Diagnostic Accuracy of Anti-Desmoglein 1 and 3 Antibodies by Enzyme-Linked Immunosorbent Assay (ELISA) in Pemphigus Vulgaris

OBJECTIVE: To determine the diagnostic accuracy of anti-Desmoglein 1 (Dsg1) and anti-Desmoglein 3 (Dsg3) antibodies detected by the enzyme-linked immunosorbent assay (ELISA) in clinically suspected cases of pemphigus vulgaris (PV). STUDY DESIGN: A cross-sectional study. Place and Duration of the Study: Department of Immunology, the Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from July to December 2024. METHODOLOGY: A total of 105 clinically suspected PV patients were enrolled using a non-probability consecutive sampling technique. Serum was analysed for the detection of Dsg1 and Dsg3 antibodies by the ELISA, with histopathology and direct immunofluorescence used as the reference methods for skin biopsy examination. The diagnostic accuracy of the ELISA was assessed through sensitivity, specificity, positive and negative predictive values, and Cohen's kappa statistics. RESULTS: A total of 105 clinically suspected cases, comprising 50 (47.6%) males and 55 (52.4%) females (male-to-female ratio 10:11), were included. PV was detected in 82 (78%) cases by both Immunofluorescence and histopathology, while 23 (22%) were diagnosed as other (non-PV). Among the PV, 70 (85.4%) were positive for both Dsg1 and Dsg3 antibodies, while 12 (14.6%) were negative. Anti-Dsg1 and 3 positivity was observed in 10 (9.5%) and 5 (4.7%) non-PV cases, respectively, diagnosed as pemphigus foliaceus and bullous pemphigoid. Both anti-Dsg1 and anti-Dsg3 yielded equal sensitivity of 85.4%; however, the specificity of anti-Dsg1 was lower (56.5%) than that of anti-Dsg3 (78.3%) antibodies. CONCLUSION: Both anti-Dsg1 and anti-Dsg3 antibodies detected by the ELISA demonstrated good sensitivity; the comparatively lower specificity of anti-Dsg1 antibodies, however, restricted its applicability in PV in resource-limited settings. KEY WORDS: Pemphigus vulgaris, Desmoglein1, Desmoglein3, Enzyme-linked immunosorbent assay, Sensitivity, Specificity, Immuno-fluorescence.