Role of Direct Immunofluorescence in the Diagnosis of Immunobullous Disorders

Introduction: Immunobullous disorders of skin are characterized by formation of autoantibodies against tissue proteins which lead to blistering of skin and mucous membrane. The most common diagnostic technique for the investigation of immunobullous disorders include conventional histopathology. Other tests that are essential as confirmative tests are Direct and Indirect immunofluorescence. In general, Clinical features and histological confirmation can make a correct diagnosis of immunobullous disorders. Confirmatory studies such as immunofluorescence will help in diagnosis of cases where histopathological features alone are not diagnostic.

Materials and Methods: In the present study 35 cases of immunobullous disorders, diagnosed based on clinical features, Tzanck smear and Histopathology were subjected to Direct Immunofluorescence (DIF) and the results were analysed.

Observations: Of these 35 cases, pemphigus vulgaris was found to be the most common disorder (43%) followed by bullous pemphigoid (34%). This was followed by CBDC (5%). Pemphigus foliaceus, IgA pemphigus, dermatitis herpetiformis, linear IgA dermatoses, bullous SLE, Lichen Planus Pemphigoides constituted 3% respectively. Overall, DIF was found to be positive in 97.1% of the cases. DIF was positive in 100% of the cases in Pemphigus group and in 94.4% of subepidermal disorders. It was positive in all cases of Pemphigus vulgaris and Bullous pemphigoid. DIF was also compared with Histopathological diagnosis which was specific in 85.7% of cases.

Conclusion: The present study reaffirms that apart from new sophisticated tests (immunoblotting, immunoprecipitation, immunoelectron microscopy), the diagnosis of Immunobullous disorders still relies on DIF findings in most laboratories. However, it is not a substitute to clinical or histopathological diagnosis but rather complementary to it.