Relationship Between Eosinophil Cationic Protein Levels And Bullous Pemphigoid

Bullous pemphigoid(BP)is an autoimmune subepidermal blistering skin disease with high incidence and mortality,characterized by anti-BP180 and BP230 IgG autoantibodies driving disease.Eosinophils(EOS)infiltration is a prominent pathological feature of BP.Studies have shown that EOS and EOS activator-eosinophil cationic protein(ECP)play important roles in the pathogenesis of BP and hope to become potential effective methods for the diagnosis and treatment of BP,and have great prospects in the development of precision medicine.EOS and ECP will have a tremendous impact on the diagnosis,treatment,and prevention of BP.From January 2012 to October 2019,forty patients with newly diagnosed BP and 40 healthy normal individuals in the Department of Dermatology,Peking Union Medical College Hospital were selected to test serum ECP.Thirty-three patients with newly diagnosed BP and 41 patients with nonimmunal blister patients were selected to test blister ECP.The levels of ECP in sera and blisters of the subjects were detected by enzyme-linked immunosorbent assay,and immunohistochemical staining on some slides of skin lesions in one BP and one non-BP was performed.The relationship between serum ECP,peripheral blood EOS and anti-BP180 antibody was analyzed.The t-test or t ￠-test is used to compare the data between both groups in accordance with the normal distribution.The Mann-Whitney U test was used to analyze the data that did not conform to the normal distribution.The relationship between serum ECP,peripheral blood EOS and anti-BP 180 antibody was also analyzed by Pearson correlation coefficient.Results1.Clinical informationOf the 73 BP patients,ratio of male to female was 1:1.The mean age was 68 years,and 73 patients had pruritus of different degrees.Thirty-one patients(42%)had an increased proportion of EOS.2.Laboratory findingsThe sera ECP levels in the BP group and control group were 116.9 ±19.3 ng/L and 93.3 ± 15.9 ng/L,respectively.The difference was statistically significant(t=5.96,p<0.001)).The blister ECP levels in BP group and control group were 665.8±189.0 ng/L,and 547.5±240.6 ng/L,respectively.The difference was significant(t=2.31,p=0.02).The difference between sera and bliter fluids of BP patients was significant(t=-16.61,p<0.001).Immunohistochemical stain showed that the cytoplasmic brown-yellow particles of ECP-positive cells in the BP group were significantly higher than the control group.There was no significant correlation between serum ECP and peripheral blood EOS percentage(r=-0.15,P=0.35).There was no significant correlation between serum ECP and anti-BP 180 antibodies(r=-0.11,p=0.47).There was no significant correlation between the percentage of EOS in BP peripheral blood and antiBP180 antibody(r = 0.19,p=0.24).Conclusion:1.BP occurs in the elderly people over 60 years,and it is often accompanied by pruritus.There is no significant difference in gender between male and female.2.Elevated EOS was found in 42% of untreated BP patients.3.ECP levels in peripheral blood and local lesional skin of BP patients were significantly increased.