Chronic spontaneous urticaria: hives, wheals & biomarkers

Chronic spontaneous urticaria (CSU) has numerous biomarkers. Some of these biomarkers appear to be useful in monitoring disease activity and severity as well as in predicting treatment response.

CSU is a mast cell-driven disease characterised by the presence and recurrence of wheals and angioedema [1]. “In patients with high disease severity, angioedema, positivity of the autologous serum skin test [autoreactivity] or a combination with physical urticaria, the overall duration of CSU tends to be longer,” said Prof. Ana Giménez-Arnau (Autonomous University of Barcelona, Spain). In her presentation, Prof. Giménez-Arnau shed light on the long list of potential biomarkers.

Bench-to-bedside

Prof. Giménez-Arnau listed a seemingly limitless list of potential biomarkers including: TAT, fibrinogen, FVIIa, FXIIa, FVIII, FIX, FII, C-reactive protein (CRP), vitamin D, B12, prolactin, DHEA-S, cortisol, histamine, anti-IgE, IgG, IFNγ, TNF, histamine, tryptase, platelet, and basophil or eosinophil count [2]. Today, the most widely accepted biomarkers of disease activity with great potential are D-dimers, IL-6, and CRP [1,3].

Besides biomarkers of disease activity, researchers have studied clinical biomarkers of severity and prognosis. For example, the presence of angioedema has been associated with a less favourable prognosis. Prof. Giménez-Arnau pointed out that angioedema has a substantial impact on the afflicted who seem to be suffering from a more active disease. She further stressed that angioedema is underdiagnosed in patients with CSU, which was shown in analyses of the ASSURE-CSU study [4].

Other scientists have looked at a subtype of CSU, namely autoimmune CSU, in which functional IgG autoantibodies to IgE or its high-affinity receptor (i.e. FceRI) induce mast cell degranulation, leading to subsequent symptoms [5]. These patients had significantly higher IgG anti-TPO levels and lower total IgE levels as demonstrated by the authors of the PURIST trial (NCT01637116). This trial showed that a positive basophil activation test was 69% predictive of autoimmune CSU and a positive basophil histamine release assay was 88% predictive. Thus, including these tests in the diagnostic workup may help identify patients with this condition who would have remained undetected by routine clinical parameters. The afflicted have a different prognosis and may benefit from specific management [5].

1. 
   
   1. Giménez-Arnau A. Phenotypes of CSU and their biomarkers. D2T05.1A, EADV 2020 Virtual Congress, 29-31 Oct.
   2. Kolkhir P, et al. Clin Exp Allergy 2017;47:19-36.
   3. Folci M, et al. J Immunol Res 2018;2018;5615109.
   4. Sussman G, et al. Allergy 2018;73:1724-34.
   5. Schoepke N, et al. Allergy 2019;74:2427-36.

Posted on 17 December, 202018 December, 2020