The Expression Of Propylthiouracil-induced Antineutrophil Cytoplasmic Antibody(ANCA) And Its Target Antigens

Research BackgroundHyperthyroidism has become the second commonest endocrine system disease next to diabetic and ways to treat hyperthyroid include anti-thyroid drug therapy, surgical treatment and radioactive iodide therapy, among which drug treatment is the most adoptable. Propylthiouracil(PTU) is a common medicine used in clinical treatment for hyperthyroid. It is reported that PTU may induce the occurrence of ANCA and to be worse it may also cause autoimmune vasculitis, which is relatively rare to be found clinically but may have diversified clinical manifestations. Had not it been taken seriously, it might aggravate the patients’ condition, and might particularly cause damage to their lungs and stomachs and even endanger the patients’ life. Some case reports address this type of drug-induced vasculitis but few researches have been done to analyze its ANCA features and its target antigens. Research ObjectivesThis research tries to conclude the expression of ANCA in the PTU treatment by detecting ANCA in different groups of patients with hyperthyroidism, analyze the distribution of its target antigens and raise people’s alertness of PTU on inducing ANCA positive vasculitis. Provide more laboratory basis for clinical diagnosis and treatment of thyroid disease. Method161 patients with primary hyperthyroidism in Zaozhuang Municipal Hospital are divided into four groups, i.e., the newly diagnosed group without any treatment(n=36), group with PTU treatment(n=55), group with MMI treatment(n=43) and the group with non-drug treatment(n=27). It first tests the TGAb and TPOAb in the newly diagnosed group without any treatment and group with PTU treatment. Second it detects all patients’ blood serum before and after drug intervention through IIF and then for those with positive ANCA uses ELISA to detect seven ANCA target antigens, namely MPO, PR3, LF, HLE, AZU, CG and BPI. ResultsCases with positive TPOAb band TGAb take up respectively 78%(28/36) and 44%(24/55) in the newly diagnosed group without any treatment and group with PTU treatment. There is no significant difference(2c =20.7814,P = 0.05148) in ANCA between patients with positive and negative TPOAb and TGAb. Cases with positive ANCA in the newly diagnosed group account for 2.8%(1/36), those in group with PTU treatment 20%(11/55), those in group with MMI treatment 4.7%(2/43), and those in group with non-drug treatment 0%(0/27). A significant difference can be found here as the proportion of positive ANCA cases among all cases in the group with PTU treatment is larger than that of the newly diagnosed group(2c =14.645, P = 0.0001298), group with MMI treatment(2c =10.8127, P = 0.001008) and group with non-drug treatment(2c = 4.8131, P = 0.02824). Among the 11 cases with positive ANCA in the group with PTU treatment, 10 belong to p ANCA, 1 XANCA. In the group with PTU treatment, the target antigen distribution is as follows: 11(100%) cases in detection of MPO, 6 cases(54.5%) in LF, AZU and CG, 5 cases(45.5%) in HLE, 3 cases(27.3%) in PR3 but no cases in BPI.3 cases among the 11 ones have one negative result in the test of anti-MPO antigen. Among the 55 cases with PTU treatment,2 of the 11 cases with negative IIF-ANCA have vasculitis-related clinical manifestations. Conclusion1. The appearance of ANCA may have nothing to do with thyroid diseases.2. PTU is relevant to the positive ANCA in patients with hyperthyroidism and cause vasculitis-related clinical manifestations among some patients.3. PTU-induced ANCA belongs mainly to p ANCA, sometimes accompanied by c ANCA. Detecting a variety of specific target antigens except MPO and PR3 is one important characteristic of PTU-induced ANCA.