Autoimmune mast cell activation test as a diagnostic tool in chronic spontaneous urticaria

Koren, Ana (author), Dejanović, Luka (author), Rijavec, Matija (author), Kopač, Peter (author), Bizjak, Mojca (author), Zidarn, Mihaela (author), Košnik, Mitja (author), Korošec, Peter (author)

Chronic spontaneous urticaria (CSU) is associated with skin mast cell activation, and its triggering mechanisms are not completely elucidated. Evidence suggests an autoimmune component of CSU. Our aim was to assess the usefulness of an autoimmune mast cell activation test (aiMAT) for diagnosing and differentiating CSU into different subtypes. We enrolled 43 patients with active, uncontrolled CSU before starting treatment with omalizumab and 15 controls. Patients were evaluated based on omalizumab response. aiMATs were performed using non-IgE-sensitized (NS) or myeloma IgE-sensitized (S) LAD2 cells, which were then stimulated with CSU/control sera (25 µL and 10 µL). The expression of CD63 was assessed with flow cytometry. CD63 response on NS-LAD2 was significantly increased in CSU patients compared to controls after the stimulation with 25 µL CSU/control sera (p = 0.0007) and with 10 µL CSU/control sera (p = 0.0001). The ROC curve analysis demonstrated an area under the curve (AUC) of 0.82. The cutoff for autoimmune-non-IgE-sensitized-MAT was 40.3% CD63+ LAD2, which resulted in 73.3% sensitivity and 81.4% specificity. CD63 response on S-LAD2 was significantly increased in CSU patients compared to controls after the stimulation with 25 µL CSU/control sera (p = 0.03). The ROC curve analysis demonstrated an AUC of 0.66. The cutoff for the autoimmune-myeloma IgE-sensitized-MAT was 58.4% CD63+ cells, which resulted in 62.8% sensitivity and 66.7% specificity. Overall, 36 out of 43 (84%) patients responded to omalizumab, and 7 (16%) were nonresponders. We found no differences between LAD2 CD63 response and response to omalizumab. In conclusion, aiMAT could represent a new diagnostic tool in CSU. Additional studies are needed to evaluate the potential benefits during omalizumab therapy.

• Language: English
• Keywords: mast cell activation test, LAD2, chronic spontaneous urticaria, omalizumab, CD63 expression
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty; MF - Faculty of Medicine; FFA - Faculty of Pharmacy
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 11 str.
• Numbering: Vol. 25, iss. 17, art. 9281
• PID: 20.500.12556/RUL-169399
• UDC: 616-097
• ISSN on article: 1422-0067
• DOI: 10.3390/ijms25179281
• COBISS.SI-ID: 206566915
• Publication date in RUL: 27.05.2025

Record is a part of a journal

• Title: International journal of molecular sciences
• Shortened title: Int. j. mol. sci.
• Publisher: MDPI
• ISSN: 1422-0067
• COBISS.SI-ID: 2779162

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: test aktivacije mastocitov, LAD2, kronična spontana urtikarija, omalizumab, izražanje CD63

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P3-0360
• Name: Celostna obravnava alergijskih bolezni in astme v Sloveniji: od epidemiologije do genetike