Lymphocyte Transformation Tests and Patch Tests to Identify Drugs Potentially Associated With Bullous Pemphigoid...

Area of Science:

• Immunodermatology
• Autoimmune Blistering Diseases

Background:

• Bullous pemphigoid (BP) is the most common autoimmune blistering disease, particularly in the elderly.
• Drug exposure is a suspected trigger for BP, but evidence and mechanisms are limited.
• Differentiating true drug associations from coincidental ones is crucial for patient management.

Purpose of the Study:

• To investigate the role of specific drugs in bullous pemphigoid pathogenesis.
• To utilize in vitro lymphocyte transformation tests (LTT) and in vivo patch testing to identify drug triggers.
• To differentiate true drug associations from coincidental findings in BP.

Main Methods:

• Enrolled 33 patients with suspected BP and no current systemic treatment.
• Performed LTT and patch tests 3 months post-diagnosis.
• Assessed BP disease activity using the Bullous Pemphigoid Disease Activity Index (BPDAI) at baseline and follow-up (3 and 6 months).

Main Results:

• LTT was positive in 60% of patients for drugs including DPP-4 inhibitors, diuretics, hydrochlorothiazide, levetiracetam, nivolumab, enalapril, and amlodipine.
• BPDAI scores decreased over the study period irrespective of LTT results.
• A trend towards clinical improvement was observed in LTT-positive patients upon drug discontinuation, though sample size was small. Patch testing confirmed one LTT-positive case.

Conclusions:

• Certain drugs may play a role in triggering BP in genetically predisposed individuals.
• LTT shows promise as a valuable tool for managing BP patients.
• Further research is warranted to confirm these findings and elucidate underlying immune mechanisms.