Association Between Disease Severity and Clinical, Histopathological, and Eosinophilic Markers in Patients With Bullous Pemphigoid (BP-EPIC) (BP-EPIC)

June 14, 2026 updated by: MURAT OZKAN, Istanbul Training and Research Hospital

Correlation of Disease Severity With Histopathological Features, Serum IgE Levels, Eosinophil Count, and Tissue Expression of Eosinophilic Cationic Protein and Periostin in Patients With Bullous Pemphigoid

Bullous pemphigoid is an autoimmune subepidermal blistering disease characterized by eosinophilic inflammation and variable disease severity. This retrospective observational study aims to evaluate the relationship between disease severity and histopathological features, serum IgE levels, peripheral eosinophil counts, and the expression of eosinophilic cationic protein (ECP) and periostin in skin biopsy specimens of patients with bullous pemphigoid.

Immunohistochemical staining for ECP and periostin will be assessed semi-quantitatively and correlated with clinical and laboratory parameters, including BPDAI scores, eosinophil counts, serum IgE levels, hospitalization history, and disease relapse. The study seeks to identify potential tissue biomarkers associated with disease activity and severity in bullous pemphigoid.

Study Overview

Status

Active, not recruiting

Conditions

Detailed Description

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease and is characterized by autoantibodies directed against hemidesmosomal proteins. Eosinophils and eosinophil-associated mediators are believed to play a central role in disease pathogenesis. Periostin and eosinophilic cationic protein (ECP) have been implicated in eosinophilic inflammation; however, their relationship with clinical disease severity in BP remains incompletely understood.

This single-center retrospective observational study will include patients diagnosed with bullous pemphigoid at the University of Health Sciences, Istanbul Training and Research Hospital. Clinical, laboratory, and histopathological data will be collected from medical records.

The study will evaluate demographic characteristics, disease severity measured by BPDAI, serum IgE levels, peripheral eosinophil counts, hospitalization history, relapse frequency, and other clinicopathological parameters. Archived skin biopsy specimens will undergo immunohistochemical staining for periostin and ECP. Staining intensity will be assessed using semi-quantitative scoring methods and correlated with clinical and laboratory findings.

The primary objective is to determine whether periostin and ECP expression levels are associated with disease severity. Secondary objectives include evaluating correlations between tissue biomarker expression and serum IgE levels, eosinophil counts, hospitalization, and disease recurrence.

Study Type

Observational

Enrollment (Estimated)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • FATİH
      • Istanbul, FATİH, Turkey (Türkiye), 34096
        • S.B.Ü. İstanbul Eğitim ve Araştırma Hastanesi

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult patients diagnosed with bullous pemphigoid and followed at the University of Health Sciences, Istanbul Training and Research Hospital. Participants will be identified retrospectively from hospital records and pathology archives. Clinical, laboratory, and histopathological data, including BPDAI scores, serum IgE levels, peripheral eosinophil counts, and immunohistochemical expression of periostin and eosinophilic cationic protein, will be evaluated.

Description

Inclusion Criteria:

  • Age ≥18 years.
  • Diagnosis of bullous pemphigoid confirmed by compatible clinical, histopathological, and/or direct immunofluorescence findings.
  • Availability of archived skin biopsy specimens suitable for immunohistochemical evaluation of periostin and eosinophilic cationic protein (ECP).
  • Availability of clinical and laboratory data, including BPDAI score, serum IgE level, and peripheral eosinophil count.

Exclusion Criteria:

  • Age <18 years.
  • Diagnosis other than bullous pemphigoid.
  • Inadequate or unavailable biopsy specimens for immunohistochemical analysis.
  • Missing clinical, histopathological, or laboratory data required for study analyses.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Bullous Pemphigoid Patients
Patients with bullous pemphigoid included in a retrospective observational study evaluating the relationship between disease severity and periostin and ECP expression in skin biopsy specimens.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation Between BPDAI Score and Periostin Immunohistochemical Expression
Time Frame: Baseline (retrospective assessment of existing clinical and histopathological data)
Correlation between BPDAI disease activity score and periostin immunohistochemical expression measured using a semiquantitative 0-3 staining score in skin biopsy specimens from patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical and histopathological data)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correlation Between Periostin Immunohistochemical Expression and Serum Total IgE Levels
Time Frame: Baseline (retrospective assessment of existing clinical, laboratory, and histopathological data
Correlation between periostin immunohistochemical expression measured using a semiquantitative 0-3 staining score in skin biopsy specimens and serum total IgE levels (IU/mL) in patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical, laboratory, and histopathological data
Correlation Between Eosinophilic Cationic Protein Immunohistochemical Expression and Peripheral Blood Eosinophil Count
Time Frame: Baseline (retrospective assessment of existing clinical, laboratory, and histopathological data)
Correlation between eosinophilic cationic protein (ECP) immunohistochemical expression measured using a semiquantitative 0-3 staining score in skin biopsy specimens and peripheral blood eosinophil count (cells/µL) in patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical, laboratory, and histopathological data)
Correlation Between Periostin Expression and Disease Relapse Frequency
Time Frame: Baseline (retrospective assessment of existing clinical and histopathological data
Correlation between periostin immunohistochemical expression measured using a semiquantitative 0-3 staining score in skin biopsy specimens and disease relapse frequency (number of relapses) in patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical and histopathological data
Correlation Between Periostin Immunohistochemical Expression and Hospitalization History
Time Frame: Baseline (retrospective assessment of existing clinical and histopathological data)
Correlation between periostin immunohistochemical expression measured using a semiquantitative 0-3 staining score in skin biopsy specimens and hospitalization history (yes/no) in patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical and histopathological data)
Correlation Between Eosinophilic Cationic Protein Expression and Disease Relapse Frequency
Time Frame: Baseline (retrospective assessment of existing clinical and histopathological data)
Correlation between eosinophilic cationic protein (ECP) immunohistochemical expression measured using a semiquantitative 0-3 staining score in skin biopsy specimens and disease relapse frequency (number of relapses) in patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical and histopathological data)
Correlation Between Eosinophilic Cationic Protein Immunohistochemical Expression and Hospitalization History
Time Frame: Baseline (retrospective assessment of existing clinical and histopathological data)
Correlation between eosinophilic cationic protein (ECP) immunohistochemical expression measured using a semiquantitative 0-3 staining score in skin biopsy specimens and hospitalization history (yes/no) in patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical and histopathological data)
Correlation Between BPDAI Score and Eosinophilic Cationic Protein Expression
Time Frame: Baseline (retrospective assessment of existing clinical, laboratory, and histopathological data)
Correlation between BPDAI disease activity score and tissue eosinophilic cationic protein (ECP) expression assessed by immunohistochemistry using a semiquantitative 0-3 staining score in skin biopsy specimens from patients with bullous pemphigoid.
Baseline (retrospective assessment of existing clinical, laboratory, and histopathological data)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Study Chair: Ayse Esra Koku Aksu, Prof.Dr., University of Health Sciences, Istanbul Training and Research Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 4, 2026

Primary Completion (Estimated)

December 24, 2026

Study Completion (Estimated)

April 25, 2027

Study Registration Dates

First Submitted

June 8, 2026

First Submitted That Met QC Criteria

June 14, 2026

First Posted (Actual)

June 16, 2026

Study Record Updates

Last Update Posted (Actual)

June 16, 2026

Last Update Submitted That Met QC Criteria

June 14, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • SBU-IEAH-KAEK-20262404-26

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data (IPD) will not be shared. This retrospective, single-center study uses patient data collected as part of routine clinical care. Data sharing is restricted due to institutional policies, ethical considerations, and patient confidentiality requirements.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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