Abstract
INTRODUCTION: Autoimmune bullous diseases (AIBDs) are a group of illnesses characterized by autoantibodies targeting adhesion molecules in the skin and mucosa. Accurate diagnosis of the specific subtype of AIBD is crucial for effective management and predicting prognosis, especially in cases with an increased risk of malignancy. However, differentiating between subtypes can be challenging due to overlapping symptoms. OVERVIEW OF DIAGNOSTIC TESTS: Direct immunofluorescence microscopy (DIF) detects in vivo bound antibodies in perilesional tissue biopsies and provides details about the probable site of autoantibody deposition within the skin/mucosae, immunoglobulin type, and pattern of antibody deposition. Indirect immunofluorescence (IIF) microscopy with organ substrate is a minimally invasive serological test that detects circulating autoantibodies. Enzyme-linked immunosorbent assay (ELISA) quantifies serum autoantibodies against specific autoantigens. Quantitative ELISA is useful for diagnosis, monitoring therapy, and assessing disease activity. Commercially available ELISA kits, including the multi-variant ones, can detect antibodies associated with AIBDs. BIOCHIP is a technique based on IIF that offers a sensitive and specific diagnostic alternative to ELISA. It uses microarrays with multiple antigenic substrates to simultaneously screen common AIBDs. The BIOCHIP slides contain different substrates, allowing the identification of multiple types of autoantibodies in a single test. INDIAN CONTEXT: While these diagnostic tests offer valuable insights into target antigens, antibody patterns, and disease subtypes, it is important to note that the availability of these tests is limited in most centers across India. This limitation can be attributed to factors such as the relatively higher cost of these investigations, challenges related to the stability of immuno-reactants, and a shortage of trained personnel capable of performing such tests. CONCLUSION: This review discusses the diagnosis of AIBDs based on resources available in India, as of today. It also provides with practically applicable diagnostic algorithms for pragmatic diagnosis of AIBDs in Indian scenario.