic,Pyramidon.Pyramidon.An algorithm which uses a two stage testing protocol is much more cost effective given the price difference between the chemical and immunological tests for fecal occult blood.Immunochemical vs.Guaiac Fecal Occult Blood Tests.2004.Technology Evaluation Center.Assessment Program vol 19,No.5.Blue Cross&Blue Shield Association.(A 27 page review.)Other non-invasive commercial tests available today:PreGen-Plus from Exact Sciences Corp.()Detection of altered DNA from exfoliated cells in stool specimen.A comparison was made among four neutrophil-derived proteins in A comparison was made among four neutrophil-derived proteins in stool as an indicator of disease activity in ulcerative colitis.stool as an indicator of disease activity in ulcerative colitis.J.Langhorst et al.Digestive Disease Week.May 2004.New Orleans,LA.SensitivitySpecificityCorrelation Lactoferrin 86.4%69.8%0.75(above 7.25 ug/g)PNM-Elastase 81.8%48.8%0.60(above 0.062ug/g)Calprotectin 72.7%60.5%0.65(above 6 ug/g)Lysozyme 54.5%48.8%0.55(above 0.6 ug/g)IBD-Scan:A commercial quantitative ELISA for measuring fecal lactoferrin.Instruments which allow for quantitationFlow through membrane test for detecting S.japonicum antibodiesTTest spotAntigenControl spotProtein ACTest Procedure1.Wet membrane2.Add serumFlow through membrane test for detecting S.japonicum antibodiesTC*Specific anti-S.japonicum antibodies are captured on the antigen test spot.*Serum antibodies are nonspecifically captured on Protein A control spot via its Fc region.0YYFcThank you The staff of MedTrend Diagnostic Forumfrom