Serological Detection Of PCA,IFA, Anti-DGP And Anti-tTG In Patients With Non-segmental Vitiligo

BackgroundsVitiligo is an acquired, idiopathic diseases prevalent in the world. It is characterized by macular depigmentation of the skin and showing the disappear of melanocytes with normal structure and function in pathology. Vitiligo is usually divided into segmental vitiligo(SV) and non-segmental vitiligo(NSV). NSV is significantly different in the pathogenesis, clinical manifestations and treatment compared from SV. The pathogenesis of NSV remains unclear until now, autoimmune mechanism, oxidative stress, genetic factors, neurochemicalagents might contribute to NSV. In recent years, there were more and more evidence to prove the autoimmune mechanism for the destruction of melanocytes. Current histopathological studies showed increased infiltration of dendritic cells, Th17 cells and CD8+ cytotoxic T lymphocytes in the margin of vitiligo and the reduced number of regulatory T(Treg) cells in the affected skin. Some scholars have found melanocyte-specific antibodies in the serum of NSV and it might induce apoptosis of melanocytes.Besides, NSV often accompanied by other autoimmune diseases, particularly autoimmune thyroid disease(AITD). The rate of NSV accompanied with AITD up to 23.8%, and about 20.8% of vitiligo patients can detect thyroid peroxidase antibody, thyroglobulin antibody, thyroid stimulating hormone receptor. On this basis, screening for AITD had been written in the guidelines for the management of vitiligo in European.AIG is a kind of autoimmune disease oin the gastrointestinal tract mediated by CD4+ T cell and more than 10% of them will develop into gastric cancer or gastric carcinoid tumors.The typical features of AIG is that PCA and Intrinsic factor antibody( IFA) canbe detectded in serum. PCA and IFA can cause iron deficiency anemia or pernicious anemia by reducing the secretion of gastric acid, intrinsic factor deficiency and vitamin B12 malabsorption. Foreign scholars reported, the positive rate of PCA in the serum of patients with vitiligo was significantly increased,There is no report in china. The relationship between vitiligo and the positive rate of IFA have not been reported.CD is an autoimmune disease of the intestinal mucosa. It is clinically characterized by gliadin sensitive, abdominal pain, bloating, diarrhea, steatorrhea, weight loss or growth disorders, constipation, and elevated transaminases. Diagnosis is based on clinical manifestations,the biopsy of small intestinal and serology tests. Serological tests include anti-tissue transglutaminase antibodies(anti-tTG), anti-deamidated gliadin protein epitopes(anti-DGP), and so on. Studies have shown that the proportion of vitiligo increased significantly associated with CD. There was also reports that repigmentation of vitiligo lesions after gluten-free diet. But there are also reports indicate that CD has nothing to do with vitiligo. ObjectivesThis study plans to dectect the positive rate of PCA, IFA, DGP and tTG antibodies in the serum of NSV patients, and to explore its clinical significance and the scientific value of serological screening of these antibodies, and to provide experimental basis for the further comprehensive assessment and treatment of NSV. Subjects and Methods1. Subjects: 165 cases of NSV patients were selectded in this study.Simple rosea, achromic nevus, nevus anemicus, piebaldism, hypopigmented mycosis fungoides and other hypopigmentation disorders had been excluded. Of which, 97 cases of male, 68 cases of female. 90 cases with age and sex-matched were selected as control group.Of which, 53 cases of male and 37 cases of females. The cases of control group were from hospital medical center, hospital workers, students, regulation Pearson, interns or family members of patients, no history or family history with vitiligo, pigment faded spots, gastrointestinal diseases and other autoimmune diseases.2. Methods: 4ml fasting venous blood are collected in NSV group and control group. ELISA has been applied to detect the level of anti-DGP, WB method has been used to detect the level of PCA、IFA、anti-tTG. between the two groups of statistics and further divided the NSV groupe by age and gender into different levels of subgroups, then add up the positive rate statistics respectively.3.Statistical Methods: Using SPSS17.0 statistical package for analysis of clinical data and Chi-square test will be used to compare the positive rate, P <0.05 was considered statistically significant. Results1.The positive rate of PCA in NSV group and control group were 10.30% and 3.33% respectively, the difference was statistically significant(χ2 = 3.91, P <0.05).2. The positive rate of IFA in NSV group and control group were 4.85% and 1.11%, there was no difference between them(χ2 = 1.42, P> 0.05).3. The positive rate of anti-DGP in NSV group and control group were 10.91% and 2.22% respectively, the difference was statistically significant(χ2 = 6.08, P <0.05).4. The positive rate of anti-tTG in NSV group and control group were 3.63% and 1.11% respectively, here was no difference between them(χ2 = 0.99, P> 0.05).5. Divide the NSV group into two groups by gender, the positive rates of PCA, IFA, anti-DGP, anti-tTG were 9.28% and 11.77%; 4.12 %% and 5.88%; 11.34% and 10.29%; 4.12% and 2.94%; respectively. Compared between groups, and the results showed no significant difference between the two groups(χ2 = 0.27, 0.27, 0.05, 0, all P> 0.05).6. Divide the two groups into four subgroups(<10 years, 11 to 20 years, 21 to 40 years, 41 to 60 years old) by age and compared the positive rates of PCA and anti-DGP between groups respectively and found no diffidence between them.7. Two patients with double positive PCA and IFA in NSV group were detected with lower vitamin B12 levels and mild anemia, oner of them was executed with gastroscopy and found multiple gastric polyps, the gastric biopsy consistent with the pathological changes of AIG. Conclusions1. PCA and anti-DGP positive rate increased significantly in non-segmental vitiligo patients, they are recommended as serology screening index for autoimmune gastritis and celiac disease.2. IFA and anti-tTG positive rate were not significantly higher in non-segmental vitiligo population, they are not recommended as serology screening index for autoimmune gastritis and celiac disease.