Immunofluorescence mapping in inherited epidermolysis bullosa: a study of 86 cases from India

Background Epidermolysis bullosa (EB) poses diagnostic challenges in infancy. In India, the diagnosis is largely clinical. There were no facilities to perform immunofluorescence mapping (IFM) until recently, and electron microscopy, which requires expertise to interpret, is limited to a few research laboratories. Objectives To describe the patterns of IFM staining in the various forms of EB in Indian patients and to correlate these findings with clinical diagnosis. Methods We conducted a cross-sectional study of IFM findings in EB. Antibodies against type IV collagen, cytokeratin 14, laminin 332 and type VII collagen were used. Clinical correlation was performed in all cases, and concordance-discordance rates were calculated. Results Eighty-six patients with a diagnosis of EB were included in the study. There were 29 with EB simplex (EBS), 18 with junctional EB (JEB) and 15 with dystrophic EB (DEB). The remaining 24 cases included rare variants, cases with overlapping clinical features and cases where the type of EB was not known. On IFM diagnosis, there were 32 cases of EBS, 15 JEB, 17 DEB and two Kindler syndrome. Two cases were not EB and 18 were inconclusive. IFM could establish the type in 12 of 15 cases (80%) that had overlapping clinical features. Most of these cases were under 1 year of age. Overall the concordance was 57% and was seen best in cases of EBS. Conclusions This is the first large study of IFM of the subtypes of EB in Indian patients. The study provides a framework for better understanding of EB in Indian patients and for better diagnosis and management, particularly in infancy.