An overview of the results of direct immunofluorescence in mucocutaneous biopsies: Single center experience

Objective: Direct immunofluorescence examination contributes to the correct and differential diagnosis and treatment management of immune-mediated dermatological diseases that can also affect the mucous membranes.

In this study, it was aimed to compare skin/mucosa biopsies performed using direct immunofluorescence and histopathological examination, compliance with the preliminary diagnosis and to evaluate the diagnostic value of immunofluorescence examination.

Patients and Methods: A total of 207 patients’ biopsies sent to the pathology laboratory between January 01, 2019 and December 31, 2019 were evaluated. Groups were formed according to the preliminary diagnosis (intraepithelial/subepithelial separation conditions, lupus erythematosus, lichen planus, vasculitis), and histological (intraepithelial/subepithelial separation, clasia, dermal mucin deposition) and direct immunofluorescence (immunoglobulin G, M, A, and C3 depositions, patterns) findings were recorded. SPSS 23.0 package software with Kappa statistics and the McNemar test were performed. P<0.05 was considered statistically significant.

Results: Direct immunofluorescence results were negative in 115 patients, positive in 91 patients and could not be evaluated in one patient. Histological agreement was found in 19 of 44 (43.2%) patients with bullous pemphigoid, 10 of 18 (55.6%) with pemphigus, 26/51 (50.9%) with lupus erythematosus, 10/15 (66.7%) with lichen planus, 6/6 (100%) with Henoch Shönlein purpuras and 37/62 (59.7%) with other vasculitides. Direct immunofluorescence positivity was found as 19/19 for bullous pemphigoid, 10/10 for pemphigus, 11/26 for lupus erythematosus, 2/10 for lichen planus, 6/6 for Henoch Shönlein purpura, and 28/37 for other vasculitides (κ = 0.021).

Conclusion: Direct immunofluorescence examination significantly supports clinical and histopathological findings in the diagnosis of immune mediated dermatologic diseases and in the differential diagnosis of vesiculobullous diseases.