Long‐Term Follow‐Up of Epidermolysis Bullosa Acquisita with Fluctuations in Serum Cytokine Levels: A Case Report

ABSTRACT We report a case of epidermolysis bullosa acquisita (EBA) in a 47‐year‐old man who suffered for more than 10 years. To evaluate the longitudinal immunological changes, we measured serum levels of anti‐basement membrane zone (BMZ) IgG antibodies by indirect immunofluorescence and anti‐type VII collagen antibodies by enzyme‐linked immunosorbent assay throughout the clinical course. In addition, serum concentrations of B‐cell activating factor (BAFF), interleukin (IL)‐9, and IL‐10 were measured. Titers of anti‐BMZ antibodies and anti‐type VII collagen antibodies fluctuated during the follow‐up period and corresponded broadly with clinical disease activity. Serum BAFF levels increased before the marked elevation of anti‐type VII collagen antibody titers, although they did not closely parallel disease activity. Serum IL‐9 showed a transient peak around the time when the anti‐type VII collagen antibody titer reached its maximum. Serum IL‐10 increased after the peak of the anti‐type VII collagen antibody titer. These temporal changes in BAFF, IL‐9, and IL‐10 observed may provide useful information for understanding the immunological phases of EBA.