Mohammadreza Barzegar1, Zahra Asadi-Kani1, Nikoo Mozafari1, Hassan Vahidnezhad2,3, Ariana Kariminejad4, Parviz Toossi1. 1. Skin Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2. Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran. 3. Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 4. Kariminejad-Najmabadi Pathology and Genetics Center, Tehran, 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.
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.
Authors: C Has; L Liu; M C Bolling; A V Charlesworth; M El Hachem; M J Escámez; I Fuentes; S Büchel; R Hiremagalore; G Pohla-Gubo; P C van den Akker; K Wertheim-Tysarowska; G Zambruno Journal: Br J Dermatol Date: 2019-08-09 Impact factor: 9.302