Acta Dermato-Venereologica Issue No. 97-5 97-5CompleteContent | Page 17

622 CLINICAL REPORT Diagnostic Value of Linear Fluorescence Along the Basement Membrane of Sweat Gland Ducts in Bullous Pemphigoid Işın SINEM BAĞCI 1,2 , Orsolya N. HORVÁTH 1 , Enno SCHMIDT 3,4 , Thomas RUZICKA 1 and Miklós SÁRDY 1 1 Department of Dermatology and Allergology, Ludwig-Maximilian University, Munich, Germany, 2 Department of Dermatology, Ankara 29 Mayıs Government Hospital, Ankara, Turkey, 3 Department of Dermatology, Allergology, and Venereology and 4 Lübeck Institute of Experimental Dermatology (LIED), University of Lübeck, Lübeck, Germany Linear IgG deposits along the basement membrane of adnexa has been proposed to be useful in the diagno- sis of bullous pemphigoid (BP), but no controlled stu- dies have been performed. This study evaluated linear IgG fluorescence of the basement membrane of sweat gland ducts (SGD) and other adnexa in perilesional biopsies from patients with BP (n  = 64) and controls (n  = 82), using direct immunofluorescence microscopy. Fluorescence intensity was graded semi-quantitatively. Positive SGDs were found in 58 (90.6%) patients with BP and 44 (53.7%) controls, a statistically significant difference (p  <  0.0001). The sensitivity of positive SGDs for BP was high (90.6%), but the specificity was low (46.3%). Only strong fluorescence intensity was associated with high specificity. In conclusion, positive SGDs in direct immunofluorescence microscopy are highly sensitive for BP; however, only strong fluorescen- ce has acceptable specificity. Weak positivity of SGDs without linear fluorescence of the epidermal basement membrane may not be sufficiently specific for BP. Key words: bullous pemphigoid; sweat gland ducts; immuno­ fluorescence; diagnostics. Accepted Jan 12, 2017; Epub ahead of print Jan 17, 2017 Acta Derm Venereol 2017; 97: 622–626. Corr: Işın Sinem Bağcı, Department of Dermatology and Allergology, Ludwig-Maximilian University, Frauenlobstr. 9–11, DE-80337 Munich, Germany. E-mail: [email protected] B ullous pemphigoid (BP) is the most common auto­ immune blistering disease of the skin. Diagnosis of BP relies on histopathological examination, including direct immunofluorescence microscopy (DIF) on peri- lesional skin biopsy specimens, in addition to detection of circulating autoantibodies by indirect immunofluo- rescence microscopy and enzyme-linked immunoassays (ELISAs) (1, 2). DIF is a specific, and the most sensitive, diagnostic test for BP (3, 4). It rev