SARS-CoV-2 vaccine-triggered conversion from systemic lupus erythematosus (SLE) to bullous SLE and dipeptidyl peptidase 4 inhibitors-associated bullous pemphigoid

Bullous systemic lupus erythematosus (BSLE) is a rare blistering disease in patients with SLE. BSLE is a heterogenous disease caused by autoantibodies to the basement membrane, mainly type VII collagen. The pathogenesis of the development of autoantibodies in BSLE remains unknown. We report a case of SLE taking dipeptidyl peptidase 4 inhibitors (DPP4i) who developed tense blister lesions after administration of SARS-CoV-2 vaccine. Initial erythematous lesion before administration of SARS-CoV-2 vaccine had not shown IgG deposition at basement membrane both direct and indirect immunofluorescence (IIF). However, the result of those examinations became positive after the administration of SARS-CoV-2 vaccine. Furthermore, IIF test results using NaCl split skin had shown positive against epidermal side. These observations suggest that SARS-CoV-2 vaccination triggered production of autoantibodies that cause bullous SLE. The present case fulfills the diagnostic criteria for both BSLE and DPP4i-associated bullous pemphigoid. Skin lesions were cleared after withdrawal of DPP4i. Therefore, physicians should ask patients who develop blisters after the vaccination whether they are taking DPP4i.

Automated summary

This article reports a case of an SLE patient who developed tense blister lesions after receiving the SARS-CoV-2 vaccine. The patient did not show IgG deposition at the basement membrane before vaccination, but became positive afterwards. Additionally, the results of testing using NaCl split skin were also positive. The findings suggest that the SARS-CoV-2 vaccine may trigger the production of autoantibodies that cause bullous SLE.