A cross-sectional study to correlate disease severity in bullous pemphigoid patients with serum levels of autoantibodies against BP180 and BP230

Context: Enzyme-linked immunosorbent assay (ELISA) for BP 180 and 230 antibodies is commonly done in patients with bullous pemphigoid. We could not find much data regarding the usefulness of this test to predict the disease severity in Indian population. Aims: We studied the correlation of IgG anti BP180 and anti BP230 antibody titer with disease severity and clinical features in bullous pemphigoid. Settings and Design: This cross-sectional study was conducted at a tertiary care center in western India. Materials and Methods: Forty-two clinically diagnosed treatment-naive cases of bullous pemphigoid were enrolled and investigated with skin punch biopsy, IgG anti BP180, and anti BP230 ELISA, direct immunofluorescence, and indirect immunofluorescence tests. Disease severity was assessed by calculating modified Autoimmune Bullous Skin Disorder Intensity Score (ABSIS) score. Thirty patients with a final diagnosis of bullous pemphigoid were included in the statistical analysis. Pearson's correlation coefficient (r) was used to study correlation. Results: The mean ABSIS skin score was 32.81 when both tests were negative, 42.13 when only BP230 was positive, 76.28 when only BP180 was positive, and 78.16 when both were positive. Pearson's correlation coefficient (r) for BP180 and ABSIS skin score was 0.6 (P value: 0.0005), and for BP230 was -0.055 (P value: 0.600). Conclusions: BP antibody titers correlate partially with disease severity. Anti-BP180 antibody is associated with more severe disease. Anti-BP230 antibody titer does not correlate with disease severity.