Letters to the Editor
To the Editor:
In a recent article, Dadzie et al1 highlighted the advances in molecular diagnosis in dermatopathology. We read the article with great interest because they made a comprehensive review of the different molecular techniques, pointing out their role as an ancillary tool for the diagnosis of different cutaneous disorders.
Among the different clinical applications, they underlined the ichthyoses group. They stated that, “Netherton syndrome … can be confirmed with in situ hybridization on cutaneous tissue to demonstrate lack of expression of the serine protease inhibitor LEKTI,” quoting our article recently published on neonatal and infantile erythroderma.2
Lymphoepithelial Kazal type–related inhibitor (LEKTI) is indeed a serine protease inhibitor encoded by SPINK5 (serine protease inhibitor Kazal type 5), the causative gene of the severe autosomal recessive ichthyotic skin disorder, Netherton syndrome (NS).3,4 However, we use immunostaining of skin sections with a monoclonal antibody against D1–D6 domains of LEKTI provided by A. Hovnanian's research laboratory, to investigate LEKTI expression in NS patients.4 This antibody is used with a classical immunohistochemistry technique and a 3-step immunoperoxidase technique on formalin-fixed sections. It allows a rapid, reliable, and highly specific diagnosis of NS. Other groups use different LEKTI antibodies, but to the best of our knowledge in situ hybridization is not a technique commonly used for the diagnosis of NS.
1. Dadzie OE, Neat M, Emley A, et al.. Molecular diagnostics-an emerging frontier in dermatopathology [review]. Am J Dermatopathol. 2011; 33:1–13; quiz 14–16.
2. Leclerc-Mercier S, Bodemer C, Bourdon-Lanoy E, et al.. Early skin biopsy is helpful for the diagnosis and management of neonatal and infantile erythrodermas. J Cutan Pathol. 2010;37:249–255
3. Chavanas S, Bodemer C, Rochat A, et al.. Mutations in SPINK5, encoding a serine protease inhibitor, cause Netherton syndrome. Nat Genet. 2000;25:141–142.
4. Bitoun E, Micheloni A, Lamant L, et al.. LEKTI proteolytic processing in human primary keratinocytes, tissue distribution and defective expression in Netherton syndrome. Hum Mol Genet. 2003;12:2417–2430.