Clinical criteria for the diagnosis of bullous pemphigoid: a reevaluation according to immunoblot analysis of patient sera.

BACKGROUND

We previously proposed a set of 4 clinical criteria for the diagnosis of bullous pemphigoid (BP) that consisted of age greater than 70 years, absence of atrophic scars, absence of mucosal involvement and absence of predominant bullous lesions on the neck and head. These results have been challenged because direct immunoelectron microscopy (IEM), which was used as the standard diagnostic criterion in our initial study, does not identify the different antigens of the basement membrane zone.

OBJECTIVE

To reassess the validity of these clinical criteria for the diagnosis of BP using immunoblot analysis of patient sera as the main diagnostic criterion, in order to precisely identify the antigens recognized by patient sera.

METHODS

One hundred and eighty-nine sera from patients with various subepidermal autoimmune blistering diseases (AIBDs) were tested by immunoblotting using dermal and epidermal extracts. IEM was used as a complementary diagnostic procedure in a few patients whose serum recognized BPAG2 exclusively or was negative in immunoblotting.

RESULTS

142 patients (75%) had at least 3 of the 4 clinical diagnostic criteria. Sera from patients who lacked the set of BP clinical criteria were more frequently immunoblot negative (34%) than sera from patients who had the criteria (18%; p = 0.025). BPAG1 was more frequently recognized by sera from patients with the set of BP clinical criteria (78%) than by sera from patients without the criteria (45%; p = 5.10(-4)). In contrast, BPAG2 was recognized by a great number of sera from patients who lacked the criteria of BP (71%), which was in accordance with the presence of numerous patients with cicatricial pemphigoid in this group. Among patients with various subepidermal AIBDs, the diagnosis of BP could be made with a sensitivity of 86%, a specificity of 90% and an excellent prognostic positive value over 95%, if 3 of these clinical criteria were present.

CONCLUSION

These results confirm the interest of this set of clinical criteria for the rapid diagnosis of BP.