Anais Brasileiros de Dermatologia (Dec 2014)

Immunofluorescence testing in the diagnosis of autoimmune blistering diseases: overview of 10-year experience

  • Samia Trigo Arbache,
  • Tarsila Gasparotto Nogueira,
  • Lívia Delgado,
  • Denise Miyamoto,
  • Valéria Aoki

DOI
https://doi.org/10.1590/abd1806-4841.20143221
Journal volume & issue
Vol. 89, no. 6
pp. 885 – 889

Abstract

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BACKGROUND: Immunofluorescence testing is an important tool for diagnosing blistering diseases. OBJECTIVE: To characterize the immunofluorescence findings in patients diagnosed with autoimmune blistering skin diseases. METHODS: We retrospectively analyzed immunofluorescence results encompassing a 10-year period. RESULTS: 421 patients were included and divided into 2 groups: group 1- intraepidermal blistering diseases (n=277) and 2- subepidermal blistering diseases (n=144). For group 1, positive DIF findings demonstrated: predominance of IgG intercellular staining (ICS) and C3 for pemphigus foliaceus-PF (94% and 73% respectively), pemphigus vulgaris-PV (91.5%-79.5%) and paraneoplastic pemphigus-PNP (66%-33%); ICS IgA in 100% of IgA pemphigus cases, and IgG deposits in the basement membrane zone (BMZ) along with ICS in one Hailey-Hailey patient. The IIF findings revealed mean titers of 1:2.560 for PV and 1:1.280 for PF. For paraneoplastic pemphigus, IIF was positive in 2 out of 3 cases with rat bladder substrate. In group 2, positive DIF findings included multiple deposits at basement membrane zone for epidermolysis bullosa acquisita-EBA (C3-89%,IgG-79%,IgA-47%,IgM-21%) mucous membrane pemphigoid-MMP (C3,IgG,IgA,IgM-80%) and bullous pemphigoid-BP (C3-91%,IgG-39%,IgA-11%,IgM-6%), and IgA at basement membrane zone for IgA linear disease (99%) and dermatitis herpetiformis-DH (dermal papillae in 84.6%). For lichen planus pemphigoides, there was C3 (100%) and IgG (50%) deposition at basement membrane zone. indirect immunofluorescence positive findings revealed basement membrane zone IgG deposits in 46% of BP patients, 50% for EBA, 15% for IgA linear dermatosis and 50% for LPP. Indirect immunofluorescence positive results were higher for BP and EBA with Salt-Split skin substrate. CONCLUSION: Our results confirmed the importance of immunofluorescence assays in diagnosing autoimmune blistering diseases, and higher sensitivity for indirect immunofluorescence when Salt-split skin technique is performed.

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