Study On Correlation Between Bullous Pemphigoid Antibodies And Disease Activity

Objective:Bullous pemphigoid is a chronic acquired autoimmune bullousskin disease.It often affects old patients like60years and older, seldom affectschildren and infants.There is no significant gender differences. The typicallesions of BP patients are tension blisters and bullae on erythematous ornormal skins. Any part of the surface can be involved except mucousa. Theclinical subtypes of Bullous pemphigoid include small blister type,localizedtype, polymorphous type,proliferation type and most commonly bullae type.Diagnosis of bullous pemphigoid is mainly based on the typical clinicalmanifestations, histopathology, immunofluorescence, serum antibodies.BPhistopathology shows that there is subepidermal blisters not accompanied byacantholysis and infiltrating inflammatory cells which mainly are eosinophilsneutrophils in the blisters.Direct immunofluorescence (DIF) and indirectimmunofluorescence (IIF) show basement membrane zone mainly has IgGantibody and C3complement linear deposition, also can have IgM, IgA, IgDand IgE deposition, this method has good application value for cases withoutclear clinical and histopathological diagnosis and cases with differentialdiagnosis.Most BP patients’ serum has BMZ autoantibodies, mainly IgG canalso be IgM, IgA, IgD and IgE, the antibody level can be partly reflect diseaseactivity. Study has found the target antigen of BP circulating antibody isbullous pemphigoid antigen(BPAG),which has two kinds:(1) the priorantigen is BPAG1, a high molecular weight polypeptide (230000).(2) theminor antigen is BPAG2, which is a low molecular weight (180000)transmembrane protein. Now with the fusion protein technology detection inbullous pemphigoid patients’ serum, the positive rate of bullous pemphigoidBPAG2antibody rises significantly, which means it plays a major role inthe occurrence of the disease.The pathogenesis of BP may be: antibody and antigen combine,triger complements, anaphylatoxins C3a andC5a formation, mast cell degranulation, release eosinophil chemotactic factor,attract eosinophils and adhesion to the basement membrane, release lysosomalenzymes, lead to basement membrane hemidesmosomes and anchor wirefracture and disappear, form a subepidermal blister.So far,the biggest problem for diagnosis and treatment of BP is to make adefinite diagnosis and predict the severity and prognosis of the disease.Primary lesions of Bullous pemphigoid are usually atypical and topicalmedical treatment makes it more difficult to differentiate from otherdiseases.Direct immunofluorescence (DIF) examination is the gold standardfor diagnosis of BP, but repeated skin biopsy makes patients suffer great pain,it is difficult to be accepted by patients, as well as a follow-upstandard.Indirect immunofluorescence (IIF) antibody titers don’t correlateparallelly with the severity and changes of the disease.Based on thepathogenesis of BP, this experiment was to detect anti-BP180antibody in BPwith ELISA and to find out its sensitivity and specificity.The experiment alsomade a score for the BP patients according to its disease activity, andinvestigate its correlation with anti-BP180antibody titer.So we can eventuallyfind a suitable index for clinical diagnosis, treatment effects evaluation andfollow-up of BP.Method:1Collect serum of40patients with BP and30non BP patients who areoutpatients and inpatients from2010-10to2012-12,detect Bp180antibody ineach of the two groups by ELISA and indirect immunofluorescence, compareand analysis the results.2Collect the confirmed BP patients’ medical records, registrate the ageand sex of patients, clinical features, lesion areas, the number of new activelesions in a week, anti-BP180antibody titer and other projects on list, thenmake a score for disease activity. Make a statistical analysis of theresults with SPSS13.0Pearson bivariate correlation, get the simple linear regression equation and draw the scatterplot, analyse the correlatiom between disease activity and anti-BP180antibody titer.Result:1Sensitivity and specificity: ELASA sensitivity:92.5%; specificity:97.5%; IIF sensitivity:77.5%; specificity:100%. Two groups have statisticalsignificant difference (P <0.01). The difference between the two methods inthe observation group is statistically significant (P <0.05).2Pearson bivariate correlation analysis shows the correlation coefficientR=0.843,analysis of variance shows bullous pemphigoid antibodies and thedisease activity score is significantly correlated (P <0.01), the linearregression equation for the disease activity score=1.132+0.022*antibodytiter.Conclusion:1This study further confirmed the ELASA method has more sensitivityand specificity in detection of anti-BP180antibody in BP patients, and thismethod has the advantages of simple operation, little trauma, objective results,combined with the clinical symptoms of the patients can promote thediagnosis rate of bullous pemphigoid.2The higher the Bullous pemphigoid antibody titer which detected byELISA method is,the more the disease activity is.BP antibody titer parallelswith the disease activity and has close correlation. It can be a great index forclinical monitoring of BP disease, curative effect evaluation, adjusting thetreatment, prognosis and follow-up.