Using immunofluorescence (antigen) mapping in the diagnosis and classification of epidermolysis bullosa: a first report from Iran

Abstract

Background: Immunofluorescence antigen mapping (IFM), is a newly introduced technique for diagnosis and classification of epidermolysis bullosa (EB) disease. The precise level of skin cleavage can be determined using monoclonal antibodies to EB-specific basement membrane zone protein.

Objective: To apply IFM technique in diagnosis and classification of EB and to identify utility and limitation of this method in our clinical setting.

Methods: IFM was done according to a described protocol by Pohla-Gubo et al. Monoclonal antibodies used for antigen mapping were against cytokeratin 5, cytokeratin 14, α6 integrin, β4 integrin, laminin 332, Collagen IV, and Collagen VII.

Results: IFM was done for 95 referred patients, compromising 49 females and 46 males, aged 5 days to 45 years (mean = 9.5 years). Ninety cases were diagnosed with EB and classified as follows: EB simplex: (n = 13), junctional EB (n = 14), dystrophic EB (n = 62), and Kindler syndrome (n = 1). Diagnosis was not made in five cases as their specimens contained no blister. Confirmatory genetic analysis was done for five junctional cases from two families with clinical features of laryngo-onycho-cutaneous syndrome. Genetic molecular studies showed nonsense mutations in the last codon of exon 39 of the laminin α3a (LAMA3) gene (p.Gln57X) and a donor splice site mutation in LAMA3 (IVS57+5G>A) in the first and second family, respectively.

Conclusion: IFM technique is relatively simple to perform, and interpretation of the results is not sophisticated. The proportion of inconclusive results will be decreased if the specimens contain freshly induced blister.