Pathological features of ectopic lymphoid structure in skin lesions of patients with pemphigus / 中华皮肤科杂志

ABSTRACT

Objective To investigate pathological features of infiltrating lymphocytes in skin lesions of patients with pemphigus,and to analyze their correlation with titers of anti-desmoglein (Dsg) 1 and anti-Dsg3 antibodies in peripheral blood.Methods A retrospective pathological analysis was performed in 93 patients with pemphigus vulgaris or pemphigus foliaceus,who visited the Department of Dermatology of Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine between 2014 and 2016.For each HE-stained section,the total number of lymphocytes per × 50 microscopic field was counted,and defined as lymphocyte density index.Enzyme-linked immunosorbent assay (ELISA) was conducted to determine the serum titers of anti-Dsg1 and anti-Dsg3 antibodies in the patients with pemphigus.The correlations between the lymphocyte density index and titers of anti-Dsg1 and anti-Dsg3 antibodies were analyzed.Immunohistochemical staining was performed in lesional skin samples from 8 patients with pemphigus vulgaris and 8 patients with pemphigus foliaceus,so as to analyze the distribution of CD3+ T cells,CD20+ B cells and CD138+ plasma cells.Results Of the 93 pathological sections,93 (100.00％) showed Grade1 lymphocyte aggregates,64 (68.09％) showed Grade 2 lymphocyte aggregates,and 10 (10.64％) showed Grade 3 lymphocyte aggregates,and the 56 cases of pemphigus vulgaris and 37 of pemphigus foliaceus showed the similar proportion of grade 1,2 and 3 lymphocyte aggregates.There was also no significant difference in the lymphocyte density index between patients with pemphigus vulgaris and pemphigus foliaceus (P ＞ 0.05),and the lymphocyte density index was uncorrelated with the serum titers of anti-Dsg1 and anti-Dsg3 antibodies in patients with pemphigus.Of the 16 cases of pemphigus,CD3+ T cells were found in all cases,CD20+ B cells in 15,and CD138+ plasma cells in 12.Of 16 sections,all showed a large amount of CD3+ T cells in Grade 1-3 lymphocyte aggregates,while lymphocyte aggregates containing CD20+ B cells and CD138+ plasma cells were found in 52.80％ ± 5.78％ and 34.59％ ± 7.42％ of sections respectively.No significant differences in the distribution of CD3+ T cells,CD20+ B cells,CD138+ plasma cells were found between the 8 cases of pemphigus vulgaris and 8 cases of pemphigus foliaceus.Conclusion Different degrees of lymphocyte infiltration generally exist in skin lesions of patients with pemphigus,which may form ectopic lymphoid structures and contribute to the development and aggravation of pemphigus skin lesions.