Korean J Dermatol.  2024 Jan;62(1):18-28.

Direct Immunofluorescence for Dermatologic Disorders: A Single-Center Retrospective Analysis for 11 Years

• Yoo DW
• Yi JH
• Park KD
• Kwon HJ
• Kim KH
• Yoon JH

Abstract

Background
Direct immunofluorescence (DIF) is a histochemical technique used to detect tissue-bound autoantibodies and diagnose various immune-mediated skin diseases.
Objective
This study aimed to evaluate the sensitivity of DIF for each disorder, and the consistency between clinical, histopathological, and DIF results.
Methods
A retrospective study was conducted in 194 patients who underwent skin biopsy and DIF testing at our hospital between January 2011 and December 2021. An antibody panel against immunoglobulin G (IgG), IgA, IgM, C3, C1q, and fibrinogen was used. The concordance rate and κ-coefficient between the clinical, histopathological, and DIF results were evaluated.
Results
DIF was observed to be positive in 87 cases; 51 cases of immune-mediated bullous diseases, seven cases of connective tissue diseases (CTDs), 25 cases of vasculitis, and four cases of other diseases. The overall sensitivity of DIF for immune-mediated bullous diseases was 71.8%, which was higher than that of histopathology (64.8%). In CTDs and vasculitis, the overall sensitivities of DIF were 30.4% and 65.8%, respectively, which were lower than those of histopathology (73.9% and 84.2%, respectively). In addition, good concordance among the clinical, histological, and DIF results was observed.
Conclusion
DIF is a useful diagnostic method, especially for immune-mediated bullous diseases, lupus erythematosus, and Henoch-Schonlein purpura. However, in other CTDs and vasculitis cases, the sensitivity of DIF is relatively low. Therefore, the diagnostic value of DIF along with clinical and histopathological findings will be maximized only when the DIF test is performed for appropriate diseases.

Keyword

Bullous skin diseases; Connective tissue diseases; Direct immunofluorescence assay; Vasculitis