In the aim to analyze the clinical features through the BPDAI scores with regards to the autoimmune response, we first measured anti-BP180 and anti-BP230 autoantibody concentrations in the BF of patients with BP. Anti-BP180 and anti-BP230 antibodies were detected in the BF of 32 (86.5%) and 16 (43.2%) patients with a mean titer of 79.4 ± 51.2 and 31.2 ± 40.3 U/mL, respectively (Table 2A). Subgroup analysis of BP patients with and without mucosal involvement showed no significant difference both within the number of BP patients who produced these antibodies and within the mean BF titer related to each antibody. We then investigated whether serum autoantibody concentrations reflected those measured in the BF of the same patients to seek a relationship between BPDAI scores and autoantibody production in the whole BP patients included. Anti-BP180 and anti-BP230 antibodies titers within the BF were highly and significantly correlated with those measured in the serum (r = 0.78 and r = 0.73; P < 0.0001, respectively) (Table 2B). Such a correlation was also found for the anti-BP180 antibody titers within the two subsets of patients with or without mucosal involvement (r = 0.74 and r = 0.89; P < 0.0001 and P = 0.01, respectively) (Table 2B). Anti-BP230 antibody titers in BF from typical BP patients were highly and significantly correlated with those measured in the serum of these patients (r = 0.74; P < 0.0001), whereas only a high tendency was found for BP patients with mucosal involvement (r = 0.75; P = 0.07) (Table 2B).